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

Feasibility Study of Economics 

and Performance of Solar 

Photovoltaics at the Standard 

Chlorine of Delaware Superfund 

Site in Delaware City, Delaware

A Study Prepared in Partnership with the 

Environmental Protection Agency for the 

RE-Powering America’s Land Initiative: 

Siting Renewable Energy on Potentially 

Contaminated Land and Mine Sites

James Salasovich, Jesse Geiger, Gail Mosey, 

and Victoria Healey

Produced under direction of the U.S. Environmental Protection 

Agency by the National Renewable Energy Laboratory (NREL) under 

Interagency Agreement IAG-09-1751 and Task No. WFD4.1001.

Technical Report

NREL/TP-7A40-58323

June 2013
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

15013 Denver West Parkway

Golden, CO 80401

303-275-3000 • www.nrel.gov

Feasibility Study of Economics 

and Performance of Solar 

Photovoltaics at the Standard 

Chlorine of Delaware Superfund 

Site in Delaware City, Delaware 

A Study Prepared in Partnership with the 

Environmental Protection Agency for the 

RE-Powering America’s Land Initiative: 

Siting Renewable Energy on Potentially 

Contaminated Land and Mine Sites

James Salasovich, Jesse Geiger, Gail Mosey, 

and Victoria Healey

Prepared under Task No. WFD4.1001

Technical Report

NREL/TP-7A40-58323

June 2013
NOTICE

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”).

This report was prepared as an account of work sponsored by an agency of the United States government. 

Neither 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, 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 the United States government or any agency thereof. The views and opinions of authors expressed 

herein do not necessarily state or reflect those of the United States government or any agency thereof.

Cover Photos: (left to right) PIX 16416, PIX 17423, PIX 16560, PIX 17613, PIX 17436, PIX 17721

Printed on paper containing at least 50% wastepaper, including 10% post consumer waste. 
iii

Acknowledgments

The National Renewable Energy Laboratory (NREL) thanks the U.S. Environmental Protection 

Agency (EPA) for its interest in securing NREL’s technical expertise. In particular, NREL and 

the assessment team for this project are grateful to the Standard Chlorine of Delaware facility 

managers, engineers, and operators for their generous assistance and cooperation. 

Special thanks go to Brigid Lowery, Patricia Corbett, Hilary Thornton, Charles Howland, Brad 

White, Jessica Trice, Shea Jones, and Lura Matthews from EPA; Katie Brown, AAAS Science & 

Technology Policy fellow hosted by EPA; and Todd Keyser and Jessica Quinn from the 

Delaware Department of Natural Resources and Environmental Control for hosting the site visit. 
iv

Executive Summary

The U.S. Environmental Protection Agency (EPA), in accordance with the RE-Powering 

America’s Land initiative, selected the Standard Chlorine of Delaware site in Delaware City, 

Delaware, for a feasibility study of renewable energy production. The National Renewable 

Energy Laboratory (NREL) provided technical assistance for this project. The purpose of this 

report is to assess the site for a possible photovoltaic (PV) system installation and estimate the 

cost, performance, and site impacts of different PV options. In addition, the report recommends 

financing options that could assist in the implementation of a PV system at the site. This study 

did not assess environmental conditions at the site. 

The Standard Chlorine of Delaware site is located in New Castle County, approximately 3 miles 

northwest of Delaware City, Delaware, and 35 miles southwest of Philadelphia. The Standard 

Chlorine site is approximately 65 acres, and a majority of the buildings and infrastructure have 

been demolished, but there is an onsite water treatment building. The Standard Chlorine of 

Delaware site opened in 1966 and was originally used to manufacture chlorinated benzene 

products. Operations at the Standard Chlorine of Delaware site were closed in 2002 after the site 

owner declared bankruptcy. 

The feasibility of a PV system installed on a Superfund site is highly impacted by the available 

area for an array, solar resource, distance to transmission lines, and distance to major roads. In 

addition, the remediation status, ground conditions, and restrictions associated with 

redevelopment of the Superfund site impact the feasibility of a PV system. Based on an 

assessment of these factors, the Standard Chlorine of Delaware site could be suitable for 

deployment of a large-scale PV system following the capping of the operable unit 3 (OU-3) 

(plant-area soils). 

The Standard Chlorine of Delaware site has a high potential to build out the site with groundmounted PV but very little potential to build out the site with a roof-mounted PV system, due to 

the low concentration of buildings on the site. There are 27.4 acres (1,193,544 ft2

) potentially 

available for ground-mounted PV systems. The area available for roof-mounted PV on the 

treatment system building is 2,165 ft2

. While the entire area does not need to be developed at one 

time due to the possibility of staging installation as area or funding becomes available, 

calculations for this analysis reflect the solar potential if the total feasible area is used. It should 

be noted that the purpose of this report is not to determine how to develop the site but to 

investigate both options and present the results in an unbiased manner. 

Of the three scenarios considered, all had a positive net present value and had a payback within 

the 25-year analysis period. Two applications were analyzed for the Standard Chlorine of 

Delaware site. The first application would be to offset the power consumption of the onsite 

pumping, and the second application would be to lease or use the open land for a large 

commercial PV system. The economic feasibility of a potential commercial PV system on the 

Standard Chlorine of Delaware site depends greatly on the price of solar renewable energy 

certificates (SRECs); without SRECs, the PV system would only be economically feasible in a 

net zero application where the electricity use of the onsite pumping would be offset by a PV 

system. The economics were analyzed using the Delmarva Medium Commercial Rate Schedule 

downloaded with the modeling software System Advisory Model (SAM). The generated 
v 

electricity sale rate used is $0.0456/kWh. Table ES-1 shows the current incentives considered. 

The net metering is available up to 2 MW, and the Delmarva Power incentives for PV are 

available only for systems up to 50 kW in size, and thus are applicable only to the small rooftop 

system case. 

Table ES-1. Summary of Incentives Evaluated

Incentive Title Modeled Value Expected End 

Solar Renewable Energy Certificates

(SRECs)

As of August 2012, 

approximately 

$189/MWh

N/A; modeled as 20 

years

Federal Investment Tax Credit 30% of total investment 2016

Net Metering Net meter up to 2 MW

capacity N/A

Delmarva Power—Green Energy Program 

Incentives

$1/W; less than $24,000

Up to 50 kW Annually funded

Table ES-2 summarizes the system performance and economics of potential systems that would 

use all available areas that were surveyed at the Standard Chlorine of Delaware site and one 

smaller variation. The table shows the annual energy output from the systems, along with the 

number of average American households that could be powered off of such a system and 

estimated jobs created. With the current SREC sale price in Delaware, the most economically 

beneficial system would be one that pursues a virtual net metering opportunity and maximizes 

land coverage by using single-axis tracking modules and covering the water treatment building

roof in flat panels. The single-axis ground-mounted system would be 3,149 kW in capacity, 

generate 5,014,100 kWh of electricity, and have a net present value of $852,452 with a payback 

of 10.2 years. This includes the current cost of energy, expected installation cost, site solar 

resource, and existing incentives for the proposed PV system. The savings and payback is 

deemed reasonable and as such, maximizing land coverage with a virtual net metering PV 

system represents a viable reuse for the site under analyzed conditions. 
vi 

Table ES-2. Standard Chlorine of Delaware Site PV System Summary
vii 

Table of Contents

1 Study and Site Background................................................................................................................. 1

2 Development of a PV System on Brownfield Sites ........................................................................... 3

3 PV Systems ........................................................................................................................................... 5

3.1 PV Overview .................................................................................................................................... 5

3.2 Major System Components .............................................................................................................. 6

3.2.1 PV Module .......................................................................................................................... 6

3.2.2 Inverter ................................................................................................................................ 8

3.2.3 Balance-of-System Components ......................................................................................... 9

3.2.4 Operation and Maintenance .............................................................................................. 11

3.3 Siting Considerations ..................................................................................................................... 12

4 Proposed Installation Location Information .................................................................................... 13

4.1 Standard Chlorine of Delaware Site PV System ............................................................................ 13

4.2 Utility-Resource Considerations .................................................................................................... 16

4.3 Useable Acreage for PV System Installation ................................................................................. 17

4.4 PV Site Solar Resource .................................................................................................................. 17

4.5 Standard Chlorine of Delaware Energy Usage .............................................................................. 19

4.5.1 Current Energy Use .......................................................................................................... 19

4.5.2 Net Metering ..................................................................................................................... 19

4.5.3 Virtual Net Metering......................................................................................................... 20

5 Economics and Performance............................................................................................................ 21

