net metering
pp. Tracking a building's electricity use as the net difference between the power consumed via the public utility grid less the power generated using solar or wind energy.
Other Forms
Dennis Myers is a poster boy for wind power.

Instead of paying for electricity in October, the Jerome man got a $4 credit from Idaho Power, courtesy of the 80-foot wind turbine he erected in June.

The turbine, with its 29-foot blades, can generate about 20 kilowatts of power, enough to meet Myers' needs, plus some extra power. . . .

Some utilities such as Idaho Power will let customers sell their power through a process called net metering, where power is sent to the grid and customers get credit if they produce more than you use.
—Margaret Wimborne, “The winds of change - Small-scale wind farms make sense for some,” Idaho Falls Post Register, December 14, 2002
1983 (earliest)
The case before the [Public Service Commission] involved an interconnection proposal made by a wind power builder, Solac Builders, and a group of 10 homeowners known as the Placitas Small Power Production Assn. The petitioners called for a "net metering option" under which the amount of power produced by the 55-kW wind generator would be gauged against the amount of electricity provided by the utility for the association.
—“PNM wins wind power case at PSC, but must file new avoided-cost rates,” Electric Utility Week, September 12, 1983
The problem with alternative energy sources such as solar and wind is that they're not always there when you need them. The sun has an irritating habit of going down every evening, and the wind is a metaphor for changeableness. The obvious solution is to make energy hay while the alternative source sun shines, but where do you store that surplus energy? Most solar and wind harvesters use batteries, but a better solution is now available in many places: the electricity grid itself.

This is done by means of a device called an inverter, which is normally used to convert the direct current produced by a solar or wind generator to the alternating current that homes prefer. The inverter can be set up to ship excess energy backward through the electric meter to the utility company. The meter literally spins in reverse (not surprisingly, a synonym for net metering is reverse metering) and the returned energy is "saved" on the grid (in the form of a kilowatt credit) for future use by the household. If the house uses less energy than it generates, the customer is either not billed or gets a rebate.

In the U.S., net metering programs are in place in 37 states, and countries such as Germany and Thailand also allow net metering. (Several Canadian provinces are considering net metering programs.) In jurisdictions where net metering isn't legal, some consumers are doing it anyway by becoming solar guerrillas.