Brownfields are sites which have been previously contaminated, frequently making them more expensive to clean up than they are worth. Oftentimes, the EPA designates certain brownfield sites as Superfund sites, providing assistance in site cleanup. For example, the Maywood Superfund site in Indianapolis site was cleaned up with the help of the EPA. Then it was capped with soil and gravel, and a groundwater containment system was installed.

Once the site is cleaned up, the owners generally want to put it back into use, and a solar development project is often suggested. However, Superfund sites are strictly regulated by the EPA, so complying with the regulations results in large added development costs. The regulations often include what can and can’t be done on the land.

Capped landfills are less restrictive than Superfund sites. Landfills have the trash at the bottom covered up by clay or sand. On top of the clay is plastic sheeting (geomembrane) that acts as a water barrier. On top of the plastic sheeting is soil and grass. Solar electric development on landfills can be very costly because of some common landfill rules:

The geomembrane cannot be pierced.

No electrical trenches can be dug.

Vehicles driving on the landfill must be tracked.

These rules add tremendous costs in terms of materials and labor. However, since landfills and other brownfield sites are, by their nature, unusable sites, converting them into sources of clean energy is an attractive prospect for cities and municipalities across the country.

A landfill in Groton, MA, is being targeted for solar electric development after a parcel of land that was previously set as the project site was found to have protected species on it. The solar developer that is chosen for the project will take advantage of solar renewable energy credits (SREC), which can be sold to get a return on investment.

The profitability of solar electric development on landfills often depends on state incentive programs (including SRECs), and tax credits. There may be up to 4000 brownfield sites across the country, according to the EPA, and that’s a lot of solar investment opportunities.

Solar electric investment is becoming more attractive and commonplace, most notably with Warren Buffett’s $15 billion investment in wind and solar, with $15 billion more on the way. Take a look at why some of the world’s largest corporations are going solar.