NREL is a national laboratory of the U.S. Department of Energy, Office of Energy 

Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, 

LLC.

Contract No. DE-AC36-08GO28308

National Renewable Energy Laboratory

1617 Cole Boulevard, Golden, Colorado 80401

303-275-3000 • www.nrel.gov

 

Produced under direction of the U.S.

Department of the Interior Office of 

Insular Affairs by the National 

Renewable Energy Laboratory (NREL) 

under Interagency Agreement IAG-10-

1773 and Task No WFF4.3000. 

Guam Initial Technical Assessment Report

Ian Baring-Gould, Misty Conrad, Scott Haase, Eliza Hotchkiss, 

and Peter McNutt

Technical Report 

NREL/TP-7A40-50580

April 2011
NREL is a national laboratory of the U.S. Department of Energy, Office of Energy 

Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, 

LLC.

Contract No. DE-AC36-08GO28308

National Renewable Energy Laboratory

1617 Cole Boulevard, Golden, Colorado 80401

303-275-3000 • www.nrel.gov

Technical Report 

NREL/TP-7A40-50580

April 2011

Guam Initial Technical Assessment Report 

Ian Baring-Gould, Misty Conrad, Scott Haase, Eliza Hotchkiss, Peter McNutt 

Disclaimer: This manuscript has been authored by employees of the Alliance for Sustainable Energy, LLC (“Alliance”) under Contract 

No. DE-AC36-08GO28308 with the U.S. Department of Energy (“DOE”). 

Neither Alliance, DOE, the United States government nor any agency thereof, nor any of their employees, makes any warranty, 

express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, 

apparatus, product, or process disclosed in this manuscript, or represents that its use would not infringe privately owned rights.

Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does 

not necessarily constitute or imply its endorsement, recommendation, or favoring by Alliance, DOE or the United States Government 

or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of Alliance, DOE or 

the United States government or any agency thereof.

Cover photo credit: NREL/PIX 18630, 18629, 18590
iii

Contacts and Team Members 

Department of the Interior

Tony Babauta 

Assistant Secretary

Office of Insular Affairs

U.S. Department of Interior 

Washington, DC 20240 

Office Phone: (202) 208-6816 

Charlene Leizear

Director of Technical Assistance

Office of Insular Affairs

U.S. Department of Interior 

Washington, DC 20240 

Office Phone: (202) 208-3239 

E-mail: charlene_leizear@ios.doi.gov 

Nikolao Pula 

Director

Office of Insular Affairs

U.S. Department of Interior 

Washington, DC 20240 

Office Phone: (202) 208-6816 

E-mail: nikolao_pula@ios.doi.gov 

Angie Williams

Guam Desk Officer

Office of Insular Affairs 

U.S. Department of the Interior 

Washington, DC 20240 

Office Phone: (202) 208-3003 

E-mail: angela_williams@ios.doi.gov 

National Renewable Energy Laboratory 

Misty Dawn Conrad

Senior Project Leader II

Office Phone: (303) 384-7467 

E-mail: misty.conrad@nrel.gov 

Ian Baring-Gould 

Technology Deployment Manager

Office Phone: (303) 384-7021/(202) 586-9136 

E-mail: ian.baring-gould@nrel.gov 

Scott Haase

Senior Engineer 

Office Phone: (303) 275-3057 

E-mail: scott.haase@nrel.gov

Eliza Hotchkiss

Analyst III

Office Phone: (303) 475-6786 

E-mail: eliza.hotchkiss@nrel.gov 

Peter McNutt

Senior Engineer 

Office Phone: (303) 384-6767 

E-mail: peter.mcnutt@nrel.gov
iv

Acknowledgments 

The National Renewable Energy Laboratory (NREL) thanks the U.S. Department of Interior’s Office of 

Insular Affairs (OIA) for providing funding for this effort. In particular, NREL would like to thank 

Assistant Secretary Tony Babauta for his vision and leadership in moving this energy assessment and 

planning process forward in the Pacific Territories.

NREL would like to acknowledge the valuable assistance of the OIA staff: Director Nikolao Pula, 

Angela Williams, and Charlene Leizear. 

In addition, NREL and the entire assessment team are grateful to the following facility managers, 

directors, engineers, and operators for their generous assistance and cooperation during the NREL 

team’s site visit to Guam:

• Guam Power Authority: Joaquin Flores, John J. Cruz, Francis J. Iriarte, Jennifer G. Sablan, 

Melinda R. Camacho, Louis Camacho 

• University of Guam: President Robert Underwood, Ph.D.; Samuel Walker; Louise M. Toves; 

Bruce Best; Michael L. Bevacqua, Ph.D. 

• Guam Community College: President Mary Okada 

• Department of Defense: Captain Peter Lynch, Regional Engineer, Joint Region Marianas and 

Commanding Officer, NAVFAC Marianas; Kevin D. Evans, Joint Region Marianas, NAVFAC 

Marianas, Supervisory Energy Manager; Derek Briggs, Naval Base Guam, Energy Manager

• United States Department of Agriculture: Joseph Diego, John Lawrence, Mark Defley

• A special thank you to Mayor Melissa Savares for taking the time to show the NREL team 

around Dededo 

• Guam Environmental Protection Agency (EPA)\Energy Office: Ivan Quinata, Administrator

• US EPA Region 9: Michael Wolfram, Michael Mann 

• Guam Energy Office: Director Lorilee Chrisostomo; Staff: David Menlo, Charlyne Guerrero, 

Richard Diego, Steven Mun 
v 

Abstract 

On March 1, 2010, Assistant Secretary Tony Babauta from the Department of Interior’s (DOI) Office of 

Insular Affairs (OIA), invited Governors Felix Camacho (Guam), Benigno Fitial (Commonwealth of the 

Northern Mariana Islands), and Togiola Tulafono (American Samoa) and their staff to meet with Senior 

Principals at the National Renewable Energy Laboratory (NREL) for discussions on ways to improve 

energy efficiency and increase the deployment of renewable energy technologies in the U.S. Pacific 

Territories. This meeting brought together major stakeholders to learn and understand the importance of 

developing a comprehensive strategic plan for implementing energy efficiency measures and renewable 

energy technologies. 

For several generations, dependence on fossil fuels and the burden of oil prices have been a major 

concern. The urgency has never been more prevelant than today. With unstable oil prices, the volatility 

of supply and future military build-up plans on Guam, energy issues have become a high priority for the 

island. Succinctly, energy security is critical to Guam’s future economic development and sustainability. 

Under an interagency agreement, funded by OIA, NREL was tasked to deliver technical assistance to the 

island of Guam by conducting an island initial technical assessment that would lay out energy 

consumption and production data and establish a baseline. This assessment will be used to conduct 

future analysis and studies by NREL that will estimate energy efficiency and renewable energy potential 

for the island of Guam. 

NREL provided an interdisciplinary team to cover each relevant technical area for energy assessments, 

system recovery, and upgrades. Experts in the following disciplines traveled to Guam for on-island site 

assessments October 11-15, 2010: 

• Integrated Wind-Diesel Generation

• Transmission and Distribution 

• Energy Efficiency and Building Technologies 

• Solar Technologies 

• Biomass and Waste-to-Energy 

• Geothermal. 

In addition to the above core disciplines, team capabilities also included expertise in program analysis, 

project financing, policy, and energy project, planning and Energy Committee facilitation. 

The intent was to provide Guam with various scenarios and approaches to deploying cost effective 

energy efficiency and renewable energy technologies in a manner that will meet Guam’s energy 

objectives. The information compiled in this energy assessment will be used as input in the development 

of a strategic plan.
vi 

Executive Summary

This document is an initial technical energy assessment for Guam, the first of many steps in developing 

a comprehensive energy strategy. The project plan for Guam includes three main objectives: 

1. Assist in establishing an Energy Task Force

2. Publish an initial island assessment report to establish a baseline and identify energy efficiency and 

renewable energy opportunities

3. Support the Energy Task Force in developing a draft energy strategic plan that will provide Guam 

with various scenarios and approaches to deploying cost effective energy efficiency and renewable 

energy technologies in a manner that will meet the island’s objectives in reducing dependency on 

imported fossil fuels. 

This report meets the second objective of establishing a baseline and identifying opportunities. A 

baseline gathers various data points to establish a reference against which progress can be measured. It 

allows comparison across sectors through trend identification and provides a tool for goal setting and 

measuring success of those goals. Before a baseline can be established, a methodology is developed.

The information compiled in this assessment will be used as input in the development of a strategic plan 

to meet the third project objective. This process sets the procedures and rationale that underlie the study. 

This document summarizes data collected regarding energy production, consumption, and efficiencies, 

and discusses renewable energy and energy efficiency technology potential and current barriers and 

opportunities. The opportunities highlighted in this report can be used to formulate an energy plan. The 

following table highlights current energy efficiency and renewable energy opportunities designating 

them a low, medium, or high priority for impact. 

Table 1. Energy Efficiency and Renewable Energy Opportunities and Potential Impacts

Opportunity Description Impact Potential

Create a strategic plan to investigate and implement energy efficiency and 

renewable energy where technically appropriate and feasible High

Increase energy efficiency standards in building codes High

Further development of the Cotal 20 MW wind site with concurrent social 

acceptance outreach High

Initiate a cool-roof program Medium - High

Assess the potential for solar hot water heating in different sectors Medium - High

Increase energy awareness through island campaigns Medium - High

Continue to evaluate potential for sea water cooling project Medium 

Establish subcommittee to review options for possible modifications to PL 25-

175 Medium

DOD and GPA continue to work together to evaluate the geothermal potential Medium

Set an energy efficiency standard for island appliances and air conditioning 

equipment Medium

Outdoor lighting technology and control improvements Low
vii 

Also within this report is a section that outlines barriers, possible next steps, and potential for technical 

assistance. Detailed technical information can be found in the appendices for further reference. 
viii

Acronyms and Abbreviations

ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers

bbl billion barrels 

Btu British thermal unit 

C&D construction and demolition 

CIA Central Intelligence Agency

CT Combustion Turbine 

DEM Digitial Elevation Model 

DOD Department of Defense 

DOE Department of Energy 

DOI Department of Interior 

EIS Environmental Impact Statement

EMD Electro-Motive Diesel

EPA Environmental Protection Agency 

F Farenheight 

FY Fiscal Year

GE General Electric 

GM General Motors

GPA Guam Power Authority 

GRPP Guam Resource Recovery Partners

GWA Guam Waterworks Authority 

GWh gigawatt hour 

HECO Hawaiian Electric Company 

HP horsepower 

IBM Izu-Bonin-Mariana

IECC International Energy Conservation Code 

IFB Invitation fore Multi-step Bid 
ix

IPP Independent Power Producers 

IRP Integrated Resource Plan 

km kilometers

kV kilovolt 

kVA kilovolt-ampere

kW kilowatt 

kWh kilowatt hour 

lb pound 

LED Light-Emitting Diode 

LEED Leadership in Energy and Environmental Design 

LFG landfill gas

LIDAR Light Detection and Ranging 

m meters

MECO Maui Electric Company 

MGD millon gallons per day 

mi miles

m/s meters per second 

MMBtu million British thermal units

MSW municipal solid waste 

MW megawatt

MWh megawatt hours 

NAVFAC Naval Facilities Engineering Command 

NDWTP Northern District Wasterwater Treatment Plant 

NOx nitric oxide

NRCS National Resources Conservation Service

NREL National Renewable Energy Laboratory 

OIA Office of Insular Affairs

PL Public Law
x 

PMC Performance Management Contract 

PUC Public Utilities Commission 

RFO residual fuel oil 

RFP Request for Proposal 

RPM revolutions per minute

RPS Renewable Portfolio Standard

SARs Severe Acute Respiratory Syndrome 

Sf square foot 

SWMD solid waste management district

USDA U.S. Department of Agriculture 

WTE waste-to-energy 
xi 

Table of Contents

Contacts and Team Members..................................................................................................................... iii

Acknowledgments...................................................................................................................................... iv

Abstract ....................................................................................................................................................... v

Executive Summary ................................................................................................................................... vi

Acronyms and Abbreviations .................................................................................................................. viii

Table of Contents ....................................................................................................................................... xi

List of Figures .......................................................................................................................................... xiii

List of Tables ........................................................................................................................................... xiii

1 Methodology ........................................................................................................................................ 1

1.1 Approach ...................................................................................................................................... 1

1.2 Background .................................................................................................................................. 2

2 Establishing a Baseline ........................................................................................................................ 6

2.1 Overall Fossil Fuel Energy Use ................................................................................................... 6

2.2 Electrical Energy .......................................................................................................................... 7

2.2.1 Electrical Generation ............................................................................................................ 7

2.2.2 Consumption and Costs ........................................................................................................ 9

2.2.3 End Use ............................................................................................................................... 13

2.2.4 Current Status of Energy Policy ......................................................................................... 17

2.2.5 Solid Waste ......................................................................................................................... 20

3 Energy Efficiency and Renewable Energy Opportunities ................................................................. 25

3.1 Energy Efficiency and Conservation .......................................................................................... 25

3.1.1 Raise Island Energy Awareness for Conservation .............................................................. 25

3.1.2 Establish a Cool-Roof Program to Improve Efficiency ...................................................... 26

3.1.3 Review and Improve Energy Efficiency Standards to Improve Efficiency ........................ 27

3.1.4 Consider Alternative Cooling Technologies ....................................................................... 27

3.1.5 Next Steps ........................................................................................................................... 27

3.2 Wind ........................................................................................................................................... 30

3.2.1 Key Challenges to Wind Development ............................................................................... 31

3.2.2 Infrastructure ....................................................................................................................... 31

3.2.3 Next Steps ........................................................................................................................... 32

3.3 Solar ........................................................................................................................................... 33

3.3.1 Solar Thermal ...................................................................................................................... 33

3.3.2 Solar PV .............................................................................................................................. 36

3.3.3 Next Steps ........................................................................................................................... 38

3.4 Geothermal ................................................................................................................................. 38

3.4.1 Next Steps ........................................................................................................................... 39
xii 

3.5 Biomass ...................................................................................................................................... 39

3.5.1 Waste-to-Energy ................................................................................................................. 39

3.5.2 Biodiesel or Vegetable Oil .................................................................................................. 41

3.5.3 Landfill Gas ........................................................................................................................ 42

3.5.4 Anaerobic Digestion ........................................................................................................... 43

3.5.5 Small-scale Biomass ........................................................................................................... 43

3.5.6 Production of Dedicated Biomass Feedstocks .................................................................... 43

3.5.7 Next Steps ........................................................................................................................... 44

4 Summary of Recommendations and Conclusions ............................................................................. 47

4.1 Key Opportunities ...................................................................................................................... 47

4.2 Conclusion .................................................................................................................................. 48

A. Utility Baseline Information ................................................................................................................ 49

A.1 Generation .................................................................................................................................. 49

A.2 GPA System Improvements in FY 2009 .................................................................................... 52

A.2.1 Major Transmission Lines Secured Underground .............................................................. 52

A.2.2 Net Metering ....................................................................................................................... 53

A.2.3 Groundwork Laid for Pre-Paid Meters ............................................................................... 53

A.2.4 Declining Sales ................................................................................................................... 54

A.3 Utility Energy Efficiency ........................................................................................................... 54

B. Energy Efficiency Baseline .................................................................................................................. 56

B.1 Current Status ............................................................................................................................. 56

B.2 Initial Observations by Sector .................................................................................................... 57

B.2.1 Commercial and Government ............................................................................................. 57

B.2.2 Residential.......................................................................................................................... 61

B.2.3 Outdoor and Street Lighting ............................................................................................... 63

B.2.4 U.S. Navy ............................................................................................................................ 64

C. Renewable Energy................................................................................................................................ 65

C.1 Solar PV ..................................................................................................................................... 65

C.1.1 Overview ............................................................................................................................ 65

C.1.2 Methodology ........................................................................................................................... 66

C.1.3 Top Seven Parcels ............................................................................................................... 69

C.1.4 Summary ............................................................................................................................. 72

C.2 Wind Technology ....................................................................................................................... 72

C.2.1 Previous Wind Assessment Activities ..................................................................................... 72
xiii

List of Figures

Figure 1. Assessment methodology ........................................................................................................... 1

Figure 2. Map of Guam .............................................................................................................................. 3

Figure 3. War in the Pacific Park ................................................................................................................ 5

Figure 4. Total fossil fuel energy use, 2010 ................................................................................................ 7

Figure 5. GPA gross generation by fuel type .............................................................................................. 8

Figure 6. GPA gross electricity production, fuel consumption and overall system heat rate ..................... 9

Figure 7. Historical annual island energy consumption (2001 – 2010) .................................................... 10

Figure 8. Overall GPA system hourly load profiles (March 1, 2009 – February 28, 2010) ..................... 11

Figure 9. Guam energy consumption by sector (2001 – 2010 average) ................................................... 12

Figure 10. Guam energy consumption by sector (2001 – 2010) ............................................................... 12

Figure 11. Guam Community College’s LEED-registered building under construction ......................... 13

Figure 12. Commercial electric sales by end-use, 1993 ........................................................................... 14

Figure 13. Annual energy sales (residential sector) ................................................................................. 15

Figure 14. Average annual costs per residential customer ...................................................................... 15

Figure 15. Residential electric sales by end user ...................................................................................... 16

Figure 16. Guam government sector energy consumption by percentage of total energy consumption .. 17

Figure 17. October 2010 waste characterization study (limited sample) .................................................. 22

Figure 18. Guam's solid waste composition, 1980 ................................................................................... 23

Figure 19. Cool roof tiles in colors other than white ................................................................................ 26

Figure 20. A common solar thermal system ............................................................................................. 34

Figure 21. Solar hot water, Hickam Air Force Base ................................................................................. 35

Figure 22. U.S. Coast Guard housing, Honolulu, Hawaii ........................................................................ 35

Figure 23. GPA transmission system map with potential solar and wind locations marked .................... 37

Figure 24. GPA installed capacity (in billions of kW) ............................................................................. 50

Figure 25. GPA buried transmission lines ................................................................................................ 53

Figure 26. Decline of GPA sales............................................................................................................... 54

Figure 27. GPA average hourly generation requirements ........................................................................ 55

Figure 28. Recovery Act funding allocated to energy efficiency measures on Guam (in millions of U.S. 

dollars) ...................................................................................................................................................... 57

Figure 29. Visible gaps in door at Dededo Senior Center ........................................................................ 58

Figure 30. Museum lights off at the Lette of Freedom ............................................................................. 60

Figure 31. Museum lights on at the Lette of Freedom .............................................................................. 60

Figure 32. Lobby lighting at the Tumon Bay Hyatt .................................................................................. 60

Figure 33. Residential housing in Dededo ................................................................................................ 62

Figure 34. Example of street lighting on during daylight hours in Tumon Bay ....................................... 63

Figure 35. Overview of Tier 1 parcels ...................................................................................................... 69

Figure 36. Boxplot of mean wind speed at 60 m for Guam Naval Ordnance (10/1/2008 – 9/30/2010) .. 74

Figure 37. Power density rose for Guam Naval Ordnance (10/1/2008 – 9/30/2010) ............................... 74

List of Tables

Table 1. Energy Efficiency and Renewable Energy Opportunities and Potential Impacts ....................... vi

Table 2. Estimated Additional Military and Associated Population in 2017 ............................................. 4

Table 3. Employment Statistics .................................................................................................................. 4

Table 4. Guam Historic Weather Summary ................................................................................................ 5

Table 5. 2010 Guam Fossil Fuel Usage ...................................................................................................... 6

Table 6. Current GPA Net Metering Customers ....................................................................................... 18

Table 7. Proposed and Interim Tip Fees ................................................................................................... 21

Table 8. Top Seven Sites Identified for Solar PV ..................................................................................... 38
xiv 

Table 9. Summary of WTE Potential ........................................................................................................ 40

Table 10. GPA Baseload Generation ........................................................................................................ 49

Table 11. Independent Power Producers .................................................................................................. 49

Table 12. GPA Generation Resources ...................................................................................................... 50

Table 13. Dededo Senior Center Indoor Temperature and Related Costs ................................................ 58

Table 14. Summary of Cool Roof Coatings by Type ............................................................................... 59

Table 15. Recommended Efficient Lamp Types by Space Use ................................................................ 61

Table 16. Recommended Efficient Lamp Types for Outdoor and Street Lighting .................................. 63

Table 17. Top Seven Sites Identified for Solar PV ................................................................................... 70

Table 18. Estimated Total Population Increase on Guam from Off-Island (Direct, Indirect, and Induced)

................................................................................................................................................................... 75
1 

1 Methodology 

To clarify the National Renewable Energy Laboratory’s (NREL) team’s understanding of the project, 

the approach and background information used for the assessment have been outlined in Sections 1.1 

and 1.2. 

1.1 Approach

Establishing the parameters of a study provides focus for the assessment team. Certain topic areas, such 

as transportation, are considered important to overall energy strategies, however were not considered 

within the Guam assessment due to budget constraints and the priority of targeting energy efficiency and 

renewable energy technologies. 

Each assessment begins with a background study to understand the site demographics and geography. 

Human and physical geography impact energy consumption and the success of implementation of 

renewable energy projects, therefore this information is essential to the types of recommendations made. 

