Republic Services and utility CPS Energy capped part of the Tessman Road Landfill in San Antonio with what they call the first-of-its-kind solar energy cover. It consists of a synthetic geomembrane typically used to seal a landfill that has reached capacity. Adhered to the cover on the landfill's south-facing side slope are more than 1,000 flexible strips with photovolatic silicon cells measuring less than a quarter-inch thick.
"The solar energy cover is easier to inspect, maintain and repair than a traditional clay cap, and is technically superior in terms of odor control and storm water management," said Tony Walker, Republic Services project manager, said in a statement last week.
Landfills are familiar sites for biogas-to-energy power generation, but conventional solar projects at landfills are becoming increasingly common. For example, there's a two megawatt PV array at the Fort Carson, Colo. landfill, while New Jersey's Erie Landfill is slated to become the home of the largest solar energy farm in the state.
Republic Services' solar energy cover spans 5.6 acres of the 680-acre Tessman Road Landfill. Along with a methane gas-to-energy system in operation at the site since 2002, the solar energy cover will generate a combined nine megawatts of electricity. The system began operating last month.
Arizona-based Republic Services and CPS Energy will track the results of the demonstration project in the hopes of constructing others in the area. The waste management company operates 213 landfills in the U.S., and said its research indicates up to 2,350 acres could be suitable for solar energy covers under the right regulatory conditions.