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Facility requires high reliability solution to rising energy costs
The number of green, energy-saving power installations is expanding, and solar photovoltaic applications are among the most popular, particularly in California. But solar panels generate power only during sunshine and cannot always best address facility load requirements. Alameda County Jail in Dublin, CA, found fuel cells a good way to reliably augment its solar installation while keeping its commitment to clean, efficient power. In doing so, the Santa Rita facility further defrayed its energy costs using cogeneration. Operated by the County of Alameda, the Santa Rita jail recently installed a 1-megawatt (MW) carbonate stationary fuel cell power plant to complement its 1.2-MW rooftop solar power system and to help meet its electrical load, estimated at 3.2 MW. In addition to meeting half the facility's annual electricity needs, the fuel cell is part of a combined heat and power (CHP) system that provides 18% of the facility's annual hot water. The CHP application boosts the overall efficiency of the fuel cell system above its already state-ofthe-art 49% electrical efficiency. further improving the plant's performance and allowing it to meet important efficiency targets. This installation is the first megawattclass fuel cell cogeneration plant in California and the first such combined use of a fuel cell with a photovoltaic solar array in the United States.
The Fuel Cell
The high-temperature, high-efficiency carbonate fuel cell provides base load power for Santa Rita using natural gas provided through the existing distribution network. This ability to use an available, proven, and relatively inexpensive fuel is an important advantage over other types of fuel cells that require external fuel processing to obtain a supply of hydrogen.
The DFC1500 fuel cell has a modular design and contains separately configured units for direct current (dc) power, electrical balance of plant, heat recovery/oxidant supply, and fuel and water treatment. Each module is arranged on its own skid to provide both efficient transport to the installation site and ease of access for future plant maintenance. Initial site work and construction for the fuel cell at Santa Rita began in October 2005, with the system coming online at full power in May 2006.
The fuel and water treatment module contains fuel cleanup and de-oxidizing reactors to...