5.1 Assumptions and Input Data for Analysis ..................................................................................... 21

5.2 SAM-Forecasted Economic Performance ...................................................................................... 22

5.2.1 Solar Investor vs. Site Owner ........................................................................................... 23

5.2.2 Single-Axis Tracking vs. Fixed-Tilt Modules .................................................................. 24

5.2.3 Policy Dependence of the System ..................................................................................... 24

5.3 Job Analysis and Impact ................................................................................................................ 24

5.4 Financing Opportunities................................................................................................................. 26

5.4.1 Owner and Operator Financing ......................................................................................... 26

5.4.2 Third-Party Developers with Power Purchase Agreements .............................................. 26

5.4.3 Third-Party “Flip” Agreements Opportunities .................................................................. 27

5.4.4 Hybrid Financial Structures .............................................................................................. 27

5.4.5 Solar Services Agreement and Operating Lease ............................................................... 27

5.4.6 Sale/Leaseback .................................................................................................................. 28

5.4.7 Community Solar/Solar Gardens ...................................................................................... 28

6 Conclusions and Recommendations ............................................................................................... 29

Appendix A. Assessment and Calculations Assumptions ................................................................... 30

Appendix B. Results from the Solar Advisor Model.............................................................................. 31

Appendix C. Results from the Job and Economic Development Impact Model................................. 43
viii

List of Figures

Figure 1. Generation of electricity from a PV cell ...........................................................................5

Figure 2. Ground-mounted array diagram .......................................................................................6

Figure 3. Mono- and multi-crystalline solar panels .........................................................................7

Figure 4. Thin-film solar panels installed on (left) solar energy cover and (middle and right) 

fixed-tilt mounting system .........................................................................................................7

Figure 5. String inverter ...................................................................................................................9

Figure 6. Aerial view of the feasible areas for PV at the Standard Chlorine of Delaware site 

(ground-mounted PV in yellow and treatment system building with roof-mounted PV 

in red) .......................................................................................................................................14

Figure 7. Views of the feasible area for ground-mounted PV at the Standard Chlorine of 

Delaware site (photos taken from the treatment system building) ..........................................15

Figure 8. Views of the feasible area for ground-mounted PV at the Standard Chlorine of 

Delaware site (photos taken from the temporary soil storage area) .........................................16

Figure 9. Location of the closest substation in relation to the Standard Chlorine of 

Delaware site ............................................................................................................................17

List of Tables

Table ES-1. Summary of Incentives Evaluated ...............................................................................v

Table ES-2. Standard Chlorine of Delaware Site PV System Summary ....................................... vi

Table 1. Ground-Mounted Energy Density by Panel and System .................................................10

Table 2. Rooftop Energy Density by Panel ...................................................................................11

Table 3. Site Identification Information and Specifications ..........................................................18

Table 4. Performance Results for 20-Degree Fixed-Tilt PV .........................................................18

Table 5. Performance Results for 20-Degree Single-Axis PV ......................................................19

Table 6. Installed System Cost Assumptions .................................................................................22

Table 7. Summary of Incentives Evaluated ...................................................................................22

Table 8. Summary of SAM Results ...............................................................................................23

Table 9. JEDI Analysis Assumptions ............................................................................................25

Table A-1. Cost, System, and Other Assessment Assumptions ....................................................30

Table C-1. Data Summary for JEDI Model Analysis of Single-Axis Tracking PV System .........43

Table C-2. Summary of Local Economic Impacts for JEDI Model Analysis of Single-Axis 

Tracking PV System ................................................................................................................44

Table C-3. Detailed Summary of Costs for JEDI Model Analysis of Single-Axis Tracking 

PV System ................................................................................................................................45

Table C-4. Annual O&M Costs for JEDI Model Analysis of Single-Axis Tracking PV System .46
1 

1 Study and Site Background

The U.S. Environmental Protection Agency (EPA), in accordance with the RE-Powering 

America’s Land initiative, selected the Standard Chlorine of Delaware site for a 

feasibility study of renewable energy production. The National Renewable Energy 

Laboratory (NREL) provided technical assistance for this project. The purpose of this 

report is to assess the site for a possible photovoltaic (PV) system installation and 

estimate the cost, performance, and site impacts of different PV options. In addition, the 

report recommends financing options that could assist in the implementation of a PV 

system at the site. This study did not assess environmental conditions at the site. 

The Standard Chlorine of Delaware site is located in New Castle County, Delaware. The 

site is located approximately 3 miles northwest of Delaware City, Delaware, which is 

35 miles southwest of Philadelphia. The Standard Chlorine of Delaware site is 65 acres, 

and the treatment system building is the only permanent building on the site. An existing

warehouse building was demolished in December 2012. Delaware City had a population 

of just under 1,700 people, according to the 2010 census. Delaware City experiences 

summers that are warm and humid with high temperatures, typically in the mid 80o

F 

range. The winters are moderately cold with some snow and with low temperatures in the 

25o

F range. Delaware City has an average of 202 days of sunshine each year. Delmarva 

Power, a deregulated utility, provides electricity to the Standard Chlorine of 

Delaware site. 

The Standard Chlorine of Delaware site opened in 1966 and was originally used to 

manufacturer chlorinated benzene products. The site was later purchased by Metachem 

Products, which continued to manufacture chlorinated benzene products there. The 

Standard Chlorine of Delaware site operations were closed in 2002 after the site owner 

declared bankruptcy. The majority of the original buildings and infrastructure at the site 

have since been demolished. 

The major contaminants at the site are related to years of manufacturing chlorinated 

benzene products there. While operational, there were spills of chlorinated benzene 

products, which is the major contaminant at the site. In 1986, a major spill occurred, 

during which time it is estimated more than 569,000 gallons of chlorinated benzene 

compounds were spilled at the site. EPA added the site to the Superfund National 

Priorities List in 1987. When Metachem Products declared bankruptcy in 2002, the site 

was closed abruptly. As a result, over 40 million pounds of chlorinated benzene and 

related compounds were abandoned in insecure storage systems and pipeline. From 2002 

to 2006, the EPA removed the hazardous materials at the site. The EPA then installed a 

low permeability slurry wall around an approximate 30-acre area that is 3 feet wide by an 

average of 65 feet deep. This slurry wall, combined with a groundwater extraction and 

treatment system that involves a network of six extraction wells, and the treatment system 

building, continues to be maintained and operated by EPA. Approximately 152,000 

people use the groundwater located within a 3-mile radius of the site.1

 

 

1 “Standard Chlorine of Delaware, Inc.” U.S. Environmental Protection Agency, 2011. 

http://www.epa.gov/superfund/eparecovery/standard_chlorine.html. 
2 

The next phase of the EPA’s remedial process calls for constructing a multilayer 

geotextile and soil cap and soil gas collection system over an approximately 23-acre area, 

which is essentially the location of the former plant. The remedial design has been 

completed and EPA is waiting for funding. Considerations for solar renewable energy 

generation at the site were incorporated into the final design for the remedy and include 

limiting the final grade of the site to a slope of 4.5%. In order to maintain the integrity of 

the cap, future uses of the site will be limited to surface applications. Ballasted groundmounted PV systems are required for this site because the cap cannot be penetrated. A 

PV system should be installed only after the cap is installed. 

The closest electrical tie-in location is located 0.6 miles (3,250 feet) to the northeast off 

of Hamburg Corner River Road. Having a substation this close to the site makes it an 

ideal location for a PV system to tie into. A detailed interconnection study will have to be 

performed through Delmarva Power to determine the feasibility of utilizing the onsite 

substation as a tie-in point for a PV system. The site currently has one building using 

electricity (the treatment system building), and there is no new construction anticipated at 

the site. The treatment system building is a potential off-taker of the electricity produced 

by a PV system. 

Feasibility assessment team members from NREL, the Delaware Department of Natural 

Resources and Environmental Control (DNREC), and EPA conducted a site visit on 

February 9, 2012, to gather information integral to this feasibility study. The team 

considered information, such as solar resource, transmission availability, community 

acceptance, and ground conditions. 
3 

2 Development of a PV System on

Brownfield Sites

Through the RE-Powering America’s Lands initiative, EPA has identified several 

benefits for siting solar PV facilities on Superfund and other environmentally impaired 

sites, noting that they: 

• Offer development opportunities 

• Can be developed in place of scarce greenfields, preserving the land carbon sink 

• Could have environmental conditions that are not well-suited for commercial or 

residential redevelopment and might be adequately zoned for renewable energy

• Generally are located near existing roads and energy transmission or distribution 

infrastructure

• Might provide an economically viable reuse for sites that could have significant 

cleanup costs or low real estate development demand 

• Can provide job opportunities in urban and rural communities 

• Can advance cleaner and more cost-effective energy technologies and reduce the 

environmental impacts of energy systems (e.g., reduce greenhouse gas emissions). 

