What Is an SREC?
/Solar renewable energy certificates (SRECs, pronounced ess-rex) are a means of tracking the production of solar energy. One SREC represents one megawatt hour (1,000 kilowatt hours) of energy produced by a solar array and tagged with a unique number.
The SREC system was put in place so that energy from renewable sources can be accurately tracked and progress toward statewide renewable energy goals can be measured. It is more cost-effective for the Commonwealth to support homeowners to produce power than to build new power plants or centralized installations. Utilities are willing to pay for SRECs generated by homeowners, thus claiming “credit” toward their renewable energy goals. SRECs make it possible to monetize the environmental and financial advantages of solar energy.
SRECs can be donated as well as sold. In 2016, one BBR member began donating SRECs to BBR’s nonprofit Reuse Center, resulting in a contribution of $92.43 for the year.
See also the Wikipedia page "Solar Renewable Energy Certificate"