Technical Report

NREL/TP-6A2-48853

September 2010

Feasibility Study of Economics 

and Performance of Solar 

Photovoltaics at the Former

St. Marks Refinery in St. Marks, 

Florida

A Study Prepared in Partnership with the 

Environmental Protection Agency for the 

RE-Powering America’s Lands Initiative: 

Siting Renewable Energy on Potentially 

Contaminated Land and Mine Sites

Lars Lisell and Gail Mosey
National Renewable Energy Laboratory

1617 Cole Boulevard, Golden, Colorado 80401-3393

303-275-3000 • www.nrel.gov

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

Office of Energy Efficiency and Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC

Contract No. DE-AC36-08-GO28308

Technical Report

NREL/TP-6A2-48853

September 2010

Feasibility Study of Economics 

and Performance of Solar 

Photovoltaics at the Former

St. Marks Refinery in St. Marks, 

Florida

A Study Prepared in Partnership with the 

Environmental Protection Agency for the 

RE-Powering America’s Lands Initiative: 

Siting Renewable Energy on Potentially 

Contaminated Land and Mine Sites

Lars Lisell and Gail Mosey

Prepared under Task No. WFD3.1000
NOTICE

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iii

Executive Summary

The City of St. Marks, Florida, received technical assistance from the National Renewable 

Energy Laboratory (NREL), under an interagency agreement funded by the Environmental 

Protection Agency (EPA) for a feasibility study to be conducted on a brownfield site located 

within the city limits. The purpose of this report is to assess the sites designated by the City of St. 

Marks for possible solar photovoltaic (PV) installation and estimate the cost, performance, and 

site impacts of three different PV options: crystalline silicon (fixed tilt), crystalline silicon 

(single-axis tracking), and thin film (fixed tilt). Each option represents a standalone system that 

can be sized to use an entire available site area. In addition, the report outlines financing options 

that could assist in the implementation of a system.

The City of St. Marks would like to explore the feasibility for installing ground-mounted PV. 

Two sites located at the former St. Marks Refinery were considered in this study, and both were 

found suitable to incorporate PV systems. The economics of the potential systems were analyzed 

using an electric rate of $0.08/kWh and incentives offered in the State of Florida and from the 

two accessible utilities, Progress Energy and the City of Tallahassee. Currently there are no 

incentives offered for commercial-size solar power systems in Wakulla County, Florida, or from 

the nearby utilities. The calculations reflect the solar potential if the total area is utilized from 

both of the sites that were visited. Table ES-1 summarizes the system performance and 

economics of a potential system that would use both available areas that were surveyed in St. 

Marks. Table ES-1 also summarizes job creation if the St. Marks location were used for PV.

Table ES-1. PV System Performance and Economics by System Typea

Annual Cost Savings 

($/year)

Payback 

Period

(years)

Array 

Tilt

(Deg)

PV 

System

Size 

(kW)

Annual 

Output 

(kWh/year)

Annual 

O&M 

($/year)

System Cost 

with 

Incentives 

($)

With 

Incentive

Jobs b

Created

Jobs c

Sustained

Crystalline Silicon (Fixed Tilt)

30.4 3,050 4,007,700 $25,925 $10,675,000 36 115 0.3

Crystalline Silicon (Single-axis Tracking)

0 2,450 3,770,550 $51,450 $10,290,000 41 111 0.6

Thin Film (Fixed Tilt)

30.4 1,200 1,576,800 $8,976 $3,696,000 32 40 0.1

a Data assume a maximum usable area of 804,942 ft2

. b Job-years created as a result of project capital investment including direct, indirect, and induced jobs. c Jobs (direct, indirect, and induced) sustained as a result of operations and maintenance (O&M) of the 

system.
iv

Table of Contents

List of Figures ............................................................................................................................................. v

List of Tables ............................................................................................................................................... v

1 Study Location...................................................................................................................................... 1

2 PV Systems ........................................................................................................................................... 2

2.1 Types of PV Systems...........................................................................................................3

2.2 PV System Components ......................................................................................................4

2.3 PV Size and Performance ....................................................................................................5

3 PV Site Locations ................................................................................................................................. 7

3.1 St. Marks Refinery...............................................................................................................7

3.2 Recently Closed North Site................................................................................................14

3.3 Summary of All Sites.........................................................................................................16

4 Economics and Performance............................................................................................................ 17

4.1 Assumptions and Input Data for Analysis.........................................................................17

4.2 Incentives and Financing Opportunities............................................................................18

4.3 Job Creation .......................................................................................................................18

5 Conclusions and Recommendations ............................................................................................... 20

Appendix A. Assumptions for Calculations........................................................................................... 21

Appendix B. Renewable Energy Incentives ........................................................................................... 25
v

List of Figures

Figure 1. Major components of a grid-connected PV system..........................................................2

Figure 2. Submerged east portion of the site ...................................................................................7

Figure 3. Large storage tanks...........................................................................................................8

Figure 4. Potential electrical connection points...............................................................................9

Figure 5. St. Marks Refinery recommended PV system placement ..............................................10

Figure 6. Solar measurement on the west border...........................................................................11

Figure 7. Solar measurement on the north border..........................................................................12

Figure 8. Partial site recommended PV system placement............................................................14

Figure 9. Recommended PV system placement on recently closed north site .............................15

Figure 10. PV Costs.......................................................................................................................17

Figure A-1. Elevation of the site....................................................................................................24

List of Tables

Table 1. Energy Density by Panel and System................................................................................3

Table 2. Entire Site PV System Options........................................................................................13

Table 3. Partial Site PV System Options.......................................................................................14

Table 4. Recently Closed North Site System Options...................................................................16

Table 5. St. Marks, Florida, Site Summary....................................................................................16

Table 6. Estimated Job Creation by PV System Type ...................................................................19

Table A-1. Total Site Usage Scenario............................................................................................21

Table A-2. Cost and System Assumptions ....................................................................................22

Table A-3. Partially Drained Site Scenario....................................................................................23

Table B-1. Brownfield Redevelopment and Renewable Energy Incentives and Financing Tools25

Table B-2. Renewable Energy Development Incentives and Financing Tools Applicable to PV 25

Table B-3. State Rebates for Commercial-Sector PV Projects......................................................26

Table B-4. State Tax Credits for Commercial-sector PV Projects ................................................31

Table B-5. U.S. Department of Energy Brightfields Program Grants...........................................38
1

1 Study Location

The City of St. Marks, Florida, is the former site of the St. Marks Refinery, which specialized in 

manufacturing and refining crude oil into jet fuel and asphalt. The facility closed in 2001, 

leaving the site vacant and contaminated. The remediation of the site started in 2004 with the 

removal of all infrastructure except for 10 above-ground storage tanks. It is anticipated that four

of the tanks will be removed this spring, leaving six tanks that will need to be removed upon the 

implementation of a redevelopment plan. After the removal of infrastructure, the site was 

cleaned using in-situ and ex-situ methods, leaving the site available for commercial or industrial 

redevelopment with strict ground disturbance restrictions. At this time, no more remediation is 

planned for the site. The site is located on the main road into St. Marks near the river. The site 

has electrical service to the buildings and to the storage tanks. The site has been designated as a 

brownfield site by the Environmental Protection Agency (EPA). The property was recently 

turned over to the city of St. Marks at no cost by the St. Marks Refinery. The site is discussed in 

Section 3 of the report. An additional site, the “Recently Closed North Site,” was included in the 

analysis due to the possibility that the site would become vacant in the near future. This site is a 

good candidate for other redevelopment but was included in the analysis due to the proximity to 

the main site. 
2

2 PV Systems

Solar photovoltaics (PV) are semiconductor devices that convert sunlight directly into electricity. 

They do so without any moving parts and without generating any noise or pollution. They must 

be mounted in an unshaded location; rooftops, carports, and ground-mounted arrays are common 

mounting locations. PV systems work very well in St. Marks, Florida, where the average global 

horizontal annual solar resource is between 4.1–6.15 kWh/m2/day. This number, however, is not 

the amount of energy that can be produced by a PV panel. The amount of energy produced by a

panel depends on several factors. These factors include the type of collector, the tilt and azimuth 

of the collector, the temperature, and the level of sunlight and weather conditions. An inverter is 

required to convert the direct current (DC) to alternating current (AC) of the desired voltage 

compatible with building and utility power systems. The balance of the system consists of 

conductors/conduit, switches, disconnects, and fuses. Grid-connected PV systems feed power 

into the facility’s electrical system and do not include batteries. 

