In addition to the solar panels, the Alcohol Education Trust also decided to invest in a Tesla Powerwall battery. This battery storage allows them to make the most of the energy they are generating. The Powerwall stores energy generated from the panels (up to 13.5 kWh) which can then be used when they are not generating on very cloudy days or at night.
The financial savings from solar PV depend on how much of the energy generated is used and how much needs to be exported to the grid. This is because the price you pay to import electricity from the grid is significantly higher than the price you get paid for exporting/selling electricity to the grid.
Battery storage gives greater control over how and when you use the energy you generate, allowing you to replace electricity bought from the grid with the free electricity your panels are generating. It also provides a back-up in the case of power cuts and ensures the café’s fridges and freezers keep running.
Although batteries are currently expensive, the cost of this technology is falling and it is expected to become more affordable in the coming years as battery systems are more widely adopted.