A turnkey solar hot water heating system installed at a federal prison will, under peak conditions, collect 4 million BTU/hr of thermal energy.
The solar system at the Federal Bureau of Prisons Correctional Facility in Englewood, Colo., consists of 160 parabolic PT-1 collector modules comprising 22,720 ft2 of collector area situated on 1.7 acres of land. Ten rows of parabolic troughs track the sun all day and focus the light onto a receiver tube.
Manufactured and installed by Abengoa Solar, Lakewood, Colo., the system’s parabolic troughs track the sun throughout the day, focusing the sun’s light onto a receiver tube at the focal point of the parabola. A mixture of water and antifreeze is pumped through the absorber tube to deliver heat to a 16,000 gal hot water storage tank. The solar system uses a single 3 hp pump that consumes just 2.2 kWh of electrical energy.
Hot water is stored in the tank at temperatures up to 185°F (85°C) and delivered around the clock to serve more than 1,000 inmates and staff for showers, kitchen use and laundry. Over a year, the solar field should reduce consumption of natural gas used to heat hot water by more than 50 percent. Over the system’s 30-year life, the installation will reduce greenhouse gases by about 13,000 tons while contributing to the U.S. government’s goal to reduce energy consumption at federal facilities.