Data collection and researching previous studies allows the assessment team to understand what the 

current baseline consumption is and what recommendations have been made in the past. The data 

collection process coincides with a site visit to interview stakeholders and survey the options to be 

included within the assessment. After the site visit, information is analyzed and opportunities are 

identified. 

The graphic in Figure 1 illustrates the major components of NREL’s assessment methodology. 

Figure 1. Assessment methodology 

Establish study parameters 

Study demographic and geopolitical climate

Survey previous reports and 

data collections

Site visit to interview 

stakeholders, collect data, and 

conduct physical survey

Synthesize information and 

identify opportunities
2 

It is essential to look at the energy picture of Guam holistically. The Department of Defense (DOD) has 

considerable representation on-island, accounting for approximately 21% to 22% of Guam’s energy 

consumption. With an impending military build-up, concerns surrounding energy use are receiving 

increased attention. An extensive understanding of the relationship between Guam’s military 

installations and the civilian side of the island is necessary to establish energy efficiency and renewable 

energy baselines from a whole island approach. NREL’s assessment team concentrated on baseline 

factors that accounted for DOD presence. 

This report focuses on island-wide utility generation and consumption patterns, not specific DOD energy 

efficiency and renewable energy activities. DOD has its own internal goals for renewable energy and 

energy efficiency. As DOD seeks to meet these goals, there may be impacts on the operations and 

economics of Guam Power Authority (GPA)—it is important for DOD and GPA to continue to work 

together to understand these impacts and seek to develop win-win solutions. 

There are many energy efficiency and renewable energy technologies on the market today. Included 

within this study’s parameters are mature technologies that are considered prime time and bankable. 

There are other technologies that Guam may want to investigate for future study, but for the basis of this 

study, technologies included had the following criteria: 

• Commercial availability

o Tested and demonstrated

o Carry warranty

o Service and parts available

• Ready for immediate deployment 

• Sound investment 

• Financing available from private sector organizations. 

This assessment focuses on clean energy technologies. There is varied opinion on what falls under this 

purview. For the purposes of this study, commercial clean energy technologies were identified under the 

current NREL portfolio, including wind, solar, biomass, energy efficiency, and geothermal. NREL did 

not assess opportunities associated with ocean thermal energy conversion, off-shore wind, marine 

hydrokinetic, nuclear, coal, or liquefied natural gas. 

This document summarizes data collected regarding energy production, consumption, and efficiencies, 

and discusses renewable energy and energy efficiency technology potential and current policy barriers 

and opportunities. 

1.2 Background

Guam is an island in the North Pacific Ocean (13o north and 144o east). Guam is an unincorporated 

territory of the United States under the jurisdiction of the Office of Insular Affairs (OIA). Guam has a 

total land area of 544 km2

 (210 mi2) with 125 km (130 mi) of coastline, making it the largest and 

southernmost island in the Mariana Archipelago. Figure 2 provides a basic map of Guam1

. 

 

1 http://coris.noaa.gov/about/eco_essays/guam/geography.html. 
3 

The island is volcanic, has coral reefs, a coralline limestone plateau, which is the source of most of the 

island’s fresh water; and cliffs along the coast and mountains in the south of the island (the highest point 

is Mount Lamlam at 406 m). Permanent crops cover 18% of the island. Natural hazards include squalls 

during the rainy season, typhoons (between June-December), and invasive predators like the brown tree 

snake that decimated the local bird population and the Rhinoceros beetle, which is destroying the 

coconut palm. 

In 2000, the island’s population was 154,8052

 and the 2010 estimate is 180,8653

 

2 Government of Guam website: 

, spread throughout 

about 20 villages. In 2000, the five largest villages were Dededo (42,980), Yigo (19,474), Tamuning 

(18,012), Mangilao (13,313), and Barrigada (8,652). According to the OIA website, the population in 

2010 was 178,000, which is slightly lower than the Central Intelligence Agency estimates of 180,865. 

The value of 180,865 is assumed in this report when making any per capita estimates. 

http://www.spc.int/prism/country/gu/stats/Census/Census.htm. 3 CIA World Factbook: https://www.cia.gov/library/publications/the-world-factbook/geos/gq.html. 

Figure 2. Map of Guam

Source: NOAA
4 

With the planned military buildup (relocating troops from Okinawa to Guam) these figures are expected 

to grow fairly significantly, but are always changing. There are many factors to consider; funding 

availability, infrastructure and construction readiness, 2011 earthquake and tsunami in Japan, etc. Table 

148 in Appendix C provides additional information provided from the Environmental Impact Statement 

(EIS). 

The military build-up will impact the electricity consumption and generation needs on Guam. As the 

surge of military activity increases, economical impacts are expected. The estimated expected 

population is summarized in Table 2.4

Table 2. Estimated Additional Military and Associated Population in 2017

 

Cultural dynamics often impact energy consumption as well. Guam is rich with diversity; ethnic groups 

include native Chamorro (37.1%), Filipino (26.3%), Pacific Islanders (11.3%), white (6.9%), other 

Asian (6.3%), other ethnic origins (2.3%), and mixed ethnicities (9.8%).5

The economy is driven mostly by military and tourism; the tourism industry has grown since the 1980s 

due to a push to attract Japanese tourists. With a total of 1-1.2 million tourists a year, Japanese tourists 

made up 76% of tourists in 2007 with direct tourist spending being $1.2 billion. The basic breakdown of 

total payroll employment and percentage of total is summarized in 

 The predominant religion is 

Roman Catholic. Languages include English (38%), Chamorro (22%), Filipino (22%), Pacific island 

languages (6%), and Asian languages (7%). Guam has a literacy rate of 99%. 

Table 3.

Table 3. Employment Statistics6

Total payroll employment (2007) 60,350

Private sector employment 45,320

Government employment 15,030

Private sector employment as a % of total 75.1%

Government employment as a % of total 24.9%

Unemployment rate 11.4%

Private sector average weekly earning $411.55

Government of Guam average weekly earnings $737.48

Guam has a tropical marine climate that is warm and humid with little seasonal temperature variation, 

illustrated in Figure 3. Climate impacts the energy consumption in a specific geographic region. 

 

4 OIA website: http://www.doi.gov/oia/Islandpages/gumpage.htm#pagetop. 5 OIA website: http://www.doi.gov/oia/Islandpages/gumpage.htm#pagetop. 6 Ibid.

Marines 

moving 

from 

Okinawa

Dependents Civilian 

Employees

Temporary 

Workers

Estimated 

Cost

8,600 ~9,000 6,000 ~20,000 $10.27 

billion
5 

The U.S. Department of Energy (DOE) has issued maps of various climate zones based on temperature 

and humidity. Guam’s climate is tropical marine with the dry season between January-June and the rainy 

season between July-December. Yearly average temperatures range between 76°F and 86°F and average 

annual precipitation is 86 inches. Table 4 summarizes the historic weather on the island over the past 47 

years. 

Table 4. Guam Historic Weather Summary7

 

7 Weather Base, Guam: http://www.weatherbase.com/weather/weather.php3?s=021219&refer. Accessed January 7, 2011.

Figure 3. War in the Pacific Park 

Source: NREL/PIX 18625
6 

2 Establishing a Baseline 

Following a review of the natural and cultural influences, site assessments incorporate historical energy 

consumption data to establish the baseline. This section summarizes observations from electrical 

generation, end-use energy consumption and costs, and solid waste management. Additional details are 

provided in the appendices. 

2.1 Overall Fossil Fuel Energy Use

With the exception of a few small renewable energy projects, Guam is 100% dependent on fossil fuels 

for meeting its energy supply needs. The primary sectors that consume fossil fuels in Guam are:

• Production of electricity

• Transportation 

• Water heating and self-generation by the commercial sector (primarily hotels)

• Propane for home cooking and small commercial operations. 

NREL obtained information on fossil fuel consumption for electricity production, transportation, and 

propane use by consumers. We did not attempt to locate data on consumption by hotels or small 

commercial sectors. In 2010, GPA consumed nearly 2.9 million barrels of fossil fuel (120,519,396 

gallons) for power generation.8 The Guam Energy Office collects data on fuel sales, including jet fuel 

and consumer propane.9

In 2010, 109 million gallons of motor fuel were sold, including gasoline, diesel, and jet fuel. Note the 

motor fuel data compiled by the Guam Energy Office does not include shipping to Guam, air transport 

and freight and DOD. 

 

In 2010, Guam used 230 million gallons of fossil fuel, or over 1,270 gallons per year for every man, 

woman, and child living on the island. This value can serve as the primary baseline for setting fossil fuel 

reduction targets and against which future program impacts can be measured. Table 5 shows the 

breakdown by end use, and Figure 4 shows these values graphically.

Table 5. 2010 Guam Fossil Fuel Usage

End Use Gallons/year

Gasoline 46,262,100

No 2 Diesel 14,105,600

Jet 44,812,200

Propane - Consumer 4,305,500

GPA 120,519,396

Total Fuel Used 230,004,796

Population 180,865

Fuel use per capita 1,272

 

8 Internal data provided to NREL by GPA.

9 Source: Guam Energy Office. Spreadsheet provided by David Meno based on retail sales by fuel distributors (Shell, Mobil 

and 76).
7 

Figure 4. Total fossil fuel energy use, 2010

Source: GPA

2.2 Electrical Energy 

2.2.1 Electrical Generation 

GPA is a full service electric utility serving about 46,000 customers. GPA owns and manages 663 miles 

of transmission and distribution lines and 29 substations throughout the island. Electricity is delivered 

through a transmission and distribution grid consisting of a combination of 115 kV, 34.5 kV, and 13.8 

kV lines. Its generation capacity is 552 MW with total energy production of 1,854 GWh (FY 2009). The 

highest peak system demand was 281.5 MW in June 2001. 

GPA’s generation includes 181 MW from Independent Power Producers. The generation mix is 33% 

steam turbine, 30% slow-speed diesel, 26% combustion turbine, and 10% fast-track diesels. GPA has 

organized 210 MW of its base load capacity under two performance management contracts (PMCs).

These PMCs provide private management using public employees to operate and maintain the plants. 

The contracts contain performance-based incentives for reducing plant operating costs. The major fuel 

types include residual fuel oil (RFO #6) and diesel #2 distillate. Figure 5 shows GPA’s generation by 

fuel type. Note that in FY 2010 99% of GPA’s electricity generation came from RFO. RFO includes 

both high and low sulfur sources.

Gasoline

20%

No 2 Diesel

6%

Jet

20%

Propane -

Consumer

2%

GPA

52%

Guam Energy Usage 2010

(% by use based on gallons consumed)
8 

Figure 5. GPA gross generation by fuel type10

Source: GPA

According to GPA, “several systemic shocks, such as the Gulf war, SARs [Severe Acute Respiratory 

Sydrome], major typhoons, and rising fuel prices occurred during this period, adversely affecting the 

Guam economy. As a result, the demand for electric power contracted or remained flat relative to FY 

1998,” (Guam Power Authority, 2008). 

The top plot in Figure 6 shows the gradual decline of generation, from a high of 1.956 billion kWh in 

2001 to 1.862 billion kWh in 2010, a 5% decline in nine years11

In 2010 the overall system heat rate was 9,670 Btu/kWh. GPA provided historical fuel heating values 

from which the average value of 6.275 MMBtu/bbl for high sulfur fuel oil and low sulfur fuel oil

. Electricity generation is measured at 

the generators in the power plants. The fuel use also declined during this same period, while the fuel 

efficiency improved between 2003 and 2004 and remained relatively flat during the last seven years. 

12. 

Although the fuel heating value of diesel is value is 5.760 MMBtu/bbl, because diesel is only a small 

proportion of the fuel mixture, it was not broken out separately. As a comparison to other island power 

systems, Hawaii’s overall system heat rate was about 10,500 Btu/kWh13 and the U.S. Virgin Island’s

system-wide average was about 15,200 Btu/kWh14. 

 

10 GPA March 2011. 11 GPA March 2011. 12 GPA March 2011. 13 E-mail correspondence with Kenneth Kelly – NREL, March 2011. 14 E-mail correspondence with Adam Warren – NREL, March 2011.

1,632 1,650 

1,491 

1,726 1,803 1,877 1,811 1,806 1,824 1,836 

325 

175 

198 

137 

91 30 

62 60 30 26 

-

200 

400 

600 

800 

1,000 

1,200 

1,400 

1,600 

1,800 

2,000 

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Generation (GWh)

RFO Diesel
9 

Figure 6. GPA gross electricity production, fuel consumption and overall system heat rate15

Source: GPA

2.2.2 Consumption and Costs

Figure 7 shows the overall annual energy consumption on Guam. The shape of the curve 

corresponds with the gross generation curve (top plot of Figure 6), showing a 6% decline in 

consumption between 2001 and 2010. The difference between generation and consumption is attributed 

to power-plant auxiliary losses, line losses, and losses from technical (billing errors, broken meters) and 

non-technical (theft) sources. Total losses in 2010 were about 12%. There is a drop in 2003 due to 

 

15 GPA March 2011.

1.935

1.956

1.826

1.689

1.862

1.893 1.907

1.873 1.866 1.854 1.862

1.650

1.700

1.750

1.800

1.850

1.900

1.950

2.000

FY00 FY01 FY02 FY03 FY04 FY05 FY06 FY07 FY08 FY09 FY10

Gross Generation (kWh)

Billions

Gross Electricity Production (kWh)

3.276

3.228

2.967

2.788 2.795

2.935

2.870 2.876 2.870

2.787

2.870

2.700

2.800

2.900

3.000

3.100

3.200

3.300

FY00 FY01 FY02 FY03 FY04 FY05 FY06 FY07 FY08 FY09 FY10

Fuel Consumption (Bbls)

Millions

Fuel Consumed (Bbls)

10,626 

10,354 

10,198 

10,360 

9,419 

9,728 

9,444 

9,636 9,655 

9,432 

9,670 

8,800 

9,000 

9,200 

9,400 

9,600 

9,800 

10,000 

10,200 

10,400 

10,600 

10,800 

FY00 FY01 FY02 FY03 FY04 FY05 FY06 FY07 FY08 FY09 FY10

Overall System Heat Rate (Btu/kWh)

Overall System Heat Rate (Btu / kWh)
10 

several tragic events; Typhoons Chata’an, Pongsonga, and Halong all impacted Guam in 2002 causing 

extensive damage to infrastructure. Additioanlly, SARS and the attacks of September 11, 2001, led to 

reduction in tourism. 

Figure 7. Historical annual island energy consumption (2001 – 2010)16

Source: GPA

Figure 8 shows three daily load profiles for the overall GPA system. The hourly data are taken over the 

one-year time period between March 1, 2009 and February 28, 2010. The green plot is the hourly 

average over the entire year. The red plot shows hourly data for the day of the year in which the hourly 

maximum load occurs (October 13, 2010), and the blue plot shows hourly data for the day of the year 

where the hourly minimum load occurs (May 7, 2009). On an annual average basis, the minimum load 

(approximately 180 MW) occurs between 04:00 and 05:00, and the peak load (around 240 MW) occurs 

between 19:00 and 20:00, representing a 25% change in load. On the day with the hourly maximum 

load, the minimum of 189 MW occurs at 04:00, and the maximum of 272 MW occurs at 19:00, 

representing a change in load of 34%. On the day with the hourly minimum load, the minimum of 144 

MW occurs at 01:00, and the maximum of 247 MW occurs at 20:00, representing a change in load of 

42%. 

 

16 GPA March 2011.

1.638

1.624

1.635 1.635

1.669

1.641

1.589

1.457

1.603

1.736

1.450

1.500

1.550

1.600

1.650

1.700

1.750

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Energy Consumption (kWh)

Billions

Guam Annual Energy Consumption (2001 - 2010)
11 

Figure 8. Overall GPA system hourly load profiles (March 1, 2009 – February 28, 2010)17

Source: GPA

Electricity is produced by imported oil (RFO #6) and diesel (#2 distillate). The total consumption of oil 

in 2007 was 14,230 bbl/day18. In 2009, the average cost of electricity was $0.23 per kWh and the GPA’s 

2010 Levelized Energy Adjustment Clause factor was $0.12465/kWh (Effective August 1, 2010)19

In order to understand where energy efficiency measures should be focused, the electricity consumption 

has been broken down by end-consumer (see 

. 

Figure 9). The energy statistics available for the island 

present energy consumption by commercial, residential, U.S. Navy, government, and street lighting 

sectors. Historical data is available for the period between 2001 and 2010, so a historical average was 

used to compare these sectors over the 10-year timeframe20

Figure 10

. The largest consumers of electricity on 

Guam are the commercial and residential sectors, followed by the U.S. Navy and government. As a 

group, private hotels dominate GPA’s commercial load, and the airport is the largest civilian critical 

load. shows the Guam energy consumption by sector between 2001 and 2010. 

 

17 GPA March 2011. 18 CIA World Factbook: https://www.cia.gov/library/publications/the-world-factbook/geos/gq.html. 19 By comparison, the U.S. Virgin Islands Water and Power Authority set a LEAC factor of $0.22/kWh in 2010. 20 Secretariat of the Pacific Community: http://www.spc.int/prism/country/gu/stats/Utilities/Utilities.htm#PH5. 

190

144

158 164 163 165 171 178

191

201

212

225 226 230 232 232 234 236 235

245 247 243

231

219

215

205 201 195 189 190 197205 209

219

229 236 237 240 244 249 254 254 250

272

262 261

249

229

0

50

100

150

200

250

300

0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00

Load (MW)

Hour

GPA Hourly Load Profiles 1 March 2009 - 28 February 2010

Day with hourly minimum load (5/7/2009) Average Day with hourly maximum load (10/13/2009)
12 

Figure 9. Guam energy consumption by sector (2001 – 2010 average)21

Source: GPA

Figure 10. Guam energy consumption by sector (2001 – 2010)22

Source: GPA

 

21 GPA March 2011. 22 Ibid.

Residential

30%

Commercial

37%

Government

12%

Street Lighting

1%

Navy

20%

Guam Energy Consumption by Sector (2001 - 2010)

0

100

200

300

400

500

600

700

FY01 FY02 FY03 FY04 FY05 FY06 FY07 FY08 FY09 FY10

Sales (kWh)

Millions

Guam Energy Consumption by Sector (2001 - 2010)

Commercial Residential Navy Government Street Lighting
13 

GPA is working with DOD during planning to ensure there is adequate capacity to serve the load of 

military projects targeted for the island. The current best estimate of the additional base load from the 

buildup is 30 MW with an additional 25 MW of transient/peaking load. GPA believes there is sufficient 

generation capacity currently in the system to meet the planned load requirements. DOD has also 

expressed that a preferred solution to complement GPA's existing generation system is to recondition up 

to five peaking/emergency combustion turbine units. GPA is working with DOD to identify transmission 

and distribution projects that would be required to meet the military service requirements. DOD has 

been committed to the principle of ensuring the civilian community is not negatively impacted by the 

cost of the buildup. 

2.2.3 End Use 

Understanding the building stock is important to know how energy is being consumed within a building, 

as energy use will vary by construction type/materials and the age of the building. Other parameters that 

impact energy use are climate and culture. The goal in reducing energy consumption is to understand 

how it is being utilized and to know where conservation and efficiency measures can be applied. By 

identifying the end-uses of energy consumption, analysis can be undertaken to identify areas where 

improvements can be made.

NREL’s site visit demonstrated that in typhoon prone areas, such as Guam, buildings are typically 

constructed of concrete to withstand the wind and water. Buildings that are lightweight and constructed 

of wood frames or are older and have deteriorating structures are vulnerable to typhoon destruction. 

Reinforced concrete is often used as the building material in typhoon ‘alleys’; this type of construction 

was observed in Guam. The building portfolio is comprised of hotels, the airport, government and 

military buildings, schools, hospitals, medical clinics, commercial property, and residential buildings, 

such as apartments and single family dwellings. The number of buildings classified within each category 

is unknown; however opportunities were identified within the energy end-use sectors as provided by the 

Government of Guam and GPA. The direction the Government is trying to head is exemplified by the 

Leadership in Energy and Envionremental Design (LEED)-registered buildings under construction on 

the Guam Community College Campus, shown in Figure 11. 

Data collected from the site visit have indicated that the highest end users of energy on Guam are 

commercial, residential, government, Navy, and then street lighting, as shown in the pie chart above in 

Figure 9. End use within the commercial, residential, and government sectors are discussed in more 

Figure 11. Guam Community College’s LEED-registered 

building under construction 

Source: NREL/PIX 18588
14 

detail in the following sections. Delving into the end use in more detail allows for solutions to be 

identified either in terms of energy conservation or energy efficiency. 

Energy conservation and energy efficiency can be combined to create an effective strategy to achieving 

overall island energy reduction. Energy conservation is any behavior that results in the use of less 

energy. Turning the lights off when you leave the room is one example of conserving energy. Energy 

efficiency, on the other hand, is the use of technology that requires less energy to perform the same 

function. A compact fluorescent light bulb that uses less energy than an incandescent bulb to produce 

the same amount of light is an example of energy efficiency23

2.2.3.1 End Use for Commercial Sector

. 

Commercial building consumption is led by offices, retail, luxury hotels, and the education sector. End 

users within commercial buildings are reported by GPA as being interior lighting, cooling, 

miscellaneous equipment, refrigeration, ventilation, exterior lighting, water heating, and cooking. The 

end use is broken out for commercial buildings in Figure 1224. 1993 is the most current end use data 

available. 

