At Phoenix Federal Correctional Institution in Arizona, the Federal Bureau of Prisons (FBP) completed a 1,584 m2 (17,040 square feet) parabolic trough solar water heating system financed, installed and operated under an Energy Savings Performance Contract (ESPC) with Industrial Solar Technology Corp (IST). The ESPC was developed under a Cooperative Research and Development Agreement with the National Renewable Energy Laboratory (NREL). The system incorporates a 87 m3 (23,000 gallon) storage tank. The system delivered 1,161,803 kWh (3,964 million Btu) of solar heat from March 1, 1999 to February 29, 2000. This energy would have cost $77,805.74 if purchased from the utility (based on the monthly average$/kWh cost). Sale of this energy to the prison provided $70,025.18 in revenue to IST (a rate negotiated at 90 percent of the monthly average$/kWh utility cost). Thus, the prison saved \$7,780.56 (the remaining 10 percent). A photograph of the collector system is presented in Figure 1. Results show that the system delivers heat reliably, with only minor operational problems which are listed and discussed. The system delivered a minimum of 80,315 kWh (274 Btu) in January 2000 to a maximum of 130,979 kWh (447 Million Btu) in October 1999. The prison pays IST for energy delivered by the solar system at a rate equal to 90 percent of the monthly average utility rate (10 percent guaranteed savings), over 20 years. Details of the establishment of the payment structure and the cost savings to the prison are discussed. Annual Emissions Savings are estimated by EPA multipliers [1] for Arizona as 627,374 kg/yr of $CO2,$ 2,324 kg/yr of $SO2$ and 2,297 kg/yr of $NOx.$ Other benefits to the prison are also discussed, such as reduced operations and maintenance on the electric water heaters and a greater capacity to deliver hot water. [S0199-6231(00)00704-8]

1.
EPA, 1991, Weisberg, Peter, “Green Lights Pollution Prevention Methodology” Washington, DC. ICF Inc. for the US EPA.
2.
APS Tariff Number E-32, 1991, Arizona Public Service Company, Phoenix Arizona Tariff Number E-32, Effective December 6, 1991, in conjunction with examination of utility bills for the facility for 1994.
3.
NREL, 1994, Solar Radiation Data Manual for Flat Plate and Concentrating Collectors, National Renewable Energy Laboratory, Golden, Colorado. NREL/TP-463-5607, DE93018229. April 1994.
4.
42 USC 8287, National Energy Conservation Policy Act Title VIII, Sections 801 to 804, Energy Savings Performance Contracts.
5.
10 CFR 436, Code of Federal Regulations Rules for Energy Savings Performance Contracting. April 10, 1995.
6.
GAMA, 1997, Consumers’ Directory of Certified Efficiency Ratings for Residential Heating and Water Heating Equipment, Gas Appliance Manufacturers Association, Arlington, VA, October 1997.