In the north eastern United States, solar panel owners and operators cannot directly sell the electricity produced from their panels. Instead, every 1000 kilowatts is bundled into a Solar Renewable Energy Credit and then these can be sold in an exchange marketplace.
By increasing the number of S.R.E.C.s that utility companies are required to purchase, the federal or even state governments can help boost the switch to renewable energy and help encourage the move from fossil fuels to renewable energy.