Figure 1 shows the major components of a grid-connected PV system and illustrates how these 

components are interconnected.

Figure 1. Major components of a grid-connected PV system

Credit: NREL

PV panels 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. PV panels are 

very sensitive to shading. When shade falls on a panel, that portion of the panel is no longer able 

to collect the high-energy beam radiation from the sun. If an individual cell is shaded, it will act 

as a resistance to the whole series circuit, impeding current flow and dissipating power rather 

than producing it. By determining solar access—the unimpeded ability of sunlight to reach a 

solar collector—one can determine whether an area is appropriate for solar panels.
3

For this assessment, the National Renewable Energy Laboratory (NREL) team used a 

SolmetricTM solar path calculator to assess shading at a particular location by analyzing the sky 

view where the solar panel will be located. If a site is found to have good potential for a PV 

system, then the next step is to determine the size of that system, which highly depends on the 

average energy use of the on-site facilities. Providing more power than a site would use is 

generally not advisable due to the economics of most net-metering agreements. In the case of 

the assessed sites, all of the electricity generated at the sites would be sold to one of the nearby

utilities because there is no electrical load. The system size would thus be determined by the 

amount of electricity the electric company would be willing to purchase or by how much land 

area is available. For the purposes of this report, the NREL assessment team assumed that the 

utilities would purchase any electricity that the site can generate. The systems will be broken 

down by site so the system size can be adjusted based on what the utility requests.

2.1 Types of PV Systems

Ground-mounted Systems 

On a $/DC-Watt basis, ground-mounted PV systems are usually the lowest cost option to install. 

Several PV panel and mounting options are available, each having different benefits for different 

ground conditions. Table 1 outlines the energy density values that can be expected from each

type of system. 

Table 1. Energy Density by Panel and System

System Type Fixed-tilt Energy Density

(DC-Watts/ft

2

)

Single-axis Tracking 

Energy Density

(DC-Watts/ft

2

)

Crystalline Silicon 4.0 3.3

Thin Film 1.7 1.4

Hybrid HE* 4.8 3.9

* Because hybrid high efficiency (HE) panels do not represent a significant portion of 

the commercial market, they were not included in the analysis. Installing panel types 

that do not hold a significant portion of the commercial market would not be feasible for 

a large-scale solar generation plant.

For the purposes of this analysis, all fixed-tilt systems were assumed to be mounted at latitude

with a tilt of 30.4 degrees. To get the most out of the available ground area, considering whether 

the site layout can be improved to better incorporate a solar system is important. If unused 

structures, fences, or electrical poles can be removed, the unshaded area can be increased to 

incorporate more PV panels. When considering a ground-mounted system, an electrical tie-in

location should be identified to determine how the energy will be fed back into the grid. For this 

report, only fixed-tilt ground-mounted systems and single-axis tracking systems were considered. 

Fixed-tilt systems are installed at a specified tilt and are fixed at that tilt for the life of the system. 

Single-axis tracking systems have a fixed tilt on one axis and a variable tilt on the other axis. 

The system is designed to follow the sun in its path through the sky. This allows the solar 

radiation to strike the panel at an optimum angle for a larger part of the day than can be achieved 

with a fixed-tilt system. A single-axis tracking system can collect nearly 30% more electricity 
4

per capacity than can a fixed-tilt tracking system. The drawbacks include increased operation 

and maintenance (O&M) costs, less capacity per unit area (DC-Watt/ft2

), and greater installed 

cost ($/DC-Watt). 

Roof-mounted Systems

In many cases, a roof is the best location for a PV system. Roof-mounted PV systems are 

usually more expensive than ground-mounted systems, but a roof is a convenient location 

because it is out of the way and usually unshaded. Large areas with minimal rooftop equipment 

are preferred, but equipment can sometimes be worked around if necessary. If a building has a 

sloped roof, a typical flush-mounted crystalline silicon panel can achieve power densities on the 

order of 11 DC-Watt/ft2. For buildings with flat roofs, rack-mounted systems can achieve power 

densities on the order of 8 DC-Watt/ft2 with a crystalline silicon panel. 

Typically, PV systems are installed on roofs that either are less than five years old or have over 

30 years left before replacement. Because no roof area is available on the sites studied, no roofmounted analysis was conducted.

2.2 PV System Components

The PV system considered here has these components:

• PV arrays, which convert light energy to DC electricity

• Inverters, which convert DC to AC and provide important safety, monitoring, and 

control functions

• Various wiring, mounting hardware, and combiner boxes

• Monitoring equipment

PV Array

The primary component of a PV system, the PV array, converts sunlight to electrical energy; all 

other components simply condition or control energy use. Most PV arrays consist of 

interconnected PV modules that range in size from 50 peak DC-Watts to 300 peak DC-Watts. 

Peak watts are the rated output of PV modules at standard operating conditions of 25°C (77°F) 

and insolation of 1,000 watts/m2. Because these standard operating conditions are nearly ideal, 

the actual output will be less under typical environmental conditions. PV modules are the most 

reliable components in any PV system. They have been engineered to withstand extreme 

temperatures, severe winds, and impacts. ASTM E1038-051

 

1 ASTM International. “E1038-05 Standard Test Method for Determining Resistance of Photovoltaic Modules to 

Hail by Impact with Propelled Ice Balls," West Conshohocken, PA, 2005, DOI: 10.1520/E1038-05. 

subjects modules to impacts from 

one-inch hail balls at terminal velocity (55 mph) at various parts of the module. PV modules 

have a life expectancy of 20–30 years, and manufacturers warranty them against excessive power 

degradation for 25 years. The array is usually the most expensive component of a PV system; it 

http://www.astm.org/Standards/E1038.htm. Accessed August 2010.
5

accounts for approximately two-thirds of the cost of a grid-connected system. A large choice of 

PV manufacturers is available.2

Inverters

PV arrays provide DC power at a voltage that depends on the configuration of the array. This 

power is converted to AC at the required voltage and number of phases by the inverter. Inverters 

enable the operation of commonly used equipment such as appliances, computers, office 

equipment, and motors. Current inverter technology provides true sine wave power at a quality 

often better than that of the serving utility. The locations of both the inverter and the balance of 

the system equipment are important. Inverters are available that include most or all of the 

control systems required for operation, including some metering and data-logging capability. 

Inverters must provide several operational and safety functions for interconnection with the 

utility system. The Institute of Electrical and Electronic Engineers, Inc. (IEEE) maintains 

standard “P929 Recommended Practice for Utility Interface of Photovoltaic (PV) Systems,”3

which allows manufacturers to write “Utility-Interactive” on the listing label if an inverter meets 

the requirements of frequency and voltage limits, power quality, and non-islanding inverter 

testing. Underwriters Laboratory maintains “UL Standard 1741, Standard for Static Inverters 

and Charge Controllers for Use in Photovoltaic Power Systems,”4 which incorporates the testing 

required by IEEE 929 and includes design (type) testing and production testing. A large choice 

of inverter manufacturers is available.

5

Operation and Maintenance (O&M) 

The PV panels come with a 25-year performance warranty. The inverters, which come standard 

with a 5- or 10-year warranty (extended warranties available), would be expected to last 10–15 

years. System performance should be verified on a vendor-provided Web site. Wire and rack 

connections should be checked. For this economic analysis, an annual O&M cost of 0.17% of 

the total installed cost is used based on O&M costs of other fixed-tilt grid-tied PV systems. For 

the case of single-axis tracking, an annual O&M cost of 0.35% of the total installed cost is used 

based on O&M costs of existing single-axis tracking systems. 