By taking advantage of these potential benefits, PV can provide a viable, beneficial reuse, 

and in many cases, generate significant revenue on a site that would otherwise go unused. 

The Standard Chlorine of Delaware site was last owned by Metachem Products, which

went bankrupt in 2002. For many Superfund and other contaminated sites, the local 

community has significant interest in the redevelopment of the site, and community 

engagement is critical to match future reuse options to the community’s vision for the 

site. The purpose of this study is to analyze all options so that an informed decision can 

be made on how to best utilize the site. 

Understanding opportunities studied and realized by other similar sites demonstrates the 

potential for PV system development. For example, the City Solar project in Chicago, 

Illinois, is the largest urban PV system in the United States, and it is built on a 

contaminated site. The brownfield site is a former industrial site that had been vacant for 

30 years. The 41-acre site is owned by the City of Chicago, who leases the land to a solar 

developer. The City Solar project was completed in 2010 and uses a 10-MW single-axis 

tracking system.2

 

The Standard Chlorine of Delaware site has potential to be used for other functions 

beyond the solar PV systems proposed in this report. Any potential use should align with 

the community vision for the site and should work to enhance the overall utility of the 

property. It should be noted that there is potential to build wind turbines on the site as 

demonstrated by the wind turbine at the neighboring site to the south. 

 

2 “Exelon City Solar.” Exelon Corporation, 2013. Accessed July 2012: 

www.exeloncorp.com/PowerPlants/exeloncitysolar/Pages/Profile.aspx. 
4 

There are many compelling reasons to consider moving toward renewable energy sources 

for power generation instead of fossil fuels, including: 

• Renewable energy sources offer a sustainable energy option in the broader 

energy portfolio 

• Renewable energy can have a net positive effect on human health and the 

environment 

• Deployment of renewable energy bolsters national energy independence and 

increases domestic energy security

• Fluctuating electric costs can be mitigated by locking in electricity rates 

through long-term power purchase agreements (PPAs) linked to renewable 

energy systems 

• Generating energy without harmful emissions or waste products can be 

accomplished through renewable energy sources.
5 

3 PV Systems

3.1 PV Overview

Solar PV technology converts energy from solar radiation directly into electricity. Solar 

PV cells are the electricity-generating component of a solar energy system. When 

sunlight (photons) strikes a PV cell, an electric current is produced by stimulating 

electrons (negative charges) in a layer in the cell designed to give up electrons easily. The 

existing electric field in the solar cell pulls these electrons to another layer. By 

connecting the cell to an external load, this current (movement of charges) can then be 

used to power the load (e.g., light bulb). 

Figure 1. Generation of electricity from a PV cell

Source: EPA 

PV cells are assembled into a PV panel or module. PV modules are then connected to 

create an array. The modules are connected in series and then in parallel as needed to 

reach the specific voltage and current requirements for the array. The direct current (DC) 

electricity generated by the array is then converted by an inverter to useable alternating 

current (AC) that can be consumed by adjoining buildings and facilities, or exported to 

the electricity grid. PV system size varies from small residential (2–10 kW), to 

commercial (100–500 kW), to large utility scale (10+ MW). Central distribution plants 

are also currently being built in the 100+ MW scale. Electricity from utility-scale systems

is commonly sold back to the electricity grid.

(-)

(+)

-

- -

-

Electron

Current flow

-

Solar cell

- - -

Load
6 

3.2 Major System Components

Figure 2. Ground-mounted array diagram

Source: NREL

A typical PV system is made up of several key components, including: 

• PV modules 

• Inverter

• Balance-of-system (BOS) components. 

These, along with other PV system components, are discussed below. 

3.2.1 PV Module

Module technologies are differentiated by the type of PV material used, resulting in a 

range of conversion efficiencies from light energy to electrical energy. The module 

efficiency is a measure of the percentage of solar energy converted into electricity. 

Two common PV technologies that have been widely used for commercial- and utilityscale projects are crystalline silicon and thin film. 

3.2.1.1 Crystalline Silicon

Traditional solar cells are made from silicon. Silicon is quite abundant and nontoxic. It 

builds on a strong industry on both the supply (silicon industry) and product side. This 

technology has been demonstrated to be consistent and highly efficient for over 30 years 

in the field. The performance degradation, a reduction in power generation due to longterm exposure, is under 1% per year. Silicon modules have a lifespan in the range of 25-

30 years but can keep producing energy beyond this range. 
7 

Typical overall efficiency of silicon solar panels is between 12% and 18%. However, 

some manufacturers of mono-crystalline panels claim an overall efficiency nearing 20%. 

This range of efficiencies represents significant variation among the crystalline silicon 

technologies available. The technology is generally divided into mono- and multicrystalline technologies, which indicates the presence of grain-boundaries (i.e., multiple 

crystals) in the cell materials and is controlled by raw material selection and 

manufacturing technique. Crystalline silicon panels are widely used based on 

deployments worldwide. 

Figure 3 shows two examples of crystalline solar panels: mono- and multi-silicon 

installed on tracking mounting systems.

Figure 3. Mono- and multi-crystalline solar panels. Photos from (left) SunPower 

Corporation, NREL 23816 and (right) SunPower, NREL 13823

3.2.1.2 Thin Film

Thin-film PV cells are made from amorphous silicon (a-Si) or non-silicon materials, such 

as cadmium telluride (CdTe). Thin-film cells use layers of semiconductor materials only 

a few micrometers thick. Due to the unique nature of thin films, some thin-film cells are 

constructed into flexible modules, enabling such applications as solar energy covers for 

landfills, such as a geomembrane system. Other thin-film modules are assembled into 

rigid constructions that can be used in fixed tilt or, in some cases, tracking system 

configurations. 

The efficiency of thin-film solar cells is generally lower than for crystalline cells. Current 

overall efficiency of a thin-film panel is between 6% and 8% for a-Si and 11% and 12% 

for CdTe. Figure 4 shows thin-film solar panels.

Figure 4. Thin-film solar panels installed on (left) solar energy cover and (middle and right) 

fixed-tilt mounting system. Pictures from (left) Republic Services, Inc., 23817; (middle) 

Beck Energy, NREL 14726; and (right) U.S. Coast Guard Petaluma site, NREL 17395
8 

Industry standard warranties of both crystalline and thin-film PV panels typically 

guarantee system performance of 80% of the rated power output for 25 years. After 

25 years, they will continue producing electricity but at a lower performance level.

3.2.2 Inverter

Inverters convert DC electricity from the PV array into AC and can connect seamlessly to 

the electricity grid. Inverter efficiencies can be as high as 98.5%. 

Inverters also sense the utility power frequency and synchronize the PV-produced power 

to that frequency. When utility power is not present, the inverter will stop producing AC 

power to prevent “islanding,” or putting power into the grid while utility workers are 

trying to fix what they assume is a de-energized distribution system. This safety feature is 

built into all grid-connected inverters in the market. Electricity produced from the system 

may be fed to a step-up transformer to increase the voltage to match the grid. 

There are two primary types of inverters for grid-connected systems: string and microinverters. Each type has strengths and weaknesses and may be recommended for different 

types of installations.

String inverters are most common and typically range in size from 1.5–1,000 kW. These 

inverters tend to be cheaper on a capacity basis, as well as have high efficiency and lower 

operation and maintenance (O&M) costs. String inverters offer various sizes and 

capacities to handle a large range of voltage output. For larger systems, string inverters 

are combined in parallel to produce a single point of interconnection with the grid. 

Warranties typically run between 5 and 10 years, with 10 years being the current industry 

standard. On larger units, extended warranties up to 20 years are possible. Given that the 

expected life of PV panels is 25–30 years, an operator can expect to replace a string 

inverter at least one time during the life of the PV system. 

Micro-inverters are dedicated to the conversion of a single PV module’s power output. 

The AC output from each module is connected in parallel to create the array. This 

technology is relatively new to the market and in limited use in larger systems due to 

potential increase in O&M associated with significantly increasing the number of 

inverters in a given array. Current micro-inverters range in size between 175 W and 

380 W. These inverters can be the most expensive option per watt of capacity. Warranties 

range from 10 to 20 years. Small projects with irregular modules and shading issues 

typically benefit from micro-inverters. 

