Keeping Your Feed-in Tariff When You Upgrade

Yes, you can usually upgrade a Feed-in Tariff system and keep your FIT. Ofgem's rules allow batteries to be added and equipment to be replaced without affecting accreditation. What changes the answer is how the upgrade is done, and in particular how it affects your meters.

The Feed-in Tariff closed to new applicants from 1 April 2019, but existing installations continue to be paid for their eligibility period. For most that is 20 years, and many solar systems registered before August 2012 have 25. For many homes that still means years of payments, so it is worth protecting them.

Key points

• Adding a battery does not affect FIT accreditation, provided your generation can still be measured separately.

• Extra panels added since 15 January 2016 earn no FIT, and shared meters are pro-rated.

• Replacing an inverter is allowed. Tell your licensee.

• A smart meter can end deemed export payments.

• You cannot be paid FIT export and Smart Export Guarantee export for the same electricity.

• Always tell your FIT licensee before you change anything.

Deemed export or metered export? Find out first

Everything below depends on how your export is paid, so check your FIT statement before planning anything.

• Deemed export is the most common for domestic systems. You are paid for a share of your generation as if it were exported, whatever you actually send to the grid. For solar, the government currently sets that share at 50 per cent of your generation meter reading, for the FIT year running to 31 March 2027. It is reviewed each year.

• Metered export means an export meter records what you actually send to the grid, and you are paid on that.

Adding a battery

Ofgem's guidance says battery storage may be added to an installation without affecting its accreditation, as long as the metering rules are still met. The key rule is that your generation meter must measure only what your panels generate, and not electricity from any other source.

How that works depends on where the battery connects:

• AC-coupled battery, alongside your existing inverter. The battery sits after your generation meter, so the meter still measures only your panels and your FIT generation readings are unaffected.

• Hybrid inverter replacing your old one. The battery sits before the generation meter. If it can charge from the grid, Ofgem's guidance says the rule can be satisfied with a bi-directional meter that shows a net value. That is what we fit on hybrid replacements. Because that meter records a net figure, Ofgem notes that battery charging losses are likely to reduce your FIT generation payments somewhat, and that in a month where the net figure is negative, no FIT can be claimed. A standard smart meter does not count as a bi-directional meter. If the battery is set so it can only charge from your panels, the existing generation meter can stay.

Deemed export can continue with a battery, provided the generation meter measures only your panels.

Metered export is where care is needed. Ofgem's guidance on co-located storage says that where it is not possible to tell whether the export meter is measuring export from your FIT installation or from another source, such as grid electricity stored in the battery, you are not entitled to export payments. Whether any alternative, such as deemed export, is available is for your FIT licensee to decide, so ask before the battery goes in.

You must tell your FIT licensee when a battery is added, usually with an updated wiring diagram and meter details.

Adding more panels

This is the one to check most carefully. Ofgem's guidance says any extension to an accredited FIT installation commissioned on or after 15 January 2016 is not eligible for FIT support, for generation or export.

If the new panels share a meter with the original system, your readings are split in proportion to installed capacity, and only the original share is paid. Ofgem's own example: a system extended by a quarter of its original size would be paid FIT on only 80 per cent of what the meter records.

That does not mean adding panels is a bad idea. The electricity they generate still cuts your bills. Their export can be paid under the Smart Export Guarantee, but only if you opt the installation out of FIT export payments, the extension is MCS certified and you have a half-hourly export meter. If you are on deemed export, that means giving up deemed export on the original panels too, so work out which arrangement suits you first. Either way, the new panels earn their keep through lower bills and export, not through FIT.

Replacing the inverter or panels

Ofgem allows you to repair or replace all or some generating equipment, meaning panels and inverters, without affecting accreditation, provided the installation still meets the scheme rules.

• A replacement inverter should not change your installed capacity, because for solar that is based on your panels.

• Replacement panels with a higher total output than the originals increase your installed capacity, and the increase counts as an unpaid extension.

Our guide to inverter replacement on a Feed-in Tariff system covers this in more detail.

Getting a smart meter

Ofgem's FIT generators page says a smart meter will not affect your generation payments, but if you currently receive deemed export payments, they stop and you are instead paid for the export the meter records.

If you then have, or later add, a battery that can charge from the grid, the metered export rule above applies. Plan the battery and the smart meter together.

Switching to a Smart Export Guarantee tariff

You can keep your FIT generation payments and take your export on the Smart Export Guarantee instead. Ofgem's guidance says you must first opt out of FIT export payments, and you do not have to opt out of generation payments. Being paid for the same export under both is not allowed.

You can change your choice no more than once every 12 months. A Smart Export Guarantee tariff needs a smart meter that records half-hourly export.

Moving house

FIT accreditation is tied to the property, not the owner. If you take your panels to a new home, they are no longer eligible.

If you buy a home with FIT panels, contact the FIT licensee to take over the payments. Ofgem's guidance says it is the new owner's responsibility to get the records they need from the previous owner, so ask for the FIT paperwork and a meter reading on completion.

When does my FIT end?

For most installations the eligibility period is 20 years from the eligibility date, and many solar systems registered before August 2012 have 25. Your FIT statement or licensee can confirm your exact end date.

Before you change anything

1. Find your FIT statement: licensee, eligibility date, and deemed or metered export.

2. Tell your licensee what you plan to do.

3. Make sure your installer designs the metering around your export arrangement.

Frequently asked questions

Will adding a battery stop my FIT?

No, provided your generation can still be measured separately. Tell your licensee. Depending on how it is connected, it may slightly reduce your FIT generation readings.

Can I add panels and still get FIT on them?

Not on panels added since 15 January 2016.

Should I get a smart meter?

It can end deemed export payments, so think it through if you are on deemed export, especially if you plan a battery.

Can I have FIT and SEG?

Yes, FIT generation plus SEG export, but not FIT export and SEG export together.

Request a battery retrofit quotation. We design the metering around your FIT arrangement before anything is installed.