Choosing a battery installer

By Daan Haket · researched and written with an AI assistant · updated 26 October 2026

The installer you pick decides more than the price. It affects whether you can be paid for exported electricity, whether you pay VAT, and whether your network operator is told. Here is what the official sources say, and a checklist for comparing quotes.

Why MCS certification matters

MCS is the certification scheme for small-scale energy installations in the UK. For a battery it matters in two ways: export payments, and the standard the installation is held to.

SEG requires installation and installer certification through MCS or an accredited equivalent.

“certified through the microgeneration certification scheme (MCS) or a scheme accredited as equivalent”

Source: gov.uk, read 19 October 2026

MCS publishes a battery installation standard.

“MIS 3012: 2025 ISSUE 1.0”

Source: mcscertified.com (PDF, page 1), read 19 October 2026

Compliance with the battery standard is mandatory for contractors certified to the stated MCS framework.

“Compliance with this Standard is mandatory for MCS Contractors certified to MCS: 2025.”

Source: mcscertified.com (PDF, page 6), read 19 October 2026

You can check whether a company is certified on the MCS website before you ask for a quote.

Ofgem directs consumers to the MCS installer search tool.

“MCS have a “Find an installer” tool on their website”

Source: ofgem.gov.uk (PDF, page 19), read 19 October 2026

What your installer should handle for you

Batteries count as generation equipment for your local network operator (DNO), so the installation has to be notified.

The ENA guide gives the single-phase equivalent as 16 A per phase and 3.68 kW.

“16 A per phase corresponds to 3.68 kW”

Source: ssen.co.uk (PDF, page 24), read 19 October 2026

The guide explicitly includes electricity storage devices.

“this includes electricity storage devices”

Source: ssen.co.uk (PDF, page 24), read 19 October 2026

For the described microgenerator notification route, the installer must notify the DNO within 28 days.

“Your installer must notify the DNO within 28 days”

Source: ssen.co.uk (PDF, page 44), read 19 October 2026

The ENA guide says the 16 A limit counts all generation in one home together: 3.68 kW on a single-phase supply and 11.04 kW on a three-phase supply.

“16 A per phase corresponds to 3.68 kW on a single-phase supply and 11.04 kW on a three-phase supply and refers to the aggregate micro-generator capacity installed in a single premises”

Source: ssen.co.uk (PDF), read 22 October 2026

The ENA guide says a battery used together with solar panels is likely to take the total above 16 A per phase, so EREC G99 applies.

“electricity storage devices in conjunction with PV (or other technologies) to offset consumption, the total connected generation is likely to be above 16A / phase and hence EREC G99 applies”

Source: ssen.co.uk (PDF), read 22 October 2026

The ENA guide says network operators run a fast-track application for some home-scale batteries, last revised in November 2022.

“DNOs have implemented a fast-track application process (last revised November 2022), for some domestic scale electricity storage”

Source: ssen.co.uk (PDF), read 22 October 2026

Ask every installer to confirm in writing that they will make this notification, and whether your system needs permission before it is connected.

VAT: installed, not just bought

HMRC includes retrofitting a battery to store electricity generated by qualifying energy-saving materials.

“the retrofitting of a battery for storing electricity generated by one or more qualifying energy-saving materials (solar panels, wind turbines and water turbines);”

Source: gov.uk, read 19 October 2026

HMRC includes installing a standalone battery to store grid electricity.

“the installation of a standalone battery for storing electricity from the grid (the mains electricity);”

Source: gov.uk, read 19 October 2026

Supplying energy-saving materials without installing them is standard-rated.

“However, if you supply energy-saving materials without installing them your supply will be standard-rated.”

Source: gov.uk, read 19 October 2026

In practice this means the VAT relief comes with an installation. Buying a battery online and having it fitted separately can cost you the relief.

What a battery typically costs

Energy Saving Trust states that battery storage tends to cost around £5,000 to £8,000.

“Battery storage tends to cost around £5,000 to £8,000.”

Source: energysavingtrust.org.uk, read 19 October 2026

Your own quote can differ a lot from this range. The calculator lets you test the price you are actually offered.

A checklist for comparing quotes

Ask each installer for the same things, so the quotes can be compared line by line:

Usable capacity in kWh, not just the “nominal” size. Usable is what you can actually use.
Power in kW: how much the battery can deliver at once (an oven, a heat pump and a kettle together).
Warranty: years, and any limit on the energy throughput or cycles, and the capacity left at the end.
Inverter: will your existing solar inverter stay, or be replaced (AC- or DC-coupled)?
Extras priced separately: scaffolding, a consumer unit upgrade, an export-capable smart meter, monitoring.
Paperwork: MCS certificate, the network operator notification, and the documents you need to apply for export payments.
Backup: does the system keep some circuits running in a power cut, and what does that add to the price?
Payment terms: how much deposit, when the rest is due, and what protection you have if the company fails.

Get more than one quote. Prices and system designs for the same house can be very different.

Compare your quotes

Compare the installed price, the usable capacity and the warranty limits on each quote. Nothing you type leaves your browser.

	Quote A	Quote B	Quote C
Installer
Total price incl. installation (£)
Usable capacity (kWh)
Warranty (years)
Warranted throughput (MWh)If the warranty states one. Leave empty if not.
£ per usable kWh
£ per warranted kWhOnly when you enter the warranted throughput
£ per kWh at one cycle a dayOur assumption about use over the warranty years, not a guarantee

“£ per warranted kWh” divides the price by the throughput (MWh) in the warranty document: a manufacturer figure. “£ per kWh at one cycle a day” divides it by usable capacity × 365 × warranty years: our assumption about use, not something anyone guarantees. Many warranties end at a throughput limit before the years run out, so the two lines are not interchangeable. A low figure only means a cheaper kWh of storage; a battery too big for your evenings can look cheap per kWh and still save less. Check power, backup and what is included as well. To compare the quotes on payback, run each price and size through the calculator with the same tariff and export rate.

Warning signs

Reasons to slow down, whoever you are dealing with:

A discount that is only valid if you sign today.
Savings promised as “up to” a figure, without a sum based on your own bills.
No mention of usable capacity, power in kW or the warranty terms in writing.
A large deposit before any work is scheduled, with no explanation of how it is protected.
No MCS certificate number you can check yourself.
Reluctance to say who notifies your network operator.

Before you sign

Run your own figures through the payback calculator with each quoted price.
Check the installer on the MCS website.
Compare the quotes above on £ per usable kWh and £ per warranted kWh.
Read the hidden costs and ask about each one.
Check that your export tariff and smart tariff work with the battery you are offered (see export rates and smart tariffs).