Adding a battery to solar panels on a Feed-in Tariff: 5 questions to ask

12 hours ago

3 min read

You want to add a battery to your solar panels, but you also want to understand what that means for your Feed-in Tariff payments.

Adding a battery is not automatically ruled out by the Feed-in Tariff scheme. Ofgem’s guidance makes accurate measurement of eligible generation, and export where it is metered, central to continued payments. The answer for your home depends on the proposed installation; it should not be reduced to a blanket promise that nothing will change. Read Ofgem’s battery-storage guidance for generators.

These five questions will help you get a clear explanation from your installer and the company handling your Feed-in Tariff payments before agreeing to the work.

1. How are my current payments worked out?

Start with your latest Feed-in Tariff statement and the terms supplied by the company handling your payments. Note the name of that company and any separate export agreement.

Ask them to confirm whether your export payments use a meter reading or an estimate, often described as “deemed export”. Deemed export is based on an estimate; metered export uses the electricity recorded as exported. Ask for the generation and export parts of your statement to be explained separately.

Put the answer alongside your electricity bill. Your spending on imported electricity and the payments you receive for solar electricity should both be visible when you compare proposals.

2. What will change in my installation?

Ask the installer for a simple before-and-after explanation. It should identify the existing panels, inverter and meters, then show where the proposed battery equipment fits.

Useful questions include:

Will my existing inverter remain in place?
Will any meter be changed or moved?
Is any change to the solar array included?
Which parts of the proposal need checking at survey?

You do not need to decide the wiring arrangement yourself. You do need an explanation of the work you are being asked to approve. Keep that explanation with the quote so later revisions can be compared against it.

3. How will eligible solar electricity be measured?

If the battery can charge from the grid as well as your panels, ask how the design distinguishes eligible solar electricity from other electricity. Ofgem’s measurement requirement is why this needs a specific answer for your installation.

Ask your installer to explain how the proposed design meets that requirement. “It works with solar” does not answer the metering question.

4. Who will deal with the required notification and paperwork?

Ofgem says your Feed-in Tariff provider must be notified when battery storage is connected to the accredited installation. Ask your provider and installer which documents they need for your proposal, who will supply them and when.

Make the responsibility explicit before booking work. Keep copies of the proposed design, correspondence and any declarations you are asked to complete. Ask for clarification if a document describes an arrangement that differs from the quote.

A useful written request is: “Please explain the effect of this proposed battery installation on my current payments and tell me which documents you need.”

5. Does the estimate account for my payments as well as my bill?

Ask for a breakdown based on your own electricity use, current agreement and proposed system. Identify any assumed tariff change separately, with a date against the rates used.

You should be able to see which figures are known, which are estimates and which questions remain open. If a proposal assumes an export payment or tariff that you have not agreed to, ask for that to be resolved before relying on the result.

Start with your latest statement

You do not need to solve the metering questions yourself. Start with your latest Feed-in Tariff statement, whatever solar paperwork you have and your electricity bill. Ask for any unresolved questions to be written down before you accept a quote.

For the wider installation conversation, use our checklist before getting a quote for a battery with existing solar panels.

Evoflo is based in Bridport, Dorset. To discuss your existing solar installation, tell us you receive Feed-in Tariff payments when you enquire, so the next steps can take that into account.