With string inverters, small amounts of shading on a solar panel will significantly affect 

the entire array production. Instead, it impacts only that shaded panel if micro-inverters 

are used. Figure 5 shows a string inverter.
9 

Figure 5. String inverter. Photo by Warren Gretz, NREL 07985

3.2.3 Balance-of-System Components

In addition to the solar modules and inverter, a solar PV system consists of other parts 

called BOS components, which include: 

• Mounting racks and hardware for the panels 

• Wiring for electrical connections. 

3.2.3.1 Mounting Systems

The array has to be secured and oriented optimally to maximize system output. The 

structure holding the modules is referred to as the mounting system. 

3.2.3.1.1 Ground-Mounted Systems

For ground-mounted systems, the mounting system can be either directly anchored into 

the ground (via driven piers or concrete footers) or ballasted on the surface without 

ground penetration. Mounting systems must withstand local wind loads, which range 

from 90–120 mph for most areas to 130 mph or more for areas with hurricane potential. 

Depending on the region, snow and ice loads must also be a design consideration for the 

mounting system. For brownfield applications, mounting system designs will be 

primarily driven by these considerations coupled with settlement concerns. 

Typical ground-mounted systems can be categorized as fixed tilt or tracking. Fixed-tilt 

mounting structures consist of panels installed at a set angle, typically based on site 

latitude and wind conditions, to increase exposure to solar radiation throughout the year. 

Fixed-tilt systems are used at many brownfield sites. Fixed-tilt systems have lower 

maintenance costs but generate less energy (kWh) per unit power (kW) of capacity than 

tracking systems. 

Tracking systems rotate the PV modules so they are following the sun as it moves across 

the sky. This increases energy output but also increases maintenance and equipment costs 

slightly. Single-axis tracking, in which PV is rotated on a single axis, can increase energy 

output up to 25% or more. With dual-axis tracking, PV is able to directly face the sun all 

day, potentially increasing output up to 35% or more. Depending on underlying soiling 

conditions, single- and dual-axis trackers may not be suitable due to potential settlement 

effects, which can interfere with the alignment requirements of such systems. 
10 

Table 1. Ground-Mounted Energy Density by Panel and System

System Type Fixed-Tilt Energy Density 

(DC-Watts/ft2

) 

Single-Axis Tracking 

Energy Density

(DC-Watts/ft2

) 

Crystalline Silicon 4.0 3.3

Thin Film 3.3 2.7

Hybrid High 

Efficiency

4.8 3.9

The selection of mounting type is dependent on many factors, including installation size, 

electricity rates, government incentives, land constraints, latitude, and local weather. 

Contaminated land applications may raise additional design considerations due to site 

conditions, including differential settlement. 

Selection of the mounting system is also heavily dependent on anchoring or foundation 

selection. The mounting system design will also need to meet applicable local building 

code requirements with respect to snow, wind, and seismic zones. Selection of mounting 

types should also consider frost protection needs especially in cold regions, such as 

New England. 

3.2.3.1.2 Roof-Mounted Systems

The Standard Chlorine of Delaware site could use the roof area of the treatment system 

building for PV. Installing PV on rooftops has many of the same considerations as 

installing ground-mounted PV systems. Factors, such as available area for an array, solar 

resource, shading, distance to transmission lines, and distance to major roads at the site, 

are just as important in roof-mounted systems as in ground-mounted systems. Rooftop 

systems can be ballasted or fixed to the roof, and it is recommended that the roof be 

relatively new (with 25 years or more useful life left) to avoid having to move the PV 

system in order to repair or replace the roof. 

There are currently no plans to build new construction buildings on the site. However, if 

the site does plan to construct buildings on the site, there are many relatively easy lowcost/no-cost measures that can be taken during the design phase so that the buildings are 

optimally built for rooftop PV systems. Design strategies, such as orienting the buildings 

so that the southern exposure is maximized and reducing the amount of mechanical 

equipment on the roof, are examples of measures that can be taken to optimize rooftop 

PV systems. A solar-ready design guide was published in order to help design teams 

optimize rooftop PV systems when designing buildings.3

 

 

3 Lisell, L.; Tetreault, T.; Watson, A. Solar Ready Buildings Planning Guide. NREL/TP-7A2-46078. 

Golden, CO: National Renewable Energy Laboratory, 2009. www.nrel.gov/docs/fy10osti/46078.pdf. 
11 

Table 2. Rooftop Energy Density by Panel

System Type Fixed-Tilt Energy Density 

(DC-Watts/ft2

) 

Crystalline Silicon 10.0 

Thin Film 4.3 

3.2.3.2 Wiring for Electrical Connections

Electrical connections, including wiring, disconnect switches, fuses, and breakers, are 

required to meet electrical code (e.g., NEC Article 690) for both safety and 

equipment protection. 

In most traditional applications, wiring from (1) the arrays to inverters and (2) inverters 

to point of interconnection is generally run as direct burial through trenches. In 

brownfield applications, this wiring may be required to run through above-ground 

conduit due to restrictions with cap penetration or other concerns. Therefore, developers 

should consider noting any such restrictions, if applicable, in requests for proposals in 

order to improve overall bid accuracy. Similarly, it is recommended that PV system 

vendors reflect these costs in the quote when costing out the overall system. 

3.2.3.3 PV System Monitoring 

Monitoring PV systems can be essential for reliable functioning and maximum yield of a 

system. It can be as simple as reading values, such as produced AC power, daily kilowatthours, and cumulative kilowatt-hours locally on an LCD display on the inverter. For 

more sophisticated monitoring and control purposes, environmental data, such as module 

temperature, ambient temperature, solar radiation, and wind speed, can be collected. 

Remote control and monitoring can be performed by various remote connections. 

Systems can send alerts and status messages to the control center or user. Data can be 

stored in the inverter’s memory or in external data loggers for further system analysis. 

Collection of this basic information is standard for solar systems and not unique to 

landfill applications.

Weather stations are typically installed in large-scale systems. Weather data, such as solar 

radiation and temperature, can be used to predict energy production, enabling comparison 

of the target and actual system output and performance and identification of underperforming arrays. Operators can also use this data to identify, for example, required 

maintenance, shade on panels, and accumulating dirt on panels. Monitoring system data 

can also be used for outreach and education. This can be achieved with publicly 

available, online displays, wall-mounted systems, or even smartphone applications. 

3.2.4 Operation and Maintenance

PV panels typically have a 25-year performance warranty. Inverters, which come 

standard with a 5-year or 10-year warranty (extended warranties available), would be 

expected to last 10–15 years. System performance should be verified on a vendorprovided website. Wire and rack connections should be checked annually. This economic 

analysis uses an annual O&M cost computed as $20/kW/yr, which is based on the 
12 

historical O&M costs of installed fixed-axis grid-tied PV systems. In addition, the system 

should expect a replacement of system inverters in year 15 at a cost of $0.25/W. 

3.3 Siting Considerations

PV modules are very sensitive to shading. When shaded (either partially or fully), the 

panel is unable to optimally collect the high-energy beam radiation from the sun. As 

explained above, PV modules are made up of many individual cells that all produce a 

small amount of current and voltage. These individual cells are connected in series to 

produce a larger current. If an individual cell is shaded, it acts as resistance to the whole 

series circuit, impeding current flow and dissipating power rather than producing it. 

The NREL solar assessment team uses a Solmetric SunEye solar path calculator to assess 

shading at particular locations by analyzing the sky view where solar panels will be 

located. By finding the solar access, the NREL team can determine if the area is 

appropriate for solar panels.

Following the successful collection of solar resource data using the Solmetric SunEye 

tool and determination that the site is adequate for a solar installation, an analysis to 

determine the ideal system size must be conducted. System size depends highly on the 

average energy use of the facilities on the site, PPAs, incentives available, and 

utility policy. 
13 

4 Proposed Installation Location Information

This section summarizes the findings of the NREL solar assessment site visit on

February 9, 2012. 

4.1 Standard Chlorine of Delaware Site PV System

As discussed in Section 1, the Standard Chlorine of Delaware site was previously owned 

by Metachem Products. Metachem Products declared bankruptcy in 2002, and DNREC

and EPA took over the remediation at the site. 

In order to get the most out of the ground and roof areas available, it is important to 

consider whether the layout can be improved to better incorporate a solar system. If there 

are unused structures that can be removed, the unshaded area can be increased to 

incorporate more PV panels. 

