Choose the right home battery storage for you

Grid services already exist in industrial and commercial energy markets. National Grid and the District Network Operators pay for grid balancing services to minimise risk of blackouts due to supply-demand mismatch. As an example, a factory that uses a lot of electricity may be paid not to operate during a period of high energy demand or when the local network is under strain. Owners of large scale batteries can also be paid to soak up excess generation or release when top up levels are required. The unit rate charged for the electricity bills for large commercial properties can vary every half hour (higher rates at times of peak demand) so commercial scale storage can be deployed to be used at peak hours, reducing the need to draw expensive energy from the grid.

It would be difficult for a single domestic scale battery to operate in the same manner as large commercial businesses: requiring half hourly billing, a plethora of contracts, and a means to control the battery in response to the signals from the grid. This is why we’re building a network of small-scale batteries, which when aggregated together can be utilised like large scale storage to help manage the peaks and troughs of energy production and customer demand for energy, thereby supporting the growth of renewables and small scale generators.

The grid services contract with the domestic battery owner is for ten years. We pay the battery owner upfront for access to the battery, in one lump sum as a discount off the price of the Powervault 3 battery (£1,560 for 4.1kWh or £2,060 for 8.2kWh battery, respectively). This is equivalent to £150 or £200 per year across the ten years of the grid services contract, depending on battery capacity. We recognise that investing in a solar battery can be a significant expense for householders, so we have given the discount upfront rather than a payment per year. Grid services with home solar batteries form a new part of the energy ecosystem, so we’re taking the financial risk on return, rather than the battery owner. 

The home batteries will all operate as a group, not individually, so an individual battery will not be responding to peaks and troughs of the grid by itself. As an example, in 24 hour period, the householder may see additional charge being fed to the battery during the night if there was excess wind energy available on the grid, but there is not enough demand on the network to make use of it. Alternatively, during the peak demand hours of early evening the battery would be used to power the house completely.  Effectively, it’d remove the household’s consumption from the grid, thereby reducing demand. At all times the health of the battery is monitored and shown in the Powervault portal, where the amount of charging up, discharging and energy savings can also be seen.

You, as the Powervault battery owner, can leave the grid services contract at any time and will be charged the discount, pro-rated on length of time remaining in the grid services contract. You can read the full terms & conditions here.

Whether you take up grid services or not, you can still make significant energy bill savings by upgrading your solar PV system with the Powervault 3 battery storage, saving your generated power for use later in the day and/or charging on cheap overnight electricity.