Last April, Republic installed landfill covers at its Tessman Road landfill that were equipped with photovoltaic (PV) solar collection strips. The strips were less than a quarter inch thick, which allowed for more flexibility than standard solar panels.
The Tessman Road landfill is in San Antonio, Texas, which offers about 300 days of sunshine per year. When combined with the facility’s existing waste-to-energy system, the landfill was able to produce 9 megawatts of power, the equivalent of energy used in 5,500 homes.
Now, Republic is partnering with Carlisle Energy Services, Inc. to further develop the technology, with the hopes that it can be optimized for use on other landfills across the country. In the meantime, Republic will move forward with installing solar strips at its Hickory Road facility in Conley, Ga.
It’s important to differentiate what is referred to as landfill cover. While all landfills feature a daily cover consisting of organic material or other waste that is added to keep rain off the landfill and traps gases such as methane inside, solar strips would only be a fit for permanent covers since they couldn’t be removed to add more waste to the landfill.
According to Republic, its landfills feature a final cover that is used for any section that is filled to capacity. This is generally a synthetic plastic liner, but in the case of the solar covers the plastic would be equipped with the solar strips. Material is added so that sections are filled to capacity one at a time, meaning that a landfill can still accept waste even though some sections no longer have room.
The next step is to determine the logistics of placement and establish a market. “You need to factor in the amount of sunshine and angles of the landfills,” said Republic Manager of Media Relations Peg Mulloy. “You also need to have a customer for the resulting energy.”
Carlisle will use Republic’s technology to begin building the landfill covers and will be contributing on the Hickory Ridge project. It will also develop the technology further, according to Mulloy.