The Standard Chlorine of Delaware site is approximately 65 acres, and there is a high 

potential to build out the site with ground-mounted PV and some potential to build out 

the site with a roof-mounted PV system on the treatment system building. There are 

15.4 acres (670,800 ft2) potentially available for ground-mounted PV systems. The area 

available for roof-mounted PV on the treatment system building is 2,165 ft2

. While the 

entire area does not need to be developed at one time due to the feasibility of staging 

installation as area or funding becomes available, calculations for this analysis reflect the 

solar potential if the total feasible area is used. It should be noted that the purpose of this 

report is not to determine how to develop the site but to investigate both options and 

present the results in an unbiased manner. 

Figure 6 shows an aerial view of the potential areas for PV at the Standard Chlorine of 

Delaware site taken from Google Earth (the feasible area for ground-mounted PV is 

shaded in yellow and the feasible area for roof-mounted PV on the treatment system 

building is shaded in red). It should be noted that the area for a ground-mounted PV 

system assumes the final design for the cap is implemented, which includes filling and 

grading of the lagoon. As shown, there are large expanses of unshaded area, which makes 

it a suitable candidate for ground-mounted PV systems. Note that the site would need the 

multilayer cap to be installed before a PV system could be installed. 
14 

Figure 6. Aerial view of the feasible areas for PV at the Standard Chlorine of Delaware site

(ground-mounted PV in yellow and treatment system building with roof-mounted PV 

in red) 

Source: Illustration done in Google Earth

PV systems are well-suited to the Delaware City, Delaware, area, where the average 

global horizontal annual solar resource—the total solar radiation for a given location, 

including direct, diffuse, and ground-reflected radiation—is 4.63 kWh/m2/day. Figure 7

and Figure 8 show various views of the Standard Chlorine of Delaware site where PV 

could be feasible. 
15 

Figure 7. Views of the feasible area for ground-mounted PV at the Standard Chlorine of 

Delaware site (photos taken from the treatment system building). Photos by James

Salasovich, NREL
16 

Figure 8. Views of the feasible area for ground-mounted PV at the Standard Chlorine of 

Delaware site (photos taken from the temporary soil storage area). Photos by James

Salasovich, NREL

4.2 Utility-Resource Considerations

The closest electrical tie-in location is located 0.6 miles (3,250 feet) to the northeast off 

of Hamburg Corner River Road. Having a substation this close to the site makes it an 

ideal location for a PV system to tie into. A detailed interconnection study will have to be 

performed through Delmarva Power to determine the feasibility of utilizing the onsite 

substation as a tie-in point for a PV system. The site currently has one building using 

electricity (the treatment system building), and there is no new construction anticipated at 

the site. The treatment system building is a potential off-taker of the electricity produced 

by a PV system. 
17 

Figure 9. Location of the closest substation in relation to the Standard Chlorine of 

Delaware site

Source: Illustration done in Google Earth

4.3 Useable Acreage for PV System Installation 

Typically, a minimum of 2 useable acres is recommended to site commercial-scale PV 

systems. Useable acreage is typically characterized as "flat to gently sloping" southern 

exposures that are free from obstructions and get full sun for at least a 6-hour period each 

day. For example, eligible space for PV includes underutilized or unoccupied land, 

vacant lots, and/or unused paved area (e.g., a parking lot or industrial site space), as well 

as existing building rooftops. 

4.4 PV Site Solar Resource

The Standard Chlorine of Delaware site has been evaluated to determine the adequacy of 

the solar resource available using both onsite data and industry tools. 

The assessment team for this feasibility study collected multiple Solmetric SunEye data

points and found a solar access of 90% or higher. 

The predicted array performance was found using PVWatts Version 2 for Delaware City, 

Delaware. 4 Table 3 shows the station identification information, PV system 

specifications, and energy specifications for the site. For this summary, array 

performance information and a hypothetical system size of 1 kW was used to show the 

estimated production for each kilowatt so that additional analysis can be performed using 

the data indicated below. It is scaled linearly to match the proposed system size. 

 

4 For more information on NREL’s PVWatts Version 2, see www.nrel.gov/rredc/pvwatts/. 
18 

Table 3. Site Identification Information and Specifications

Station Identification

Cell ID 0266373

State Delaware

Latitude 39.8° N

Longitude 75.3° W

PV System Specifications

DC Rating 1.00 kW

DC to AC Derate Factor 0.8 

AC Rating 0.8 kW

Array Type Fixed Tilt 

Array Tilt 20°

Array Azimuth South

Energy Specifications

Cost of Electricity $0.18/kWh

Table 4 shows the performance results for a 20-degree fixed-tilt PV system in Delaware 

City, as calculated by PVWatts.

Table 4. Performance Results for 20-Degree Fixed-Tilt PV

Month Solar Radiation

(kWh/m2

/day)

AC Energy

(kWh)

Energy Value

($)

1 2.80 70 12.60

2 3.53 80 14.40

3 4.96 120 21.60

4 5.39 123 22.14

5 5.96 137 24.66

6 6.25 135 24.30

7 5.95 131 23.58

8 5.75 127 22.86

9 5.17 113 20.34

10 4.19 98 17.64

11 2.96 69 12.42

12 2.55 62 11.16

Year 4.63 1,265 227.70
19 

Table 5 shows the performance results for a 20-degree single-axis tracking PV system in 

Delaware City, as calculated by PVWatts. 

Table 5. Performance Results for 20-Degree Single-Axis PV

Month Solar Radiation

(kWh/m2

/day)

AC Energy

(kWh)

Energy Value

($)

1 3.43 89 16.02

2 4.28 99 17.82

3 6.21 153 27.54

4 6.67 155 27.90

5 7.36 171 30.78

6 7.82 171 30.78

7 7.47 167 30.06

8 7.14 159 28.62

9 6.40 142 25.56

10 5.25 125 22.50

11 3.56 85 15.30

12 3.06 76 13.68

Year 5.73 1,592 286.56

4.5 Standard Chlorine of Delaware Energy Usage

The Standard Chlorine of Delaware site currently has one building on the site that uses 

electricity, which is the treatment system building. The treatment system building is a 

potential off-taker of the electricity produced by a PV system. It is important to 

understand the energy use of the site to allow for a full analysis of whether or not energy 

produced would need to be sold or if it could offset onsite energy use.

4.5.1 Current Energy Use

The treatment system building is currently the only building on site that uses electricity. 

No detailed electricity usage or cost data was available for the site, but the staff 

associated with the site estimate the pump energy use to be 170,000 kWh/yr, which could 

be offset with a 130-kW PV system. 

4.5.2 Net Metering

Net metering is an electricity policy for consumers who own renewable energy facilities. 

In this context, "net" is used to mean "what remains after deductions"—in this case, the 

deduction of any energy outflows from metered energy inflows. Under net metering, a 

system owner receives retail credit for at least a portion of the electricity it generates. As 

part of the Energy Policy Act of 2005, under Sec. 1251, all public electric utilities are 

required upon request to make net metering available to their customers:
20 

(11) NET METERING.—Each electric utility shall make available upon 

request net metering service to any electric consumer that the electric 

utility serves. For purposes of this paragraph, the term ‘net metering 

service’ means service to an electric consumer under which electric energy 

generated by that electric consumer from an eligible on-site generating 

facility and delivered to the local distribution facilities may be used to 

offset electric energy provided by the electric utility to the electric 

consumer during the applicable billing period. 

Delaware’s net-metering law, which was significantly expanded in 2007, allows for 

various renewable energy technologies, addresses issues related to who owns the 

renewable energy certificates (RECs), and has a system capacity limit of 2 MW for nonresidential systems within Delmarva’s service territory. 

4.5.3 Virtual Net Metering

Some states and utilities allow for virtual net metering (VNM). This arrangement can 

allow certain entities, such as a local government, to install renewable generation of up to 

a 1-MW limit at one location within its geographic boundary and to generate credits that 

can be used to offset charges at one or more other locations within the same geographic 

boundary. Delaware is one of seven states (Delaware, California, Colorado, Connecticut, 

Massachusetts, New Jersey, and Pennsylvania) that currently allows for VNM. 
21 

5 Economics and Performance

The economic performance of a PV system installed on the site is evaluated using a 

combination of the assumptions and background information discussed previously, as 

well as a number of industry-specific inputs determined by other studies. In particular, 

this study uses the System Advisor Model (SAM).5 

SAM is a performance and economic model designed to facilitate decision making for 

people involved in the renewable energy industry, ranging from project managers and 

engineers to incentive program designers, technology developers, and researchers. 

SAM makes performance predictions for grid-connected solar, solar water heating, wind, 

and geothermal power systems and makes economic calculations for both projects that 

buy and sell power at retail rates and power projects that sell power through a PPA. 

