Store the solar power you don't use during the day, or charge on a cheaper overnight rate, and use it in the evening. We fit home batteries with new solar panels or alongside the ones you already have unconfirmed.
Choose your panels and battery online and see an instant quote.
Already have solar panels? Ask about adding a battery
Solar panels make most of their power in the middle of the day, when many homes use the least. Without a battery, the spare goes to the grid for a small export payment, and you buy power back in the evening at the full rate. Solar battery storage keeps that spare power for later.
A home battery can also charge from the grid overnight on a cheaper time-of-use tariff, then run your home through the expensive evening hours. With the right equipment, it can keep some or all of your home running in a power cut.
A battery tends to suit you if:
It may not pay its way if you're home all day using your solar as it's made, or your system is small and rarely has power to spare. If that's you, we'll say so.
We design the panels, a hybrid inverter and the battery as one system, sized to your roof and your usage from the start. The online designer shows battery options alongside the panels.
Most existing systems can take a battery unconfirmed. Depending on your inverter, we fit a battery that works alongside it or replace it with a hybrid inverter that runs both. If you're on the Feed-in Tariff, we set the battery up so your payments carry on as before unconfirmed. Send us a photo of your inverter and a recent bill and we'll tell you what's possible.
A battery can work without panels, charging overnight on a cheap tariff and running your home at peak times. Ask us whether it makes sense for your home and tariff.
We're not tied to one manufacturer. We recommend the battery that suits your home, your inverter and your budget, then install it, set it up and register it.
| Battery | What it's like | Where we've fitted it |
|---|---|---|
| Tesla Powerwall 3 | 13.5 kWh with a built-in inverter unconfirmed; more units can be added; whole-home backup with Tesla's Backup Gateway unconfirmed | Trevor Little's home in Derby; a home with a Powerwall 3, an expansion unit and Backup Gateway unconfirmed until the video is approved |
| Fox ESS | Modular batteries with a hybrid inverter; good value and an easy monitoring app, and a favourite of our installers | Dave Samworth's home in Grantham (10.36 kWh) unconfirmed; a home in Burton-on-Trent (EP12 battery) unconfirmed until the video is approved |
| EcoFlow PowerOcean | Modular batteries with an app and a home display | A home in Hilton, near Derby (two 5 kWh batteries) unconfirmed until the video is approved |
| Enphase IQ Battery 5P | 5 kWh units unconfirmed that pair with Enphase micro-inverters, good for roofs with shading |
We also fit batteries from Sungrow, SolaX and SolarEdge.
The price depends on the battery's size and make, and on whether it goes in with new panels or alongside existing ones. As a guide, our solar systems with a battery start from about £7,000 for 3.68 kW of panels and about £8,100 for 7 kW unconfirmed. For a battery added to panels you already have, the price depends on your current inverter; we'll give you a fixed written quote after the survey.
0% VAT. Batteries fitted to homes, with or without solar, are zero-rated for VAT until 31 March 2027 unconfirmed.
Spread the cost. Finance is available through our finance partners, Hometree and Phoenix. Finance is subject to status.
No pressure. A 14-day cooling-off period on home installations, and a price match promise (terms apply).
Use the online designer, or, if you already have panels, send us a photo of your inverter and a recent bill.
We check where the battery can go, your consumer unit and any existing system. A garage wall or an outside wall usually works; current guidance keeps batteries out of lofts, bedrooms and escape routes unconfirmed.
A battery adds to what your system can export, so we notify or apply to your network operator (DNO) under G98 or G99, as the rules require.
A battery on its own usually takes a day; with new panels, one to two days unconfirmed.
We set up the app and a charging schedule around your tariff, show you how it all works and send your certificates.
A battery does most for you on a tariff with cheaper hours, and we'll talk you through the options when we set it up. Questions about Octopus accounts or tariffs? Octopus can help at hello@octopus.energy.
Eight 480 W LONGi panels, a 3.68 kW inverter and two 5 kWh batteries. Because the inverter is 3.68 kW, the system came under G98: we installed straight after the survey and told the DNO afterwards unconfirmed until the video is approved.
A 5 kW Fox ESS hybrid inverter with an EP12 battery and eight 480 W LONGi all-black panels, powering the house and the car charger. In one month the household's bill was £20, and they earned £30 back in export payments unconfirmed until the video is approved.
Trevor Little's 16-panel GSE in-roof system and Tesla Powerwall 3, fitted alongside his new roof.
Read Trevor's story"…what impressed me most was how proactive the Mercia team were. They installed the batteries first so I could benefit from part of the system straight away, and then returned promptly to complete the panel installation once the scaffolding was sorted."
"Brandon walked us through the process calmly ( and patiently ) answering question after question. He never pushed us into purchasing anything we didn’t require…"
We fit home batteries across Derbyshire, Staffordshire, Nottinghamshire, Leicestershire and the West Midlands unconfirmed.
For many homes, yes, but not all. A battery earns its keep by moving free solar or cheap overnight power into the evening, so it pays best if you use most of your electricity after dark, drive an EV or use a time-of-use tariff. If you're home all day using your solar as it's made, it may not.
The homes we fit usually have between 5 and 20 kWh of storage unconfirmed. The right size depends on how much you use in the evening and overnight, how big your solar system is and your tariff. We size it from your bills and your usage, not from a standard package.
Yes. A home battery can work without solar panels unconfirmed: does Mercia fit batteries without solar?: it charges overnight on a cheap tariff and runs your home at peak times. It suits homes that use most of their electricity in the evening or are on a time-of-use tariff. Ask us whether it makes sense for your home and tariff.
Only if the system is designed for it. Most batteries switch off with the grid for safety unconfirmed. Systems with backup, such as a Tesla Powerwall 3 with its Backup Gateway, can keep some or all of your home running unconfirmed. Tell us if backup matters to you and we'll design for it.
Usually on a garage wall or an outside wall, close to the inverter and the consumer unit. Current guidance keeps home batteries out of lofts, bedrooms and escape routes unconfirmed. We agree the spot with you at the survey, so it's safe, tidy and easy to reach.
Yes. Most batteries can charge from the grid at off-peak times and run your home at peak times, and some tariffs pay more for power you export at set times. We set up the schedule around your tariff. Questions about Octopus accounts or tariffs? Octopus can help at hello@octopus.energy.
Design a solar and battery system online, or call us about adding a battery to the panels you have.
Already have solar panels? Send us a message.
We check where the battery will go, your electrics and any existing system.
A battery sized to how you use power, with a clear written quote.
Installation, grid paperwork, set-up around your tariff, and support.
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