Solar Panel Finance UK
Right, quick honesty check before we start: 0% VAT isn’t actually competing with a loan or a green mortgage. It’s a discount that applies whichever one you pick. Once that’s straight, here’s exactly how the real financing routes compare, with real 2026 rates.
Let’s sort something out before we get into rates and numbers. “Solar panel finance” searches usually turn up a jumble of loans, green mortgages, and 0% VAT all lumped together as if you’re choosing one of three. You’re not, not really. Two of those are ways to pay. The other is a discount on the price, and it applies no matter which of the first two you choose. Once you see that, the whole decision gets a lot simpler.
I’ve gone through the actual 2026 numbers, Nationwide’s own scheme details, current personal loan rates, and what half a dozen other lenders are offering, so you can work out which route genuinely costs you the least.
The Bit Most Guides Get Wrong
0% VAT isn’t a financing option. It’s a tax relief on the purchase price of your solar system, confirmed by HMRC until 31 March 2027, and it applies automatically whether you pay in cash, spread the cost with a personal loan, or borrow through a green mortgage. So the real question isn’t “loan vs mortgage vs VAT”. It’s “loan vs green mortgage vs cash” — and 0% VAT quietly reduces the bill either way.
0% VAT, Explained Properly
Since April 2022, residential solar panels, battery storage and the associated installation labour have carried 0% VAT in Great Britain, instead of the standard 20% rate. HMRC confirmed this stays in place until 31 March 2027, after which it’s due to revert to 5%. You can read the official rules in HMRC’s VAT Notice 708/6 on GOV.UK.
The important bit: it applies automatically when you buy supply and installation together from an MCS-certified installer. You don’t apply for it or claim it back, the installer simply charges you 0% VAT on the invoice. On a typical £7,000 4kWp system, that’s the difference between paying £7,000 and paying £8,400 at the standard rate, a saving of £1,400 baked straight into the price before you’ve even thought about how you’re funding the rest.
Multiply your quoted system price by 0.20. That’s roughly what you’re saving compared with the standard rate. Our UK Solar Grant & VAT Savings Checker does this automatically and flags any other grants you might be eligible for at the same time.
Personal Loans for Solar Panels
A personal loan is the most straightforward way to spread the cost if you don’t want to touch your mortgage. You borrow a fixed amount, pay it back monthly with interest, and own the system outright from day one. In 2026, standard unsecured personal loan rates for good credit typically sit around 5% to 15% APR, with the exact rate depending heavily on your credit score, income, and the loan term. Loans specifically labelled “green” or “eco” by a lender are often 1 to 2 percentage points cheaper than the equivalent standard loan, since the bank is factoring in the lower risk profile of an asset that reduces your bills.
A few things worth knowing before you sign anything:
- Compare the total amount repayable, not the monthly figure. A longer term looks cheaper month to month but usually costs more overall once interest adds up.
- Credit unions are worth a call. Regional credit unions sometimes beat high-street bank rates for members, particularly for shorter-term borrowing.
- Watch installer “0% finance” carefully. Genuinely interest-free installer finance exists, but it’s common for the underlying system price to be quoted 10–15% higher than the cash price to cover the cost of offering “free” credit. Always ask for the cash price separately and compare.
- Check the lender is FCA-authorised. You can verify any UK lender at register.fca.org.uk before handing over any details.
If you’re still working out what size system you actually need before pricing up a loan, our solar panel calculator is a quick way to get a realistic figure to borrow against, and our guide to solar panels for a 3-bedroom house breaks down typical costs by system size.
Green Mortgages, Explained Properly
“Green mortgage” is a commercial label, not a regulated product category, there’s no single legal definition, and every lender sets its own rules. In practice it means one of three things: a discounted interest rate for an already energy-efficient home (usually EPC A or B), a cashback reward for installing solar or similar measures, or extra borrowing on top of your existing mortgage specifically to fund the work. The number of these products has exploded, from around 4 in 2019 to over 90 by 2026, according to the Green Finance Institute.
If you’re an existing Nationwide mortgage customer, this is very likely the cheapest way to finance solar panels anywhere in the UK right now. You can borrow £5,000 to £20,000 at genuinely 0% interest, repaid over 2 or 5 years, provided your combined loan-to-value stays under 90% and every penny goes on qualifying energy improvements, solar panels and battery storage both count. You need to have made your first mortgage payment before applying.
Nationwide expanded the scheme in March 2026 to support 10,000 households, and has lent around £60 million since launch at an average of roughly £13,000 per household, enough to cover a fully installed 4kWp system with battery storage outright, interest-free.
Other major lenders take a different approach, usually rewarding an already-improved EPC rating rather than lending interest-free for the work itself:
| Lender | What’s on offer | Typical requirement |
|---|---|---|
| Nationwide | 0% additional borrowing, £5k–£20k | Existing mortgage customer |
| Skipton BS | Green additional borrowing up to £50k | 50%+ of loan on green works |
| Halifax / Lloyds | Up to £1,000 cashback (solar/battery) | EPC A/B or qualifying install |
| Barclays | Up to £1,000 cashback | Existing residential mortgage customer |
| HSBC | Cashback up to roughly £500–£750 | EPC A/B rating |
| NatWest | Rate reduction + green additional borrowing | EPC A/B rating |
| Santander | Up to £500 cashback | Additional borrowing for energy works |
| Ecology Building Society | 0.25% rate discount per EPC band improved | Specialist, more flexible criteria |
Standard mortgage further-advance rates for green borrowing outside these dedicated schemes typically run at around 4–5%, broadly tracking the Bank of England base rate, which has been held at 3.75% since the June 2026 meeting. It’s a lower rate than most personal loans, but remember you’re paying it over a much longer term, so the total interest can end up higher even though the monthly cost looks smaller.
