Batteries

An uninterruptible power supply is a supply that is not interrupted by the power switching source.  Inverters are the heart of such a system allowing the mains (or other source, i.e. diesel generator) to take over when batteries become depleted.  This type of system is an excellent way of providing power to a house without having to worry that the power is going to go off.

Batteries store the power generated by an energy source for use when it's needed.  e.g.  If your wind turbine is generating power when you're not at home, the batteries can store that power until you need to use it.

Batteries are also useful when large amounts of power are required.  When an oven or other large electricity consumer is turned on, the demand may exceed the output of the turbine but not the batteries.