Community solar programs could help meet Zero Net Energy goals, study finds

Employing community solar programs to meet Zero Net Energy (ZNE) goals could benefit consumers and the environment, a study released Wednesday found.

The study, conducted by The Brattle Group and released by the National Rural Electric Cooperative Association (NRECA) and the Natural Resources Defense Council (NRDC), compared two tactics for meeting ZNE goals for new housing development. One involved requiring solar installations on each home to offset electricity use. The other involved creating a community solar program in which homeowners receive a share of a combined solar array.

“This research suggests that when we take a more expansive and flexible approach to reducing carbon emissions, and residential development, both consumers, and the environment can win,” Keith Dennis, principal for end-use energy efficiency at NRECA, said.

ZNE homes are designed to generate as much energy from clean on-site energy sources as they use each year.

The research found that community solar for new housing in non-urban areas could lower total solar project costs by approximately 13 percent per watt of electricity, as compared to ZNE homes. Using community solar could also result in 25 to 30 percent higher annual energy output than ZNE homes, the study found.

According to the researchers, a community solar project could serve a 200-home development for 30 to 35 percent lower total project costs relative to conventional ZNE configurations. For the same amount of money, a community solar array results in an additional 40 to 45 percent carbon emission savings as compared to individual rooftop installations.

“The study points to a good policy option to reduce the costs of meeting a Zero Net Energy goal. For utilities and solar developers moving forward, partnering with housing developers may serve as a new business model for community solar projects,” Dylan Sullivan, senior scientist for the NRDC, said. “For community solar to be a viable option in meeting a building code like California’s, homeowners, builders, and code officials will need assurance that the community solar project serves the building for the long-term.”