2.3 PV Size and Performance

The PV arrays must be installed in unshaded locations on the ground or on building roofs that 

have an expected life of at least 25 years. The predicted array performance was found using 

PVWATTS, a performance calculator for grid-connected PV systems created by NREL’s 

Renewable Resource Data Center.6

 

2 Go Solar California, a joint effort of the California Energy Commission and the California Public Utilities 

Commission, provides consumer information for solar energy systems. See 

The performance data was used to calculate the amount of 

http://www.gosolarcalifornia.org/

equipment/pvmodule.php. 3 IEEE. “ANSI/IEEE Std 929-1988 IEEE Recommended Practice for Utility Interface of Residential and 

Intermediate Photovoltaic (PV) Systems–Description.” 

http://standards.ieee.org/reading/ieee/std_public/description/powergen/929-1988_desc.html. Accessed July 2010. 4 UL 1741. “Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed 

Energy Resources.” http://ulstandardsinfonet.ul.com/scopes/1741.html. Accessed July 2010. 5 Go Solar California approves inverters. 6 PVWatts. http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/. Accessed July 2010.
6

revenue that could be expected each year. The project economics were based on this analysis,

and the calculations can be found in Appendix A. 
7

3 PV Site Locations 

This section summarizes the findings of the NREL solar assessment site visit on January 28, 

2010. 

3.1 St. Marks Refinery

This site is environmentally contaminated and, according to the onsite staff, cannot be used again 

for any sort of residential development. There is the potential for industrial redevelopment, 

however, on parts of the site. The site has had extensive remediation resulting in a partial cap 

and water containment infrastructure. The site is a total of 55 acres, with the useful solar area a 

total of 17 acres, calculated by taking measurements of the site using Google Earth. There is a 

significant portion of the site that is covered in forest and wetland. In order for the full 17 acres 

to be usable, the eastern half of the site would need to be drained. At the time of the site visit 

there was water approximately 4 feet deep on the east end of the site. If none of the water from 

the site can be drained, only 50% of the 17 acres would be acceptable for a solar array, leaving 

only 8.5 acres available. See Figure 2 for an image of the submerged area. The State of Florida 

is currently unwilling to do any additional remediation on the site, but the site staff is 

investigating the feasibility of releasing the water. The water level on the site is controlled by a 

gate on the eastern berm, but the water cannot be lowered without proper authorization. 

Figure 2. Submerged east portion of the site

Credit: Lars Lisell, NREL

There is currently some remaining manufacturing infrastructure on the site in the form of large 

chemical storage tanks and truck-filling stations. See Figure 3 for an image of the remaining 

infrastructure. 
8

Figure 3. Large storage tanks

Credit: Lars Lisell, NREL

The site has plans to remove the four westernmost tanks and the filling stations during the 

summer of 2010. The remaining tanks will need to be removed as part of the implementation of 

the solar system. The buildings on the western side of the site are not included in the site area. 

The site has excellent sky exposure, with the only shading coming from the forested area on the 

east, some shading from the buildings on the west, and some shading in the northern areas due to 

the forest and the jagged property line. The site was well kept and mowed at the time of the site 

visit. The forest on the north and west sides is a mature forest with trees in the range of 50–70

feet tall. The site has electrical tie-ins at the building site on the west side of the site and also in 

the southwest corner of the site where the large storage tanks were connected to the grid. The 

connections in the southwest corner were high voltage connections that were formerly used for 

industrial equipment. Across the road from the site is a power plant that would possibly accept 

the power from the system. See Figure 4 for two of the possible electrical connection points. 
9

Figure 4. Potential electrical connection points

Credit: Lars Lisell, NREL

This site needs to have a ballast-mounted system implemented on a portion of the site due to the 

cap that was installed during the remediation of the site. A ballast-mounted system is preferred 

in order to avoid any ground penetrations. Ballasted systems are placed on top of the ground and 

held in place by adding weight to the mounting frame. This is different than traditional 

mounting systems which require anchors to be put in the ground, potentially disturbing the cap. 

Some uncapped portions of the site would not require ballasted mounts. According to a site map 

that identifies the capped areas, 1.7 acres of the site would require ballasted mounts. This site 

map can be found in the Calculation Appendices in Figure A-1. This represents approximately 

10% of the total available area. 
10

*Proposed system location is shaded in blue in the figure.

Figure 5. St. Marks Refinery recommended PV system placement 

Credit: Google Earth

Solar Access Measurements

The PV system placement and area calculation are based on solar access measurements that were 

taken on the site. This was accomplished by taking solar measurements around the perimeter of 

the site to determine if there were any obstructions that would shade out any portions of the site. 

The portions of the site that were found to be shaded for a significant portion of the year were 

eliminated from the usable site area. Two of the measurements are located in Figure 6 and 

Figure 7.
11

Figure 6. Solar measurement on the west border
12

Figure 7. Solar measurement on the north border

Entire Site Options

Options for different system types that utilize the entire site are listed in Table 2 and assume that 

all of the water on the site will be drained. The three lines listed in the table are three different 

styles of solar systems that have different characteristics. Each of the lines is a standalone 

system that is sized to utilize the entire available site area. The site staff is in the process of 

having the water on the site tested to determine contamination levels. If the test results show that 

the water can be drained from the site, the majority of the site will have the potential to be used 

for a PV system. There is a water level adjustment gate in the northwest corner of the site that 

could be used to lower the water level. According to Florida state law, utilities are required to 

allow interconnection to their electrical grid for systems 2 MW and below. The total system size 

for the fixed-tilt crystalline silicon system that would utilize all available area at the St. Marks 

Refinery site may exceed this limit. This would require the utility to agree to exceed the 2 MW 

interconnection limit. In order to gain this approval, it would be beneficial to begin conversations 

with the utility early. 
13

Once the shaded areas were removed from consideration, it was assumed that 90% of the 

remaining area would be usable for a PV system. This results in remaining usable area of 

667,400 ft2 (15.3 acres).

Table 2. Entire Site PV System Options

System Type 

Potential 

System Size 

(kW)

Annual Energy 

Output (kWh)

Annual Cost 

Savings ($)

Annual 

O&M ($)

System 

Cost ($)

Crystalline Silicon—

Fixed Tilt

2,500 3,285,000 262,800 30,600 8,650,000

Crystalline Silicon—

Single-axis Tracking

2,000 3,078,000 246,240 63,000 8,300,000 

Thin Film 1,000 1,314,000 105,120 11,220 2,980,000

Partial Site Options

Draining all the water on the site may not be possible, but draining a portion of the water may be 

an option. If the water level cannot be drained completely, it would be beneficial to lower the 

water level slightly, which would allow several acres on the west end of the containment pond to 

become dry and suitable for solar installation. This would still allow for a holding pond on the 

far east side of the site. This configuration could allow for the objectives of the PV system to be 

satisfied while at the same time making sure that contaminated water does not enter the St. 

Marks river. Figure 8 shows the area assuming partial water drainage, which would increase the 

usable area to 13 acres. 
14

*Proposed system location is shaded in blue in the figure.

Figure 8. Partial site recommended PV system placement

Credit: Google Earth

See Table 3 for a summary of the different system types that could be implemented using the 

partially drained site. 

Table 3. Partial Site PV System Options

System Type 

Potential 

System Size 

(kW)

Annual Energy 

Output (kWh)

Annual Cost 

Savings ($)

Annual 

O&M ($)

System 

Cost ($)

Crystalline Silicon—

Fixed Tilt

2,000 2,628,000 210,240 17,000 7,000,000

Crystalline Silicon—

Single-axis Tracking

1,500 2,308,500 184,680 31,500 6,300,000

Thin Film 800 1,051,200 84,096 5,984 2,464,000

3.2 Recently Closed North Site

There is another site just north of the St. Marks Refinery site that will potentially be turned over 

to the City of St. Marks in the near future. This site has a significant amount of infrastructure 

currently on the site that is spaced out evenly across the site. Without the removal of this 
15

infrastructure, there is very little space available for a solar array. The site is surrounded by 

forest that ranges from 50–100 feet tall that shades a large strip of land around the edge of the 

site. The storage tanks in the middle of the site are also tall, shading out a large portion of the 

center of the site. The only unshaded area on the site is in the northwest corner. The onsite staff 

said that this site is not heavily contaminated and could potentially be redeveloped. Business 

redevelopment would be preferable over developing the site for a solar array, given the extensive 

infrastructure removal that would need to take place in order to prepare the site for solar. If all 

infrastructure was removed from the site, there would be 3.5 acres available for a solar array. 