SAM consists of a performance model and financial model. The performance model 

calculates a system's energy output on an hourly basis (sub-hourly simulations are 

available for some technologies). The financial model calculates annual project cash 

flows over a period of years for a range of financing structures for residential, 

commercial, and utility projects. 

The model calculates the cost of generating electricity based on information provided 

about a project's location, installation and operating costs, type of financing, applicable 

tax credits and incentives, and system specifications.

5.1 Assumptions and Input Data for Analysis

Cost of a PV system depends on the system size and other factors, such as geographic 

location, mounting structure, and type of PV module. Based on significant cost 

reductions seen in 2011, the average cost for utility-scale ground-mounted systems has 

declined from $4.80/W in the first quarter of 2010 to $2.79/W in the first quarter of 2012. 

With an increasing demand and supply, potential of further cost reduction is expected as 

market conditions evolve. 

For this analysis, the installed cost of the baseline fixed-tilt roof-mounted systems was 

assumed to be $2.79/W. This same cost was assumed for the fixed-axis ground-mounted 

systems. Single-axis tracking systems were assumed in this analysis to have a 20% 

increase over the fixed-axis system cost of $3.35/W. Single-axis tracking is only 

available for use on the ground. These costs represent remediation consideration cost case 

scenarios for PV installation price on EPA brownfields. Additional costs apply to systems 

built on landfills and land that require minimal disturbance. These systems use ballasting 

to minimize ground impact and increase the overall installation price of 20%. 

 

5 For additional information on the NREL System Advisor Model, see https://sam.nrel.gov/cost 
22 

Table 6. Installed System Cost Assumptions

System Type Fixed Tilt 

($/WDC) 

Single-Axis Tracking 

($/WDC) 

Baseline System 2.79 3.35

+20% Ballast +0.56 +0.67

Ballasted GroundMounted System3.49 4.02

This price includes the PV array and BOS components for each system, including the 

inverter and electrical equipment, as well as the installation cost. This includes an 

estimated national average labor rate but does not include land cost. The economics of 

grid-tied PV depend on incentives, the cost of electricity, the solar resource, and panel tilt 

and orientation. 

It was assumed for this analysis that relevant federal and state incentives are received for 

taxable entities, whom would be the owners of the system either through PPA or site 

leasing. It is important to consider all applicable incentives or grants to make PV as costeffective as possible. The full list of incentives used in this study can be found in Table 7. 

The net-metering program and the Delmarva power incentive were only applied to the 

roof system case. 

Table 7. Summary of Incentives Evaluated

Incentive Title Modeled Value Expected End 

Solar Renewable Energy Certificates

(SRECs) 

As of August 2012, 

approximately 

$189/MWh for 20 years N/A

Federal Investment Tax Credit 30% of total investment 2016

Net Metering

Net meter up to 2 MW

capacity N/A

Delmarva Power—Green Energy Program 

Incentives $1/W; less than $24,000 Annually funded

For the purpose of this analysis, the project is expected to have a 25-year life, although 

the systems can be reasonably expected to continue operation past this point. The panel 

coverage rate is the same for both ground and roof-mounted systems. The SAM modeling 

software downloaded a utility rate for the Delmarva Medium Commercial Schedule. The 

generation rate of $0.046/kWh and an estimated sale rate for electricity generated on site

of $0.02/kWh were used. A full list of standard assumptions can be found in Appendix A. 

5.2 SAM-Forecasted Economic Performance

Using varied inputs and the assumptions summarized in Section 5.1, the SAM tool 

predicts net present value (NPV) and PPA. Three scenarios were run for the Standard 

Chlorine of Delaware site. Two models represent filling the entire available space with 
23 

PV arrays; the third represents modeling roof coverage. There are multiple factors 

beyond NPV and PPA that go into choosing the best scenario(s); however, Table 8 shows 

the different options and their results. 

Table 8. Summary of SAM Results

The best economic case for the Standard Chlorine of Delaware site is to pursue a VNM

system, maximizing land space coverage with single-axis tracking modules and covering

the roof with fixed-axis panels. The reason for this economic favorability is the SRECs 

offered through the Delaware legislature and the VNM provision might allow the system 

to be used to offset the energy use of many different users. The SREC price currently 

offered, $0.189/kWh, accounts for more than 80% of the system revenue. The site has a 

favorable solar resource, and combined with progressive incentives, could produce a 

NPV of more than $850,000 over 25 years. With such reliance on incentives, however, 

the site should proceed cautiously and mitigate policy risk. If the site is unable to secure a 

community virtual provision, the site should pursue leasing the land to a local industry 

partner for a 2-MW net-metering system using single-axis tracking. Regardless of how 

the ground-mounted systems are used, the site should place flat panels on the roof of the 

pump house. 

5.2.1 Solar Investor vs. Site Owner 

The choice between going with a solar investor or PV system ownership will depend on 

the desire for involvement and the risk and tax appetite of the owner. While ownership of 
24 

the system will bring a higher payback for the owner, it will also require hiring the 

contractors to permit, install, and maintain the system. A solar investor inherits that risk 

and profit, and the Standard Chlorine of Delaware site owner in turn will receive lease 

payments from the PV system. The model assumes that an investor will proceed with the 

investment if they could attain a 15% internal rate of return (IRR) for the duration of the 

project. The recommendation of the feasibility team is to pursue a solar investor to lease 

the land to. 

5.2.2 Single-Axis Tracking vs. Fixed-Tilt Modules 

For the Standard Chlorine of Delaware site, there are two area types that could contain 

solar panels: roof and ground space. Fixed-axis panels will be the system used for 

covered roof space regardless of how the ground space is utilized. According to the 

simulations, single-axis tracking for the ground-mounted system will provide the best 

NPV for a slightly lower cost. Installation costs could vary from the model due to 

availability of installers and equipment and might change the scenario favorability. Under 

current assumptions, it is the recommendation of the feasibility study to pursue a singleaxis system for the ground-mounted portions of the Standard Chlorine of Delaware site.

The single-axis tracking system is able to gather a significantly greater portion of the 

sun’s energy, with fewer modules than a fixed-axis system. However, the same capacity 

system requires a larger footprint. The fixed-axis system gathers less solar energy but 

has no moving parts. The fixed-axis tracking system is also economically feasible but not 

as favorable as the single-axis panels. If the fixed-axis price were to drop to about $0.82 

below the single-axis price, the fixed-axis tracking system would become more favorable 

from a NPV basis. 

5.2.3 Policy Dependence of the System

The economics of this system are highly dependent on the SREC market. With the bestknown price point, a PV investment is highly favorable, but that price may not remain for 

the entirety of the project planning process or once the project is installed. The breakeven 

SREC price before none of the modeled systems are favorable is $160/MWh. A more 

thorough study should be conducted to determine a more accurate breakeven price and 

the overall risk of the PV investment. 

The entire results and summary of inputs to the SAM is available in Appendix B. 

5.3 Job Analysis and Impact

To evaluate employment and economic impacts of the PV project associated with this 

analysis, the NREL Jobs and Economic Development Impact (JEDI) models are used.6

JEDI estimates the economic impacts associated with the construction and operation of 

distributed-generation power plants. It is a flexible input-output tool that estimates, but 

does not precisely predict, the number of jobs and economic impacts that can be 

reasonably supported by the proposed facility. 

 

6

 The JEDI models have been used by the U.S. Department of Energy, the U.S. Department of Agriculture, 

NREL, and the Lawrence Berkeley National Laboratory, as well as a number of universities. For 

information on the NREL Jobs and Economic Development Impact tool, see 

www.nrel.gov/analysis/jedi/about_jedi.html.
25 

JEDI represents the entire economy, including cross-industry or cross-company impacts. 

For example, JEDI estimates the impact the installation of a distributed-generation 

facility would have on not only the manufacturers of PV modules and inverters but also 

the associated construction materials, metal fabrication industry, project management 

support, transportation, and other industries that are required to enable the procurement 

and installation of the complete system. 

For this analysis, inputs, including the estimated installed project cost ($/kW), targeted 

year of construction, system capacity (kW), O&M costs ($/kW), and location, were 

entered into the model to predict the jobs and economic impact. It is important to note 

that JEDI does not predict or incorporate any displacement of related economic activity 

or alternative jobs due to the implementation of the proposed project. As such, the JEDI 

results are considered gross estimates as opposed to net estimates. 

For the Standard Chlorine of Delaware site, the values in Table 9 were assumed from the 

single-axis ground net-metering system. 

