This system derives its energy from the sun and uses it to help power the house. The system is also electrically grid-tied, eliminating the need batteries, which provide electricity to the house when photovoltaic PV is not producing.
When the system produces more power than the house needs the extra power flows back into the utility grid. The power is sold, and flows to the nearest neighbor who needs it. They are essentially also using renewable-energy!
On the roof of the house are 20 solar-electric collectors. They are called photovoltaic, or PV modules, and they convert sunlight into electricity. In sun level with high irradiance values all the PV modules together can produce about 2.5 kilowatts of electricity.
The electricity from the groups of PV modules (called a PV array) travels through various safety devices and is then converted from DC to AC power that the house uses. The machine that changes the PV power into the household power is called an inverter, and it has other important jobs. It works with the utility power to manage the changing needs of the house and the changing production of the PV array.
A Copper Cricket solar water heating system was installed on the roof of the home. This is a passive, self-pumping, self-regulating solar water heater. It requires no electric power, pumps, valves, or moving parts making it almost maintenance free. The sun's power is harnessed to transport solar heated water from a collector to a hot water tank when there is sufficient solar radiation and remains dormant when there is not. And, if solar radiation is available but not sufficient to fully heat the water, the Copper Cricket can still function by providing preheating for water before it is fed into the electrical water heating unit. In this way, the Copper Cricket helps to reduce electrical energy needed for water heating.