Figure 12. Commercial electric sales by end-use, 1993

Source: GPA

Many assumptions were made by the authors commissioned to calaculate the sector break-down for 

GPA; therefore some scrutiny may be necessary when analyzing these results. A more detailed study 

may be required in commercial buildings to determine whether interior lighting is truly higher than 

cooling. 

Additionally, more information on the end-users within the ‘miscellaneous’ category would be helpful. 

By understanding more about the equipment and plug loads that are consuming energy, a commercial 

organization will have better control over managing and reducing their energy consumption. An 

example is a company that leaves computers, printers, and fax machines on or on standby overnight. 

Without knowing what the components of the ‘miscellaneous’ category are it is difficult for the 

organization to know how to make reductions. 

2.2.3.2 End Use for Residential Sector

GPA reports that consumption by the residential sector is impacted by the rate of electricity, which 

fluctuates primarily based on the cost of fuel. Despite a growth in population and in electricity 

 

23 Energy Information Administration, http://www.eia.doe.gov/energyexplained/index.cfm?page=about_energy_efficiency. 24 Guam Power Authority, Demand Side Management Plan, April 1993, Section II.
15 

customers, Figure 13 shows that the average kWh sales per residential customer declined by 16% 

between 2001 and 201025

Figure 14

. This decrease is thought primarily to reflect reduced consumption due to 

higher rates (shown in ). From 2001 through 2010, the average annual fuel bill for GPA’s 

residential customers has increased by 44%. The graphs show the actual activity in the thicker, blue line; 

the average trend lines are shown in the thin, black line. 

Figure 13. Annual energy sales (residential sector)

Source: GPA

Figure 14. Average annual costs per residential customer 

Source: GPA

 

25 End use data provided by GPA.

10,000 

11,000 

12,000 

13,000 

14,000 

15,000 

16,000 

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

kWh/year

Year

Electrical Use per Residential Customer 

(kWh/year)

$-

$500 

$1,000 

$1,500 

$2,000 

$2,500 

$3,000 

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

$/Year

Year

Annual Electricity Cost/Residential Customer ($/yr)
16 

In 1993, the highest energy consumption in Guam within the residential sector was water heating, 

followed by air conditioning and household appliances, as shown by the end use of energy in residential 

buildings shown in Figure 1526

2.2.3.3 End Use for Government Sector

. This tells us the best opportunities for the residential sector include 

reducing electrical use for water heating, improving air conditioning, improving appliances, and 

changing to more efficient lighting. 

A snapshot glimpse for the Guam Government sector indicates that the largest consumption of fuel for 

November 2010 was related to a few specific agencies. The Guam Waterworks Authority (GWA) had 

the largest energy consumption, followed by the Department of Education, the University of Guam, and 

the hospital. This breakdown is shown in Figure 16. 

 

26 GPA, Demand Side Management Plan, April 1993, Section II. This is the latest year that has data available.

0

20000

40000

60000

80000

100000

120000

MWh

Energy End-User

Residential Electric Sales by End-Use (MWh), 1993

Figure 15. Residential electric sales by end user

Soure: NREL
17 

Figure 16. Guam government sector energy consumption by percentage of total energy consumption27

Source: NREL

While this type of assessment is not comprehensive in its review of energy consumption, it provides a 

glimpse of where energy is being consumed within the sector. Ideally, an assessment would cover 

multiple years worth of data and be compared to the total floor area of each agency. The energy 

consumption per floor area provides a more comprehensive form of benchmarking energy consumption 

activities within buildings and highlights where energy is being consumed more thoroughly. 

Without further investigation it is difficult to confirm assumptions; however assumptions can be made 

about the end use within each agency. For example, the energy consumption at GWA may be a result of 

typical energy end use, such as lighting, air conditioning, and equipment; however motors, drives, and 

pumps may contribute significantly to the consumption. GWA is responsible for treating and pumping 

water, therefore it can be assumed that the primary energy consumers are due to these main activities. 

The Department of Education, the University of Guam, and Guam Community College are most likely 

responsible for a large building portfolio with high cooling, lighting, and plug loads, whereas the 

hospital presumably has the same loads, but on a 24-hour demand scale. 

2.2.4 Current Status of Energy Policy

Across the global landscape, many communities are turning to policy as a way to institute clean energy 

technologies. Many states, territories, local governments, and communities are interested in adopting 

strategies that promote energy efficiency and renewable energy. Policy is a mechanism many 

governments use to advance and support energy efficiency and renewable energy objectives. Policy 

implementation can aid in market adoption and assist in laying a foundation for a green economy while 

providing investors with reassurance within market transformation. Policy can be an effective tool Guam 

can use to implement their energy efficiency and renewable energy goals, increase energy diversity, and 

decrease dependence on imported fossil fuels. Additionally, there are environmental benefits such as 

emissions reduction, reduction of water consumption, thermal pollution and adverse land-use impacts. 

Oftentimes, these environmental effects can be beneficial in a cost-benefit analysis when factoring in 

future fossil fuel generation. 

The following subsections discuss energy policies currently in place in Guam. 

 

27 Data provided by the Guam Energy Office for November 2010.

0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

30.00%

35.00%

% of total
18 

2.2.4.1 Net Metering

Net metering for distributed generation was enacted in December 2004 under Guam Public Law (PL) 

27-132.28

Through interviews it has been learned that the PUC has currently enacted these rules. If the energy the 

customer produces is zero or negative during a particular billing cycle, the customer shall pay only the 

non-energy charge portion; if the customer’s net energy is negative they will be credited the kilowatt 

hour different in the next billing cycle.

The net metering policy is an agreement between GPA and its customers for a variety of 

renewable technologies; fuel cells, microturbines, wind energy, biomass, hydroelectric, solar, or hybrid 

solar systems. In order to participate in this program the system cannot exceed the eligible size of 25 

kW. GPA will pay for any additional meters needed as well provide customer-generators with a bidirectional energy meter. Customers must meet all prescribed safety guidelines and electric codes. GPA 

does not require additional measures, controls, or supplemental insurance once these requirements have 

been met. Customers who take advantage of net metering can request billing on either a monthly, semiannual, or annual basis. Systems that produce excess generation will be compensated; however, the rules 

for this policy have yet to be set by the Guam Public Utilities Commission (PUC), which was required 

within 120 days of the authorizing legislation. 

29 Table 6 lists the current net metering customers. 

Table 6. Current GPA Net Metering Customers

Location Technology Size (KW) Cust Type Activation 

Date

Golondrina Avenue, Barrigada Heights PV 8.4 KW Residential 2/17/2009

Flores Rosa Loop,Barrigada Heights PV 8.4 KW Residential 5/19/2009

Daisy Lane,Latte Heights PV 7.7 KW Residential 4/17/2009

Tun Emeterian Camacho St.,Oka,Tam. PV 8.4 KW Residential 9/25/2009

Acho Latte St.,Macheche,Dededo(2 ea.) PV 7.7 KW (2 

ea.)

Commercial 1/22/2010

Toto Canada Rd.,Barrigada PV 2.96 KW Residential 12/1/2009

Toto Canada Rd.,Barrigada Wind 1.8KW Residential 6/22/2009

Chalan Villagomez,Latte Heights Wind 1.8KW Commercial 6/1/2009

Mangilao , GCC Compound, New Learning 

Center

PV 24.8KW Commercial 12/10/2010

Mangilao , GCC Compound, Allied Health 

Center

PV 29.4KW Commercial Under 

Construction

2.2.4.2 Energy-Efficient Appliance Rebate Program

The “State Rebate Program” sponsored by DOE through the American Recovery and Reinvestment Act 

of 2009 rolled out in Guam 201030

2.2.4.3 Solar-Ready Residential Building Requirement

. Unfortunately, funds are limited and this program has not been 

locally invested and therefore will have a short lifespan. However, incentives to replace inefficient 

equipment with new ENERGY STAR certified products, including washing machines, refrigerators, and 

air conditioners (both room and split type models), will no doubt show measureable savings. 

Approximately $160,000 was set aside for this program. 

Effective in October 2000, the Guam Energy Code adopted installation requirements for new residential 

low-rise buildings. The building code now requires that all new residential construction must include the 

appropriate solar thermal equipment that would allow future solar thermal unit installation31

 

28 http://www.guamlegislature.com/Public_Laws_27th/P.L.%2027-132.pdf. 

. 

29 Net Metering Program Interconnection Policy, 2/26/2009. 30 http://www.guamenergy.com/announcement-to-appliance-retailers/. 31 http://www.dsireusa.org/documents/Incentives/GU01R.htm. 
19 

2.2.4.4 Building Codes

The current building codes in Guam are outdated. The Guam Energy Code uses ASHRAE 90.1-1989 for 

commercial buildings and follows the 1992 Model Energy Code for residential buildings32

The most current green building codes to be recommended are: 

. These codes 

were adopted more than 12 years ago with provisions to allow the Department of Public Works to 

administer the latest edition of the code for design and construction. 

• Commercial: ASHRAE 90.1 2010, Energy Standard for Buildings Except Low-Rise Residential 

Buildings/International Energy Conservation Code (IECC), 2009 

• Residential: International Energy Conservation Code, 2009. 

These codes are set up to address heat loads, but tropical areas can choose what is applicable as the 

IECC tends to group energy requirements and discount tropical climate impacts on buildings. 

As of October 28, 2010, Guam adopted the 2009 IECC. Part of the requirements of that adoption are to 

establish a Guam Building Code Council whose responsibilities will include providing 

“recommendations for further amending or adding to the codes adopted with this legislation, including 

the possible amending or adoption of Appendices A, B, and D of the International Building Code, 2009 

edition, the International Property Maintenance Code, 2009 edition, the International Energy 

Conservation Code, 2009 edition, the Model Tropical Energy Code, and any other construction codes as 

the Council may deem appropriate,”33

2.2.4.5 Renewable Portfolio Standard

. Adoption of the Tropical Building Code is only the first step to 

addressing energy use in new construction and major renovations; but current building stock is a 

concern. Compliance and enforcement are other issues that must be addressed. 

Guam has not adopted the traditional Renewable Portfolio Standard (RPS) but has an RPS goal that was 

introduced as Guam Bill 166 and enacted in March 2008 through the Guam legislature—Guam Public 

Law 29-6234

If Guam is to move toward decreased fossil fuel use and increased energy diversity, an RPS can be a 

very effective tool. The following is Guam’s timeline for renewable energy integration as spelled out in 

their 2008 RPS goal. 

. This law was an attempt to address three important initiatives: (1) promote the 

development of renewable energy, (2) establish an RPS, and (3) study the feasibility of a rate structure 

through the PUC that would support renewable energy implementation. It established a renewable 

energy goal of 25% renewable energy by 2035. This goal is not compulsory like a traditional RPS, 

which is legally binding. 

• 5% of net electricity sales by December 31, 2015 

• 8% of net electricity sales by December 31, 2020 

• 10% of net electricity sales by December 31, 2025 

• 15% of net electricity sales by December 31, 2030 

• 25% of net electricity sales by December 31, 2035. 

Here are a couple island examples: 

 

32 http://bcap-ocean.org/state-country/guam. 33 Government of Guam Bill No. 460-30 (COR), passed October 28, 2010. 34 http://www.guamlegislature.com/Public_Laws_29th/P.L.%2029-62%20%28Bill%20No.%20166%20EC%29.pdf. 
20 

U.S. Virgin Islands has passed legislation and established that “peak demanded generating capacity” 

come from a renewable source of 30% by 2025.35

Hawaii has established a 70% fossil fuel reduction target by the year 2030, 40% of its net electricity 

sales. 

 

These goals are all inclusive of energy usage as a whole and include the transportation sector.36

2.2.5 Solid Waste

 

Solid waste generation and disposal represent significant costs and challenges for island communities 

like Guam. Solid waste represents a potential source of material that can be converted to energy. The 

first step in determining the potential is to understand present waste management practices, waste 

generation quantities, waste composition, disposal costs, and regulatory environment.

Solid waste management issues in Guam are complicated. Under a Consent Decree issued in 2004, the 

United States District Court ordered the Government of Guam to plan for the closure of Ordot Dump 

and to construct a new sanitary landfill that would be fully compliant with subtitle D of the Resource 

Conservation and Recovery Act37

Over the next four years, the Government of Guam made little progress in implementing the Consent 

Decree. In March 2008, the District Court of Guam issued a Court Order

. 

38

The Layon landfill is scheduled to be completed and opened in the summer of 2011. In January of 2011, 

Senator Tom Ada introduced a bill to create an autonomous agency—the Guam Solid Waste 

Management Authority—to take over solid waste management responsibilities from GBB when the 

terms of the Consent Decree are fulfilled.

 to appoint consulting firm 

Gershman, Brickner and Brayton (GBB) as the Federal Receiver to enforce compliance with the 

Consent Decree. Under the terms of this order, GBB took control of the Guam Solid Waste Management 

Division and assumed all of its responsibilities. GBB is presently managing the closure of Ordot and the 

construction of the new Layon Landfill. 

The total cost of constructing Layon Landfill and related consent decree projects was estimated to be 

$98 million in the August 2010 Quarterly Receiver Report.39

To cover debt repayment and ongoing operations and maintenance costs, the new Solid Waste 

Management Authority will need to charge a tipping fee and maintain a minimum flow of municipal 

solid waste (MSW) into the landfill. In July 2009, the U.S. Navy, GBB, and the Government of Guam 

signed a letter of intent stating that it is the intent of the U.S. Navy to negotiate a contractual 

arrangement for solid waste management services with the new entity that will run the landfill. 

Essentially, U.S. Navy waste is needed to help meet project cash flow and revenue requirements for 

landfill operations and bond repayment. If U.S. Navy waste is included, it will also lower rates for the 

 GBB developed the financing plan for the 

process and assisted the Government of Guam with raising the funds. GBB is continuing to identify 

cost-saving measures for construction of the landfill. 

 

35 http://www.dsireusa.org/incentives/incentive.cfm?Incentive_Code=VI06R&re=1&ee=1. 36 Ibid. 37 Consent Decree for the Closure of Ordot Dump, Feb 2004, available online at 

http://iconguam.com/guamsolidwaste/docs/Federal%20Consent%20Decree%20[2-12-04%20in%20Civil%20Case%2002-

22].pdf accessed January 31, 2011. 38 The Court Order can be found at http://www.guamsolidwastereceiver.org/pdf/court_order.pdf accessed January 31, 2011. 39 Quarterly Report of the Receiver, August 11, 2010. pg 29. Accessed online on March 3, 2011:

http://www.guamsolidwastereceiver.org/pdf/Tab_1_Quarterly_Report_of_the_Receiver_8_11_10.pdf. 
21 

rest of the island. Final tipping fees have not yet been approved by the PUC40. However, proposed rates 

have been submitted to the PUC and are shown in 

. 

Table 7. Proposed and Interim Tip Fees

With 

Military

Without 

Military

Commercial ($/ton) $ 156 $ 174

Residential ($/month) $ 28 $ 32

Effective Date

Self Drop 

(< 3 CY)

Self Drop (> 

3 CY)

Current $ 2.50 $ 5.00

September 1, 2010 $ 4.00 $ 8.00

March 1, 2011 $ 5.50 $ 11.00

September 1, 2011 $ 7.50 $ 15.00

Transfer Station Rates:

Landfill Tip Fees:

The impacts of increased tipping fees on waste collection rates are not known at this time. However, it is 

likely that higher tip fees will lead to increased illegal dumping and reduce the amount of waste going to 

landfills. Depending upon the cost of recycling, it may also lead to increased participation in recycling 

programs. 

2.2.5.1 Guam Waste Generation and Composition Analysis 

Minimal data on the amount and format of Guam’s solid waste stream is available. In the August 2010 

Quarterly Report, the Receiver reported that from June 1, 2009, through June 1, 2010, 80,500 tons of 

solid waste was delivered to Ordot. This is quite a bit lower than a previous estimate. In a report entitled 

Estimation of Potential Landfill Gas Yields for the Ordot Dump41

This annual total also does not include DOD solid waste. The amount of waste generated by DOD is 

estimated in the Final Environmental Impact Statement for the build-up

, Duenas Associates and URS 

Corporation estimated that between 2004 and 2007 approximately 120,000 tons per year were being (or 

would be) disposed of in the Ordot Dump. As the Duenas/URS figure was based on estimates and the 

2010 figure is based on scaled data, NREL will assume an annual waste estimate of 80,500 tons/year. 

This figure does not include green waste and corrugated cardboard, which were banned from Ordot 

several years ago. These materials are now being recycled by the private sector on Guam. 

42

 

40 Quarterly Report of the Receiver, December 9 2010, pg 34. Accessed online on March 3, 2011:

http://www.guamsolidwastereceiver.org/pdf/Tab_1_Quarterly_Report_of_the_Receiver_12_9_10_Final.pd. 

. The quantity of waste 

produced by DOD is highly dependent upon the population of military and non-military personnel 

associated with the build-up and related activities. DOD is also implementing an aggressive recycling 

program, with a target diversion rate of 50% by 2015 and every year thereafter. It is presumed that some 

of the material diverted to recycling would also be potentially suited for conversion in a waste–to-energy 

(WTE) plant. 

41 Estimation of Potential Yields of Landfill Gas from the Ordot Dump. Duenas & Associates and URS Corp. July 2005. 

Accessed online at: http://guamsolidwastereceiver.org/pdf/RFP%20SWD001-11%20-%201b%20-

%20Est.%20of%20Poten.%20LFG%20Yields%20Ordot%20Dump.pdf.. Accessed January 29, 2011. 42 Solid Waste data provided by Captain Peter Lynch to Scott Haase via email March 20, 2011. Table is entitled Table 2.4-1 

Projected Solid Waste Estimates, pg 2-109 and 2-110. All data in the table are based on per capita waste generation estimates 

of 7.4 pounds per person per day. 
22 

The table shows a total solid waste volume from DOD and non-DOD personnel and construction 

activity starting at 30,467 tons/year in 2010 (including 10% recycling of DOD waste) and reaching a 

peak of 66,900 tons/year in 2015 (including 50% recycling), and then declining to 37,425 tons/year in 

2019. For purposes of this report, NREL will assume the lowest value, or 30,467 tons/year of waste 

produced by DOD. This value is potentially conservative and there may be significantly more material 

available from DOD for a WTE plant. 

Thus the total potential waste stream available is 110,967 tons/year. This is the number that we will use 

later to estimate the potential energy that could be produced from Guam’s waste.

To our knowledge there are no recent, statistically-valid waste composition analysis studies that have 

been conducted on Guam’s waste stream. In its December 2010 Quarterly Report, the Receiver provides 

information on a new waste characterization study being performed by the Solid Waste Management 

District (SWMD)43

Figure 17

. This is a limited study in that it is only focusing on the waste generated by 

participants in SWMD’s pilot recycling program. As part of the pilot recycling program, some residents 

have agreed to have their waste collected separately and sorted into categories and weighed over the 

next year. The first sort was conducted on October 12, 2010. A total quantity of 457 pounds of waste 

from eight residents was sorted into categories. The breakdown of materials into categories is shown in 

. Glass and metals (non-combustible) represent 13% of the stream.

Figure 17. October 2010 waste characterization study (limited sample)

Source: NREL

In addition, NREL located a reference to a 1995 study quoted in a memo from the Receiver; the 

Receiver provided NREL with a copy of this report44

 

43 Quarterly Report of the Receiver, December 9 2010. Available on line at: 

http://www.guamsolidwastereceiver.org/pdf/Tab_1_Quarterly_Report_of_the_Receiver_12_9_10_Final.pd

. The 1995 report estimates that Guam produces 

over 600 tons of solid waste per day. However, this number is not based on scaled data and it is 

Accessed on March 3, 2011.

44 Guam Solid Waste Weight Composition and Recycling Feasibility Study Final Report. Guam Environmental Protection 

Agency, May 19, 1995.

Papers/cardboard

30%

Plastics

Other/Misc 19%

16%

Food

16%

Metals/Cans

7%

Yard Waste

3%

Glass

6%

Textiles

3% Annual Available Waste:

94,322 tons per year
23 

considerably higher than the actual scaled data reported by GBB for the 2009-2010 timeframe. The 1995 

study did conduct a detailed waste sort and characterization. The study found that approximately 13% of 

the material was either metal, glass, aluminum, or hazardous material. 

NREL also located a 1982 study that categorized Guam’s waste in 1980. The breakdown of the 1980 data 

is shown in 

Figure 18. Comparing the limited sample from 2010 with the analyses conducted in 1980 and 1995, 

glass and metals (which are non-combustible and should be removed from any calculations estimating 

available WTE conversion) were estimated at 13% of the total in 2010 and 1995, and 15% of the total in 

1980. 

As the 2010 sample is only from eight households, and pending the location of any more recent data, we 

will use the 15% value from the 1980 study as being the most representative and most conservative. 

Figure 18. Guam's solid waste composition, 198045

Source: Rossi Nayve Consulting Service and Associates

Assuming that the composition is still the same, and that the percentages also apply to the DOD stream, 

about 15% of the stream is non-combustible metals and glass and should be subtracted from the 110,967 

tons per year of available waste. This leaves a potential available feedstock of 94,322 tons per year. We 

will use this value to estimate WTE potential in Section 3 of this report.