Table 9. JEDI Analysis Assumptions

Input Assumed Value

Capacity 2,000 kW

Placed In Service Year 2013

Installed System Cost $8,592,000

Location New Castle, Delaware

Using these inputs, JEDI estimates the gross direct and indirect jobs, associated earnings, 

and total economic impact supported by the construction and continued operation of the 

proposed PV system. 

The estimates of jobs associated with this project are presented as either construction 

period jobs or sustained operations jobs. Each job is expressed as a whole, or fraction, 

full-time equivalent (FTE) position. An FTE is defined as 40 hours per week for one 

person for the duration of a year. Construction period jobs are considered short-term 

positions that exist only during the procurement and construction periods. 

As indicated in the results of the JEDI analysis provided in Appendix C, the total 

proposed system is estimated to support 61.1 direct and indirect jobs per year for the 

duration of the procurement and construction period. Total wages paid to workers during 

the construction period are estimated to be $2,992,200, and total economic output is 

estimated to be $7,453,300. The annual O&M of the new PV system is estimated to 

support 0.6 FTEs per year for the life of the system. The jobs and associated spending are 

projected to account for approximately $32,600 in earnings and $53,600 in economic 

activity each year for the next 25 years. 
26 

5.4 Financing Opportunities

The procurement, development, construction, and management of a successful utilityscale distributed-generation facility can be owned and financed a number of different 

ways. The most common ownership and financing structures are described below. 

5.4.1 Owner and Operator Financing

The owner/operator financing structure is characterized by a single entity with the 

financial strength to fund all of the solar project costs and, if a private entity, sufficient 

tax appetite to utilize all of the project’s tax benefits. Private owners/operators typically 

establish a special purpose entity (SPE) that solely owns the assets of the project. An 

initial equity investment into the SPE is funded by the private entity using existing funds, 

and all of the project’s cash flows and tax benefits are utilized by the entity. This equity 

investment is typically matched with debt financing for the majority of the project costs. 

Project debt is typically issued as a loan based on each owner’s/operator’s assets and 

equity in the project. In addition, private entities can utilize any of federal tax 

credits offered. 

For public entities that choose to finance, own, and operate a solar project, funding can be 

raised as part of a larger, general obligation bond; as a standalone tax credit bond; 

through a tax-exempt lease structure, bank financing, grant and incentive programs, or 

internal cash; or some combination of the above. Certain structures are more common 

than others, and grant programs for solar programs are on the decline. Regardless, as taxexempt entities, public entities are unable to benefit directly from the various tax-creditbased incentives available to private companies. This has given way to the now common 

use of third-party financing structures, such as the PPA. 

5.4.2 Third-Party Developers with Power Purchase Agreements

Because many project site hosts do not have the financial or technical capabilities to 

develop a capital intensive project, many times they turn to third-party developers (and/or 

their investors). In exchange for access to a site through a lease or easement arrangement, 

third-party developers will finance, develop, own, and operate solar projects utilizing 

their own expertise and sources of tax equity financing and debt capital. Once the system 

is installed, the third-party developer will sell the electricity to the site host, a local utility

[such as one subject to a renewable portfolio standard (RPS)], or a third party via a 

PPA—a contract to sell electricity at a negotiated rate over a fixed period of time. The 

PPA typically will be between the third-party developer and the site host if it is a retail 

“behind-the-meter” transaction or directly with an electric utility or other buyer if it is a 

wholesale transaction. 

Site hosts benefit by either (or both) receiving competitively priced electricity from the 

project via the PPA or land lease revenues via lease payments for making the site 

available to the solar developer. These lease payments can take on the form of either a 

revenue sharing agreement or an annual lease payment. In addition, third-party 

developers are able to utilize federal tax credits. For public entities, this arrangement 

allows them to utilize the benefits of the tax credits (low PPA price, higher lease 

payment) while not directly receiving them. The term of a PPA typically varies from 20–

25 years.
27 

5.4.3 Third-Party “Flip” Agreements Opportunities 

The most common use of the third-party financing model involves a site host working 

with a third-party developer who then partners with a tax-motivated investor in an SPE

that would own and operate the project. Initially, most of the equity provided to the SPE 

would come from the tax investor, and most of the benefit would flow to the tax investor 

(as much as 99%). When the tax investor has fully monetized the tax benefits and 

achieved an agreed-upon rate of return, the allocation of benefits and majority ownership 

(95%) would “flip” to the site host (but, in accordance with IRS regulations, not within 

the first 5 years). After the flip, the site host would have the option to buy out all or most 

of the tax investor’s interest in the project at the fair market value of the tax investor’s 

remaining interest. 

A flip agreement can also be signed between a developer and investors within an SPE, 

where the investor would begin with the majority ownership. Eventually, the ownership 

would flip to the developer once each investor’s return is met.

5.4.4 Hybrid Financial Structures

As the solar market evolves, hybrid financial solutions have been developed in certain 

instances to finance solar projects. A particular structure, nicknamed “The Morris Model” 

after Morris County, New Jersey, combines highly rated public debt, a capital lease, and a 

PPA. Low-interest public debt replaces more costly financing available to the solar 

developer and contributes to a very attractive PPA price for the site hosts. New markets 

tax credits have been combined with PPAs and public debt in other locations, such as 

Denver and Salt Lake City. 

5.4.5 Solar Services Agreement and Operating Lease

The solar services agreement (SSA) and operating lease business models have been 

predominately used in the municipal and cooperative utility markets due its treatment of 

tax benefits and the rules limiting federal tax benefit transfers from nonprofit to for-profit 

companies. Under IRS guidelines, municipalities cannot enter capital leases with forprofit entities when the for-profit entities capture tax incentives. As a result, a number of 

business models have emerged as a workaround to this issue. One model is the SSA,

wherein a private party sells “solar services” (i.e., energy and RECs) to a municipality 

over a specified contract period (typically long enough for the private party to accrue the 

tax credits). The nonprofit utility typically purchases the solar services with either a onetime up-front payment equal to the turn-key system cost minus the 30% federal tax credit 

or could purchase the services in annual installments. The municipality could buy out the 

system once the third party has accrued the tax credits, but due to IRS regulations, the 

buyout of the plant cannot be included as part of the SSA (i.e., the SSA cannot be used as 

a vehicle for a sale and must be a separate transaction).

Similar to the SSA, there are a variety of lease options that are available to municipalities 

that allow the capture of tax benefits by third-party owners, which result in a lower cost 

to the municipality. These include an operating lease for solar services (as opposed to an 

equipment capital lease) and a complex business model called a sale/leaseback. Under the 

sale/leaseback model, the municipality develops the project and sells it to a third-party 

tax equity investor who then leases the project back to the municipality under an 
28 

operating lease. At the end of the lease period, and after the tax benefits have been 

absorbed by the tax equity investor, the municipality may purchase the solar project at 

fair market value.

5.4.6 Sale/Leaseback

In the widely accepted sale/leaseback model, the public or private entity would install the 

PV system, sell it to a tax investor, and then lease it back. As the lessee, it would be 

responsible for operating and maintaining the solar system, as well as have the right to 

sell or use the power. In exchange for use of the solar system, the public or private entity 

would make lease payments to the tax investor (the lessor). The tax investor would have 

rights to federal tax benefits generated by the project and the lease payments. Sometimes 

the entity is allowed to buy back the project at 100% fair market value after the tax 

benefits are exhausted. 

5.4.7 Community Solar/Solar Gardens 

The concept of “community solar” is one in which the costs and benefits of one large 

solar project are shared by a number of participants. A site owner may be able to make 

the land available for a large solar project that can be the basis for a community solar 

project. Ownership structures for these projects vary, but the large projects are typically 

owned or sponsored by a local utility. Community solar gardens are distributed solar 

projects wherein utility customers have a stake via a prorated share of the project’s 

energy output. This business model is targeted to meet demand for solar projects by 

customers who rent/lease their homes or businesses, do not have good solar access at 

their site, or do not want to install solar system on their facilities. Customer prorated 

shares of solar projects are acquired through a long-term transferrable lease of one or 

more panels, or they subscribe to a share of the project in terms of a specific level of 

energy output or the energy output of a set amount of capacity. Under the customer lease 

option, the customer receives a billing credit for the number of kilowatt-hours their 

prorated share of the solar project produces each month; this is also known as VNM

(which must be permissible under the state’s net-metering regulations). Under the 

customer subscription option, the customers typically pay a set price for a block of solar 

energy (i.e., 100 kWh per-month blocks) from the community solar project. Other models 

include monthly energy outputs from a specific investment dollar amount or a specific 

number of panels. 

