The batteries can provide power instantly, either directly as DC or via an inverter as AC, thereby ensuring that critical systems continue to operate until emergency generators are ready to take over, or the main electricity supply is restored.
In some instances, the batteries may also be required to support “black start capability” for a power station. This capability is provided for selected power stations to enable them to start operating after a national power cut without relying on power from the external transmission network. Once the power stations with black start capability have resumed operation, they can supply other power stations with energy so that they can also restart. Black start capability is therefore essential for the security of the country’s power supplies.