This excludes the areas along the perimeter of the site that would be shaded by the surrounding 

forest. There is a potential electrical connection near the middle of the site, allowing for a 

convenient electrical tie-in. 

*Proposed system location is shaded in blue in the figure.

Figure 9. Recommended PV system placement on recently closed north site 

Credit: Google Earth

Once the shaded areas were removed from consideration, it was assumed that 90% of the 

remaining area would be usable for a PV system. This results in a remaining usable area of

137,565 ft2 (3.2 acres).
16

Table 4. Recently Closed North Site System Options

System Type 

Potential System 

Size (kW)

Annual Energy 

Output (kWh)

Annual Cost 

Savings ($)

Annual 

O&M ($)

System 

Cost ($)

Crystalline Silicon—

Fixed Tilt

550 722,700 57,816 4,675 1,925,000 

Crystalline Silicon—

Single-axis Tracking

450 692,550 55,404 9,450 1,890,000 

Thin Film 200 262,800 21,024 1,496 616,000 

3.3 Summary of All Sites

Both sites that were visited were found suitable to incorporate PV systems. The economics of 

the potential systems were analyzed using an electric rate of $0.08/kWh and the 30% federal 

investment tax credit (ITC). Incentives that are offered in the State of Florida and from the two 

accessible utilities, Progress Energy and the City of Tallahassee, were also investigated. 

Currently there are no incentives offered for commercial-size solar power systems in Wakulla 

County, Florida, or from the nearby utilities. The only incentive that could potentially be 

captured is the 30% federal ITC. The calculations reflect the solar potential if the total area is 

utilized from both of the sites that were visited. The results are summarized in Table 5. 

Table 5. St. Marks, Florida, Site Summarya

Array Tilt 

(Deg)

PV System 

Size (kW)

Annual 

Output 

(kWh/year)

Annual Cost 

Savings 

($/year)

Annual 

O&M 

($/year)

System 

Cost with 

Incentives 

($)

Payback 

Period with 

Incentive 

(years)

Crystalline Silicon (Fixed Tilt)

30.4 3,050 4,007,700 $320,616 $25,925 $10,575,000 36

Crystalline Silicon (Single-axis Tracking)

0 2,450 3,770,550 $301,644 $51,450 $10,190,000 41

Thin Film (Fixed Tilt)

30.4 1,200 1,576,800 $126,144 $8,976 $3,696,000 32

a Data assume a maximum usable area of 804,942 ft2

.
17

4 Economics and Performance

4.1 Assumptions and Input Data for Analysis

For this analysis, the following input data were used. It is assumed that the installed cost of 

fixed-tilt roof-mounted systems will be $6/W, and fixed-tilt ground-mounted systems will be 

$5/W. These prices include the PV array and the balance of system components for each system, 

including the inverter, electrical equipment, and installation. The economics of grid-tied PV 

depend on incentives, the cost of electricity, and the solar resource including panel tilt and 

orientation. For this analysis, it was assumed that the cost of electricity was $0.08/kWh. 

A system DC to AC conversion of 77% was assumed. This includes losses in the inverter, wire 

losses, PV module losses, and losses due to temperature effects. Figure 10 summarizes average 

system installation costs for grid-tied U.S. PV systems in 2008; however, the costs have dropped 

significantly since 2008. PVWATTS was used to calculate energy performance.

Figure 10. PV Costs7

It is assumed for this analysis that federal incentives are received. It is important to find state 

incentives or grants to make PV cost effective. A private, tax-paying entity that owns PV 

systems can qualify for a 30% federal business energy investment tax credit (ITC) and 

accelerated depreciation on the PV system, which are worth about 15%. The total potential tax 

benefits to the tax-paying entity are about 45% of the system cost. Because the city government 

does not pay taxes, private ownership of the PV system would be required to capture tax 

incentives. 

 

7 Wiser, R.; Barbose, G. ; Peterman, C. ; Darghouth, N. Tracking the Sun II. Environmental Energy Technology 

Division. Berkeley, CA : Lawrence Berkeley National Laboratory, 2009.
18

4.2 Incentives and Financing Opportunities

The Database for State Incentives for Renewable Energy (DSIRE) provides a summary of net 

metering, interconnection rules, and incentives available to Florida utility customers8

Renewable energy systems, including commercial solar PV, are subject to interconnection rules 

promulgated at the state level. In Florida, the limit is currently set at 2 MW, but this may be 

negotiable, depending on how flexible the utility is. The utility would need to be contacted 

directly to determine what they are willing to do. Florida does not currently have a statewide 

Renewable Portfolio Standard (RPS). 

. The power 

from this system could be sold to either Progress Energy or the City of Tallahassee. 

There are currently no incentives offered by Wakulla County, Florida, or by the nearby utilities. 

Incentives greatly affect the economics of a system, and the current lack of incentives in Florida

will have a large impact on the feasibility of a system at this site. The federal incentive can be 

captured if the system is owned by a tax-paying entity. 

The system facilitator could potentially pursue an agreement with either the City of Tallahassee 

or Progress Energy that would negotiate a higher price for the electricity produced by the 

potential system. Any power that is produced by a solar PV system would be a great opportunity 

for utilities to get a jump on diversifying their energy mix with clean energy. It has been 

demonstrated across the country that people are willing to pay a premium for certified clean 

energy9

There are a couple of options for getting a solar PV system financed. At a site like St. Marks, 

when the land has been turned over to the city, securing financing is one of the most important 

parts of the process. A typical financing option is third party ownership; however, this type of 

agreement is prohibited in the State of Florida. Florida law specifically states that the entity that 

owns the system must use the power. This eliminates most of the options for a commercial size 

PV system. In order for the system to feed power to the power company, the power company 

needs to be the owner of the system. In this configuration, the land that the solar system is on 

would need to be leased to the utility for the duration of the system life. The city would retain 

the ownership of the land and lease it to the power company while the power company owns the 

system. Another option is to attract a business to the site in order to use the power that is 

generated on site. This would require the business to own the system, and there may be

difficulties trying to set up this sort of configuration. 

, and the utilities could potentially start a pilot program with energy from this site. 

4.3 Job Creation

The implementation of this project would represent a large amount of money entering the clean 

energy industry of the United States. The Council of Economic Advisors (CEA) calculated the 

number of jobs created due to federal spending using economic models developed with real 

 

8 DSIRE. http://www.dsireusa.org/incentives/index.cfm?re=1&ee=1&spv=0&st=0&srp=1&state=FL. Accessed July 

2010.

9 Xcel Energy’s Windsource Program is a largely successful voluntary renewable energy purchase program. 

http://www.xcelenergy.com/Colorado/Residential/RenewableEnergy/Windsource_/Pages/WindSource.aspx. 

Accessed July 2010.
19

world data. CEA found that $92,000 in federal spending is equivalent to one job-year. This 

means that for every $92,000 of federal money that is spent, there is a job created that can be 

sustained for one year. See Table 6 for an estimate of job creation by system type if both sites 

studied at St. Marks were used for solar PV. This project represents a large amount of money 

that would create a significant number of jobs. A portion of these jobs, including the installation 

and system maintenance jobs, will be created within the community. The jobs created column 

refers to the number of job-years that would be created as a result of the one-time project capital 

investment. This means that the jobs will be created and sustained for one year. The jobs 

sustained column refers to the number of jobs that would be sustained as a result of the O&M of 

the system. These jobs will be sustained for the life of the system, due to the annual cost to keep 

the system operating. 

