Keep your daytime power for the evening.
A battery stores what your panels make at midday for the 5pm to 10pm peak, and charges from the grid at off-peak rates on dark winter days. It is the part of the system that makes the numbers work in Scotland.
Price-cap electricity rate, October to December 2026. What every evening unit costs without a battery.
Typical off-peak rate on EV and smart tariffs. A battery filled then runs your morning for a quarter of the price.
Retrofit and standalone batteries have been zero-rated since February 2024. That ends 31 March 2027.
Why nearly every Forth Solar design includes one
Solar peaks at midday. A house in Musselburgh or Dunfermline uses most of its power between five and ten at night. Without storage, about half of what the panels make goes to the grid at 15 to 18p a unit and comes back a few hours later at the price-cap rate of 26.32p. With a battery, self-consumption goes from around 40% to 70 or 80%, and the money that was leaking out at export rates stays in the house.
Winter
December output is roughly a fifth of June's. That's why we set the battery up on a smart tariff from day one. It fills overnight at around 7p a unit and runs the morning and evening peaks, so it keeps saving money on days when the panels do very little.
How big
A 5.1 kWh battery covers the evening in a typical three-bed home. Homes with an EV, a heat pump or four-plus bedrooms usually justify 10.2 kWh, and modules stack to 15 or 20 kWh where the usage is there. We size from your bills and the solar design together.
Power cuts
East Lothian, Fife and the Angus coast know about outages. With an EPS circuit, the battery keeps lights, fridge, router and boiler controls running when the grid drops. Say so on the form and we design it in.
10-year battery warranty
Lithium iron phosphate cells rated for more than 6,000 cycles. Safer chemistry than the older lithium-ion packs.
Smart tariff ready
Charge schedules for the Octopus, EDF, E.ON and OVO off-peak windows are set up on install day.
Already have panels?
If your solar went in before 2020 you probably have a string inverter and no storage. We can add an AC-coupled battery beside the existing inverter, or swap the inverter for a hybrid unit and DC-couple the battery, which is cleaner and a little more efficient. Either way your Feed-in Tariff payments carry on. Retrofit batteries are zero-rated for VAT until 31 March 2027 and we handle the DNO notification for the extra capacity.
Price my retrofit batteryIs a battery worth it in Scotland?
For most homes, yes. Without a battery around half of what you generate is exported at 15, 18p per kWh while you buy it back in the evening at the price-cap rate of 26.32p. A battery stores the daytime surplus for the evening peak, and on a smart tariff it can also charge overnight at off-peak rates in winter.
What is the Smart Export Guarantee and can I get it?
The SEG pays you for every kWh you export to the grid. Rates in September 2026 run from about 15p to 25p per kWh depending on supplier, and you need a smart meter plus an MCS or Flexi-Orb certificate for the installation. All installations are commissioned and certified through our MCS-registered partner, so you qualify for Smart Export Guarantee payments.
How long does the installation take?
Scaffold goes up the day before, and most residential installs are completed in 1 day. Larger systems or complex roofs can take two. Your smart meter and export tariff application follow once the commissioning certificate is issued.
Find out what size battery your house needs.
Send us a recent bill and your postcode. The written design comes back within 48 hours with the right capacity and one fixed price.