Warm Homes Loan for solar panels and batteries: what the £15,000 caps cover

Quick answer: how do I get a loan for solar panels?

Under the Warm Homes Loan Scheme you apply to one of the ten lenders named on GOV.UK, not to the government. The scheme covers up to £15,000 for solar panels and up to £15,000 for a battery, and a battery can be funded without solar. The business doing the work must be MCS certified for that technology. The government's contribution is a grant to the lender, up to 20% of the loan, which has to be passed on as a lower interest rate: up to 5 percentage points below the lender's own rate for a similar loan, on terms of three years or more. Lenders set the actual rates. GOV.UK publishes none, and we could not find a lender rate card or APR on 28 October 2026. The application steps are in our step-by-step guide, and the ten lenders are in our lenders guide.

What are the Warm Homes Loan caps for solar panels and batteries?

Source: DESNZ, Warm Homes Loan Scheme Rules (version 3, September 2026) and factsheet, accessed 28 October 2026. Heat pump caps are separate (£20,000 air-to-water and £35,000 ground source, before any Boiler Upgrade Scheme grant) and are outside this guide.

The caps apply to the total cost including ancillary work, and DESNZ reserves the right to change them over time. For solar and a battery together, the Scheme Rules list two separate £15,000 caps. One lender, Sunsave, states £30,000 for the pair on its own page, so ask any lender how it applies the caps to a combined job.

Can I get a Warm Homes Loan for a battery only?

Yes. A battery can be funded on its own or paired with solar, up to £15,000. Standalone batteries have also been zero-rated for VAT since 1 February 2024, so the installation relief applies whether or not you are fitting panels.

Does the firm fitting my solar panels have to be MCS certified?

Yes. The business must be MCS certified for the specific technology at the point of installation, and the product must be MCS certified. There is no scheme-level approved list: your quote needs the business's MCS number, and lenders check it against the MCS register at quote stage and after the work. Lenders can add their own approvals, though. The DESNZ factsheet says some work only with specific firms and others accept any MCS-certified firm, and Tandem Bank says it lends only through firms it has approved. You cannot do the work yourself.

Our installation teams are MCS-certified and fully insured. Whether a particular lender accepts a particular firm is the lender's decision, so ask the lender before you rely on it. Our guide to what MCS certification is explains the scheme, and how to check a certificate is genuine covers the paperwork.

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What does the £15,000 cap typically cover, in Clearline's own prices?

For scale, here are the prices already published on our own product pages, each installed and including 0% VAT, set beside the cap for that measure. These are cash prices for the work. They are not loan quotes, and they are not a statement that any lender will fund them.

Clearline package prices as published on our solar panels and battery storage pages, checked 28 October 2026. All include 0% VAT, which ends on 31 March 2027. The Duracell packages are priced for fitting with new solar, and the Powerwall 3 prices are "from", subject to survey.

Two things follow. A ten-panel array or any one of these batteries sits inside its own cap. And because the Rules list solar and battery as separate caps, a combined job priced above £15,000 is not by itself a problem, though you should confirm with the lender how it applies them. The cap counts total costs on the quote, so extras on the same quote, such as an EV chargepoint, count towards it. Our battery cost page and solar cost guide explain how those prices are built.

How does a solar loan work?

A Warm Homes Loan is an ordinary loan with a government subsidy inside it. You borrow from a participating lender, which decides whether to lend to you, sets the rate and chooses how to pay out: upfront, as a deposit, direct to the firm, or after the work is verified. After the installation is verified, DESNZ pays the lender a grant of up to 20% of the loan, and the lender must pass it on by lowering the nominal interest rate. The cut is meant to be up to 5 percentage points off the rate the lender would charge for an equivalent loan without the subsidy, and where the 20% cap bites, which is more likely on longer loans, the cut is smaller. The grant cannot take the rate below zero.

• Term. Grant support is only available for loans of three years or more. The DESNZ factsheet says some lenders offer up to thirty years, and MoneySavingExpert warns that higher rates often apply above 20 years.
• Type of loan. Unsecured personal loans, including point-of-sale finance offered alongside a quote, and secured personal loans as a first or second charge mortgage. MoneySavingExpert warns that a longer term raises the total cost.
• Rate. The Scheme Rules use nominal annual fixed rates, which are not the same as APR, so ask a lender for both.
• Not covered. Subscription, leasing and property-linked products, and lending to businesses, are not supported in the first phase.
• Checks. The lender runs credit and affordability checks. The scheme itself has no income test.

The government's factsheet carries its own worked example of what the subsidy can save. We do not reproduce repayment examples or monthly costs here, because they depend on a lender's rate, term and fees, none of which is published yet. Read the DESNZ factsheet and the Scheme Rules for the official position. The live status of the scheme is on our Warm Homes Loan page, and our Warm Homes Plan guide shows where the loan sits alongside the Boiler Upgrade Scheme and the Local Grant.

Is a solar loan worth it?

It depends on three things you can check: the total you will repay compared with the cash price, what the money would otherwise do, and what the system saves you. We cannot answer it with a number, because GOV.UK publishes no rates and we found no lender rate card or APR on 28 October 2026. What we can do is set out how to test it.

• Total repayable against cash price. GOV.UK's factsheet tells you to compare the total repayable, the term and any monthly fees. A longer term lowers each payment but raises the total, and it also shrinks the subsidy, because the grant is capped at 20% of the loan.
• A benchmark for ordinary loans. MoneySavingExpert's 26 October 2026 report put the cheapest mainstream personal loans at typically about 5.9% APR for £7,500 or more. That is a benchmark for ordinary loans, not a Warm Homes Loan rate.
• The price of the work itself. MoneySavingExpert also warns that firms offering subsidised loans could raise the product price, so compare the cash price for the same work with and without the loan.
• What the system saves. The government says a heat pump, battery and solar together could save up to £550 a year, and a further £300 with a time-of-use tariff. That is a government estimate for that combination, not a result. For solar and a battery alone, work from your own bills; our guides to whether solar panels are worth it and whether a battery is worth it without solar show how.

Take the pessimistic reading of each: the highest total repayable a lender quotes you, against the lowest saving you can verify. If the loan still comes out ahead on those numbers, it is worth considering. If it only works on the optimistic ones, it is not.

Is 0% VAT still available on solar and batteries?

Yes, for now. HMRC's VAT Notice 708/6 has installations of solar panels and batteries in homes zero-rated until 31 March 2027, reverting to the reduced rate of 5% from 1 April 2027. The relief covers installations: supplying materials without installing them is standard-rated. The 28 October 2026 Budget did not extend the relief: the Red Book lists the return to the reduced rate as planned (paragraph 6.215), so 5% applies from 1 April 2027. The loan does not extend the date, and the relief does not depend on borrowing. Our VAT guide and VAT deadline guide cover the detail.

Caps, rules and dates were checked against GOV.UK, the DESNZ factsheet, the Scheme Rules and HMRC on 28 October 2026, and Clearline prices against our own product pages the same day. This guide is factual information about a government scheme, not financial advice. Confirm every detail with the lender before you apply.