Solar Panel Finance Options UK 2026: Loans, 0% Deals & What to Avoid
Every way to finance solar panels in the UK compared — cash, green loans, 0% installer deals, mortgage additions, and why you should avoid solar leases. With real cost comparisons.
Not everyone has £6,000–£10,000 sitting in a savings account ready to spend on solar panels. The good news is that several financing options make solar accessible without paying the full cost upfront. The bad news is that some of these options are significantly better than others — and a few should be avoided entirely.
This guide covers every way to finance solar panels in the UK in 2026, with real numbers on what each option actually costs you over time.
Option 1: Pay Cash (Best Value)
If you can afford it, paying upfront is always the cheapest option. You avoid all interest charges and start saving from day one.
- Typical cost: £5,000–£10,500 depending on system size (0% VAT included)
- Payback period: 6–9 years
- Total cost over 25 years: Just the purchase price
- Savings over 25 years: £12,000–£20,000+
Even if the money is in a savings account earning 4–5% interest, solar panels typically deliver a 10–15% annual return through bill savings and SEG income — comfortably beating any savings account or cash ISA. See our full cost breakdown.
Option 2: Green Home Loans
Several banks and building societies now offer dedicated green home improvement loans with preferential rates for energy efficiency upgrades including solar panels.
| Lender | Typical APR | Loan Term | Notes |
|---|---|---|---|
| Nationwide (Green Additional Borrowing) | From 2.5% | Up to 25 years (added to mortgage) | Existing mortgage customers only |
| Barclays Green Home Mortgage | From 3.0% | Up to 25 years | Additional borrowing on existing mortgage |
| Lendology (formerly Wessex Resolutions) | From 3.5% | Up to 10 years | Government-backed, available through local authorities |
| Standard personal loan (various banks) | 6–10% | 1–7 years | Widely available, no green discount |
Worked example: £6,500 system on a green loan
- Loan: £6,500 at 3.5% APR over 10 years
- Monthly repayment: ~£64
- Total interest paid: ~£1,180
- Total cost: £7,680
- Annual solar savings: ~£730
- Net position: The system pays for the loan repayments from year 1 (£730 savings vs £768 annual repayments). After the loan ends in year 10, you keep all the savings
At 3.5% APR, the loan essentially pays for itself through solar savings. At rates above 7–8%, the maths becomes less favourable and you may want to consider waiting until you can pay cash.
Option 3: Installer Finance (0% Interest Deals)
Some solar installers offer 0% interest finance deals, typically over 2–5 years. These are genuinely interest-free — the installer absorbs the finance cost as a marketing expense.
- Typical terms: 0% APR over 2–5 years
- Monthly cost: £108–£271/month for a £6,500 system (depending on term)
- Total cost: Same as cash price — no interest
- Catch: The system price may be slightly higher than from an installer not offering finance. Always compare the total price, not just the monthly payment
If a genuine 0% deal is available from an MCS-certified installer with good reviews, this is an excellent option. You keep your cash earning interest elsewhere while the solar savings cover the repayments.
Option 4: Adding to Your Mortgage
If you have an existing mortgage, you may be able to borrow additional funds to cover the solar installation. This spreads the cost over your remaining mortgage term at your existing mortgage rate.
- Pros: Lowest monthly payments (spread over 15–25 years), mortgage rates are typically lower than personal loan rates
- Cons: You pay more total interest over the longer term, requires lender approval, increases your mortgage balance
- Best for: Homeowners who want the lowest possible monthly impact
Worked example: £6,500 added to mortgage
- Rate: 4% over remaining 20 years
- Monthly addition: ~£39
- Total interest: ~£2,860
- Total cost: £9,360
The monthly payment is very low (£39), but you pay significantly more in total interest. However, the solar savings (£730+/year) far exceed the annual loan cost (£468), so you are still cash-positive from year 1.
Option 5: Solar Panel Leases (Avoid)
Some companies offer to install solar panels for free in exchange for a long-term lease agreement. You typically pay a monthly fee and may not own the panels for 20–25 years.
- Monthly cost: £30–£80/month
- Total cost over 25 years: £9,000–£24,000
- Who owns the panels: The leasing company, not you
- SEG income: Usually goes to the leasing company, not you
- House sale: The lease transfers to the buyer, which can complicate sales
We do not recommend solar leases. You typically pay more over the lease term than you would buying outright, you do not own the equipment, and the lease can make your property harder to sell. See our guide to free solar panel claims for more detail.
Option 6: Power Purchase Agreements (PPAs)
Similar to leases, a PPA involves a company installing panels on your roof and selling you the electricity they generate at a discounted rate. You do not own the panels.
- Electricity rate: Typically 15–20p/kWh (vs 24–30p/kWh from the grid)
- Savings: Modest — you save on the rate difference, but the bulk of the benefit goes to the PPA provider
- Contract length: 20–25 years
- Ownership: The PPA provider owns the panels
PPAs can make sense for commercial properties with large roof areas and high daytime electricity usage. For residential properties, buying panels outright (even with a loan) is almost always better value.
Comparison: Total Cost Over 25 Years
| Finance Option | Total Cost | Total Savings (25yr) | Net Benefit | Rating |
|---|---|---|---|---|
| Cash (upfront) | £6,500 | £18,250 | +£11,750 | Best |
| 0% installer finance (3yr) | £6,500 | £18,250 | +£11,750 | Excellent |
| Green loan (3.5%, 10yr) | £7,680 | £18,250 | +£10,570 | Good |
| Mortgage addition (4%, 20yr) | £9,360 | £18,250 | +£8,890 | Acceptable |
| Personal loan (8%, 5yr) | £7,900 | £18,250 | +£10,350 | Acceptable |
| Solar lease (£50/mo, 25yr) | £15,000 | £0 (you don't own it) | -£15,000 | Avoid |
Every option except leasing delivers a positive return. The key factors are interest rate and loan term — keep the rate under 5% if possible, and prefer shorter terms to minimise total interest paid.
Government Schemes and Grants
Beyond financing, there are a few schemes that can reduce the cost of solar:
- 0% VAT — saves ~£1,300 on a typical installation. Automatically applied by MCS-certified installers
- Warm Homes Plan — the replacement for ECO4, offering subsidised energy improvements for low-income households. Contact your local authority to check eligibility
- Local authority schemes — some councils offer additional grants or interest-free loans for solar. Check your council's website or our solar grants guide
Which Option Is Right for You?
- Have £6,000+ in savings? Pay cash — it is the best return on investment
- Installer offering 0%? Take it — same total cost, keep your cash earning interest
- Good credit, no savings? Green home loan at 3–4% — the solar savings cover the repayments
- Want lowest monthly payments? Add to mortgage — lowest monthly cost, highest total interest
- Offered a "free" lease? Walk away — you will pay more and own nothing
Whatever route you choose, start by getting quotes from MCS-certified installers in your area. Many offer multiple finance options, and comparing total costs (not just monthly payments) will help you make the right decision.
John Rooney is the founder of Solar Info and has been covering the UK solar energy market since 2023. He fact-checks all content against official MCS and Ofgem data and maintains relationships with MCS-certified installers across the UK.