2.2.5.2 Construction Waste 

There will be considerable construction and demolition (C&D) waste associated with the military buildup on Guam. Section 18.2.5.1 of the EIS document states that the preferred alternative will be to dispose 

of this material in the U.S. Navy-owned landfill at Apra Harbor46

 

45 Rossi Nayve Consulting Services and Associates, A Study of Guam’s Recyclable Wastes, Guam Solid Waste Management 

Plan, 1982. Referenced online: http://www.co.hawaii.hi.us/env_mng/iswmp_orig/Chapter%2003.pdf, pg 5. Accessed 

February 1 2011.

. While there will be a temporary 

46 Guam and CNMI Military Relocation, Final EIS. Accessed online on March 3, 2011: 

http://www.guambuildupeis.us/documents/final/volume_6/Vol_06_Ch18_Hazardous_Materials_and_Waste.pdf. 
24 

increase in C&D waste associated with the build-up, the quantity will vary and it is not a reliable 

feedstock that will be available over the 20-year life of any WTE plant, so it will not be added to the 

estimate of available waste for conversion to energy.

2.2.5.3 Recycling 

Recycling provides a landfill diversion opportunity, as well as an economic opportunity within the 

commercial sector. Observations on-island and interviews with stakeholders indicated there is presently 

minimal recycling in Guam. Should a more comprehensive recycling program be implemented, the 

amount of material available for WTE could potentially be reduced depending on the materials that are 

recycled. Solid waste managers and planners need to carefully consider all of the costs and benefits of 

both WTE and recycling within a unified framework. The lifecycle economics of recycling on Guam 

need to be carefully evaluated. On-island markets are likely to be limited and the costs of shipping 

overseas need to be considered. 

2.2.5.4 Regulatory Framework 

During the site visit, the legalities surrounding PL 25-175 and the ramifications were noted. PL 25-175, 

"An Act to Approve and Amend the Integrated Solid Waste Management Plan," prohibits construction 

or operation of solid waste incinerators or WTE facilities on Guam. Specifically, PL 25-175 states: 

Section 73113 is hereby added to Chapter 73, Division 3 of Title 10 of the Guam Code Annotated 

to read as follows: 

Section 73113. Municipal Solid Waste Incinerators Prohibited. Notwithstanding any other 

provision of law, it shall be unlawful for any person to construct or operate on Guam a 

municipal solid waste incinerator or a waste-to-energy facility, as defined by the rules and 

regulations of the United States Environmental Protection Agency or the laws of the United 

States of America47

NREL understands that the main reason this legislation was passed was to prohibit implementation of a 

controversial 1996 agreement between the Government of Guam and a company called Guam Resource 

Recovery Partners (GRRP). The agreement was entered into by the Executive Branch of the 

Government of Guam. It is NREL’s understanding that the legislature had concerns that the agreement 

required the Government of Guam to provide GRRP with minimum quantities of waste that were 

beyond the amount of waste generated on the island. The legislature therefore passed a law prohibiting 

WTE. 

. 

It is clear that without legislative action or creative thinking, it is extremely unlikely that anyone will be 

able to develop a WTE plant on Guam in the near term. However, we will still estimate the potential 

energy that could be produced from waste in Section 3. 

 

47 PL 25-175 is available online, http://www.guampowerauthority.com/special/documents/PL25-

175_prohibitIncinerator_plandocs.pdf, accessed on 2/1/2011.
25 

3 Energy Efficiency and Renewable Energy Opportunities

Guam represents a high priority location for the development of an integrated energy plan due to its 

strategic importance to the U.S. military, high energy costs, dependence on imported fossil fuel, and the 

expected future pressure on the island’s energy resources from the planned increase in military and 

civilian populations. 

There are many energy efficiency and renewable energy opportunities for Guam. This section outlines 

the opportunities that have been identified based on the initial assessment. However the Task Force will 

need to determine where priorities lie and which opportunities will need to be considered further. The 

initial opportunities identified are summarized in Table 1. Energy Efficiency and Renewable Energy 

Opportunities and Potential Impacts. 

This section of the report provides information on various opportunities as they relate to developing a 

strategic plan. Specific savings are difficult to quantify due to the amount of data available at the time of 

the site visit. Savings could be calculated based on energy audits from private industry and scaled up 

across the sector, or more detailed audits could be conducted to determine specific savings. The areas of 

opportunities presented in this section are based solely upon observations made during the site visit 

conducted by the NREL team while on-island the week of October 11, 2010. 

The energy efficiency and renewable energy opportunities discussed below are: 

• Energy efficiency and conservation 

• Wind

• Solar 

• Geothermal 

• Biomass.

3.1 Energy Efficiency and Conservation

The opportunities that have been identified for energy efficiency and conservation measures include 

raising island energy awareness in the various sectors, creating a cool-roof program, and establishing 

metrics for improvement within the island building codes and equipment standards. 

Due to administration changes, it is unclear at this time the direction Guam will take on building codes. 

It is recommended that a review of the existing building codes and equipment specification standards be 

conducted by the Energy Task Force, utilizing available technical assistance. The end goal of a building 

code and specification analysis would be to highlight areas where improvements could be made and 

where Guam could benefit by changing the building code and standards. Other island nations with 

energy efficiency standards already incorporated into codes and standards could be used as a model. 

Energy efficiency integrated into tropical building codes, training, and enforcement are all potential next 

steps after a review of the existing codes is conducted. 

3.1.1 Raise Island Energy Awareness for Conservation

Energy audits have been funded on island, most recently, by the Guam Energy Office (e.g. audits of 

government facilities and homes), the Department of Education (schools), and by GPA and Johnson 

Controls (e.g. hotels, the airport, etc). 

It is recommended that building audit results from the current activities on Guam (e.g. within hotels, 

schools, government agencies, and homes) be applied to developing a strategy where conservation 
26 

measures are relevant to multiple buildings within a specific sector. For example, hotel audits may 

indicate the need for better lighting controls; this should be integrated into a strategy to improve controls 

in all hotels, not just those being audited. 

These audits may identify both behavioral and technical improvement and are summarized by sector 

below. 

 Residential 

o Campaigns for local communities, as discussed in more detail in Appendix B 

o Pilot the campaign in Dededo where there’s interest and the potential for the largest 

impact as discussed in more detail in Appendix B 

 Commercial 

o Work with various sectors to increase awareness through posters, stickers, fact-sheets, 

etc. 

o Work with island suppliers and retailers to source energy efficient technologies 

 Construction industry 

o Provide training for the construction industry on design practices and energy efficiency 

measures that should be incorporated into new construction and renovations, such as 

external shading for windows, coating coastal air conditioning unit coils to protect from 

sea mist, insulation, high SEER air conditioning units, etc. 

3.1.2 Establish a Cool-Roof Program to Improve Efficiency 

DOE’s Secretary Steven Chu launched a series of initiatives in July 2010 to encourage cool-roof 

technologies in the federal government. Secretary Chu has directed all DOE offices to install cool roofs 

whenever cost effective over the lifetime of the roof, when constructing new or replacing old roofs, and 

in areas where cool roofs will be beneficial to energy efficiency savings (typically in hot climates). 

While these initiatives are targeted at federal buildings, the cool-roof program has materials and 

resources that would be beneficial to Guam. Cool roofs are roofs that are designed to maintain a lower 

roof temperature than traditional roofs while the sun is shining, typically through reflectance 

technologies. Not all cool roofs need to be white, as indicated by the cool-roof tiles in Figure 1948. 

Figure 19. Cool roof tiles in colors other than white 

Source: DOE 

 

48 DOE, Guidelines for Selecting Cool Roofs, July 2010: http://www1.eere.energy.gov/femp/pdfs/coolroofguide.pdf. 
27 

A cool-roof program could be implemented island-wide by using low-cost technologies, such as 

Elastomeric paint (~$40/gallon), which would need to be applied to roofs and maintained through a 

cleaning program (to prevent debris and mold build-up). More information about selecting buildings and 

implementing a cool-roof program can be found on the DOE website49. 

3.1.3 Review and Improve Energy Efficiency Standards to Improve Efficiency 

Building codes were accepted by government officials of Guam; however, energy efficiency should be 

incorporated into building codes. Building codes should be reviewed and revised to include energy 

efficiency parameters as soon as possible. The building industry will need time to learn building codes 

and train personnel to meet these codes, so integrating energy efficiency as early as possible will assist 

with a faster implementation rate of energy efficiency measures in new construction. Equipment 

standards should also be reviewed to eliminate/reduce energy intensive equipment, such as window air 

conditioning units and machinery being imported to Guam. The European EcoLabel scheme or 

ENERGY STAR ratings are good models to follow for establishing equipment and buildings that meet 

specific criteria for meeting Guam’s energy reduction targets. The EPA Portfolio Manager is useful for 

managing building stock and benchmarking buildings across a portfolio. 

3.1.4 Consider Alternative Cooling Technologies 

Cooling is one of the highest end users on Guam within all sectors. Considering and implementing 

promising alternative cooling technologies will assist with reducing fossil fuel consumption related to 

conditioning indoor spaces. There are a number of options available under the umbrella of alternative 

cooling technologies. 

One lower-cost option in buildings with no requirements for conditioning for moisture control is to 

install ceiling fans. Where moisture buildup is not a concern it may be possible to utilize natural 

ventilation (from breezes and open structures of windows, doors, etc.), and ceiling fans, which are in 

operation only when needed. There may be open structures where this could be a suitable option. 

Planting ‘green roofs’ may also be a lower cost option to consider. Where roofs are flat and structurally 

sound they can be used to plant vegetation, which not only provides a thermal barrier, but also creates a 

wicking-type action. The wicking of moisture and heat upwards and out of the building is beneficial in 

reducing cooling loads in buildings50. 

A medium-cost option is to install solar air conditioning units. While relatively new on the market, solar 

air conditioning units are available from a number of manufacturers and suppliers, and have a variety of 

different installation applications from split wall window units to larger outdoor units. This technology 

is an efficient type of air conditioner (upwards from a SEER 20) that operates off of a solar photovoltaic 

(PV) panel, which reduces the energy demand from the grid during times when cooling and conditioning 

are needed. 

A high-cost option to reduce Guam’s energy consumption related to space cooling is a sea-water cooling 

system. This technology is being investigated by private consultants for the U.S. Navy and also by GPA 

and JCI for the hotel loop in Tumon Bay. The Energy Task Force is encouraged to review the findings 

of that investigation to determine whether the cost-benefit analysis is in the island’s favor. 

3.1.5 Next Steps 

The following next steps are recommended: 

1. Continue energy and water audits and apply measures where they are more broadly applicable. 

 

49 http://www1.eere.energy.gov/femp/features/cool_roof_resources.html. 

50 http://www1.eere.energy.gov/femp/pdfs/fta_green_roofs.pdf. 
28 

Audits have already begun on Guam in specific sectors, such as the airport, Joint Region 

Marianas sites, and within a few hotels. These audits should continue and, where possible, the 

measures that are applicable to similar buildings should be gleaned from audit reports and 

implemented across the building stock. For example, if five of the island’s hotels are being 

audited the measures that are most commonly recommended may be applicable to the remaining 

hotels. These measures may include improving lighting fixtures and controls; installing low-flow 

faucets, toilets, and showerheads; or installing thermostatic controls to reduce the energy 

consumption of air conditioning units. A strategy for identifying and implementing the measures 

that are most commonly recommended could be a next step, but would require disclosure from 

the entities conducting the energy and water audits. 

2. Begin an energy awareness campaign within the various building sector types. 

An energy awareness campaign is a low-cost solution for implementing energy conservation. 

Pilot projects could be carried out within specific buildings or communities to highlight the 

impact of the campaign on energy consumption. For example, Dededo has an actively engaged 

Mayor who may be willing to promote energy conservation. In order to begin an awareness 

campaign the audience would need to be identified, materials prepared, and launch dates 

selected. Campaigns are ongoing and need to be renewed every few months to communicate 

specific messages to target audiences. Materials within a community such as Dededo may 

include articles in newsletters or the weekly newspaper insert, posters and flyers, stickers for 

light switches and equipment, and events for children and adults that are fun and educational. A 

different campaign should be created for each specific audience and may include the following: 

a) Hotel staff and guests 

b) Medical staff 

c) Education staff, teachers, and students 

d) Community residents (adults and children). 

3. A strategy for implementing a cool roof program should be designed, beginning with identifying 

buildings to be used as pilots for a cool roof pilot program. 

These buildings should be selected following the guidelines established in the materials on 

DOE’s website51. Buildings would ideally have engaged facilities management staff who could 

monitor the energy consumption prior to and after the cool roof installation to indicate any 

change in energy consumption. Buildings that vary with sector and cool roof application type 

would be most beneficial to display what is most effective at reducing energy consumption. 

Facilities in need of roof replacement, particularly if there is a budget for replacement in the 

near-term, may be most applicable as initial projects. Once this pilot program has been 

completed the results should be analyzed and the most effective cool roof type should be 

replicated throughout the building stock, with continued monitoring and savings reports. 

4. Create training materials for the design and construction industry to increase knowledge relating 

to energy-efficient technologies and practices. 

Training materials could take the form of curriculum for workshops, handbooks, presentations, 

websites, and other tools. A training module would need to begin with an assessment of the 

current level of knowledge and indicate areas of the greatest need for improvement. The 

audience would need to be assessed so that materials could be tailored to be the most effective. 

5. Encourage the use of alternative cooling technologies, where appropriate, within retrofits and 

new construction. 

 

51 http://www1.eere.energy.gov/femp/features/cool_roof_resources.html. 
29 

Review the results of the salt-water cooling research and determine if implementation in specific 

industries (e.g. hotels) is beneficial to reducing fossil fuel consumption. 

6. Develop a strategic energy plan. 

There is great opportunity for policy and technology development in Guam. Through the 

assistance of Guam’s Energy Task Force and the development of a strategic energy plan, policy 

and technology can be addressed. Ongoing efforts will be needed to support the Task Force on a 

multitude of levels. Although the Task Force has been established, Guam has currently elected a 

new governor and administrators; this change can set timelines back. However, Governor Calvo 

and his administration were quick to be informed and fully support this effort. Maintaining 

momentum is key to success. The Task Force will require some assistance in deciphering data 

and directing subcommittee levels while setting goals and objectives. Several deeper dives 

within technology development and cross-cutting policies will need to be examined to determine 

best strategies. 

7. Develop a policy framework strategy. 

Policy is an effective tool in addressing clean energy adoption and subsequent development, and 

the process of policy development addresses the interconnectedness of social concern. Below is 

an outline of a policy framework strategy Guam may want to use in developing its strategic plan. 

 How is the energy discussion being framed? 

o What high-level support is there (federal, territorial, local)? 

o Identify the support; finances, technical assistance, education and outreach 

activities. 

o How does clean energy address island core values? Find and identify all the 

connections 

o Is there energy literacy in the community, in the business sector, and in the local 

trades? 

 What are the energy goals (federal, territorial, local)? 

o This should cover all sectors; water, agriculture, aquaculture, recreation, tourism 

 Stakeholder analysis 

 Identifying all barriers 

o Social awareness and acceptance 

o Financial 

o Technical 

o Workforce 

o Education 

 Surveying current policy 

o What are Guam’s policy nuances? 

o Are they effective? 

o Is there a local-territorial government connection? 

 Policy analysis 

o What technologies support Guam’s goals, objectives, and budget? 

o What are the policies and programs to support those technologies? 

o What existing policies support or hinder Guam’s energy goals? 

 Implementation and action plan 

o Implementation strategies 

o Budgets and timelines 

o Measurement and verification 

o Re-assessment 
30 

Addressing all these topics through the development of a strategic plan with the appropriate expertise 

sets a sturdy foundation for assessing opportunities and achieving energy goals. 

3.2 Wind 

Wind energy has the potential to play a major role in supplying electrical energy to Guam. The available 

wind resource combined with a high level of infrastructure, high energy costs, and a strong federal 

presence on the island, make wind technology a very viable option. Additionally, several wind 

assessments have been conducted by both the U.S. Navy and GPA. 

Through an Interagency Agreement between the Naval Facilities Engineering Service Center and NREL 

a 60 m met tower has been installed on the western boundary of the Ordnance Annex just below Mount 

Alifan. This measurement station is installed on an island high point andprovides an excellent wind 

resource reference for the island, the only such reference currently available. The measurement site was 

installed in September 2008 and thus far shows a very good class 5 resource on the island with a mean 

wind speed in the region of 7.9 m/s, with stronger winds during the winter months. A summary of the 

data collected to date is provided in Appendix C and clearly demonstrates that the island has a viable 

resource if an appropriate development site can be identified. 

Although not verified, viable wind sites have been identified by GPA for up to 20 MW of installed 

capacity in a large-scale wind development, with the potential of several smaller, 1 MW to 5 MW scale 

projects at several locations around the island. Additional large-scale wind development project 

locations may still be identifiable, primarily on the northeast coast or buttressing eastern ridges on the 

southern end of the island. However, the identification of the GPA Cotal site, combined with the 

potential sites on U.S. Navy property provides a key focal area for near-term project development. 

In a study conducted by DNV-Global Energy Concepts for GPA, the Cotal site area, which is located 

just to the north of the Cross Island Road (HWY 17) east of Mount Alifan and the community of Apra 

Heights. This site could support approximately 10 large wind turbines along two ridges, with a total 

capacity of approximately 20 MW. The site has good road access, is close to a 34.5 kV transmission 

line, and is within several miles of a substation. The site was reviewed during the NREL island visit and 

proved to be a good location. The turbines would be installed upwind from several homes and a larger 

potential development area. The site sits directly south of the Leo Palace Resort and although not close, 

will be clearly visible from the resort. The elevation of the site is around 200 m, which puts it only 

approximately 50 m lower that the island high spots and approximately 3 mi. from the U.S. Navy met 

mast, which shows an annual wind speed in the area of 8 m/s. Land in this area is primarily owned by 

the Department of Agriculture with several smaller private holdings. 

As stated, several other sites have been investigated though various assessments, including on the south 

end of the island, along the main island ridge near the U.S. Navy magazine, on the Apra Harbor 

breakwater, land to the south of the Cross Island Road (HWY 17) in the area of the Cotal site, and some 

locations along the northern and northeastern coast. Most of these sites could be given additional 

consideration although all of them have one or two critical siting shortcomings, such as a reduced or 

more turbulent wind resource, limited local transmission infrastructure, or more complex siting, 

indicating that none of the sites identified thus far seem to be as viable as the Cotal site. 

More information regarding the wind assessments that have been conducted, including a summary of 

data collected through the U.S. Navy-sponsored project and the GPA-funded studies is provided in 

Appendix C. 

3.2.1 Key Challenges to Wind Development 

There are several key elements that need to be taken into account when considering the deployment of 

wind technologies. In the context of Guam, environmental impact, specifically relating to threatened 
31 

species and ground cover, radar/communications impacts, social acceptance, and the impact of wind on 

grid stability will be critical components for wind deployment on the island. 

The environmental and radar impacts of wind deployment are two of the most critical due to their binary 

nature in that if the proposed site and/or turbine is likely to have adverse environmental or radar impact, 

the site is likely non-viable. Grid impacts are primarily technical in nature and can be addressed using a 

number of techniques, many of which will have a cost impact on the project. Due to the high cost of 

conventional power generation it is likely that even with the additional cost of power control system 

modifications, the wind project will remain financially viable, reducing the likely impact of this barrier. 

Social acceptance of wind technology could become a major issue in successful project development 

and thus must be carefully orchestrated. Due to the small size of Guam and generally high population 

density, any development site, primarily in the north, will result in a social impact. This impact will 

likely be in the form of noise and visual clutter; although infra-sound, adverse health, and flicker (the 

strobe effect of shadow caused by the wind turbine blades) could also be brought up as concern. Local 

opposition could develop around these issues if people felt that the site of the wind turbines would 

negatively impact island life. This is especially true if the owners of the Leo Palace Resort felt that a 

proposed project at Cotal would impact their business model, as this could represent a funding 

mechanism for a local anti-wind development advocacy group. 

Generally speaking, project implementation is greatly improved if the local community feels that the 

project provides community or personal benefit. The fact that the wind project can represent a means to 

reduce the cost of power to all of the island’s communities and that it would reduce dependence of 

imported energy sources will decrease the likelihood of potential community criticism; however the 

control of this communication will be critical for eventual project success. Examples of wind 

developments on other islands, and input from residents of those communities regarding perceived and 

actual impacts, can assist in addressing potential societal concerns. 

3.2.2 Infrastructure 

The infrastructure for the development of large scale wind deployment on Guam, although problematic, 

is not seen as a critical issue. Although this may differ for other island locations, in the context of a 

potential project at Cotal, the road, transmission, general construction, and shipping infrastructure onisland is adequate for large wind turbine implementation. 

The only current limiting factor is the availability of a heavy lift crane to support turbine installation. It 

could be that such a device will be available on-island due to the pending military-driven infrastructure 

improvements, or a crane will have to be shipped to the island. In either case this issue will reflect on 

project economics but will not impact the technical viability of the project. 

Typhoons do pose an important risk in the use of wind technologies. All larger wind turbines are 

designed to stop operating in high wind conditions, meaning that in all except the most extreme cases 

storm-related damage is going to focus on that caused by airborne debris, typically to the turbine blades. 

