Store more of the solar energy you generate. Explore battery installation and retrofits, compare equipment and find the right questions to ask.
The companies below have not provided enough specific coverage information for postcode matching here. Check their stated areas and confirm your postcode directly before booking.
Selected from reviewed company information. Latest review: 2026-09-19. This is a starting list, not a ranking or endorsement.
Office: By Stair, Scotland
Solar and Wind Applications offers solar PV installation, battery retrofits and maintenance. It also says it can repair PV systems installed by other companies.
Confirm service area directly.
Ask about your projectOffice: Farnham, South East
DJK Renewables offers solar PV and battery installation, and describes using Enphase microinverters and IQ batteries. Confirm the proposed models and current manufacturer status directly.
Confirm service area directly.
Ask about your projectOffice: Cottingham, Yorkshire and The Humber
East Riding Energy offers solar panel and battery installation and maintenance. It describes Tesla Powerwall installations and UK-wide coverage for commercial solar projects.
Stated area: UK-wide commercial solar projects
Ask about your projectOffice: Sevenoaks, South East
Evolve Renewables describes domestic and commercial solar work delivered with installation partners. Its equipment information includes SolarEdge inverters and battery options; confirm the contracting installer and final specification.
Confirm service area directly.
Ask about your projectOffice: Carnforth, North West
Lakes Solar offers residential and commercial solar and battery storage. It describes Sunsynk battery and hybrid-inverter installations and support; manufacturer accreditation claims should be checked separately.
Confirm service area directly.
Ask about your projectOffice: Taunton, South West
SolarGain offers solar PV and battery installation. Its stated battery brands include Sigenergy and Fox ESS, with system selection based on the property and electricity use.
Stated area: Somerset, Devon, Cornwall, Dorset, Avon
Ask about your projectOffice: Oakham, East Midlands
Redmile Energy designs and installs battery storage, either alongside a new solar PV system or as an addition to an existing installation.
Confirm service area directly.
Ask about your projectOffice: Chesham, South East
Chiltern Solar describes solar PV and battery storage services for homes and businesses across southern England.
Stated area: southern England
Ask about your projectA retrofit enquiry starts with the system you already own. Send the installer the make and model of your inverter, the solar array size, installation date and any monitoring data. Ask whether their proposal retains your current equipment or replaces part of it, and have that decision explained in the quotation.
Ask for a compatibility assessment rather than choosing a battery by brand alone. Request a diagram showing how the proposed battery connects, which inverter controls it and whether the existing monitoring app will still show the whole system.
Request one coordinated design for panels, inverter and storage. Ask the company to explain how it arrived at the panel and battery sizes, and to separate the battery’s additional cost from the rest of the installation.
Solar and Wind Applications and Redmile Energy explicitly describe retrofit or existing-system battery work in our reviewed company information. That makes them relevant starting points for this type of enquiry; it does not establish compatibility with every system or coverage of your address.
Battery capacity in kWh describes stored energy. Power in kW describes how quickly energy can be supplied. Ask for both figures: a capacity figure alone does not tell you which appliances the installation can run together.
Give each installer the same electricity-use information, ideally including when you use it. Ask them to explain their proposed size against daytime solar generation, evening demand, charging opportunities and any reserve you want to retain. Request a smaller alternative if you want to understand what the extra capacity buys you.
Do not assume the quoted battery package includes backup. Ask the installer to state whether it operates during an outage, which circuits it would supply, the output limit, any additional equipment and how the changeover works. Put essential appliances on your enquiry so the proposed design can be checked against them.
Energy Saving Trust explains that batteries can store solar electricity or charge using a time-of-use tariff. Storage involves energy losses, and savings may not justify the upfront cost. Read its battery storage guidance.
A battery price and an installed-system quotation answer different questions. Before comparing totals, check that each proposal covers the same equipment and work. Our reviewed listings do not provide enough comparable quotations to calculate a directory-wide average installed price.
For independent context, Energy Saving Trust gives around £4,600 for a 5kWh battery system in its guidance updated 19 August 2026. This is its indicative figure, not a quotation from the companies here or a guaranteed total for your property. Check the source and its context.
| Item | Details to compare |
|---|---|
| Battery and inverter | Exact models, quantity, usable capacity and charge/discharge power. Identify any existing equipment being replaced. |
| Electrical and building work | Cabling, consumer-unit work, mounting, access, making good and removal of old equipment. List exclusions. |
| Backup | Included circuits, gateway or other equipment, changeover arrangements and additional cost. |
| Total and payment | A complete installed total, VAT treatment, deposit, payment stages and quotation expiry. |
| Warranty and support | Product and workmanship cover separately; who diagnoses faults and pays for visits, labour and replacements. |
| Forecasts | Consumption, generation and tariff assumptions, losses, export income and ongoing costs behind any savings estimate. |
Request the forecast in writing with its assumptions visible. Ask what happens if your tariff changes, electricity use shifts or the battery is used less than expected. A comparison that gives you the assumptions is more useful than an unexplained payback headline.
Use the company’s listing to check the services it describes, then ask about recent installations similar to yours. Confirm which team carries out the work, who is responsible for aftercare and whether it supports equipment installed by another business. Check accreditation and manufacturer-authorisation claims with the relevant organisation.
If you have a particular product in mind, our Tesla Powerwall installer guide brings together the reviewed companies mentioning that brand and links to Tesla’s installer finder. Brand availability alone does not establish suitability for your home.
For an existing system with a fault, start with solar panel repairs and inverter diagnosis so you can distinguish the repair work from a proposed storage upgrade.
Guide reviewed by the SolarInstallersUK directory team on 19 September 2026. General guidance sources: Energy Saving Trust and Energy Networks Association, linked above. Installer services come from the dated company sources on each listing; inclusion is not independent certification or a recommendation.
Some companies listed here explicitly offer retrofits. Ask the installer to assess your existing inverter, battery compatibility, available space and electrical installation before recommending a system.
Request the usable capacity, exact battery and inverter models, installation work, monitoring, backup capability if required, warranty terms and total price including applicable VAT. A hardware-only price is not an installed quote.
No. The reviewed company information does not provide enough comparable, current installed packages to support one. Request a site-specific quotation.
Tell us about your property and project. We’ll try to match you with local or nationwide installers, confirming the proposed companies with you before sharing details.
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