Before you read on, the VAT position is worth a quick look. See do home batteries qualify for 0% VAT for the detail.
Why a battery is worth adding to solar
Solar panels make most of their power in the middle of the day. That is exactly when most homes use the least. Without a battery, that surplus is exported to the grid for a few pence a unit.
Add a battery and the surplus is stored instead. You use it in the evening at full value, rather than buying power back at the standard rate of 26.11p. Your panels finally work the hours you do.
Most people who fit solar without a battery come back for one. It is the upgrade that makes the panels pay properly. See how battery storage installation fits around an existing system.
How the retrofit works
The usual route is called AC coupling. We add a separate battery inverter next to your existing solar inverter. Your panels and your current inverter stay exactly as they are. This works with almost any system, including older string inverters.
If your system already runs a hybrid inverter, one unit that handles both solar and a battery, the retrofit can be simpler still. The battery may connect straight through it.
A typical retrofit does not touch the roof. We survey your inverter, meter and consumer unit, mount the battery on a wall or floor, wire it in with the right protection, then commission it and set up monitoring. Most jobs are done in a day.
Will it work with an older system?
Usually, yes. Many solar systems installed years ago retrofit without trouble, as long as the existing install is safe and compliant. We confirm that at survey.
We are not tied to one manufacturer, so we match the battery to your setup rather than forcing a fit. Our own engineers do the work to BS 7671 wiring standards under MCS certification, and we handle the network operator notification as part of the job. You do not fill in a single form.
If you do not have solar yet, a battery still works on cheap night rates alone. Adding solar later means the battery fills itself from your roof for free.
