The cost of installing small scale solar fell by 7% between 2024/25 and 2025/26, while the cost of larger installations fell by 9%, according to government data reported by Which?1. The figures cover systems of 0-4kW and 4-10kW respectively1.
Solar panel systems on homes are typically around 4kWp, and a system of this size can generate more than 3,000kWh of electricity per year1. For comparison, a home using a medium amount of electricity gets through 2,500kWh a year on average, according to energy regulator Ofgem, while a high using household takes 3,800kWh a year1. A typical solar panel system of 4.5kWp costs around £7,600 to install, according to estimates from the Energy Saving Trust1.
Which? worked with the Royal Institution of Chartered Surveyors to produce average prices for various sizes of solar PV system, covering the supply and installation of a new, typical standard design system including all fixings, inverter and control system1. Those prices do not include solar panel battery storage1. The full price tables sit behind a Which? membership login, and the article states that prices were correct in November 2025, with materials costs based on national average best trade prices representing typical prices in autumn 20251. The prices include materials, labour, preliminary work, contractor costs, VAT and profit1.
The Federation of Master Builders estimates that installation costs typically account for around 9% of the overall system cost, so a £7,600 4.5kWp system would carry installation costs of around £684, with rates varying by location1.
On support, the article states:
"In January 2026, the government announced low and zero interest loans for solar panels as part of its Warm Homes Plan."
The article adds that all homeowners will be able to apply for these government-backed loans, but that it is not known when they will be available1. It also states there are no dedicated government grants for solar panels, though funding may be available through other schemes, and that some low-income families in England can get free solar panels installed where they are on a low income, receive certain benefits or live in a specific postcode area1.
To receive Smart Export Guarantee payments for electricity exported to the grid, a household needs a solar PV system installed by a registered MCS installer or equivalent1. MCS is described as the most widely accepted certification, with the equivalent scheme offered by the Flexible Energy Oversight Registration Body also accepted by most SEG rate providers1. SEG rates are often less than what a household pays for electricity1.
Why it matters for households
Falling installation costs change the arithmetic of a home generating its own electricity. A smaller outlay for the same system size shortens the period before a system has paid for itself, though the article does not give payback figures. The relationship between system size and household use is central: a typical 4kWp system can generate more than 3,000kWh a year, against average medium use of 2,500kWh, so generation can exceed annual consumption on paper1. In practice, panels generate mostly during the day, so without a battery a household still buys from the grid, particularly on dark winter evenings, and battery cost is excluded from the quoted prices1. Export payments under the SEG provide a route to value for surplus electricity, but at rates often below the import price1. For energy independence, the figures point to a lower entry cost for self-generation, with the degree of independence still shaped by whether storage is added and by the gap between export and import rates.
What happens next
The government-backed low and zero interest loans announced in January 2026 under the Warm Homes Plan have no confirmed launch date, and the article states it is not known when they will be available1. Eligibility for free installations in England depends on local council funding1.
Sources1 cited
- How Much Do Solar Panels Cost? - Which?, which.co.uk