Generation Types

There are several different types of generation systems that are easily available and environmentally sound. Read below for more information about each type.


The wind turns a propeller connected to a generator in this renewable technology system. A direct current wind generator will provide its energy to direct current loads. Alternating current for refrigerators, computers, TV, etc. would have to be provided by an inverter. If the wind turbine generator produces 60 cycle alternating current, the generator could serve AC loads directly. 

Wind energy experts recommend placing an 80 to 120 foot high residential wind turbine on no less than one acre of land. Smaller lots generally are not acceptable for safety and noise reasons.

The economics of a 5 to 10 kw residential system are sensitive to the average wind speed and the cost of electricity. As a general rule, an economical system requires an average wind speed of at least 10 MPH at the turbine's location. 

Solar photovoltaic panels

Solar photovoltaic panels (PV) generate direct current electricity. These solar cells consist of positive and negative layers on a silicon wafer. Sunlight striking the panels is absorbed, freeing electrons in the silicon crystal. Electrons activated by the sunlight move through the crystal and out to the load or battery. This type of electric generation is typically 10 to 15 percent efficient; meaning 10 to 15 percent of the energy striking the panels is converted to electricity. Research continues to increase this efficiency.

Cost of a PV system depends largely on the application. Systems containing 100 watts or more generally cost between $6 and $10 per watt. Smaller systems are more expensive on a per watt basis.

The cost of the panels is usually one-third to one-half of the total system cost. Each watt of panel typically produces between two and six watt-hours of energy a day depending on the season and location. Solar panels can generate electricity in cloudy weather, although their output is diminished.

Energy produced on an overcast day will be much less than the amount generated on a bright, sunny day.

A typical 3-kilowatt rooftop solar system covers approximately 30 percent of a customer’s monthly electricity needs. This is about enough energy to power the home’s electric water heater each month. The average solar customer relies on the shared electrical grid for about 70 percent of their needs.

Solar infographic

Other resource types:

A complete list of eligible net metering resources can be found in the state specific net metering schedule.

PDF California