Community solar garden and customer subscription-based projects can be owned solely

by the utility, owned solely by third-party developers with facilitation of billing provided 

by the utility, or a joint venture between the utility and a third-party developer leading to 

eventual ownership by the utility after the tax benefits have been absorbed by the thirdparty developer. 

There are some states that offer solar incentives for community solar projects, including 

Washington State (production incentive) and Utah (state income tax credit). Community 

solar is also known as solar gardens depending on the location (e.g., Colorado). 
29 

6 Conclusions and Recommendations 

Investing or attracting investors in a large PV array is an economically viable option 

currently, but changes in SREC prices could make a PV system at the Standard Chlorine 

of Delaware site economically unviable. It is the suggestion of the feasibility study to 

lease the land to PV investors who would absorb the risk, as well as some of the 

economic benefit. 

Installing an economically feasible PV system on the Standard Chlorine of Delaware site 

could potentially generate 5,014,169 kWh annually. As summarized in Section 5, 

the SAM economic analysis predicts the best NPV and LCOE of $852,452 and less than 

$0.1449/kWh, respectively, for the 3,149 kW single-axis tracking case. In a solar 

investor/PPA case, the best possible PPA price is $0.0483/kWh. 

The economics for the potential PV systems at the Standard Chlorine of Delaware site 

depend primarily on the SREC market, and if the SREC price were to drop below 

$0.16/kWh, the system would likely not be economically feasible. A more thorough 

study is suggested before proceeding forward with the project. This next study should do 

the following: 

• Gauge the interest of local solar developers in developing the site 

• Discuss with the local utility interconnection issues and required studies 

• Solicit community input

• Better define and determine requirements for the VNM options for local users. 
30 

Appendix A. Assessment and Calculations 

Assumptions

Table A-1. Cost, System, and Other Assessment Assumptions

Cost Assumptions

Variable Quantity of 

Variable

Unit of Variable

Cost of Site Electricity ~0.05 $/kWh

Annual O&M (fixed) 25 $/kW/year

System Assumptions

System Type Annual energy 

kWh/kW

Installed Cost 

($/W)

Energy Density 

(W/sq. ft.)

Ground Fixed 1,265 $3.49 4.0

Ground Single Axis 1,592 $4.02 3.3

Rooftop Fixed 1,265 $2.93 4.0

Other Assumptions

Ground 

utilization

90% of available 

area
31 

Appendix B. Results from the Solar Advisor Model 

Figures B-1 through B-12 shows the graphs from the SAM models. 

Figure B-1. Modeled output for full coverage fixed-axis ground system
32 

Figure B-2. Modeled output for full coverage single-axis tracking PV system
33 

Figure B-3. Modeled output for 2-MW net-metering single-axis tracking PV system
34 

Figure B-4. Modeled output for 2-MW net-metering fixed-axis PV system
35 

Figure B-5. LCOE for owner purchase of full coverage fixed-axis system
36 

Figure B-6. After tax cash flow for owner purchase of full coverage fixed-axis system 
37 

Figure B-7. LCOE for 2-MW net-metering fixed-axis system 
38 

Figure B-8. After-tax cash flow for 2-MW net-metering fixed-axis system
39 

Figure B-9. LCOE for owner purchase of full coverage single-axis tracking PV system
40 

Figure B-10. After-tax cash flow for owner purchase of full coverage single-axis tracking 

PV system
41 

Figure B-11. LCOE for a 2-MW net-metering system single-axis tracking PV system
42 

Figure B-12. After-tax cash flow for 2-MW net-metering single-axis tracking PV system
43 

Appendix C. Results from the Job and Economic 

Development Impact Model

Tables C-1 through C-4 provide results from the JEDI model. 

Table C-1. Data Summary for JEDI Model Analysis of Single-Axis Tracking PV System

Project Location Delaware

Year of Construction or Installation 2013

Average System Size - DC Nameplate Capacity (kW) 2,000.0

Number of Systems Installed 1

Project Size - DC Nameplate Capacity (KW) 2,000.0

System Application Utility

Solar Cell/Module Material Crystalline Silicon

System Tracking Single Axis

Total System Base Cost ($/kWDC) $4,020 

Annual Direct Operations and Maintenance Cost ($/kW) $20.00

Money Value - Current or Constant (Dollar Year) 2012

Project Construction or Installation Cost $8,040,000

 Local Spending $4,343,995

Total Annual Operational Expenses $972,640

 Direct Operating and Maintenance Costs $40,000

 Local Spending $36,800

 Other Annual Costs $932,640

 Local Spending $0

 Debt Payments $0

 Property Taxes $0
44 

Table C-2. Summary of Local Economic Impacts for JEDI Model Analysis of Single-Axis 

Tracking PV System

Jobs Earnings Output

During construction and installation period $000 (2012) $000 (2012)

 Project Development and Onsite Labor Impacts

 Construction and Installation Labor 9.6 $623.5

 Construction and Installation Related Services 15.2 $761.3

 Subtotal 24.8 $1,384.9 $2,496.9

 Module and Supply Chain Impacts

 Manufacturing Impacts 0.0 $0.0 $0.0

 Trade (Wholesale and Retail) 2.9 $186.1 $524.1

 Finance, Insurance and Real Estate 0.0 $0.0 $0.0

 Professional Services 4.0 $200.9 $607.8

 Other Services 6.6 $597.1 $1,867.4

 Other Sectors 9.5 $69.5 $218.5

 Subtotal 22.9 $1,053.6 $3,217.9

 Induced Impacts 13.3 $553.8 $1,738.5

 Total Impacts 61.1 $2,992.2 $7,453.3

Annual Annual

Annual Earnings Output

During operating years Jobs $000 (2012) $000 (2012)

 Onsite Labor Impacts

 PV Project Labor Only 0.4 $22.3 $22.3

 Local Revenue and Supply Chain Impacts 0.1 $7.0 $21.0

 Induced Impacts 0.1 $3.3 $10.3

 Total Impacts 0.6 $32.6 $53.6

Notes: Earnings and Output values are thousands of dollars in year 2012 dollars. Construction and

operating period jobs are full-time equivalent for one year (1 FTE = 2,080 hours). Economic impacts "During 

operating years" represent impacts that occur from system/plant operations/expenditures. Totals may not 

add up due to independent rounding.
45 

Table C-3. Detailed Summary of Costs for JEDI Model Analysis of Single-Axis Tracking 

PV System

Delaware Purchased Manufactured

Installation Costs Cost Locally (%) Locally (Y or N)

Materials & Equipment

 Mounting (rails, clamps, fittings, etc.) $430,675 100% N

 Modules $2,750,843 100% N

 Electrical (wire, connectors, breakers, etc.) $105,386 100% N

 Inverter $409,100 100% N

 Subtotal $3,696,005

Labor

 Installation $623,544 100%

 Subtotal $623,544

Subtotal $4,319,549

Other Costs

 Permitting $43,862 100%

 Other Costs $969,353 100%

 Business Overhead $2,707,236 100%

 Subtotal $3,720,451

Subtotal $8,040,000

Sales Tax (Materials & Equipment Purchases) $0 100%

Total $8,040,000
46 

Table C-4. Annual O&M Costs for JEDI Model Analysis of Single-Axis Tracking PV System

Cost Local Share Manufactured 

Locally (Y or N)

Labor

 Technicians $24,000 100%

 Subtotal $24,000

Materials and Services

 Materials & Equipment $16,000 100% N

 Services $0 100%

 Subtotal $16,000

Sales Tax (Materials and Equipment Purchases) $0 100%

Average Annual Payment (Interest and Principal) $932,640 0%

Property Taxes $0 100%

Total $972,640

Other Parameters

Financial Parameters

Debt Financing

 Percentage Financed 80% 0%

 Years Financed (term) 10

 Interest Rate 10%

Tax Parameters

 Local Property Tax (Percent of Taxable Value) 0%

 Assessed Value (Percent of Construction Cost) 0%

 Taxable Value (Percent of Assessed Value) 0%

 Taxable Value $0

 Property Tax Exemption (Percent of Local Taxes) 0%

 Local Property Taxes $0 100%

 Local Sales Tax Rate 0.00% 100%

 Sales Tax Exemption (Percent of Local Taxes) 0%

Payroll Parameters Wage Per Hour Employer Payroll Overhead

 Construction and Installation Labor

 Construction Workers/Installers $21.39 45.6%

 O&M Labor

 Technicians $21.39 45.6%