Lasted edited by Andrew Munsey, updated on June 15, 2016 at 1:20 am.
A balance-of-system is needed together with a power source (eg wind turbine, PV-array, ...) to make a working system for homes. It is composed of following parts:
a series of batteries
a charge controller
a inverter or grid-interactive inverter. The whole is also sometimes referred to as "power conditioning equipment"
groundings, safety disconnects and surge protector. The whole is also sometimes referred to as "safety equipment"
battery meters (for charging rate and voltage), and meters for power consumption and electricity provision to the regular power grid