Domestic batteries allow you to:
- Buy cheap electricity at off peak rates
- Sell electricity back to the grid at peak rates
- Store surplus power from PV Solar panels until it is required
- Provide back up in the event of a power cut.
Domestic batteries are being increasingly installed in combination with solar photovoltaic panels in order to store surplus power until it is required. It also allows you to buy cheap electricity at off peak rates and sell electricity back to the grid at peak rates. Batteries also allow you to provide electrical power in the event of a power cut.
The installed cost of a Tesla Powerwall 2 starts at £7700 + VAT (June 2021). The units measure 1,150 mm tall, 755 mm wide, and 155 mm deep and hold 13.5 kWh of electricity when fully charged giving a cost of around £570 + VAT per kWh (June 2021).
Most backup systems are wired into the building mains to provide backup either to the entire building or to a particular set of circuits. Both set-ups work on the same principle that you need to create an ‘islanded’ electricity network which must be isolated from the grid mains by means of a changeover switch. The only difference between complete and partial backup is the physical arrangement of the parts.