A stand-alone solar electric system consists of 4 basic parts:
- Photovoltaic (solar electric) panels,
- Charge controller,
The photovoltaic panels make DC electricity, which is fed to the charge controller. The controller feeds the current to the batteries at a regulated rate. The batteries store electricity for when it is needed and then sends it to an inverter . An inverter is an electronic device which takes the direct current from the batteries and changes it to alternating current (AC). Most households run on AC because AC wiring is cheaper and somewhat safer than DC wiring. Inverters are made to convert from 12, 24, 48, 225 volts DC to 120 or 240 AC. The AC output of inverters is either a modified sine wave or true sine wave. Most residential systems use modified sine wave inverters, which are somewhat less expensive.