The other potential issue would be the wind loading on the turbine structure exceeding the tower or 

foundation design loads, which are controllable factors, although they can cause increased 

implementation costs representing an engineering design issue. Although there has not been much 

experience with large turbines in the Pacific, a number of turbine installations in the Caribbean have not 

reported major issues, including a small system of four turbines installed at Guantanamo Bay on the 

eastern end of Cuba, an area with common hurricane (typhoon) activity. 

Looking at the implementation of turbines installed in areas with known typhoon or extreme weather 

events, consideration must be given to both turbine selection and an assessment of the risk for the 

turbine structure, which may lead to the purchase of insurance. Every large wind turbine is designed 
32 

around an international standard for wind intensity, provided in a class rating. The class rating will also 

impact the size of the wind turbine rotor, which will have an impact on the resulting energy generation 

from the turbine. 

At least two manufactures have a typhoon-rated wind turbine, although it is not clear if this relates to 

Class V typhoons. Additionally the wind turbine manufacture Vergnet makes a 220 kW turbine that is 

designed to be lowered during potential typhoon events and is production testing a larger turbine where 

the rotor of the turbine is removed. In all cases however, the purchase of insurance, or in cases of selfinsured companies, an assessment or risk is used to assess the appropriateness of installing wind in any 

environment. 

Historically insurance companies have not been willing to provide insurance for turbines in Class V 

typhoon areas, but with the development of turbines rated for typhoon environments, it may now be 

possible to do so. In any case, one of the first steps in the development of potential projects will be to 

contact wind turbine manufactures, either informally or through a competitive process, to better 

determine what products are available; survival wind speed, as well as typhoon experience, should 

clearly be one of the key competitive requirements. 

3.2.3 Next Steps 

The following next steps are recommended: 

1. Conduct a detailed wind development assessment for the Cotal site. 

With the expectation that the development of this site will be conducted through a 

competitive request for tender, the more information that is available about the site will result 

in improved project design and economics. This activity would lay the groundwork by 

conducting all of the initial screening studies that will be required for site development. 

Other elements of the study would include: 

o Resource assessment combined with data correlation. This would include the 

installation of a 50 m or 60 m met mast for a minimum of one year. It will also be 

critical to an overall analysis to correlate the wind resource data with the U.S. 

Navy Mt. Alifan tower. If at all possible, both met towers should be installed for a 

full overlapping year. 

o Land title assessments 

o Initial environmental impact assessments 

o Geotechnical assessments 

o Initial grid interconnection assessment 

o Initial social acceptance documentation (noise and visual simulations) 

o Typhoon risk analysis and impact of economics of wind generation. 

This activity would be followed by more detailed feasibility and economic assessment of the 

project. Aside from the resource assessment, these activities should cost approximately 

$50,000. Additionally, costs of resource assessments can be significantly reduced if the met 

tower is classified as a temporary structure and not subjected to typhoon building codes. 

2. Support a direct collaboration between GPA and the U.S. Navy regarding wind project 

development on both military and non-military property. 
33 

The military and GPA have overlapping activities that should be coordinated to spur 

collaboration. Additionally, the installation of wind turbines will have some impact on 

military operations, so these issues should be addressed at the onset of the project. 

3. Initiate an active social acceptance outreach and education activity around wind. 

For successful project development it will be critical to get ahead of the information around 

the deployment of wind technologies on Guam. This would include the quantifying of 

potential impacts, such as job creation, economic development, and consumer savings while 

developing information regarding potential negative impacts, such as conducting a noise 

impact assessment and visual simulations. All of this information should be publically 

available with open forum discussions conducted by GPA or another organization to identify 

and address potential issues. If at all possible this should be implemented during the initial 

assessment phase (within the next year) to get ahead of the development of inaccurate 

preconceived notions. This activity and the information generated through it should not 

directly advocate for a wind project, but should provide fair and balanced information on the 

impacts of wind development. 

4. Expand investigation of additional potential sites for community and large wind 

development. 

Given the potential savings that could result from expanded wind deployment on the island 

and clear access to a viable wind resource, efforts should be made to identify additional 

potential sites on Guam for expanded wind development in addition to expanded 

collaboration on sites being considered by the U.S. Navy. This would include an island-wide 

screening study using land ownership, resource through an island-wide wind map, 

environmental sensitivities, and known development limitations. This would allow the 

potential identification of additional locations that could be developed at varying degrees of 

cost. This information would then be used to support longer range strategic planning. 

5. Conduct an initial screening of potential turbine options for typhoon environments. 

If wind development is to be seriously considered, this would include both an assessment of 

available equipment as well as a risk assessment considering the frequency of typhoons of 

different classes. Through turbine manufactures or independently, insurance companies could 

be contacted to determine if insurance policies for wind turbine projects in Guam could be 

obtained and, if so, at what cost. 

3.3 Solar 

Solar energy technologies are often broken down by solar thermal and solar PV applications. Solar 

thermal technologies capture energy from the sun to heat a fluid or air, which is generally used to heat 

water. Solar PV technologies are used to capture the photons from the sun to create electricity. These 

two technologies and their applications are outlined in this section. 

3.3.1 Solar Thermal 

Solar thermal technologies, also known as solar hot water, are typically low- to medium-cost and easy to 

install. Conversations with several hotel engineers on Guam have indicated that the second largest 

energy cost for hotels is hot water (after air conditioning and chiller loads). The current practice on 

Guam is to heat water using diesel fuel, although some hotels on Guam are using vegetable oil to heat 

water. Solar hot water is a low to medium cost application that should be considered within the larger 

industries where hot water consumption is high. 
34 

Figure 20 shows a common solar thermal system used for hot water heating52. 

A solar collector captures the heat from the sun and then gravity typically draws a fluid out of the 

collector to act as a heat exchanger to transfer the heat to another material, such as water in a tank. 

Pressure relief valves and circulation pumps are needed to maintain pressure and keep the fluid moving 

through the distribution system. Basically, these systems convert sunlight to thermal energy by 

absorbing the sun’s radiation to produce heat which is transferred to water. Like most technologies, 

there are several types of systems that follow this basic operation and can be applied to various 

applications in both residential and commercial sectors. This technology works well in recreational 

settings such as pool heating. 

Solar thermal heating works well in most situations. The system efficiency is improved with the use of 

evacuated tubes, however even low-tech collectors are able to generate a low grade heat, which offsets 

the amount of energy required to heat water in most applications. By reducing the amount of hot water 

being generated through conventional forms of heating, the demands on fossil fuels can be lessened. 

Solar thermal technologies should be considered for hotels, hospitals, laundromats, assisted living 

facilities, and residences where hot water demands offset the capital costs of installing solar thermal 

panels. 

Panels should be installed where there is exposure to the sun without shading from buildings or 

vegetation. They should also be installed in locations where they will not be vandalized or tampered 

with, and they should be installed according to building regulations, plumbing, and access codes53

 

52 http://www.nrel.gov/docs/gen/fy04/36831m.pdf. 

. 

53 http://www.nrel.gov/docs/fy99osti/26579.pdf. 

Figure 20. A common solar thermal system

Source: NREL
35 

Figure 21. Solar hot water, Hickam Air Force Base 

Source: NREL/PIX 09188

As a comparitive case study, the United States Coast Guard in Honolulu, Hawaii, installed 62 

active/direct solar thermal system units in 1998. The average cost at that time was $4,000 per system 

with an additional discount of $800.00 from the utility. The utility had previously initiated a rebate 

program as an incentive for solar hot water installation for residences. The energy savings was 3,008 

kWh per year with a demand savings of 1.62 kW per house.54 Figure 22 refers to the average hourly 

power per household within a 24 hour period. 

With the current market, solar thermal systems have reduced significantly in price and increased in 

efficiency. With the end-use statistics mentioned in Section 2.2.3, both commercial and residential solar 

hot water systems are opportunities for fossil fuel replacement and energy savings.

Figure 22. U.S. Coast Guard housing, Honolulu, Hawaii

Source: NREL

 

54 Walker, A., Christensen C., and Yanagi, G., “Time-of-Use Monitoring of US Coast Guard Residential Water Heaters with 

and without Solar Water Heating in Honolulu, HI” ASME International Solar Energy Conference 2003, March 2003, Kohala 

Coast, Hawaii. 
36 

3.3.2 Solar PV

Winzler and Kelly, on behalf of GPA and in support of GPA’s Integrated Resource Plan (IRP), evaluated 

various Guam properties for potential use as a PV solar power plant (see Figure 23). This evaluation will 

be included as an attachment to GPA’s upcoming Invitation for Multi-Step Bid (IFB) for renewable 

energy resources to provide guidance and background information to potential solar power plant 

developers. Solar power is just one of several options that will be considered under the IFB. 

The criteria that were used to evaluate sites were developed in conjunction with GPA and R.W. Beck, 

which is also providing consultation services in support of GPA’s IRP. It should be noted that this 

evaluation is only presented as a guide and does not establish any specific requirements that potential 

solar power plant developers must follow to satisfy the requirements of the IFB. The criteria and 

resulting evaluation of sites contained herein are merely presented as a starting point for potential 

developers to utilize as they desire. It is also important to note that no land owners of sites evaluated 

herein have been contacted nor has any effort been made to evaluate potential real estate or other costs. 

In general, the scope of work for this evaluation included the following: 

• Investigate between three and six sites outside of DOD property. Note: R.W. Beck provided 

footprint information of 60-80 acres per 10 MW plant, to which GPA gives preference 

• Review topological data, access roads, proximity to GPA transmission/distribution systems, 

other improvements, and land use and property ownership (based on publicly available 

information at the Department of Land Management, no title reports required) 

• Submit Technical Memorandum that describes advantages and disadvantages for the potential 

solar development locations, including potential plant sizes in investigated areas.
37 

Figure 23. GPA transmission system map with potential solar and wind locations marked

Source: GPA
38 

3.3.3 Next Steps

The following next steps are recommended: 

1. Create a subcommittee within the Energy Task Force to address all possibilities of policies and 

programs for solar hot water systems for all sectors. 

2. Consider a renewable energy interconnection study. 

3. Conduct field assessments of each site to determine how many acres of each site can actually 

accept solar arrays, and to determine the potential energy output (in MWh) from those more 

detailed solar plants assessments. 

The top seven parcels for installing solar arrays identified during this study are shown in Table 8. 

The third column is an estimate of the total amount of the array output at a conservative 

(relatively low) value for the array density, and the fourth column is an estimate at an optimistic 

(relatively high) value. Assuming every acre of every lot could be populated with PV modules, 

the potential for solar PV could range from 315 MW to 631 MW. 

Table 8. Top Seven Sites Identified for Solar PV

Lot Number(s) Total Size 100-kW / acre 200-kW / acre

 acres kW PV kW PV

L450-R3 1,125 112,450 224,900 

L177-4-R2 1,072 107,200 214,400 

L7163 416 41,550 83,100 

L10140-R5 and 

L10164-R3 

 191 19,070 38,140 

L57-2 169 16,890 33,780 

L0 111 11,090 22,180 

L186NEW-1 72 7,150 14,300 

Totals 3,154 315,400 630,800 

3.4 Geothermal 

Due to the enormous need for clean baseload generation and the increasing need for energy diversity, 

geothermal potential must be assessed and determined to be a likely technology to implement or not. 

Baseload geothermal power would be a tremendous asset if it could be found and developed on Guam. 

A team from NREL and the U.S. Navy’s Geothermal Program Office in China Lake, California, 

conducted a reconnaissance assessment of the geothermal potential of the island for DOD in April 2010. 

Guam has no obvious surface features suggesting geothermal potential and has never been the focus of a 

geothermal exploration campaign, nor even a rigorous geothermal assessment. Guam lies on a regional 

trend of high heat flow, the Izu-Bonin-Mariana (IBM) volcanic arc system. However, while the central 

and northern portions of the IBM arc are volcanically active, Guam is not, and has not been, for millions 

of years. Nonetheless, active submarine volcanism occurs in deep water tens of miles west of Guam. 

The NREL/U.S. Navy team uncovered a reliable report of a steam vent in an abandoned limestone 

quarry on the southwest corner of Tumon Bay in fall 2010. The team located the quarry and spoke 

extensively with Professor John Randall, University of Guam (retired) who visited the quarry in the 
39 

early 1970s specifically to observe the steam phenomenon. The evidence of the steaming vent, and a 

report of a hot water well in the Ylig Valley, suggest that geothermal fluids are present in the subsurface 

on Guam. Certainly, there appears to be enough information to warrant further investigation and 

exploration for geothermal systems on Guam. 

3.4.1 Next Steps

The U.S. Navy is conducting an assessment to identify potential geothermal locations using Light 

Detection And Randing (LIDAR) technology during spring 2011. The U.S. Navy has committed funds 

to drill temperature gradient holes starting in summer 2011. The specific locations where the 

temperature gradient holes will be drilled will be guided by the results of the on-going LIDAR study.

3.5 Biomass

Biomass is generally defined as any organic feedstock available on a renewable basis. Typical biomass 

resources include wood and wood waste, MSW, landfill gas (LFG), agricultural and crop residues, 

human solid waste, and animal manures. One of the primary benefits of biomass is that feedstocks can 

be stored, thus allowing for baseload, dispatchable generation. If using a biofuel, such as biodiesel, the 

fuel can be used directly in the existing equipment, thus allowing for renewable fuel switching at 

minimal capital cost. 

Biomass resources that are potentially suitable for Guam include:

• MSW electricity generation Biodiesel or straight vegetable oil production and use in existing fuel 

oil boilers or engines 

• LFG capture for energy recovery 

• Anaerobic digestion to generating biogas at waste water treatment plants and small-scale 

digesters for converting animal manure to biogas 

• Dedicated feedstock productionto produce solid or liquid biofuels 

During the site visit, the NREL team evaluated potential opportunities to develop each of these options. 

3.5.1 Waste-to-Energy

The generation and disposal of MSW presents challenges for most communities, but especially islands. 

Converting MSW to energy is one option that many communities have either undertaken or are 

considering. There are several challenges to developing a WTE facility on Guam, not the least of which 

is a law that was passed by the legislature in 2001, that effectively prohibits WTE projects in Guam. 

These challenges were outlined in Section 2.2.5 of this report.

As discussed in Section 2.2.5, our best estimate is that Guam produces approximately 111,000 tons of 

MSW per year, of which 94,321 tons are deemed to be potential feedstock. There may be other 

feedstocks available, such as tires, sludge from wastewater treatment plants, green waste, and some 

small quantities of agricultural residues. As these resources have not been quantified, and to do so is 

beyond the scope of this report, they are not included in the following analysis. There is also the 

potential for increased waste generation associated with the DOD build-up. These numbers must also be 

quantified for future efforts.

As shown in Table 9, we estimate that 94,321 tons per year of MSW would be sufficient to fuel a 4.7 

MW to 7.0 MW (net output) plant with an 85% capacity factor. The actual generation will be highly 

dependent on the selected technology, the overall composition of the feedstock, how the feedstock is 

handled and prepared (e.g. is it processed into refuse derived fuel or used as is?), system design, and 

overall operating conditions. 
40 

Table 9. Summary of WTE Potential

Total Waste 

(tons/year) 110,967

Estimated non 

combustibles (%) 15%

Combustible waste 

(tons/year) 94,321

Capacity Factor 85%

Tons/operating day 304

Net power - low 

efficiency (MW) 6.5

Net power - high 

efficiency (MW) 9.7

Net energy - low 

efficiency (MWh) 48,103

Net energy -high 

efficiency (MWh) 84,889

The value for “low efficiency” in Table 9 is based on an assumed yield value of 510 kWh per ton of 

MSW processed. This is equivalent to a typical mass burn combustion plant today. The value for “high 

efficiency” assumes a conversion factor of 900 kWh/ton MSW. This is equivalent to what some 

manufacturers of advanced conversion technology gasifiers and plasma units are claiming to be able to 

obtain from their systems. 

It should be pointed out that there are no commercial advanced conversion technology WTE projects 

operating in the United States, although there are several reported to be operating in Asia and Europe. 

Of the commercially-viable WTE systems that are operating in the United States, nearly all (if not all) of 

the plants use either stoker or fluidized bed combustion technology. Combustion technology is fully 

commercial and lenders are willing to make loans to well-structured projects that have a guaranteed 

supply of MSW and a power purchase agreement with a credit-worthy customer. 

The numbers in Table 9 above assume that 15% of the output from the plant will be used for parasitic 

loads. In terms of net capacity, NREL estimates that between 6.5 MW and 9.7 MW of power could be 

provided from waste on Guam. Because WTE can be operated 24/7, a WTE plant produces more energy 

over a year than an equivalent wind or solar plant. So a 6.5 MW WTE plant would produce 

approximately the same amount of energy each year as an 18 MW wind farm (at 35% capacity factor), 

or 54 MW of solar at an 18% capacity factor. The WTE plant would take up far less space as well and 

could be co-located at the Layon Landfill. 

The estimated capital cost of this project is $102 million. This is calculated based on assumed capital 

costs of $400,000 per ton per day. For comparative purposes, the 16.5 MW (net) WTE plant under 

development in the U.S. Virgin Islands is estimated to cost $160 million ($457,000/ton/day). This cost 

includes setting up two material recovery facilities for converting MSW to refuse derived fuel through a 

proprietary process called WastAway. Material from the two WastAway plants will then be sent to the 

centralized WTE plant. The developer states that the WastAway process creates a product that is dry and 

has a Btu content of 7,500 Btu/lb. The energy content of Guam’s waste stream has not been reported but 

we estimate it to be similar to the U.S. average of 5,900 Btu/lb. 
41 

For Guam, NREL conducted a preliminary economic analysis of a low-efficiency WTE plant. Results 

indicate that if a private developer were to come in and build, own, and operate the plant, and the 

developer was not paid a tipping fee, electricity would need to be sold to GPA for $0.26/kWh

(escalating at 3% per year) to make the project economically attractive. For the developer to be able to 

sell power to GPA at $0.15/kWh (with a 3% annual escalation), the developer would need to receive a 

tipping fee of approximately $75/ton. 

It must be pointed out that the numbers above are preliminary and need to be investigated in greater 

detail. We are using rule-of-thumb numbers and there are many companies and technologies available. It 

may be possible for a developer to make the economics work using various technical and economic 

configurations. The best way to determine what the market can deliver is for GPA to develop a request 

for proporals (RFP) for WTE (after regulatory/legal issues are addressed) and see what bids are 

received. 

The major barrier to WTE is PL 25-175. Until Guam changes the law and allows WTE projects to be 

developed, there is little to be gained through speculation on various technologies, configurations, 

technical performance, and cost. A more immediate short term need would be to focus on legislation that 

would allow flexibility on the development of WTE plants, bearing in mind local desires for clean 

technology and debt repayment on Layon Landfill. This could be an action for the legislative 

subcommittee of the Energy Task Force. 

3.5.2 Biodiesel or Vegetable Oil

The use of biodiesel or vegetable oils in diesel generators and boilers is gaining wider acceptance around 

the world. The ability of biodiesel to be used within existing utility diesel infrastructure is a compelling 

reason for exploring this option. There are minimal capital costs associated with using a biodiesel or 

vegetable oil/diesel blend in existing diesel or residual fuel-oil-fired generators, combustion turbines, or 

boilers. Biodiesel blends of 2% up to 20% can typically be used in existing equipment with only minor 

modifications. There have been several testing programs, particularly in Hawaii, aimed at firing 100% 

biodiesel in utility-scale boilers, turbines, or generators. Several utilities have been running biodiesel in 

standby generators as a way to implement peak load reduction and reduce emissions associated with 

running the generators beyond their annual permitted hours. 

The use of 100% biodiesel in utility-scale generators is being pioneered in Hawaii, where there are at 

least three different projects underway: 

1. Hawaiian Electric Company (HECO) recently completed co-firing tests of various blend 

percentages of petroleum diesel and biodiesel fuels at the 90 MW Kahe Power Plant. On January 

28, 2011, HECO issued a press release stating that they successfully tested 100% biodiesel in 

Kahe at the full load of 90 MW. Tests will be continuing for the next several months. The next 

test will demonstrate 24-hour operation on biofuels. One of the major observed results of the 

tests is that the use of biodiesel reduced opacity, NOx, and criteria pollutant emissions below the 

levels associated with ultra low sulfur diesel fuel55

2. Maui Electric Company (MECO) uses biodiesel to start up and shut down two of its generators. 

MECO is also conducting tests to determine the long term impact of using biodiesel on heat 

rates, emissions and engine reliability.

. 

3. HECO’s Campbell Industrial Park Generating Station, Combustion Turbine Unit 1, is a new 

(2009) 110 MW combustion turbine unit designed to run on 100% biodiesel. Renewable Energy 

 

55 HECO Press Release. Available online at:

http://www.heco.com/portal/site/heco/menuitem.508576f78baa14340b4c0610c510b1ca/?vgnextoid=9fbfb7ba04ecd210VgnV

CM1000005c011bacRCRD&vgnextfmt=default&cpsextcurrchannel=1. Accessed 1/31/2011.
42 

Group of Iowa presently has a contract to supply three to seven million gallons of biodiesel per 

year. All biofuel procured by HECO must meet stringent sustainability guidelines. 

HECO has determined that the use of biodiesel is its most cost-effective option for complying 

with Hawaii’s renewable energy targets.

