Design of a 100 kW flat panel photovoltaic system at a Washington, DC area waste treatment plant. Final report, October 1, 1978-March 31, 1979

The design of a 100 kilowatt flat panel photovoltaic (PV) system is presented. The application is industrial; to supply power to an inductive motor load at a Washington, DC area sewage treatment plant. The sewage treatment plant operation and electrical load characteristics are briefly described. The cells and modules produced by two manufactures are discussed with respect to similarities/differences in performance and fabrication. A design description of the resulting PV arrays using each module is presented. The system elements common to either array are discussed. They include: (1) a power conditioning system consisting of a line-commutated, line feeding inverter with solid state controls, (2) isolation transformers, (3) an instrumentation and control system, and (4) a power distribution system. The inverter is operated in a maximum power tracking mode that automatically maximizes array output power for a given set of operating conditions. Results of a performance analysis using the SOLCEL PV system simulation model are presented in the form of annual power utilization, total load satisfaction, annual energy flow, and 20 year life-cycle levelized busbar energy costs. A discussion of key technical, legal, institutional, and environmental issues for this specific application concludes the report.