Landfill cover acts as energy source

Energy and waste-disposal companies recognize that landfills aren’t burial sites for garbage, but reactors in which gases produced by decomposing waste can be used for energy production. Republic Services Inc., Phoenix, Az., a national waste-management company, incorporates biogas-to-energy recovery systems into many of its 213 landfills. In San Antonio, Texas, Republic Services is taking energy recovery to a whole new level, installing a landfill cover with flexible solar technology that will help power a sustainable energy park.

Republic Services will cover closed landfill cells with flexible, laminate-type photovoltaic solar collection strips, manufactured by United Solar Ovonic LLC, Rochester Hills, Mich., and adhered to synthetic green-colored geomembrane. The solar strips will be configured to maximize hours of sunlight throughout the year. In its initial trial at the Tessman Road landfill, Republic Services and partner CPS Energy, San Antonio, Texas, deployed more than 1,000 flexible solar strips to 5.6 acres of the landfill’s south-facing slope. The companies estimate that the combined energy output of the biogas-to-energy and solar capture systems will be nine megawatts, sufficient to power an estimated 5,500 homes.

“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 stormwater management,” says Tony Walker, Republic Services project manager. If the initial results of the Tessman Road pilot are good, the company could integrate the technology into many of its other landfills nationwide. For more information, visit www.republicservices.com.