SRECs are awarded according to cumulative energy production from solar power systems interconnected to the power grid. In most state markets*, SRECs are generally awarded for every 1,000 kWh (or 1 MWh) generated.
SRECs are only ever awarded in whole units; there is no such thing as a partial SREC. Accordingly, excess energy production (anything less than the threshold for a full SREC) will always roll over to the following reporting period. For instance, a solar system that generates an 3,450 kWh in a given 3-month reporting period (or generation quarter) will be awarded three whole SRECs; those excess 450 kilowatt-hours roll over to the following generation quarter.
* Please note that in the Massachusetts state market only, SREC II systems interconnected between January 8th, 2018 and November 26th, 2018 are subject to a 0.8 SREC factor and will therefore earn an SREC for every 1,250kWh.