Brattle Study: Alternative Approach to Meeting Zero Net Energy Goals Can Benefit Consumers and the Environment

A flexible approach to meeting Zero Net Energy (ZNE) goals could benefit consumers and the environment, according to a study authored by Brattle economists released by the National Rural Electric Cooperative Association (NRECA) and the Natural Resources Defense Council (NRDC).

ZNE homes are designed to produce as much energy from clean on-site energy sources as they consume each year. The study compares two approaches to meeting a ZNE goal for new housing developments: requiring solar installations on each home to offset annual electricity use or a community solar program in which homeowners receive a share of a combined solar array.

The analysis produced the following findings:

  • The economies of scale and technological advantages of community solar for new housing in non-urban areas would provide roughly 13 percent lower total solar project costs per watt of electricity generated than ZNE homes, and a 25 to 30 percent greater annual energy output than ZNE homes.
  • A community solar approach to ZNE could serve a 200-home development with a total project cost savings of approximately 30 to 35 percent relative to conventional ZNE configurations. Looked at another way, for the same amount of money, a community solar array yields an additional 40 to 45 percent carbon emission savings over individual rooftop installations.