Table 6. Estimated Job Creation by PV System Type

System Type Jobs Createda

(job years)

Jobs Sustainedb

(number of jobs)

Crystalline Silicon (Fixed Tilt) 115 0.3

Crystalline Silicon (Single-axis Tracking) 111 0.6

Thin Film (Fixed Tilt) 40 0.1

a Job-years created as a result of project capital investment including direct, indirect, and induced 

jobs. b Jobs (direct, indirect, and induced) sustained as a result of operations and maintenance (O&M) 

of the system.
20

5 Conclusions and Recommendations 

The sites considered for a solar PV system in this report are promising areas in which to 

implement a solar system. The availability of land that cannot be used for other purposes 

represents an area that minimizes the environmental impact of a solar generation plant and 

allows for the reuse of land that would otherwise make little to no contribution to productivity in 

the City of St. Marks. It is recommended that the site facilitator contact Progress Energy and the 

City of Tallahassee Utility to attempt to set up an agreement to sell the electricity generated at 

the site. According to the site production calculations, the most cost-effective system in terms of 

return on investment is the fixed-tilt thin film technology. The lower cost of the system 

combined with the cheap land available on the site makes a thin film system a good fit for this 

site. Thin film technology is a proven technology that can be successfully implemented with a

traditional or ballasted-style mounting system. The other two system styles could also be 

implemented, but the increased cost of the crystalline silicon panels may extend the payback 

period. When the system goes out to bid, a design-build contract should be issued requesting the 

best performance (kWh/year) at the best price. The vendor should optimize system configuration 

including tilt. If the site can be modified by removing the storage tanks and lowering the water 

level, the feasibility of a PV system can be greatly improved. All payback calculations assumed 

a 30% federal tax credit would be captured for the system. 

Installing solar facilities on contaminated land can reduce pressure on greenfields for installing 

these facilities. In addition, developing solar facilities on contaminated land can provide an 

economically viable reuse option for sites with significant cleanup costs or sites that local 

economic conditions prohibit traditional reuse. This is the case with St. Marks. The site has 

existing transmission capacity, roads, industrial zoning, and all other critical infrastructure in 

place for this renewable energy project. This site is an ideal candidate to help the United States 

further its goal of increasing clean energy use and reducing environmental impact.
21

Appendix A. Assumptions for Calculations

Table A-1. Total Site Usage Scenarioa

Location

Array 

Tilt 

(deg)

Maximum

Usable 

Area (ft2)

Rounded 

PV 

System 

Size (kW)

Annual 

Output 

(kWh/year)

Annual Cost 

Savings 

($/year)

Annual 

O&M 

($/year)

System Cost 

with 

Incentivesb ($)

Payback 

Periodc

(years)

System Cost 

without Incentives 

($)

Crystalline Silicon (Fixed Tilt)

St. Marks 

Refinery 30.4 667,377 2,500 3,285,000 $ 262,800 $21,250 $ 8,750,000 36 $ 12,500,000

Recently 

Closed 

Site 

30.4 137,565 550 722,700 $ 57,816 $4,675 $ 1,925,000 36 $ 2,750,000

Crystalline Silicon (Single-axis Tracking)

St. Marks 

Refinery 0 667,377 2,000 3,078,000 $ 246,240 $42,000 $ 8,400,000 41 $ 12,000,000

Recently 

Closed 

Site

0 137,565 450 692,550 $ 55,404 $9,450 $ 1,890,000 41 $ 1,890,000

Thin Film (Fixed Tilt)

St. Marks 

Refinery 30.4 667,377 1,000 1,314,000 $ 105,120 $7,480 $ 3,080,000 32 $ 3,080,000

Recently 

Closed 

Site

30.4 137,565 200 262,800 $ 21,024 $1,496 $ 616,000 32 $ 616,000

a The calculations in this table were conducted with the assumption that all 17 acres of the site would be 

fully utilized.

b The incentives include the 30% federal tax credit. 

c The payback period was calculated using the system cost with incentives.
22

Table A-2. Cost and System Assumptions 

Name of Variable Quantity of Variable Unit of Variable

Cost of Site Electricity 0.08 $/kWh

Annual O&M (fixed) 0.17% % of installed cost

Annual O&M (tracking) 0.35% % of installed cost

System Type Annual energy production kWh/kW Installed Cost ($/W) Energy Density (W/ft2)

Ground Fixed Tilt 1,314 $5.00 4.0

Ground Single-axis Tracking 1,539 $6.00 3.3

Thin Film Fixed Tilt 1,314 $4.40 1.7

Assumptions

1 acre = 43,560 ft2

1 MW = 1,000,000 W

Ground Utilization = 90% of available area

Incentives: Federal Tax Credit
23

Table A-3. Partially Drained Site Scenarioab

Location Array Tilt 

(deg)

Maximum

Usable Area 

(ft2)

PV System 

Size (kW)

Annual Output 

(kWh/year)

Annual Cost 

Savings 

($/year)

Annual 

O&M 

($/year)

System Cost 

with Incentives 

($)

Payback Period 

with Incentive 

(years)

Crystalline Silicon (Fixed Tilt)

St. Marks 

Refinery 30.4 500,040 2,000 2,628,000 $210,240 $17,000 $7,000,000 36

Crystalline Silicon (Single-axis Tracking)

St. Marks 

Refinery 0 500,040 1,500 2,308,500 $184,680 $31,500 $6,300,000 41

Thin Film (Fixed Tilt)

St. Marks 

Refinery 30.4 500,040 800 1,051,200 $84,096 $5,984 $2,464,000 32

a The calculations address the PV system in the event that the site can only be partially drained. The 

calculations reflect the land required to facilitate a 2 MW crystalline silicon PV system. This system 

configuration would allow for a water holding area to prevent contaminated water runoff and allow for the 

rest of the site to be utilized by a solar system.

b The calculations assume that the 30% federal tax credit is secured.

The following image shows the elevation of the site, outlining the locations where the 

containment berms were installed and showing the location of the permanently capped areas. The 

areas with the permanent caps in place would need to implement a ballasted-style mounting 

system in order to avoid disturbing the cap that is in place. 
24

Figure A-1. Elevation of the site

Credit: EarthTech
25

Appendix B. Renewable Energy Incentivesa

Table B-1. Brownfield Redevelopment and Renewable Energy Incentives and Financing Tools

Agency Incentive Name

Incentive 

(I), Finance 

Tool (FT) Public Private Funding Range

HUD

Brownfield Economic 

Development Initiative (BEDI) 

Competitive Grant Program

I X

Xb $17.5 million appropriated 

in FY10. Award cap TBD 

as of 2/27/10

HUD Section 108 Loan Guarantee 

Program FT X Xb

Up to five times public 

entity’s latest approved 

Community Development 

Block Grants (CDBG)

amount

a Must be used in conjunction with Section 108 loan guarantee commitment.

b Through re-loan from public entity.

Table B-2. Renewable Energy Development Incentives and Financing Tools Applicable to PV

Agency Incentive Name

Incentive 

(I), Finance 

Tool (FT) Public Private Funding Range

DOE Loan Guarantee Program FT X X Not specified

DOE Renewable Energy Production 

Incentive (REPI) I X $0.021/kW

HUD CDBG I X Based on community 

needs formula

Treasury

1603 Renewable Energy 

Grant Program

*option to Investment Tax 

Credit (ITC)

I X

30% of the cost basis of 

the renewable energy 

project

Treasury Business Energy ITC 

*option to 1603 

I X 30% of project 

expenditures

Treasury Clean Renewable Energy 

Bonds (CREB) FT X Varies

Treasury Modified Accelerated CostRecovery System (MACRS) FT X Various depreciation 

deductions

Treasury Qualified Energy Conservation 

Bonds (QECB) FT X Varies

USDA Rural Energy for America 

Program (REAP) Grants I X X

25% of project cost. 

Payment range $2,500–

$500,000

USDA REAP Loan Guarantees FT X X Up to 75% of project 

costs. Max $25M/Min $5K

Sources: DSIRE and Efficiency 2009; U.S. Department of Housing and Urban Development 2009
26

The programs included in Table B-3 are ongoing rebate and grant programs administered by 

state agencies or by third-party organizations on behalf of state governments. In addition to the 

programs highlighted in Table B-2, about 75 utilities in the United States offer PV rebates. In 

some states, such as Colorado and Arizona, solar rebates are available nearly statewide from 

utilities that must comply with state RPSs, but these are not shown in the table. Finally, programs 

that are purely performance-based, such as the State of Washington's production incentive and 

California's feed-in tariff, are not included in this table.

Table B-3. State Rebates for Commercial-sector PV Projects

State Program 

Name

Incentive Amount Renewable Energy 

Certificate (REC)

Ownership

Funding Source

California California Solar 

Initiative

Varies by sector and 

system size.

Remains with 

project owner

Rate-payer funded

California CEC - New 

Solar Homes 

Partnership

Varies. Incentives are 

adjusted based on 

expected performance 

and will decline over 

time based on the total 

installed capacity.