Biodiesel is made through the transesterification of animal fats or vegetable oils. The feedstock can 

come from waste sources, such as grease from restaurants, or from virgin sources, such as oil seeds, 

coconut, palm, jatropha, or algae. In Hawaii, biodiesel is procured from the mainland and Malaysia, 

though long term plans call for production of feedstocks locally. 

The major issue to evaluate whether biodiesel makes sense for Guam is supply and cost. The amount of 

waste grease produced in Guam is not known as there is no known inventory of fats, oils, and greases. 

However, anecdotal evidence suggests the figure is on the order of 10,000 gallons per month56

Also, there are significant costs associated with converting vegetable oils to biodiesel. The process 

requires methanol and lye, both of which would need to be imported from the mainland. There is also a 

question over economies of scale, and it is likely that the supply of feedstock in Guam is too limited to 

warrant construction of a biodiesel plant. 

. There 

are also some concerns over shelf life, with some evidence suggesting biodiesel can begin to break down 

after six months. This concern can be addressed by ensuring that the supply is evenly matched to 

potential demand. 

There is limited agricultural land available for in Guam for production of commercial quantities of oil. 

Dr. Marutani from the University of Guam has been conducting research on the oil yields of Jatropha 

and Calophyllum and has planted test plots of these species. The research is on-going and focused 

primarily on the quality of the oil. Research on production costs, available land and potential yields has 

not yet been undertaken. 

While not likely to be a significant source of fuel for Guam, the use of waste oil in boilers and engines 

should be explored further, as should the economics of producing oil from local plants. 

3.5.3 Landfill Gas 

There are three potential locations on Guam where LFG-to-energy might be possible. The sites include 

Ordot Dump, the DOD landfill on Anderson Air Force Base, and the landfill on the U.S. Navy base at 

Apra Harbor. 

In 2004, a study on the potential for LFG generation at Ordot was conducted57

There is a great deal of uncertainty over the potential for LFG capture at Ordot. The authors conclude 

that any LFG–to-energy plant would likely need to be sized below 500 kW to have a greater chance of 

. The study used the 

EPA’s LandGEM model to estimate potential methane generation and decay rates over time. This was a 

first level analysis utilizing a number of assumptions and estimates due to lack of specific data for Guam 

and Ordot. The model results indicated a rapid falloff in methane production after about 10 years. Under 

a middle-of-the-road scenario, the authors estimated that there was sufficient gas for nearly 3 MW of 

production in 2007, but that by 2017 there would only be sufficient gas for 150 kW. 

 

56 Dr. Mari Marutani of the University of Guam conducted a survey of reasturants. Her data indicate approximately 3500 

gallons/month. However, this survey did not capture all of the sources of grease. There are several grease haulers and 

pumpers on Guam and they indicated that the value of 3500 gallons/month is low compared to the actual volumes.

57 Estimation of Potential Yields of Landfill Gas from the Ordot Dump. Duenas & Associates and URS Corp. July 2005. 

Accessed online at: http://guamsolidwastereceiver.org/pdf/RFP%20SWD001-11%20-%201b%20-

%20Est.%20of%20Poten.%20LFG%20Yields%20Ordot%20Dump.pdf accessed January 29, 2011.
43 

running beyond five years. Given that most projects need to run for at least 10 to 15 years to pay off the 

investment, the willingness of an investor to finance a LFG project in Guam is questionable. 

The authors suggest that if the landfill were capped and proper drainage installed there could be the 

potential to slow down the landfill decay rate and prolong gas generation. Given the high degree of 

uncertainty over the data and the model results, it is likely that the most economic option will be a capand-flare system. 

3.5.4 Anaerobic Digestion

As part of the military build-up, significant improvements are planned to Guam’s wastewater treatment 

infrastructure. The designs for the new sewage treatment plants have not yet been finalized. As the 

design team moves forward, the potential for installing anaerobic digesters as part of the improvements 

should be studied. The U.S. EPA estimates that between 491 kWh and 525 kWh of energy can be 

produced for each million gallons of sewage flow58

The Northern District Wastewater Treatment Plant (NDWTP) is presently treating about 6 million 

gallons per day (MGD) of flow. At one point this facility did have working anaerobic digesters although 

these have not been used due to disrepair for about the past 10 years. The NDWTP was designed to 

handle about 12 MGD of flow. 

. 

The Hagatna Waste Water Treatment Plant is designed to handle about 12 MGD and presently handles 

about 4.4 MGD. The U.S. Navy owns and operates a treatment plant at Apra Harbor, which is designed 

to handle 4.3 MGD and presently handles about 2.9 MGD. The Agat-Santa Rita plant is designed to 

handle .75 MGD although current flows into the plant presently exceed this design capacity. There are 

several other smaller plants that all treat less than 1 MGD.

To understand the potential, NREL assumed current sewage flow of 15 MGD. If 500 kWh can be 

produced per million gallons, the current potential on Guam is for 7,500 kWh/day. Assuming a capacity 

factor of 90%, this equates to about 350 kW of potential capacity at Guam’s waste water treatment 

plants. While not a large amount, the economics should be explored to see if this option warrants further 

development. 

3.5.5 Small-scale Biomass 

There may be niche opportunities within the agricultural sector for small-scale biomass or biogas 

utilization. This opportunity is lower priority in terms of generation potential. The University of Guam 

Department of Agriculture and the U.S. Department of Agriculture’s (USDA) National Resources 

Conservation Service (NRCS) are best situated to lead future efforts in this area.

3.5.6 Production of Dedicated Biomass Feedstocks

The production of dedicated biomass feedstocks for biofuels or for use in a solid fuel plant has not been 

investigated in detail. Many island communities are investigating this option. For example, there are 

several companies and groups in Hawaii that are developing plans for locally grown biofuels production. 

However, based on the initial site visit, NREL believes that growing bioenergy feedstocks on Guam will 

present the following challenges:

• Small land area with steep hills, rocky cliffs, and densely growing jungle 

• There is not a large agricultural industry in Guam, and there are very few commercial operations

 

58 Opportunities for and Benefits of Combined Heat and Power at Wastewater Treatment Facilities; Eastern Research Group 

and Energy and Environmental Analysis, U.S. Environmental Protection Agency: Washington, DC, 2007; Available online 

at: http://www.epa.gov/CHP/documents/wwtf_opportunities.pdf (accessed on March 28, 2011).
44 

• There are a large number of small-scale farmers with acreages from 1 to 50 acres

• NRCS and local agricultural interests would like to promote food production instead of energy, 

given the limited agricultural land available

• Clearing overgrown forestland to establish energy plantations presents risks from unexploded 

ordnances; the first cost of establishing a plantation will be very expensive. 

3.5.7 Next Steps

Biomass utilization and WTE should make up some component of a wider energy strategy for Guam. 

Biomass offers many strategic benefits, including that biofuels can fit into the existing oil based 

infrastructure nearly seamlessly. Other resources such as WTE, LFG, and methane from wastewater 

treatment plants can be used to produce baseload power and are not subject to intermittent outages as are 

wind and solar. 

One of the next steps would be to conduct a comprehensive biomass resource assessment and analysis of 

opportunities. The assessment could be performed all at one time by a single entity, or the work could be 

split up amongst a team of researchers. Several activities would lend themselves to being performed by 

students and staff from the University of Guam. 

Major next steps for each of the biomass sub-technologies are described below. Detailed budget 

estimates would need to be prepared for each category. The cost would be dependent on level of detail 

required. 

1. WTE is a small but important part of any strategic effort to develop renewable resources on 

Guam. The cost to further evaluate WTE could range from $25,000 for a pre-feasibility 

evaluation, to $300,000+ for a detailed waste characterization and investment grade 

economic and technical analysis of WTE options. 

o Work with the Receiver and the SWMD to obtain any additional waste 

composition analysis data. The 1980 study referenced herein is old, and the 2010 

waste sorts are being conducted on such a small number of samples that it is not 

statistically valid data. The 2010 sorts are also being performed only on the 

residential sector, so waste from other sectors (e.g. commercial, government, 

industrial, etc) is not being counted. 

o Evaluate other potential sources of feedstock for a WTE plant including tires, 

corrugated cardboard, and green matter, which are no longer allowed to be 

dumped in Ordot. 

o Explore the development of new regulations on WTE. This is an action that the 

Energy Task Force could undertake or establish a sub-committee to explore. 

Clearly, existing laws and legal challenges by GRRP need to be included in this 

analysis. The need for minimum flows and tip fees of materials going to the new 

landfill also need to be considered. 

o One potential arrangement for a WTE facility would be to locate a plant “behind 

the fence” of the new landfill. In this manner, tip fees could be paid at the gate 

which could be used for landfill bond repayment. Rather than burying the material 

directly in the landfill, it could be directed to a WTE plant to produce and sell 

energy. The residual ash and non-combustibles could then be recycled and/or sent 

to the landfill. Production of energy would extract additional value from Guam’s 

solid waste and prolong the life of the new landfill by reducing the amount of 

material that gets buried. A detailed cost benefit analysis of this option would 
45 

need to be undertaken. The cost of this analysis is not included in the cost 

estimate projected above.

o Evaluate local recycling efforts, markets, and options and determine potential 

impacts on the waste stream and the economics of WTE. 

o GPA should consider developing a separate WTE RFP once legal and regulatory 

issues have been resolved.

2. The production of, or use of biodiesel or vegetable oil warrants further investigation. The 

state of Hawaii is using both locally produced and imported biofuels to help meet its 

renewable energy targets. The cost impact of this analysis is estimated to be $25,000 - 

$50,000, excluding the costs of a direct test in GPA’s engines. The cost for that would need 

to be ascertained based on HECO’s experiences.

o Conduct a survey of waste grease supplies on Guam. Determine who produces the 

material, how it is collected and disposed, what the costs are, and whether there 

are any opportunities for a local business to manufacture biodiesel locally. 

o Determine the expected costs of procuring biodiesel from the mainland or Asia. 

o Gather case study data associated with the use of biofuels or vegetable oil in 

diesel systems in Hawaii, other islands, or other communities. 

o Determine equipment modifications needed to use biodiesel or vegetable oils in 

the GPA system. Based on other case studies or work done in Hawaii, it would be 

useful for GPA to conduct a test of biofuel use within its system. This would be a 

comprehensive assessment that evaluates costs, impacts on heat rates and 

performance, fuel storage and handling, air emissions, and overall feasibility.

o Estimate the levelized cost of energy produced from biodiesel in various blends of 

biodiesel/petroleum diesel percentages.

o Prepare a report and briefing for GPA and the Energy Task Force to communicate 

results of the detailed assessment.

3. Based on the previously-mentioned study by Duenas Associates and URS, the production of 

energy from LFG from Ordot does not appear to be very promising. Estimated cost of these 

activities is less than $5,000.

o Gather additional data on the potential for Ordot to produce and capture landfill 

gas post closure, as appropriate. This could be accomplished through a brief 

meeting with the Receiver and SWMD.

o Meet with Naval Facilities Engineering Command (NAVFAC) to discuss DOD 

landfills, and whether they have any plans for assessing methane potential at onbase landfills. 

o Monitor GPA RFPs for any possible LFG bids. 

4. The additional cost of the analysis of this option would be $25,000 for a preliminary 

assessment to $100,000 for a detailed feasibility study. 

o Determine who has responsibility for the design of wastewater treatment plants 

associated with the military build-up. Meet with the responsible parties to discuss 

present construction plans and proposed wastewater treatment technologies. 

Identify whether it is possible to evaluate the economic and technical feasibility of 

adding anaerobic digestion to the wastewater treatment plants prior to final 

system design and capitalization.
46 

5. While there may be challenges to growing dedicated biomass for energy, it still makes sense 

to explore this option further. The following steps are recommended. The cost to perform this 

analysis is estimated at $25,000 to $50,000. 

o Using geographical information systems, filter out all steep lands and developed 

areas to identify areas that are simply not suitable for biomass feedstock 

production. 

o Overlay land use and vegetation maps to determine current usage of the land base. 

o Evaluate land ownership of large contiguous parcels. The objective would be to 

identify potential lands suitable for growth of biomass feedstocks. DOD is likely 

to have the land—whether it is available for purposes of biofuel production would 

need to be determined. 

o Estimate the acreage available as well as potential yields of various species.

o Evaluate technical and economic feasibility of producing biofuels or solid 

feedstocks.
47 

4 Summary of Recommendations and Conclusions

The site visit and subsequent research on Guam’s energy efficiency and renewable energy opportunities 

is a basic, preliminary overview to provide the Energy Task Force with a set of next steps. The areas of 

opportunity that have been identified are based on this preliminary review. Further investigation or 

consultation may be required before undertaking any next steps. The key opportunities, potential steps 

for policy, and concluding points are summarized in this section. 

4.1 Key Opportunities

Examples of energy efficiency and renewable energy opportunities to include in strategic planning or for 

further consideration are summarized below. 

General

• Based on existing overall baseline energy use, develop specific goals to reduce overall fossil fuel 

consumption. 

• Develop a Strategic Energy Plan and Implementation Strategy to implement near-term 

opportunities identified in this report, and to develop approaches for further feasibility analysis 

for identification and implementation of longer-term opportunities. 

• Policies, programs, regulations, and codes/standards should be reviewed for energy efficiency 

and renewable energy targets. High standards should be set to push the industry in the direction 

of reducing overall fossil fuel consumption. 

• Conduct a transportation assessment to determine energy useage, analyze options, and identify 

reduction and renewable strategies.

Energy Efficiency

• Work with technical experts to design educational materials for Guam to address specific 

information and outreach needs. Flyers, posters, and stickers can be designed that could be 

distributed among the appropriate building sectors. 

• Develop training courses and materials for both architects and workers in the construction sector 

to improve energy awareness. Energy efficiency in retrofit, renovation, and new construction can 

be included in terms of design, materials, and equipment. 

• Create guidebooks and self-assessment checklists. These guidebooks could be designed as standalone products for specific sectors or integrated into the training courses described above. 

• Create a cool-roof program by identifying potential buildings that can be used as pilot projects. 

• Continue existing energy audits with private companies and utilize the results to benefit the 

entire building portfolio. 

Renewable Energy

• Conduct and analyze results from wind anemometry studies to capture wind potential. 

• The Energy Task Force should continue to work with GPA to identify potential sites for solar PV

installation.

• Develop solar thermal strategies for residential, commercial, and governmental buildings 

• DOD and GPA should continue to work cooperatively on the drilling of geothermal temperature 

gradient holes. 

• Consideration should be given to all alternative fuel potential in the form of WTE, LFG, 

biofuels, and biomass crops. 
48 

4.2 Conclusion

There are many opportunities found in Guam for the adoption of energy efficiency and renewable 

energy technologies, and development and implementation of energy policy, standards, and codes that 

has been outlined in this report. 

Due to fluctuating energy prices, including the record high price for oil in 2008, and the imminent 

military build-up, Guam has focused attention on the need to develop alternatives to its near 100% 

reliance on fossil fuels. Guam is in a unique position to undertake a concerted effort to address current 

energy and environmental challenges. Due to its geographic isolation, non-renewable resources are 

extremely limited and subject to large volatility in pricing and availability. Energy security is 

fundamental to Guam’s economic future and sustainability. Consequently, creating a stable investment 

atmosphere remains challenging, while the quality of life for residents and visitors continues to be 

affected. However, the unique position of Guam also offers many natural advantages. The island is 

endowed with diverse sources of alternative energy. 

With NREL’s assistance, an Energy Task Force has been established and the following mission and 

vision of the have been adopted: 

Vision 

Create a sustainable future for Guam by reducing dependence on fossil fuels.

Mission

Unite the citizenry through the vision and enhance the well-being of Guam’s population, ensure national 

and economic security through energy independence and diversification, improve the local 

environmental quality, decrease Guam’s vulnerability as a small island state, and further the 

development of the territory by developing a comprehensive energy plan that will embrace energy 

efficiency and conservation. 

In conclusion, a strong energy plan surveys and assesses need and provides analysis and 

recommendations for appropriate technologies and programs relevant to its environment while 

addressing economic viability. It addresses a full range of energy options, with a focus on energy 

efficiency and renewable energy technologies and lays out a road map for socioeconomic development. 

Plans to develop an implementation plan are next steps once an energy strategic plan has been 

completed. A plan is only part of the solution—it lays the groundwork. Action strategies will develop 

the roadways in which these vehicles can drive energy efficiency and renewable energy market adoption 

and deployment. 
49 

A. Utility Baseline Information 

A.1 Generation

GPA must meet or exceed the following generation performance standards: 

• 90% or greater of generation to come from base load plants 

• 10% or less of generation to come from Combustion Turbine (CT)/Diesel generation. 

Table 10 lists the base load generation. Table 11 is a list of the Independent Power Producers. Table 12

is a list of the total generation resources (traditional fuels) on the island and Figure 24 shows the 

installed capacity over time. 

Table 10. GPA Baseload Generation

Table 11. Independent Power Producers

Plant IPP Plant Capacity (MW) Contract Effective 

Date

Contract 

Termination Date

Piti Unit 7 

(Combustion 

Turbine)

TEMES 40 December 1997 December 2017

Piti Unit 8&9 (Slow 

Speed Diesel)

MEC 88 January 1999 January 2019

Tanguisson Unit 1&2 

(Steam)

Pruvient 53 August 1997 August 2017
50 

Table 12. GPA Generation Resources

Figure 24. GPA installed capacity (in billions of kW)59

Source: EIA

 

59 EIA Guam Energy Profile.
51 

In 1995 and 1996, GPA commissioned Cabras #3 and #4. These units use a slow-speed diesel 

technology and were the largest units available in this class. This technology converted fuel into 

electrical energy using about a 25% to 30% less fuel than Cabras #1 & #2. The newly commissioned 

Cabras units #3 and #4 experienced high forced outage rates over the next two years. However, by 1997 

GPA had reduced loss-of-load outage durations due to lack of generation from over 600 hours each in 

FYs 1995 and 1996 to about an hour. 

The Cabras plant includes two 66 MW steam turbine generator units (#1 and #2), and two 40 MW slow 

speed (102.9 RPM) diesel engine generator units. All generator sets operate in base load service. The 

steam turbines are General Electric (GE) 66 MW, 3,600 RPM with GE 77,647 kVA, 0.85 pf, 13,800 

volts, 3,249 amps generators, and the diesel generators are ABB, SA, type W.950/95/70, 49,280 kVA, 

0.8 pf, 102.9 RPM, 13.8 kV, 2062 amps, 3 phase wye, 70 poles; air cooled. . Seawater is used as the 

cooling medium in the main condensers of Cabras units #1 and #2. It is also the jacket (engine) cooling 

medium for Cabras Units #3 and #4. All 4 generators produce electricity at 13,800 volts. The voltage is 

then stepped up to 115,000 volts (115 kV) in the main transformers (2 x 80 MVA for #1 and #2, and 2 x 

50 MVA for #3 and #4) for transmission and distribution. 

The Tanguisson plant consists of two 26 MW steam turbine generator units. Both units are operated in 

base load service. The turbines are GE 26,500 kW, 3,600 RPM. The generators are GE 29,412 KVA, 

0.90 pf, 13,800 volts, 1,179 amps. 

The Dededo combustion turbine plant consists of two GE Frame 5 machines. CT #1 (CT1) is a Model 

MS 5001 PA (advanced version) rated at 23 MW. CT #2 (CT2) is a Model MS 5001 P (standard 

version) rated at 22 MW. The units are used for peaking and emergency operations. The combustion 

turbines are rated 5,100 RPM (turbine), 25,000 kW. The generators are GEC Ahlstom; 26,200 kVA; 

3600 RPM; 13.8 kV. Their rated outputs are 23 MW (CT1), and 22 MW (CT2). The generators produce 

electricity at 13,800 volts. The voltage is stepped up to 34,500 volts (34.5 kV) in the main transformers 

(30 MVA maximum rating) for transmission and distribution. 

The Dededo diesel plant consists of four General Motors (GM) Electro-Motive Diesel (EMD) diesel 

engine generators. Each diesel generator is rated at 2.5 MW. The plant’s total generating capacity is 10 

MW. The units are used for peaking and emergency service. The diesel engines operate at 900 RPM. 

The generators are GM-EMD; Model A20-C1; 3,250 kVA, 0.8 pf, rated output 2.5 MW, 4,160 volts, air 

cooled. The engines can operate with just one fan in operation at a slightly reduced load (2.2 MW). The 

generator voltage is stepped up to 24 kV for transmission and distribution. 

The Macheche and Yigo combustion-turbine plants each consist of one GE LM2500 CT generator unit.

Each unit is rated at 22 MW. These units are used for peaking and emergency operations. The 

combustion turbines are 3,600 RPM, 25,000 kW. The generators are Brush Electric Model BDX7-167E, 

3m600 RPM, 13,800 volts, 25,000 kW, type HC/OP/OPLTR, class OA/FA/FA, 18/24/30 MVA, 13.8 

.90 pf, air cooled (rated output 22 MW). The generator voltage is stepped up to 34.5 kV for transmission 

and distribution. 

