RECs Defined

Utilities must abide by government regulations to reduce the carbon footprint of the electricity they purchase. RECs (Renewable Energy Certificates) are instruments that can be purchased on the open market to offset greenhouse gases. Solar panels on your property generate both electricity (kWh) and the fact that this electricity is carbon-free (RECs). When an electric utility buys RECs, they are buying the right to claim clean energy. You still use the actual energy generated by your solar array (and sell any excess to CMLP via net metering (see here and here)), but the RECs certifying this as renewably-sourced energy are now owned by that utility.  This regional cap-and-trade program provides financial incentives to expand solar while also mandating that utilities supply their customers with increasingly clean power over time.

You can watch an EPA video explaining RECs here.

Each MWh (megawatt-hour) of renewable power produced generates one REC.  You can guestimate your REC production by multiplying your solar system size by 1.2.  For example, a 5 kW(DC) system can be expected to produce about 6 RECs each year.

RECs Past and Present in Concord

REC program eligibility is based on the date that a renewable power source began operating.  All renewable generation (solar photovoltaic (PV), solar thermal, geothermal, low impact hydropower, wind power, aerobic digester gas, etc.) built in New England since 1997 is eligible for Class I RECs.  Your array may have been eligible for more lucrative RECs based on programs offered during certain time periods:

Past:

Class I RECs: renewable generation that went online anytime since 1997
Class II RECs: renewable generation that went online anytime up to 1998
SREC (Solar REC) Programs: because these are generated exclusively by solar arrays they command a higher value on the open market
     SREC I: January 2010 to April 2014
     SREC II: April 2014 to November 2018
MLP Solar Program: January 2019 to July 2022: System owners received a state rebate in exchange for REC ownership. RECs from these arrays are owned by CMLP and retired to reduce the carbon footprint of Concord's electricity (see more here)

Present:

Currently, all solar projects built in Concord are eligible for Class I RECs.  Projects must include a production meter socket.  Solar installers must include customer-owned equipment in that socket - either a production meter (enabling the property owner to produce Class I RECs) or jumpers (meaning the owner cannot produce Class I RECs).

Potential REC Actions

If you choose to put a production meter in your array's production meter socket you can sell or retire the Class I RECs generated by your system.  If you choose to put jumpers in that socket you cannot generate Class I RECs, so you cannot sell or retire them.

Sell: 

the state tracking program sees how much energy your solar panels produced and an electric utility buys the environmental value (but not the electricity) produced by your solar panels

SRECs are valued in the hundreds of dollars and Class I RECs sell for tens of dollars each on the open market. Most solar owners use a REC aggregator who decides when to sell the RECs for the best price. You can shop around for an aggregator for this service – see the link in the middle of this page. Or you might want to be hands-on and do the trading yourself – see the broker / trader link at the bottom of that same page.  Keep in mind questions such as the number of payments per year, the REC price, and the commission percentage.

Retire: 

the state tracking program sees how much energy your solar panels produced, but the environmental value is not for sale to utilities

On the other hand, you may elect to retire your RECs, meaning you will not gain any financial value from them.  In doing so, you retain the rights to claim that your solar array produces 100% carbon-free energy.

Opt Out:

the state tracking program does not know about your solar array and the environmental value of your solar production is not for sale to utilities

If you put jumpers in your production meter socket (instead of a production meter), the regional renewable energy tracking program cannot tally any production from your solar array.  You will not generate any RECs and will not gain any financial value from them.  Just like retiring RECs, you will retain the rights to claim that your solar array produces 100% carbon-free energy.