Remains with 

system owner

Rate-payer funded

Connecticut CCEF - OnSite 

Renewable DG 

Program

For for-profit owners: 

$3.00/W for first 100 

kW, $2.00/W for next 

100 kW. Not-for-profit 

system owners: 

$4.50/W for first 100 

kW, $4.00/W for next 

100 kW. Additional 

$0.10/W premium for 

buildings that meet 

LEED Silver 

certification. CCEF 

also compensates 

system owners based 

on the estimated 

present value of the 

system's RECs.

RECs transfer to 

CCEF for systems 

50 kW-PTC and 

larger. CCEF 

compensates 

system owners 

based on estimated 

present value of the 

system's RECs 

over 15 years.

Connecticut Clean 

Energy Fund (public 

benefits fund)

Delaware Green Energy 

Program 

Incentives

Delmarva: 25% of 

installed cost (35% for 

non-profits, 

government); DEC: 

33.3% of installed cost; 

Minis: 33.3% of 

installed cost except 

25% for Dover, 

Remains with 

project owner

Green Energy Fund 

(Delmarva), DEC 

Renewable 

Resources Fund, 

Municipal Utility 

Green Energy Fund 

(public benefits 

funds)
27

State Program 

Name

Incentive Amount Renewable Energy 

Certificate (REC)

Ownership

Funding Source

Seaford; PV system 

cost may not exceed 

$12/W

District of 

Columbia

Renewable 

Energy 

Incentive 

Program

$3/W DC for first 3 kW; 

$2/W DC for next 7 

kW; $1/W DC for next 

10 kW

Remains with 

system owner

Sustainable Energy 

Trust Fund (public 

benefits fund)

Illinois DCEO - Solar 

and Wind 

Energy Rebate 

Program

Note (02/2010): 

Funding for FY 2010 

has been fully 

allocated; no additional 

rebates are available. 

Residential and 

commercial: 30%; Nonprofit and Public: 50%

Remains with 

customer/producer

Illinois Renewable 

Energy Resources 

Trust Fund (public 

benefits fund)

Maine Solar and Wind 

Energy Rebate 

Program

$2/W AC Remains with 

customer/producer

Funded by 

assessment of up to 

0.005 cents/kWh on 

transmission and 

distribution utilities. 

Plus $500,000 per 

fiscal year (FY2009-

2010 and FY2010-

2011) for two years 

using Recovery Act

funding.

Maryland Mid-size Solar 

Energy Grant 

Program

$500/kW for first 20 kW 

DC; $250/kW for next 

30 kW; $150/kW for 

next 50 kW

Remains with 

project owner

Recovery Act

Maryland Solar Energy 

Grant Program

$1.25/W DC for first 2 

kW; $0.75/W for next 6 

kW; $0.25/W for next 

12 kW

Remains with 

project owner

General Revenue 

Funds (appropriated 

annually); FY 2009 

funds supplemented 

with RGGI proceeds

Massachusetts CEC -

Commonwealth 

Solar II 

Rebates

$1/W DC base; 

$0.10/W DC adder for 

MA components; 

$1.00/W DC adder for 

moderate home value 

or for moderate income

Remains with 

project owner

Massachusetts 

Renewable Energy 

Trust
28

State Program 

Name

Incentive Amount Renewable Energy 

Certificate (REC)

Ownership

Funding Source

Massachusetts CEC -

Commonwealth 

Solar Stimulus

$1.50/W (DC) for first 

25 kW; $1.00/W (DC) 

for > 25 kW to 100kW; 

$0.50/W (DC) for > 100 

kW to 200 kW

Remains with 

project owner

Recovery Act 

Nevada NV Energy –

Renewable 

Generations 

Rebate 

Program

(2010-2011 program 

year) Residential and 

small business: 

$2.30/W AC; Public 

Facilities/Schools: 

$5.00/W AC

NV Energy Rate-payer funded

New Jersey New Jersey 

Customer-sited 

Renewable 

Energy 

Rebates

Standard residential: 

$1.55/W DC; 

Residential with energy 

efficiency: $1.75/W 

DC; Residential new 

construction: varies by 

efficiency, $1.00–

$1.75/W DC; Standard 

non-residential: 

$0.90/W DC; Nonresidential with 

efficiency: $1.00/W DC

Remains with 

project owner

New Jersey Societal 

Benefits Charge 

(public benefits fund)

New Jersey Renewable 

Energy 

Manufacturing 

Incentives (for 

End-Use PV 

Installations)

Varies by equipment 

type, sector, and 

system size. Ranges 

from $0.05–$0.55/W 

DC.

Not applicable New Jersey Societal 

Benefits Charge 

(public benefits fund)

New York NYSERDA -

PV Incentive 

Program

Residential (first 5 kW): 

$1.75/W DC; Nonresidential (first 50 

kW): $1.75/W DC; 

Non-profit, 

government, schools: 

(first 25 kW): $1.75/W 

DC; Bonus incentive: 

$0.50/W for Energy 

Star homes and BIPV 

systems

First 3 years: 

NYSERDA, 

thereafter 

customer/generator

RPS surcharge

Ohio ODOD -

Advanced 

$3.50 per DC-Watt, 

may be reduced by 

Not specified Ohio Advanced 

Energy Fund
29

State Program 

Name

Incentive Amount Renewable Energy 

Certificate (REC)

Ownership

Funding Source

Energy 

Program 

Grants - Nonresidential 

Renewable 

Energy 

Incentive

shading

Oregon Energy Trust -

Solar Electric 

Buy-down 

Program

Residential: $1.50/W 

DC for Pacific Power; 

$1.75/W DC for PGE; 

Residential, third party: 

$1/W DC for Pacific 

Power; $1.25/W DC for 

PGE; Commercial: 

$1/W - $0.50/W for 

Pacific Power; $1.25/W 

- $0.75/W for PGE; 

Non-profit/government: 

$1.25/W - $0.75/W for 

Pacific Power; $1.50/W 

- $1/W for PGE

Residential: RECs 

for first 5 years 

owned by 

customer/producer; 

Non-residential: 

RECs for first 5 

years owned by 

consumer/producer, 

Energy Trust owns 

RECs for years 6–

20

Energy Trust of 

Oregon (public 

benefits fund)

Pennsylvania Pennsylvania 

Sunshine Solar 

Rebate 

Program

Residential: $2.25/W 

DC; Commercial: 

$1.25/W DC for first 10 

kW, $1.00/W DC for 

next 90 kW, $0.75/W 

DC for next 100 kW; 

Low-income: 35% of 

installed costs

Not specified, but 

net metering 

customers 

generally retain title 

to RECs

Pennsylvania Energy 

Independence Fund 

(state bonds)

Puerto Rico Puerto Rico -

State Energy 

Program - Sun 

Energy Rebate 

Program

Solar PV: Residential 

and commercial $4/W

DC; Solar PV: 

Governmental $8/W

DC

Not addressed Recovery Act State 

Energy; Program 

funds

Tennessee Tennessee 

Clean Energy 

Technology 

Grant

40% of installed cost Not specified State of Tennessee 

Economic and 

Community 

Development Energy 

Division

Vermont Vermont SmallScale 

Renewable 

Individuals/businesses: 

$1.75/W DC; Multifamily, low-income: 

Not addressed Utility settlement 

funds and the 

Vermont Clean 
30

State Program 

Name

Incentive Amount Renewable Energy 

Certificate (REC)

Ownership

Funding Source

Energy 

Incentive 

Program

$3.50/W DC Energy Development 

Fund

Wisconsin Focus on 

Energy -

Renewable 

Energy CashBack Rewards

Residential/business: 

$1.00/kWh/1-yr.; Nonprofit/government: 

$1.50/kWh/1-yr.; 

(Estimated 1-yr. 

production using 

PVWATTS). Efficiency 

First participants: add 

$0.25/kWh/1-yr.