The Manenggon plant consists of two Wartsila-ABB diesel engine generators. Each diesel generator is 

rated at 5 MW. The plant’s total generating capacity is 10 MW. The units are used for peaking and 

emergency service. The diesel engines are 5,522 kW, 720 RPM. The generators are ABB Stromberg; 

type HSG 900 LS10; 7,250 kVA; 13.8 kV; 303 amps; air cooled. The generator voltage is stepped up to 

34.5 kV for transmission and distribution. 
52 

The Marbo plant consists of one Fiat TG 16 CT generator unit. This unit is rated at 16 MW and is used 

for peaking and emergency operations. The CT operates at 4,914 RPM. The generator operates at 1,800 

RPM, 19,000 kVA, 13.8 kV, 794.9 amps, 0.8 pf, air cooled. The generator voltage is stepped up to 34.5 

kV for transmission and distribution. 

The Tenjo plant consists of six Caterpillar-Kato diesel engine generators (two units are currently being 

overhauled). Each unit is rated at 4.88 MW each. The units are used for peaking and emergency service. 

The diesel engines are Caterpillar; Model 3616, 6,095 HP, 16 cylinder, V-type, turbocharged, 900 RPM, 

#2 fuel (diesel) oil. The generators are Kato: Model A256730000, 4,880 kW, 6,100 kVA, 0.8 pf, 13.8 

kV, 255 amps, air cooled. The generator voltage is stepped up to 34.5 kV for transmission and 

distribution. 

A major project aimed at reducing forced power outages was completed after two years. The project 

focused on automating generation controls, which allows for other generators to increase power output 

in the event one of the larger base load units trips and is forced offline. These forced outages caused 

power outages in many areas while reserve generators were being brought online to restore power. The 

upgrade enables standby generators to quickly make up for the loss of generation through automation 

instead of coordinating a restoration of power through the slower manual processes. 

GPA increased the number of Fast Track generating units online. Work at three 20 MW combustion 

turbine units (Dededo CT No. 2, Macheche, and Yigo CT) resulted in an additional 60 MW of reserve 

that can be brought online to support maintenance, overhauls, or emergency shutdowns at other GPA 

base load generating units. 

The Fast Track units represent one part of the generating mix that is used to provide recovery and 

support during typhoon restorations and blackouts. Bringing these units online adds operational 

flexibility during hours of peak demand today and anticipated additional load from the pending military 

buildup tomorrow. 

The Fast Track units are a component in the project that connects large load centers to major substations 

via underground transmission lines. The Dededo CT Plant is connected to Andersen Air Force Base via 

an underground transmission line, the Yigo CT is within close range of Andersen Air Force Base, and 

the Macheche CT is connected to the Guam International Airport Authority. 

Figure 23 in Section 3.3.2 of the report shows a map of the island’s transmission system as well as

potential locations for solar and wind systems. This indicates where GPA could collaborate with PV and 

wind installers to tie into the existing electric grid. 

A.2 GPA System Improvements in FY 2009

A.2.1 Major Transmission Lines Secured Underground

Electricity is delivered through a transmission and distribution grid consisting of a combination of 115 

kV, 34.5 kV, and 13.8 kV lines. GPA energized the final portion of the massive project to move main 

transmission lines underground (as shown in Figure 25), where they are shielded from typhoons and 

other disasters and contribute to timely recovery of power and other services for the entire island). 

Funded by a grant from the Federal Emergency Management Agency, the project cost $25 million and

took four years to complete.

The final leg of the project was completion of the Harmon to Macheche underground transmission line, 

which provides a secure, direct line from the Macheche Power Plant to the Guam International Airport 

Authority. Since 2005, GPA placed major transmission lines underground that serve the Guam 

Memorial Hospital and central areas of Harmon, Tamuning, and Tumon. 
53 

GPA also buried a significant portion of line connecting the Tanguission Power Plant to the Harmon 

Substation. The Tanguission Power Plant is capable of producing over 50 MW—this number added to 

the 20 MW from Macheche Power Plant means that GPA can potentially transmit 70 MW of 

uninterrupted power during tropical storms or typhoons via the underground network. 

Avoiding repairs on the underground lines is a savings to rate payers that protects revenue and restores 

island power to residences and businesses after a major storm. The hospital and airport will have the 

potential for uninterrupted power during tropical storms and typhoons. In addition, GPA’s restoration 

crews will be able to work on restoring service to neighborhood homes, schools, and businesses if lines 

to major substations, the hospital, airport, and businesses and hotels along Tumon Bay are sheltered 

from storm damage.

Figure 25. GPA buried transmission lines

Source: GPA

A.2.2 Net Metering 

The first use of “net metering” was implemented at a residence in Barrigada in 2009. Net metering 

allows the GPA customer to offset power consumption by generating renewable energy, such as solar 

power. The renewable power incentive program was made possible by passage of PL 27-132 and 

adoption by the PUC. The legislation was intended to encourage the use of new power generation 

technologies to defer the need for additional capital investment by GPA. 

A.2.3 Groundwork Laid for Pre-Paid Meters

The cost of residential electricity is about $0.23/kWh, where $0.15 is the cost of fuel and $0.08 is for 

infrastructure. A pilot project to determine the feasibility of pre-paid meters for residential customers 

was launched in 2009. One hundred households—primarily those of GPA employees—volunteered to 

participate in the project, which is spearheaded by the GPA Engineering Department. The technology 

used in the project has features that easily interface with GPA’s existing computer systems.
54 

In the future, pre-paid meters will allow residential customers to manage their electric utility accounts. 

Families will be able to manage their accounts by monitoring consumption and conservation of 

electricity. Instead of monthly bills and security deposits, customers will be able to choose the payment 

schedule that is best suited for their personal needs. If the pilot project is successful, GPA will offer prepaid meters to more residential customers. 

A.2.4 Declining Sales

GPA’s sales have been trending downward for the last few years as is shown in Figure 26. While the 

number of customers is growing, the average usage is declining as a result of conservation efforts by 

many of GPA’s customers. These conservation measures are the result of the steep increases in the fuel 

portion of the bill for the last few years. GPA expects to see positive growth for FY 2011 as 

conservation measures become fully realized, the impacts of the military buildup begin to show, and the 

economy begins to recover from the impact of the world-wide economic crisis.

Figure 26. Decline of GPA sales

Source: GPA

A.3 Utility Energy Efficiency

GPA staff came up with PMCs to improve base load plant reliability and efficiency. GPA staff 

recognized that GPA did not have sufficient plant management, technical, and plant operation acumen at 

GPA to run its base load facilities well. Keeping many of these skill sets full-time at GPA is 

economically prohibitive. 

Additionally, GPA already had difficulty recruiting to fill technical and professional positions. Also, the 

Government of Guam’s procurement practices do not support an operations environment well 

as procurement issues often result in prolonged unit outages. Furthermore, GPA recognized the need for 

better, consistent training of its plant staff. Finally, staff foresaw that performance-based compensation 

would best drive exemplary performance and better protect the ratepayer from poor performance. 

Peaking unit technologies are relatively inexpensive and quick to install but expensive to operate. 

Therefore they are ideally operated only during system peak demand periods or as reserve units in the 
55 

absence of reliable base load capacity. Efficient base load units require much longer permitting and 

construction lead times. However, they possess much higher capital requirements for installation but are 

less expensive to operate. Intermediate units have unit characteristics between peaking and base load. 

Guam's year-round tropical climate and tourism-based economy results in a relatively flat load cycle 

with high load factor. Such characteristics tend to favor base load technology additions since operation 

near the peak is the norm (flat load profile). As an example, Figure 27 shows the GPA average demand 

hourly load shape for the period April 29–30, 2008. Note that GPA requires peaking capacity for only 

four hours for about 15 MW to 19 MW incremental peak. 

Figure 27. GPA average hourly generation requirements

Source: GPA

Regarding the distribution system, savings would be realized by improving technical efficiency 

(improved connections, reducing line resistance, correctly sizing transformers to their loads, etc.) as well 

as improving nontechnical efficiency (inaccurate billing, meters not being calibrated, etc.). 
56 

B. Energy Efficiency Baseline

Sectors of energy consumption are categorized by the Secretariat of the Pacific Community and GPA as 

commercial and government, residential, U.S. Navy, and street and outdoor lighting. 

Within the commercial and government sectors we can include the hospitality industry, medical, 

government, commercial, and higher education. The construction of buildings on Guam is consistent 

with tropical island building code, which emphasizes construction methods to withstand typhoons 

typical of the area. From observations, the majority of commercial and residential buildings are 

reinforced concrete buildings with high air conditioning loads. The heat and humidity levels dictate the 

use of air conditioning on island. Some buildings are constructed of concrete or wood with tin roofs, but 

seem to be mostly residential. These buildings are not preferred due to their lack of withstanding 

typhoon conditions. Glazing is either single or double-glazed with external typhoon shutters attached to 

the building to be closed during inclement weather.

B.1 Current Status

The Guam Energy Office has identified measures to improve energy efficiency on the island; Recovery 

Act funding was requested to implement many of these tasks. Certain activities were entered into 

memorandums of understanding or RFPs, including the following: 

• Improve municipal lighting 

o Replace old metal halide and high pressure sodium light bulbs along highway and major 

suburban roadways with energy-saving Light Emitting Diode (LED) lights 

• Retrofit public facilities

o Energy audits performed by energy services companies at public facilities, such as 

schools, housing, and community centers to identify potential retrofits. Facilities will be 

retrofitted based on audits. 

• Financial incentives for building improvements 

o Rebates for residents, non-profit organizations, and businesses for energy efficiency 

measures, including solar hot water heating, lighting, insulation, air conditioning, and 

windows. 

• Resource conservation manager program 

o Reduce government expenditures for energy, water, fuel oil, solid waste disposal, and 

other utilities by improving energy use practices, auditing utility billing and services, and 

installation of resource management equipment.

• Residential energy performance score

o Home energy audits to identify opportunities for efficiency improvements and encourage 

voluntary retrofits by providing information to the real estate market. Members of Guam 

Contractors Association, building code inspectors, and GPA staff will be trained to 

deliver the audits.

• Community education and outreach 

o Guam Department of Education will work with island schools and other organizations to 

increase energy awareness and promote future conservation of resources. Also, education 

curriculum and courses in Energy Technician Training and Building Code compliance 

will be developed. 

• Sustainable Development Forward
57 

o Energy saving guidance for households, database to evaluate savings estimates for 

residential and commercial facilities, and adoption of state-of-the-art building energy 

codes that will increase energy efficiency in new buildings by 30% or more. 

Recovery Act funding was requested and granted for the state energy program, weatherization assistance 

program, energy efficiency conservation block grants, and the energy efficiency appliance rebate 

program. This funding assists with implementing a few of the measures outlined by the Energy Office, 

however does not provide funding for all measures identified. A summary of the program and the 

funding allocation for each area is summarized in Figure 2860

While the Energy Office has determined areas of focus and has been granted funding to implement 

specific measures the work has only just begun and there are gaps in the level of coverage on-island. 

NREL’s goal in assessing the current level of energy efficiency is not intended to provide duplication of 

efforts, but rather to assist the island in identifying areas that have not been noted previously for energy 

conservation measures. 

. 

B.2 Initial Observations by Sector

B.2.1 Commercial and Government

Of all sectors on-island the commercial and government buildings seemed to have the most 

comprehensive implementation plan. During the island site visit, investment grade energy audits were 

being conducted at the airport and five hotels, new construction at Guam Community College was being 

built to achieve LEED certification, and community offices at Dededo were undertaking low-cost 

measures toward energy reduction. NREL staff were not able to visit any medical buildings to observe 

current practices, however this may be an area to explore further with investment-grade audits. 

 

60 DOE Recovery Act State Memo, Guam (June 1, 2010): 

http://www.energy.gov/recovery/documents/Recovery_Act_Memo_Guam.pdf. 

Figure 28. Recovery Act funding allocated to energy efficiency measures on Guam (in millions of 

U.S. dollars)

Source: DOE
58 

In general, observations and interviews within the commercial and government sector indicated an 

overall need for energy awareness. Simple, low-cost measures could be implemented to increase energy 

efficiency and conservation on island. Examples of this include temperature settings on air conditioning 

units/systems and better lighting controls. 

B.2.1.1 Temperature

The Dededo Senior Center is a good example of temperature control within a community building, and 

simple improvements could be made. The thermostat was set to 65°F on a forced air system with ceiling 

vents. The temperature at ceiling level was 2°F cooler than at floor level, indicating striation. The air 

conditioning was turned on, windows were open in the bathrooms, and gaps between the glass doors 

allowed cool air to leak out of the building as shown in Table 13. 

Table 13. Dededo Senior Center Indoor Temperature and Related Costs 

Dededo Senior Center

Hours of Operation 8am – 8pm

Cost/kWh 28¢/kWh

Monthly Consumption 1400-1700 kWh/month

Thermostat setting 65°F

Temperature gradient 2°F between floor and 

ceiling

Low-cost measures that could be implemented at the Dededo Senior Center include the following: 

• Add vent guards to the ceiling vents to direct air downward to cool the occupants below 

• Close windows and add door foam or brush seals to prevent cool air from leaking outdoors (gaps 

are shown in Figure 29). 

• Set the thermostat to a higher temperature, gradually increasing it over a few months to 74°F. 

ASHRAE states that there is only a 10% dissatisfaction rate for temperatures between 74o

-78o F61

 

61 ASHRAE Standard 55 – Thermal Environmental Conditions for Human Occupancy.

. The 

challenge is creating a culture change where people are encouraged to dress appropriately for external 

conditions and not expect buildings to be cooled to ~60o F. 

Figure 29. Visible gaps in door at Dededo Senior Center

Source: NREL/PIX 18584
59 

Humidity control in hot, humid climates prevents mold growth, damp rot in building structures, and 

health and comfort problems among occupants. Unfortunately, conventional air conditioners cannot 

control temperature and humidity independently of one another. ASHRAE recommends a 60% relative 

humidity maximum at a temperature setting of 78o F. Simple actions can be taken to lessen the need for 

dehumidification within a building, including: 

• Do not set thermostats to ‘fan on’ position as this will blow moist air whether the cooling system 

is on or not 

• Use exhaust fans in bathrooms, utility rooms with dryers, and kitchens to direct moist air 

outdoors.

Higher-cost options for community buildings like the Dededo Senior Center include measures such as 

improvements to the air conditioning system or creating a cool roof. Modifications at this level should 

be done during major renovation as the capital costs will be lower than if it is a stand-alone project. 

• When replacing an air conditioning system consider a modern desiccant cooling system, which 

removes humidity at a lower rate of energy consumption

• Retrofit an existing roof into a cool roof by using reflective materials to lower the heat 

absorption on the roof. 

Desiccant cooling is a technology that is advancing and systems are available on the market. These 

systems typically use water as a coolant and silica gels or lithium-chloride inside desiccant wheels to 

dehumidify. There are two types of desiccant systems, either solid or liquid. The solid systems can be 

utilized with a solar heating system that acts as a heat exchanger, however, these systems often need 

special design modifications in hot, humid climates. Standard configurations of the desiccant cycle are 

not typically able to reduce humidity low enough for direct evaporative cooling. Liquid systems have 

shown higher air dehumidification rates at the same operational temperature as solid desiccant systems. 

A cool roof is defined as a roof that has a lower roof temperature than traditional roofs, while the sun is 

shining. Cool roofs are designed to reflect sunlight and emit heat more efficiently than typical roofs 

through solar reflectance and thermal emittance. Dark roofs absorb approximately 90% of solar energy 

and the temperature on the roof can reach up to 150°F. Higher roof temperatures increase the internal 

temperatures, which impacts the demand on the air conditioning system. Light colored roofs, on the 

other hand, absorb less than 50% of the solar energy, reducing roof temperature and air conditioning 

loads. 

Cool roof materials vary from coatings that can be rolled, brushed, or sprayed to tiles and shingles. 

Before any cool roof is applied, the roofing structure and integrity should be checked and leaks or 

problems should be repaired. Coatings are available in acrylic, silicone, and urethane, as summarized in

Table 14. Coating varies by manufacture and improper application can cause flaking. Installers should 

follow manufacturer-specific recommendations. 

Table 14. Summary of Cool Roof Coatings by Type

Coating Type Properties Cost

Acrylic

Water based, easy to handle, good adhesion to most

roof types, most commonly used reflective coating, 

cures by evaporation, reasonably strong, very sensitive 

to weather

Moderate

Silicone Solvent based, typically used for spray polyurethane 

roofs, weather very well, weaker tensile strength, good 

water resistance

More 

expensive
60 

Urethane

Solvent based, 3-10 times stronger than acrylic, greater 

adhesion to most roof types than acrylic, most cure with 

exposure to air, less sensitive to weather, more difficult 

to work with

More 

expensive

Tile roofs can be designed as cool roofs by selecting tiles with specific reflectance and emittance 

qualities. Permanent or unfading tiles are often preferred as they retain their surface properties and can 

yield better lifetime energy savings. With all cool roofs, maintenance is essential to prevent build-up 

from pollution, debris deposited by wind and storms, mold or algae growth. Any of these naturally 

occurring deposits will decrease reflectance, leading to a less effective cool roof. 

More information about cool roofs can be found on DOE’s website on cool-roof resources62

B.2.1.2 Lighting 

. 

Lighting efficiency could be improved through the use of more efficient technologies and energy 

conservation techniques. Observations indicated the use of less efficient bulbs/lamps and a lack of 

sensors or awareness in turning lighting off when daylighting was adequate and did not require the use 

of additional lighting. 

Figures 30-32 are examples of adequate daylighting levels without the need for internal lighting. Figure 

30 and Figure 3

again, on an overcast day. 

1 are examples of effective daylighting levels without the need for internal lighting, 

Figure 3

lighting on and 

0 is a photograph of the museum at the Lette of Freedom with the 

Figure 3

no noticeable difference in the light level readings in foot candles (fc) with the lights on or off. When 

NREL staff entered the museum it was unoccupied and all lighting had been left on. 

1 is a photograph of the same museum with the lighting switched off. There is 

The hotel lobby in Figure 32 has large windows which, even on an overcast day, allow enough light in 

the lounge areas of the lobby. The red circles emphasize the lights that are turned on, but are not 

effective in providing additional lighting. Hotel staff were asked if the lights could be switched off, 

however their investigation into the situation indicated the lighting system is wired in such a way to 

prevent isolation of specific banks of lighting. The entire lobby seems to be on the same circuit, which 

does not facilitate control of lighting during daylight hours. 

 

62 US DOE-FEMP: Cool Roof Resources: http://www1.eere.energy.gov/femp/features/cool_roof_resources.html. 

Figure 30. Museum lights off at the 

Lette of Freedom 

Source: NREL/PIX 18586

Figure 31. Museum lights on at the 

Lette of Freedom 

Source: NREL/PIX 18587

Figure 32. Lobby lighting at 

the Tumon Bay Hyatt 

Source: NREL/PIX 18585
61 

Hotel lighting would benefit from daylight sensors and wiring that allow lighting to be isolated and 

switched off when daylighting is adequate. Public areas, such as the museum, would benefit from 

motion sensors to turn lights on when people approach the museum and switch off if the space is 

unoccupied. 

Effective lighting operation through the use of controls (timers, motion sensors, or daylight sensors) can 

conserve energy. Lamp type also impacts lighting energy consumption through the light level output and 

the amount of energy required to generate the light. 

Lighting technology has improved significantly in the last decade, evident in the options of higher 

efficiency lamps. One example is the shift in use of tubular fluorescent lamps from higher wattage lamps 

to lower wattage lamps. T12 lamps are tubular fluorescent lamps with a larger diameter than either T8 or 

T5 lamps. The T8 and T5 lamps are lower wattage bulbs. Generally T8 lamps can directly replace T12 

lamps, whereas T5 lamps may need an adaptor for the fittings on either end, or an entirely new ballast. 

Savings of up to 10% are achievable by replacing a T12 lamp with a T8 lamp in switch-start luminaires.

Other technological advancements have been made in direct replacement bulbs for other lamp types. 

Compact fluorescent lamps act as direct replacements with lower wattage for incandescent bulbs. LEDs

have the highest efficiency of all lamp types, but are not appropriate for all applications. LEDs generate 

very little heat, but are most effective in directional applications, such as halogen bulb replacements for 

retail displays. These technologies are becoming less expensive and new applications are being designed 

at a quick pace. This is a market to monitor for energy efficiency and lighting design within retrofits and 

new construction. 

Table 13 summarizes the recommended lamp types by application, either internal or external and the 

space that is being used. 

Table 13 Recommended Efficient Lamp Types by Space Use 

Space Use Recommended Lamp Type

Internal

Offices Triphosphor tubular fluorescent, compact 

fluorescent, halogen replacement lamps (LED)

Hotels Triphosphor tubular fluorescent, compact 

fluorescent, LED

Hospitals Triphosphor tubular fluorescent, compact 

fluorescent

Retail Metal halide, white sodium, compact fluorescent,

LED, halogen replacement lamps (LED)

Emergency exit signs LED

External

Parking lots High pressure sodium, metal halide, compact 

fluorescent

Floodlighting Metal halide, high pressure sodium

Feature lighting Metal halide, high pressure sodium, triphosphor 

tubular fluorescent, LED

Sports facilities Metal halide

B.2.2 Residential

The NREL team was not able to assess the residential sector in great detail; however this sector may be 

one where low-cost measures can be implemented easily through an awareness campaign in each 

village. 
62 

Figure 33 is one example of the type of housing found on island. Interviews on-island indicated a 

general lack of energy awareness despite high monthly electricity bills. 