A mortgage, and any additional borrowing secured against your home, is a loan secured on your property. Your home may be repossessed if you do not keep up repayments on your mortgage or any other debt secured on it. This isn’t specific to solar borrowing, it applies to any secured lending, but it’s worth taking seriously before extending a mortgage rather than using unsecured credit.
There’s a genuine secondary benefit worth knowing too: solar panels typically add 6 to 10 SAP points to your home’s energy rating, often enough to move a Band D property into Band C. Homes with solar panels have been shown to sell for around 6–7% more than comparable homes without, which on a £280,000 property is roughly £18,800 in added value, separate from anything you save on bills. That improved EPC can then unlock a better green mortgage rate on your next remortgage, even if you didn’t have one when you first installed.
The Numbers, Side by Side
Here’s how it actually plays out on a typical £7,000 4kWp system, the size solarbriton readers most often ask about. All figures already include the 0% VAT saving, since as we covered above, that applies regardless of how you pay.
Illustrative example only, based on a £7,000 system and the rates discussed above. Your own quote, credit profile and lender eligibility will change these figures, always get a personalised illustration before deciding.
| Feature | Personal Loan | Green Mortgage | Cash + 0% VAT |
|---|---|---|---|
| Typical rate | 5–15% APR | 0–5% APR | N/A, no interest |
| Speed to arrange | Days | Weeks | Immediate |
| Secured against home? | No | Yes | No |
| Credit check needed? | Yes | Yes | No |
| Best for | Non-Nationwide customers | Existing Nationwide customers | Anyone with savings available |
Which One Should You Actually Pick?
Take the 0% Green Additional Borrowing
- Genuinely interest-free, no catch on the headline rate
- Covers most full residential systems outright
- Apply once you’ve made your first mortgage payment
Pay cash, keep it simple
- No interest, no credit check, no paperwork delay
- Still benefits from the same 0% VAT saving
- Weigh up against what that cash could earn elsewhere first
Shop personal loan rates properly
- Try your own bank and a credit union before an installer’s finance
- Compare total repayable, not monthly cost
- Ask installers for the cash price to check for finance markup
One more sense-check worth doing regardless of route: compare your expected monthly repayment against your expected monthly saving. Our SEG income estimator can help you work out the export income side of that equation, on top of the roughly £820 a year most solarbriton readers save from a 4kWp system in reduced bills alone.
Other Routes Worth Knowing About
Loans, green mortgages and 0% VAT cover most homeowners, but they’re not the whole picture. If you’re on a lower income or don’t fancy borrowing at all, it’s worth checking the Warm Homes: Local Grant, which offers up to £15,000 for homes with an EPC rating of D to G, delivered through local councils. The broader £15 billion Warm Homes Plan, launched in January 2026, is also expected to offer 0% interest loans to all homeowners regardless of income once fully operational in 2027.
If you want the full rundown of every possible way to fund solar, including buy-now-pay-later style installer deals, group buying schemes, and grants for specific circumstances, our guide to solar panels with no upfront cost covers the complete list. This article focused specifically on the three routes most homeowners actually end up comparing.
And whichever way you finance it, it’s worth reading up on solar panel insurance too, if you’ve financed or leased your system rather than bought it outright, who legally owns the panels can affect what you need to declare to your insurer.
Frequently Asked Questions
Should I use a loan or a green mortgage to pay for solar panels?
It depends on whether you’re an existing Nationwide mortgage customer. If you are, Nationwide’s 0% Green Additional Borrowing (£5,000–£20,000, interest-free over 2 or 5 years) is very likely the cheapest route available anywhere in the UK. If not, a personal loan or credit union loan is usually quicker to arrange than switching mortgage products, though it will typically carry interest, commonly in the 5–15% APR range depending on your credit profile.
Does 0% VAT apply on top of a loan or green mortgage?
Yes. The 0% VAT rate on residential solar panels and battery storage, confirmed until 31 March 2027, is a discount on the purchase price itself, not a separate financing method. It applies automatically when you buy supply and installation together from an MCS-certified installer, regardless of whether you pay cash, use a personal loan, or borrow through a green mortgage.
What is Nationwide’s 0% Green Additional Borrowing and who can get it?
It’s an interest-free additional borrowing product for existing Nationwide mortgage customers, letting you borrow £5,000 to £20,000 over 2 or 5 years at 0% interest, provided the combined loan-to-value stays under 90% and 100% of the money is spent on qualifying energy improvements. Nationwide expanded the scheme in March 2026 to support 10,000 households, with an average loan of roughly £13,000.
Related reading on SolarBriton
Sources: HMRC VAT Notice 708/6 (GOV.UK); Nationwide official press materials on Green Additional Borrowing; Bank of England Monetary Policy Committee minutes, June 2026; Green Finance Institute green mortgage market data. Rates, cashback amounts and lender terms change frequently, always confirm current offers directly with the lender before applying, and consider speaking to a whole-of-market mortgage broker for tailored advice.