Not addressed Focus on Energy 

Program

Source: DSIRE 2010

Note: The information provided in this table presents an overview of state incentives, but it should not be 

used as the only source of information when making purchasing decisions, investment decisions, tax 

decisions, or other binding agreements. For more information about individual programs listed above, visit 

the DSIRE Web site at http://www.dsireusa.org/.
31

Table B-4. State Tax Credits for Commercial-sector PV Projects

State

Program 

Name Eligible Recipients

Incentive 

Amount

Third-party 

Owner 

Eligible

Non-profit/

Government 

Eligible

Arizona Nonresidential 

Solar & Wind 

Tax Credit 

(Corporate)

Any non-residential 

installation is eligible, 

including those for 

non-profits and 

governments. 

Individuals, 

corporations, and 

S corporations and 

partnerships may claim 

the credit. Third-party 

financiers/installers/mfrs. 

of eligible system may 

claim the credit.

10% Yes Yes

Georgia Clean 

Energy Tax 

Credit 

(Corporate)

Any GA taxpayer who 

has constructed, 

purchased, or leased 

renewable energy 

property and placed it in 

service.

35% Yes Not specified

Hawaii Solar and 

Wind Energy 

Credit 

(Corporate)

Hawaii taxpayer that 

files a corporate net 

income tax return or 

franchise tax return. 

Credit may be claimed 

for every eligible 

renewable energy 

technology system that 

is installed and placed in 

service. Third-party 

taxpaying entities may 

claim the credit if they 

install and own a system 

on a commercial 

taxpayer’s building or on 

a non-profit or 

government building. 

Multiple owners of a 

single system may take 

a single tax credit. The 

credit is apportioned 

between the owners in 

proportion to their 

35% Yes Yes
32

State

Program 

Name Eligible Recipients

Incentive 

Amount

Third-party 

Owner 

Eligible

Non-profit/

Government 

Eligible

contribution to the

system's cost.

Iowa Renewable 

Energy 

Production 

Tax Credits 

(Corporate)

Producers or purchasers 

of renewable energy 

from qualified facilities. 

Installations must be at 

least 51% owned by a 

state resident or other 

qualifying owner and 

placed in service on or 

after July 1, 2005, and 

before January 1, 2012. 

Electricity must be sold 

to an unrelated person 

to qualify for the tax 

credit.

$0.015/kWh 

for 10 years 

after energy 

production 

begins.

Yes, credits 

may be 

claimed by 

system 

owner or by 

purchaser of 

electricity. 

System 

owners must 

meet certain 

eligibility 

criteria.

Schools and 

cooperative 

associations are 

eligible owners. 

Credits may be 

transferred or 

sold one time.

Kentucky Renewable 

Energy Tax 

Credit 

(Corporate)

Any installation on a 

dwelling unit or on 

property that is owned 

and used by the 

taxpayer as commercial 

property

$3/DC-Watt Not specified Not specified

Kentucky Tax Credit 

for 

Renewable 

Energy 

Facilities

Companies that build or 

renovate facilities that 

utilize renewable energy

100% 

Kentucky 

income tax 

or limited 

liability entity 

tax

Not specified Not specified

Louisiana Tax Credit 

for Solar and 

Wind Energy 

Systems on 

Residential 

Property 

(Corporate)

A taxpayer who 

purchases and installs 

an eligible system or 

who purchases a new 

home with such a 

system already in place

50% No No

Maryland Clean 

Energy 

Production 

Tax Credit 

(Corporate)

All individuals and 

corporations that sell 

electricity produced by a 

qualified facility to an 

unrelated person. Net 

metering arrangements 

qualify.

$0.0085/kWh 

for 5 years 

after facility 

is placed in 

service.

Not specified No
33

State

Program 

Name Eligible Recipients

Incentive 

Amount

Third-party 

Owner 

Eligible

Non-profit/

Government 

Eligible

Montana Alternative 

Energy 

Investment 

Tax Credit 

(Corporate)

A corporation, 

partnership, or small 

business corporation 

that makes a minimum 

investment of $5,000

35% No No

New 

Mexico

Advanced 

Energy Tax 

Credit 

(Corporate)

Any taxpayer 6% No No

New 

Mexico

Renewable 

Energy 

Production 

Tax Credit 

(Corporate)

A taxpayer who holds 

title to a qualified energy 

generator that first 

produced electricity on 

or before January 1, 

2018, or a taxpayer who 

leases property upon 

which a qualified energy 

generator operates from 

a county or municipality 

under authority of an 

industrial revenue bond 

and if the qualified 

energy generator first 

produced electricity on 

or before January 1, 

2018.

Varies 

annually 

over 

10 years; 

$0.027/kWh 

average

Not specified Not specified

New 

Mexico

Solar Market 

Development 

Tax Credit

Residents and noncorporate businesses, 

including agricultural 

enterprises

10% of 

purchase 

and 

installation 

costs

No No

North 

Carolina

Renewable 

Energy Tax 

Credit 

(Corporate)

Any NC taxpayer who 

has constructed, 

purchased, or leased 

renewable energy 

property and placed it in 

service.

35% 

(distributed 

7% per year 

for 5 years 

for nonresidential 

installations)

Yes. For 

leasing, a 

taxpayer may 

take credit for 

property that 

the taxpayer 

leases if 

written 

verification is 

received from 

the owner 

that states 

No
34

State

Program 

Name Eligible Recipients

Incentive 

Amount

Third-party 

Owner 

Eligible

Non-profit/

Government 

Eligible

that owner 

will not take 

credit for 

renewable 

energy 

installation.

North 

Dakota

Renewable 

Energy Tax 

Credit

Corporate taxpayers

filing a North Dakota 

income tax return. 

System must be 

installed on a building or 

on property owned or 

leased by the taxpayer 

in North Dakota.

15% 

(distributed 

3% per year 

for 5 years)

A passthrough entity 

that installs 

the system at 

a property it 

owns or 

leases is 

considered 

the taxpayer. 

The credit 

amount 

allowed is 

determined 

at the passthrough entity 

level and 

must be 

passed 

through 

proportionally 

to corporate 

partners, 

shareholders,

or members.

No

Oklahoma Zeroemission 

Facilities 

Production 

Tax Credit

Any non-residential 

taxpayer who sells 

electricity to an 

unrelated person. Any 

nontaxable entities, 

including agencies of 

the State of Oklahoma, 

may transfer their credit 

to a taxpayer.

$0.0050/kWh 

for first 10 

years of 

operation

Yes Yes, nontaxable 

entities, including 

agencies of the 

State of 

Oklahoma or 

political 

subdivisions 

thereof, can take 

advantage of the 

tax credit by 

transferring it to a 

taxable entity.
35

State

Program 

Name Eligible Recipients

Incentive 

Amount

Third-party 

Owner 

Eligible

Non-profit/

Government 

Eligible

Oregon Business 

Energy Tax 

Credit

Trade, business, or 

rental property owners 

who pay taxes for a 

business site in Oregon 

are eligible for the tax 

credit. The business, its 

partners, or its 

shareholders may use 

the credit. A project 

owner also can be an 

Oregon non-profit 

organization, tribe, or 

public entity that 

partners with an Oregon 

business or resident 

who has an Oregon tax 

liability. This can be 

done using the passthrough option.

50% 

(distributed 

10% per 

year for 5 

years)

Yes A project owner 

can be a nonprofit, tribe, or 

public entity that 

partners with a 

business or 

resident to take 

advantage of the 

pass-through 

option. The passthrough option 

allows a project 

owner to transfer 

the 35%

Business Energy 

Tax Credit project 

eligibility to a 

pass-through 

partner for a 

lump-sum cash 

payment. The 

pass-through 

option rate for 

5-year Business 

Energy Tax 

Credits effective 

October 1, 2003,

is 25.5%. The 

pass-through 

option rate for 

1-year Business 

Energy Tax 

Credits (those 

with eligible costs 

of $20,000 or 

less) effective 

October 1, 2003,

is 30.5%.

Puerto

Rico

Puerto Rico -

Solar Tax 

Credit 

(Corporate)

Any Puerto Rican 

taxpayer who has 

acquired, assembled, 

and installed eligible 

solar electric equipment.