In Guam the highest energy consumption in the residential sector is water heating, followed by air 

conditioning, and household appliances. 

Areas of improvement suggested by island residents during the October 2010 site visit included 

increasing knowledge of energy conservation within the construction industry. Working with local 

architects to improve standard building practices, reviewing the building code for energy efficiency 

specifications and ensuring only energy-efficient equipment and appliances are imported to Guam would 

contribute to the overall conservation on island. 

• Construction and design practices that would be beneficial include using appropriate insulating 

and reflective building materials (while avoiding reflecting sunlight and heat to neighboring 

buildings), utilizing external window shading to prevent solar gain through glazing, installing air 

conditioning systems with an efficient SEER, and installing lighting systems with higher 

efficiencies. 

• Controlling the electrical equipment imported to Guam is another area that would be beneficial. 

If the industry specified an efficiency standard of equipment and appliances on-island, greater 

efficiency would result. 

While construction improvements may be possible through the USDA’s Rural Development Housing 

and Community Facilities Program63

An awareness campaign could be carried out through the local schools and village mayor’s offices to 

encourage residents in each village to reduce energy consumption. Basic measures, such as switching off 

lights and air conditioners when they’re not being used, raising thermostat temperatures on air 

conditioners, and switching to more efficient light bulbs and appliances, are all actions that can be taken 

within communities. Teaching children to be more energy conscious in schools is often an effective 

approach to reducing energy consumption within homes. Friendly competitions could be held between 

each village and school to encourage implementation. One option is to pilot such a program in Dededo, 

where the mayor and staff are enthusiastic about energy conservation and where the population is 

largest. The potential for energy savings is highest and could also set a precedent among other villages 

and mayor’s offices. 

or increasing energy efficiency specifications within the tropical 

island building code, there are basic measures that can be implemented by residents and communities. 

 

63 http://www.rurdev.usda.gov/rhs/. 

Figure 33. Residential housing in Dededo 

Source: NREL/PIX 18583
63 

B.2.3 Outdoor and Street Lighting

Outdoor and street lighting does not consume the largest portion of Guam’s energy, but there are 

obvious measures that could be undertaken to reduce this sector of energy consumption. 

The NREL team observed that outdoor lighting on buildings and street lights were left on during 

daylight hours when lighting was not needed. On NAVFAC property a call was suggested to turn off a 

building’s external lighting and island residents confirmed that street lighting control was problematic. 

The two measures that would be beneficial to this sector are improving the lamps themselves and 

improving controls. 

• Energy-efficient outdoor lighting is available that will reduce the wattage while providing the 

same quality of light, but should be chosen for specific applications, as summarized in Table 16. 

• Lighting controls should be installed and maintained to either switch lights off during daylight 

hours, be set for specific operational times through the use of timers or use motion detectors to 

provide light when movement is detected by humans (or in some cases, animals, depending on 

the application). 

Table 16. Recommended Efficient Lamp Types for Outdoor and Street Lighting

Space Use Recommended Lamp Types

External Street lighting Induction lighting could be trialed, LED, high 

pressure sodium

Parking lots High pressure sodium, metal halide, compact 

fluorescent

Floodlighting Metal halide, high pressure sodium

Feature lighting Metal halide, high pressure sodium, triphosphor

tubular fluorescent, LED

Sports facilities Metal halide

Figure 34. Example of street lighting on during daylight hours in Tumon Bay

Source: NREL/PIX 18589
64 

B.2.4 U.S. Navy

The U.S. Navy consumes approximately 20% of the island’s total energy. While this is an area where 

improvements could be made, NREL has not included recommendations in this study due to the fact that 

the U.S. Navy has undertaken numerous studies and is currently in the process of implementing energy 

conservation measures and renewable energy. 

All military bases on Guam could benefit the island as a whole by ensuring that energy efficiency is a 

priority during the proposed military build-up, not only for its own facilities and personnel, but also for 

the facilities that will accommodate the construction workers who will live on-island during the buildup 

process. 

Temporary housing is often constructed with the intent of dismantling the housing once it is no longer 

needed, however in many cases temporary housing continues to be used for many decades and becomes 

more permanent than initially anticipated. As such, the military could influence the island’s energy loads 

by working with contractors to encourage, and where within operational control, specify those additional 

facilities apply energy efficiency standards. 

One area for improvement is temporary housing and water treatment plants. Water treatment is 

discussed in other areas of this report.
65 

C. Renewable Energy 

C.1 Solar PV

C.1.1 Overview

This section contains discussion of the site parameters used in the Siting Study. These site parameters 

were investigated using the best available data and following the methodology described in the next 

section. 

The island of Guam contains approximately 46,800 parcels on 133,900 acres. The northern part of the 

island is relatively flat and is more developed as compared to the southern part of the island. The 

island’s electricity is generated by a number of relatively small fossil-fuel-burning power plants. GPA 

electricity is delivered through a transmission and distribution grid consisting of a combination of 115 

kV, 34.5 kV, and 13.8 kV lines. 

A suitable site for a solar electric generating facility on Guam would have the following general 

characteristics in order to enhance the cost effectiveness of the project: 

• Adequate unoccupied area (60-80 acres)

• Flat or gradual southerly sloped terrain with minimal vegetative cover

• Close proximity to electrical transmission/distribution lines, access roads, and electrical load 

centers

• Favorable land-use designation or a clear indication that the land use designation can be changed 

to accommodate the solar project.

The following sections provide further information on the site parameters used in this analysis. 

Land zoned for military use as well as land zoned as conservation was ruled out of the analysis. All 

other zoning designations were considered to be either suitable or relatively easy to change. 

Parcels that are substantially occupied were ruled out of the analysis. It should be noted that the parcel 

map used is two years old and some parcels have been subdivided since this data was created. Therefore, 

several large parcels in the analysis below contain a number of residences, but have large areas 

unoccupied. In cases such as these, the unoccupied areas of the parcel were considered suitable and it is 

assumed that the subdivided portions of the parcel do not substantially interfere with the potential future 

use of the unused areas.

R.W. Beck provided footprint information of 60-80 acres per 10 MW plant, which GPA accepted as a 

target parameter for the basis of this memorandum. Based on this parameter, highly irregularly shaped 

parcels may not be suitable if their shape prohibits the existence of the 60-acre area. However, for the 

purposes of the IFB, the minimum size is 5 MW. 

Relatively flat areas are ideal, but a slope of up to 10% was considered acceptable for this study. 

Anything beyond 10% was considered unacceptable. 

Areas with a southern-facing slope aspect are ideal, but any slope between 90° and 270° (based on 

compass degrees) was considered acceptable. Any aspect north of this line was considered unacceptable.

An ideal site has close proximity to access roads. Most if not all of the sites are adjacent to roads that 

have access to village streets or highways. Thus, in general this site parameter was satisfied by most 

properties that were evaluated.
66 

For economic reasons, an ideal site shall be located in close proximity to electrical transmission or 

distribution lines and also the electrical load center. A 34.5-kV feeder connection to the transmission 

system could be up to 15 or 20 mi. in length without incurring significant voltage drop. A 13.8-kV 

feeder connection to the distribution system could be up to 2 mi. in length without incurring significant 

voltage drop. The actual voltage drop and energy losses in the feeder line will be dependent on the wire 

size, circuit length, and line configuration, as well as on the magnitude of the current (amperes) flowing 

in the line. 

Monitory considerations, such as cost of step-up transformers, switching and protective devices, and 

pole line construction, will also have a significant impact in determining the point of connection and 

system voltage. 

Although GPA’s preference is to have the solar power plant connect to the transmission system (34.5 

kV), there are potential cost and equipment factors that may make a connection to the distribution 

system more advantageous for certain locations. Potential solar power plant developers will be required 

to undertake a System Impact Study to analyze the benefits, impacts, and necessary upgrades to the GPA 

transmission (34.5 kV) or distribution (13.8 kV) systems due to their proposed system(s). Figure 23

shows the existing GPA transmission and distribution systems near the proposed sites that were selected 

in this study. Additional information on the transmission and distribution systems can be obtained from 

GPA for other areas of the island, upon request. 

C.1.2 Methodology

The following sections outline the step-by-step methodology used to screen all known parcels on the 

island. All steps below were undertaken in the GIS software program ArcInfo by ESRI, using the Spatial 

Analyst toolset.

C.1.2.1 Source Data and Known Data Gaps

The data used for the analysis in this report was primarily obtained from the following GIS layers:

1. Parcels (Cadastre2007.shp) - last updated March 2007 

2. Zoning (ZoneMap_update.shp) - last updated March 2006 

3. Digital Elevation Model (ned_35956460_GuamGCS93.shp) - created March 2009. 

It should be noted that the parcel layer was obtained through existing Government of Guam GIS 

databases being used by GWA and other government agencies. This layer is missing lot numbers and 

ownership information on approximately 11% of the island due to “holes” in the data. However, these 

land areas were evaluated for slope and slope aspect and it was found that only two areas contain 

potential sites (the other “holes” consist of areas that are too steep). These lots are identified by the lot 

number “L0” and will require further research by any interested developers to determine land ownership 

and confirm the extents of the parcels because they are not in the currently available Cadastre files.

A total of 46,819 parcels are in the parcel layer, 586 of which were zoned “Military” and one of which 

was zoned “Conservation.” These 587 parcels were removed from consideration, leaving 46,232 parcels, 

under the following zoning designations: 

• Agricultural

• Commercial

• Industrial 

• Residential. 
67 

Once inappropriately zoned parcels were eliminated, the remaining parcels were screened to eliminate 

all parcels less than 60 acres, leaving 134 appropriately zoned parcels. Of these parcels, none were 

eliminated due to highly irregular shapes/dimensions that made the parcel unusable. The remaining 134 

appropriately zoned parcels that were >60 acres were of sufficient quantity to eliminate the need to 

search for parcels smaller than 60 acres. However, it should be noted that additional candidate sites may 

exist in the form of multiple contiguous parcels smaller than 60 acres. For instance, two contiguous 

parcels that are each 50 acres (and each matching the necessary slope and aspect criteria) could be 

joined to create a 100-acre parcel. However, this approach was not utilized for this initial screening. 

Next, the 134 remaining parcels were placed into Tiers using the screening criteria discussed below 

(occupancy, percent of slope, and aspect of slope). Tier 1 represents parcels that appear to be the best 

suited for the intended purposes. Tier 2 represents parcels that have some problems, but are generally 

well suited according to most screening criteria. Tier 3 represents parcels that appear to have fatal flaws 

(such as being primarily occupied).

Of the 134 parcels remaining for consideration, many were occupied. Occupied parcels were divided 

into two categories: primarily occupied and minimally occupied. Minimally occupied parcels may have 

included large tracts of land with residential or other uses on their periphery. Primarily occupied parcels 

were placed into Tier 3. It should be noted that some occupied parcels could have lot line adjustments to 

move unoccupied portions into combination with neighboring parcels. However, this level of analysis 

was not considered in this study. 

Percent of slope was calculated based on a Digital Elevation Model (DEM) with a 100-foot resolution. 

This means that elevation data for the entire island was divided into discrete cells, each consisting of 

10,000 square feet (100’ x 100’). This DEM was used to generate each cell’s slope through the 

following process: 

1. The average elevation of each cell is compared to the eight cells surrounding it 

2. The degree of change in elevation from the cell to its immediate neighbors is determined 

3. An average slope value (in %) is assigned to the cell based on this degree of change in elevation. 

In this way, an average slope was calculated for each 10,000 sf block of land on the island. All cells with 

a slope value great than 10% were symbolized, while all cells with a slope value of 10% or less were not 

symbolized. The result is a Percent of Slope layer in which areas that are too steep (according to the site 

parameter criteria established above) are shaded red.

All parcels were evaluated to identify contiguous areas internal to the parcel that were at least 60 acres 

and had a slope value of 10% or less. Parcels that did not meet these criteria were placed into Tier 3. 

The same DEM referenced above was used to generate each cell’s aspect through a similar process as 

was used to calculate percent of slope. All cells with a northerly aspect were symbolized, while all cells 

with a southerly aspect were not symbolized. The result is an Aspect of Slope layer in which areas in 

which the slope is at the wrong aspect (according to the site parameter criteria established above) are 

shaded yellow. 

When the Aspect of Slope layer is overlaid on the Percent of Slope layer, the result is as follows: areas 

that are too steep are shaded red, areas that are at the wrong aspect are shaded yellow, while areas that 

are both too steep and at the wrong aspect are shaded orange. 

All parcels were evaluated to identify contiguous areas internal to the parcel that were at least 60 acres 

and had the appropriate slope aspect. Slope aspect was not weighed as heavily as percent of slope. 
68 

Therefore, many parcels with the wrong slope aspect were permitted into Tiers 1 and 2, as long as the 

slope percent was acceptable.

For the Tier 1 parcels, distance to roadway was calculated and recorded.

For the Tier 1 parcels, distance to the nearest power transmission or power distribution lines was 

calculated and recorded. For an overview of Tier 1 Parcels, see Figure 35. 
69 

Figure 35. Overview of Tier 1 parcels

Source: GPA

C.1.3 Top Seven Parcels

The top seven parcels from Tier 1 identified during this study are shown in Table 17. The third column 

is an estimate of the total amount of the array output at a conservative (relatively low) value for the array 
70 

density, and the fourth column is an estimate at an optimistic (relatively high) value. Assuming every 

acre of every lot could be populated with PV modules, the potential for solar PV could range from 315 

MW to 631 MW. What remains to be done now is to do field assessments of each site to determine how 

many acres of each site can actually accept solar arrays. 

Table 17. Top Seven Sites Identified for Solar PV

Lot Number(s) Total Size 100-kW / acre 200-kW / acre

acres kW PV kW PV

L450-R3 1,125 112,450 224,900 

L177-4-R2 1,072 107,200 214,400 

L7163 416 41,550 83,100 

L10140-R5 and 

L10164-R3 191 19,070 38,140 

L57-2 169 16,890 33,780 

L0 111 11,090 22,180 

L186NEW-1 72 7,150 14,300 

Totals 3,154 315,400 630,800 

The remainder of this section briefly describes these seven parcels. 

Parcel L57-2

This parcel is located roughly in the center of the South Island.

Advantages

• Large area with gradual slope and favorable aspect

• The land is largely undeveloped 

• Reasonably close proximity to: 

o Electrical transmission/distribution lines

o Access road

o Electrical loads

Disadvantages 

• Southern portion of parcel appears to have varied topography, including some areas with slope 

greater than 10% and northerly aspect 

• Parcel appears to be heavily forested

• Not as close to electrical infrastructure, roads, and electrical loads as L7163, LO, or L186NEW-1 

This parcel is located in the central part of the island. 

Parcel L177-4-R2

Advantages 

• Very large parcel

• The land is largely undeveloped 

• Reasonably close proximity to: 

o Electrical transmission/distribution lines

o Access road

o Electrical loads
71 

Disadvantages 

• Substantial portions of parcel appears to have varied topography, including some areas with 

slope greater than 10% and northerly aspect 

This parcel is located at roughly mid latitude on the island close to the Eastern shore in close proximity 

to Parcel LO, which is described above.

Parcel L186NEW-1

Advantages 

• Close proximity to Parcel LO

o Parcels could be combined into one large project site 

• Close proximity to: 

o Electrical transmission/distribution lines

o Access road

o Electrical loads

Disadvantages 

• Parcel appears to have varied topography, including some areas with slope greater than 10% and 

northerly aspect 

• Some structures do exist along the southern edge of the parcel 

• Parcel appears to be heavily forested

This parcel is located in the central part of the island. 

Parcel L450-R3

Advantages 

• Very large parcel

• The land is largely undeveloped 

• Near the Ordot Landfill 

• Reasonably close proximity to: 

o Electrical transmission/distribution lines

o Access road

o Electrical loads

Disadvantages 

• Substantial portions of parcel appears to have varied topography, including some areas with 

slope greater than 10% and northerly aspect 

This parcel is located on a bluff on the North Eastern shore of the Island. 

Parcel L7163

Advantages 

• Large area with a high percentage of flat or gradually sloped land

• Close proximity to: 

o Electrical transmission/distribution lines

o Access road

o Electrical loads

• A significant portion of the property appears to have been cleared previously 

• The land is undeveloped (i.e. no structures exist on parcel) 

Disadvantages 

• Potential impacts to recreation
72 

This parcel is located at roughly mid latitude on the island close to the Eastern shore. 

Parcel LO

Advantages 

• Large area with a high percentage of flat or gradually sloped land

• Close proximity to: 

o Electrical transmission/distribution lines

o Access road

o Electrical loads

• A significant portion of the property appears to have been cleared previously 

• The land is undeveloped (i.e. no structures exist on parcel) 

Disadvantages 

• None apparent 

These adjacent parcels are located roughly in the center of the North Island. 

Parcels L10164-R3 & L10140-R5

Advantages 

• Together, these parcels have a reasonably large area with gradual slope and favorable aspect

• Close proximity to: 

o Electrical transmission/distribution lines

o Access road

o Electrical loads

Disadvantages 

• Parcels both have some residential and agricultural development on them

• Parcel L10164-R3 does have some area that is greater than 10% slope.

o However, this area is southerly facing.

• The undeveloped area on these parcels appears to be moderately forested

• Closest proximity to electrical infrastructure appears to be to either transmission or distribution 

lines, not both. 

o Data was not sufficient to make a further determination on this point 

C.1.4 Summary

Based on this preliminary study it appears that there are numerous properties available on Guam that 

could support a 10 MW solar power plant. However, potential developers must include provisions to 

perform a System Impact Study for any potential site they may consider. This should include a review of 

the adjacent GPA transmission and/or distribution systems, load centers, line losses, proximity to roads 

and improvements that may be required to satisfy other aspects of the IFB. 

C.2 Wind Technology

C.2.1 Previous Wind Assessment Activities

Both GPA and the U.S. 

The Cotal area could support approximately 10 large wind turbines along two ridges, with a total 

capacity of approximately 20 MW. The site has good road access, is close to a 34.5 kV transmission 

line, and is within several miles of a substation. The site was reviewed during the NREL island visit and 

proved to be a good location. The turbines would be installed upwind from several homes and a larger 

Navy have conducted wind development assessments on Guam. In a study 

conducted by DNV-Global Energy Concepts for GPA, two viable wind sites have been identified; the 

larger one is in the area of Cotal, along the Cross Island Road (HWY 17). The second site was in the 

area of Pulantat. 
73 

potential development area. The site sits directly south of the Leo Palace Resort and although not close, 

will be clearly visible from the resort. The elevation of the site is around 200 m, which puts it only 

approximately 50 m lower that the island high spots and approximately 3 mi. from the U.S. Navy met 

mast, which shows an annual wind speed in the area of 8 m/s. Land in this area is primarily owned by 

the Department of Agriculture with several smaller private holdings. GPA has been working to 

implement a 50 m met tower at this site to allow detailed wind resource characterization and the 

development of project economics. The initial attempt to compete a RFP for the installation was 

hampered by the requirement of any measurement equipment being able to withstand a Class V typhoon. 

Due to the very high resulting costs proposed, the RFPs had to be canceled and next steps assessed.

The Pulantat site sits very close to the Leo Palace Resort and could support approximately five wind 

turbines with a total capacity of around 10 MW. This site is much more complicated due to proximity to 

local residents and facilities, local topography, the airport, and other communications/radar facilities. 

The site also sits on private land holdings and is lower in elevation then the Cotal site. This site is 

considered secondary to the Cotal location.

GPA has also conducted a long term wind measurement program as part of its air abatement activities. 

The met tower is a nominal 60 m tower and installed near the Cabras-Pili power plant. The site is 

generally sheltered and is on the leeward side of the island, so likely will not provide a good correlation 

for wind project assessment. 

The U.S. Navy, through an Interagency Agreement between the Naval Facilities Engineering Service 

Center (NFESC) and NREL, has been funding a wind resource assessment on U.S. Navy lands. As part 

of this project one 60 m met tower was installed on the western boundary of the Ordnance Annex just 

below Mt. Alifan. This measurement station was installed in September 2008 and although it would be 

very difficult, if not impossible, to install wind turbines in this area due to environmental impacts, it 

does provide a very good free wind speed reference site for any additional wind assessment programs. 

The data collected thus far shows it to be a very good Class 5 resource with a mean wind speed in the 

region of 7.9 m/s. A monthly plot of wind speed is shown in Figure 36. The winds peak midday and 

come primarily from the east and south by southwest, as shown in Figure 37. Since the installation of 

turbines along the ridge is not likely in the near term, the U.S. Navy has considered installing turbines at 

other locations, such as the U.S. Navy port breakwater, for community-scale wind projects of one to 

three multi-MW wind turbines. The location and assessment status of these projects is not currently 

known but do represent additional installed wind capacity on the island. 
74 

Figure 36. Boxplot of mean wind speed at 60 m for Guam Naval Ordnance (10/1/2008 – 9/30/2010)

Source: NREL

Figure 37. Power density rose for Guam Naval Ordnance (10/1/2008 – 9/30/2010)

Source: NREL
75 

Table 148. Estimated Total Population Increase on Guam from Off-Island (Direct, Indirect, and Induced)

Source: Guam and CNMI Military Relocation Final EIS (July 2010), Pg. ES-.8