Solar power systems have enabled many homeowners to generate their own electricity from the sun and reduce their power bills as a result. Most of these solar power systems are installed on homes that use them to help augment the power normally supplied to them the local power utility. This additional free power from the sun simply allows them to buy less of this power each month. These types of homes are usually referred to as grid-connected homes because even though they generate some of their own power, they still rely on the power grid for a portion of their electricity.

Other homes that are located in remote areas and don’t have easy access to power lines are called off-grid homes. Many of these homes use solar power to generate their electricity and unlike grid-connected homes, they have to make additional provisions for their electrical needs when the sun sets. Because these off-grid homes can’t simply buy power in the evenings when the solar panels are dormant, they have to add some type of additional storage mechanism like a bank of batteries that can be used in the evenings and on cloudy days.

In a conventional grid-connected home, the solar power system is normally designed to generate more power than is needed during the day for use by the home. This excess power is then sent back up the power lines to the local utility to generate a credit for the homeowner. Then in the evenings when the home needs additional power, they can buy some power back from the local utility with these energy credits. If the system is balanced correctly the excess generated during the day will cancel out the amount needed in the evenings. This is a critical design criteria since many states limit the amount of credit you can receive to the exact amount of power you typically use. This means that if you size your system too large you’ll be spending money on equipment you don’t need and generating power you won’t be given a credit for.

The challenge for an off-grid stem is that these homes don’t have a local power utility that they can send their excess power to for later retrieval. In the case of an off-rid home, this excess power needs to be stored locally in a bank of batteries. This way when there is excess power being generated during the day, it can be used to charge the battery bank. Then in the evenings when the solar panels are inactive these batteries can be used to feed the inverter and supply the power for the home. As long as this battery bank is sized correctly, this arrangement works well for most off-grid homes.

Another option that many homeowners are using to help with these off-grid homes is to install a small wind turbine that will help to augment the solar power system in the evenings. Unlike solar power, wind power will work around the clock as long as a breeze is blowing. These two styles of alternative energy compliment each other and will provide a very robust solution for an off-grid home.