An electricity-generating system that operates independently from the utility grid, providing all of the electricity needed in the home, and is generally more expensive than a grid-tied system.

Ideal for homes in remote locations, stand-alone systems can be more cost effective than extending a power line to the electricity grid; the cost of which can range from $15,000 to $50,000 per mile.*

These systems are also used by people who live near the grid and wish to obtain independence from the power provider or demonstrate a commitment to nonpolluting energy sources.

Successful stand-alone systems generally take advantage of a combination of techniques and technologies to generate reliable power, reduce costs and minimize inconvenience. Some of these strategies include using fossil fuel or renewable hybrid systems and reducing the amount of electricity required to meet the homeowner’s needs.

In addition to purchasing photovoltaic panels, a wind turbine, or a small hydropower system, the homeowner will also need to invest in some additional equipment, called "balance-of-system,” to condition and safely transmit the electricity to the load that will use it.

*http://energy.gov/energysaver/grid-or-stand-alone-renewable-energy-systems