75% during 

FY 2007-

2008 and 

2008-2009; 

50% during 

FY 2009-

Not specified Potentially; the 

tax credit may be 

transferred, sold,

or otherwise 

given to "any 

other person."
36

State

Program 

Name Eligible Recipients

Incentive 

Amount

Third-party 

Owner 

Eligible

Non-profit/

Government 

Eligible

2010 and FY 

2010-2011; 

25% starting 

FY 2011-

2012

Rhode 

Island

Residential 

Renewable 

Energy Tax 

Credit 

(Corporate)

Rhode Island taxpayer 

who (1) owns, rents, or 

is the contract buyer of 

the dwelling(s) served 

by the system. The 

dwelling or dwellings 

must be in the main or 

secondary residence of 

the person who applies 

for the tax credit, or of a 

tenant; (2) owns, or is 

the contract buyer of the 

system and pays all or 

part of the cost of the 

system; or (3) is the 

contractor that owns the 

dwelling for speculative 

sale in which the system 

is installed

25% Yes. Credit is 

available to 

RI taxpayers 

who are the 

contract 

buyers of 

eligible 

systems and 

pay all or part 

of the cost of 

the system.

No

South 

Carolina

Solar Energy 

and Small 

Hydropower 

Tax Credit 

(Corporate)

Taxpayers who 

purchase and install an 

eligible system in or on 

a facility owned by the 

taxpayer

25% for 

2010; was 

30% in 2009

No No

Utah Renewable 

Energy 

Systems Tax 

Credit 

(Corporate)

Any company that owns 

a qualified system

Residential: 

25%; 

Commercial: 

10%

No No
37

State

Program 

Name Eligible Recipients

Incentive 

Amount

Third-party 

Owner 

Eligible

Non-profit/

Government 

Eligible

Vermont Business 

Tax Credit 

for Solar 

(Corporate)

Corporations that pay 

corporate income tax in 

Vermont that do not 

receive grants/funding 

from CEDF.

30% of 

expenditures 

(for systems 

placed into 

service on or 

before 

12/31/2010).

Not specified No

Source: DSIRE 2010

Note: The information provided in this table presents an overview of state incentives, but it should not be 

used as the only source of information when making purchasing decisions, investment decisions, tax 

decisions, or other binding agreements. For more information about individual programs listed above, visit 

the DSIRE Web site at http://www.dsireusa.org/.
38

Table B-5. U.S. Department of Energy Brightfields Program Grants

Award 

Year

Award 

Amount

Project Project Description Project Status

2000 $30,000 Brockton, MA: 

Brownfields to 

Brightfields 

Project

“This project involved attracting a photovoltaic 

system manufacturer to a Brockton Brownfield 

and building a solar array on a second site. 

Anticipation: This array will bring into productive 

use up to 27 acres of idle property and the array 

could also generate up to 6 MW of electricity. To 

create sufficient local demand to attract the 

manufacturer, other potential sites for 

photovoltaic applications will be surveyed.”

425 kW facility 

commercially 

operated since 

September 27, 

2006.

Expanded by 

35 kW to 460 

kW in July 

2007. Gridconnected 

selling 100% of 

output into New 

England Power 

Pool

$50,000 Atlantic City, 

NJ: Cityscape 

SolarPowered Bed 

and Breakfast 

on an Urban 

Brownfield.

“Involves the construction of a solar-powered 

bed and breakfast on an urban Brownfield site in 

Atlantic City, New Jersey, as part of an overall 

neighborhood redevelopment plan with a 

sustainability theme. The project will showcase 

the use of photovoltaics in supplying renewable 

energy and also contain sustainable features 

such as recycled building materials and Energy 

Star appliances and will be located in the 

"Cityscape Neighborhood," an area designed to 

promote renewable energy, sustainable building 

materials, and concepts of New Urbanism.”

Project 

canceled

$50,000 Hanford, WA: 

Brightfield 

Project

“This project will ultimately be the largest 

photovoltaic installation of its kind and will bring 

the Brightfield concept to one of the worst Super 

Fund sites in the nation. The funding provided 

will cover a portion of the pilot phase of the 

project, involving 40 kW. Later phases will use a 

wind/solar green energy blending strategy to 

finance development up to 1 MW or larger. This 

solar array will act as a nucleation site around 

which Energy Northwest intends to grow a 

renewable energy industrial park.”

38.7 kW 

system 

installed in May 

2002

2004 $65,400 Cedar Rapids, 

IA: Bohemian 

Commercial 

Historic 

District Solar 

Development 

“The Iowa Department of Natural Resources 

(IDNR) will partner with the City of Cedar Rapids, 

the Iowa Renewable Energy Association, Alliant 

Energy, and Thorland Company to install a 7200

Watt solar array in Cedar Rapids on a multiuse 

converted former warehouse building in a 

7.2 kW 

installed
39

Program designated Brownfields redevelopment area.”

The IDNR has established partnerships with the 

City of Cedar Rapids, Alliant Energy, the Iowa 

Renewable Energy Association, and the building 

owner to increase the economic and 

environmental viability of a redeveloped 

Brownfield area and expand the value and 

viability of solar projects.”

$59,400 Brockton, MA: 

Solar Energy 

Park: 

Deploying a 

Solar Array on 

a Brownfield

“The City of Brockton will build New England's 

largest solar array at a remediated 27 acre 

Brownfield site in fall 2004. The 500 kW solar PV 

array—or "Brightfield"—will be installed in an 

urban park setting with interpretive displays. The 

Brightfield could include as many as 6,720 solar 

panels connected in strings that span the site. 

The Brightfield will grow incrementally to 1 MW 

with expansions financed through positive annual 

cash flow generated by the sale of renewable 

energy certificates (RECs) and electricity.”

425 kW facility 

commercially 

operated since 

September 27, 

2006. 

Expanded by 

35 kW to 460 

kW in July 

2007. Gridconnected 

selling 100% of 

output into New 

England Power 

Pool.

$125,000 Raleigh, NC: 

Brightfield 

Technology 

Demonstration 

at NCSU

“Carolina Green Energy, LLC proposes to 

partner with the North Carolina Solar Center to 

design and install a 30-kW grid-tied PV system. 

As part of its continued efforts to bolster support 

for renewable energy, the Solar Center will 

incorporate the "Brownfield to Brightfield" project 

at Lot 86 into its ongoing education and outreach 

programs.”

75.6 kW PV 

generation 

project 

operational 

since October 

2007.

Source: U.S. Department of Energy State Energy Program 2006

Note: According to EPA, the term brightfields refers to “the conversion of contaminated sites into usable 

land by bringing pollution-free solar energy and high-tech solar manufacturing jobs to these sites, 

including the placement of photovoltaic arrays that can reduce cleanup costs, building integrated solar 

energy systems as part of redevelopment, and solar manufacturing plants on brownfields.” For more 

information, see: http://epa.gov/

brownfields/partners/brightfd.htm
F1147-E(10/2008)

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1. REPORT DATE (DD-MM-YYYY)

September 2010

2. REPORT TYPE

Technical Report

3. DATES COVERED (From - To)

4. TITLE AND SUBTITLE

Feasibility Study of Economics and Performance of Solar 

Photovoltaics in St. Marks, Florida: A Study Prepared in Partnership 

with the Environmental Protection Agency for the RE-Powering 

America’s Lands Initiative: Siting Renewable Energy on Potentially 

Contaminated Land and Mine Sites

5a. CONTRACT NUMBER

DE-AC36-08-GO28308

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S)

L. Lisell, G. Mosey

5d. PROJECT NUMBER

NREL/TP-6A2-48853

5e. TASK NUMBER

WFD3.1000

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401-3393

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NREL/TP-6A2-48853

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NREL

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14. ABSTRACT (Maximum 200 Words)

This report presents the results of an assessment of the technical and economic feasibility of deploying a 

photovoltaics (PV) system on a brownfield site in St. Marks, Florida. The site was assessed for possible PV 

installations. The cost, performance, and site impacts of different PV options were estimated. The economics of the 

potential systems were analyzed using an electric rate of $0.08/kWh and incentives offered in the State of Florida 

and from the two accessible utilities, Progress Energy and the City of Tallahassee. According to the site production 

calculations, the most cost-effective system in terms of return on investment is the fixed-tilt thin-film technology. The 

report recommends financing options that could assist in the implementation of such a system.

15. SUBJECT TERMS

feasibility study; solar photovoltaics; PV system; ground-mounted PV; St. Marks; brownfields; cost; performance; site 

impacts; financial incentives; financing options

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