The average UK household electricity bill now sits at £1,179 a year, nearly double what it was in 2020. That single number is driving more homeowners to consider solar panels than at any point since the Feed-in Tariff ended in 2019.
As reported by the Financial Times, the question of whether it is time to go solar has resurfaced with new urgency. The answer, for a growing number of UK households, is yes, but only if the sums stack up for your specific roof.
What it costs a typical 3-bed semi
Installing a 4 kW solar panel system, the most common size for a 3-bed semi-detached house in the UK, now costs between £5,000 and £7,000 including installation. That is down from around £9,000 in 2020, according to Energy Saving Trust data. The 0% VAT on energy-saving materials, introduced in 2022 and extended through March 2027, shaves another £200-£300 off the bill.
Annual electricity generation for a south-facing 4 kW system in the Midlands or southern England is roughly 3,800 kWh. With the current price cap at 24.5p per kWh, that means avoided purchases of about £930 a year if you use all the power. In practice, most homes export 40-50% of what they generate, so the real saving is lower, around £300-£500 once the Smart Export Guarantee payments are included.
Who qualifies, and who doesn’t
Orientation matters. A south-facing roof with a pitch of 30-40 degrees is ideal. East-west arrays produce about 15% less power but can still be viable. Flat roofs and north-facing slopes are harder to justify economically without battery storage, which adds £1,500-£2,500 to the upfront cost.
Shading is the silent killer. A chimney or neighbouring tree that casts a shadow over part of the array between 10am and 2pm can cut generation by 20-30%. The Energy Saving Trust recommends a free online assessment tool before you call an installer.
But the biggest barrier remains the upfront cost. Even at £6,000, a solar system is a significant outlay. The Boiler Upgrade Scheme does not cover solar panels, it is limited to heat pumps and biomass. Grants for solar are patchy: some councils offer local schemes, but there is no national programme comparable to the old Feed-in Tariff.
What this misses
The financial case for solar assumes you stay in your home for at least 7 to 10 years. If you move sooner, the payback period may not be reached, though solar panels can add 2-3% to a property’s value, according to estate agent data cited by the Energy Saving Trust. They also improve an EPC rating by one or two bands, moving from D to C can unlock lower mortgage rates from some lenders.
Battery storage is the wild card. Adding a 5 kWh battery pushes the total cost to £8,000-£9,000 but allows you to use 70-80% of the solar power you generate instead of 50-60%. At current electricity prices, that extra self-consumption adds about £150-£200 in annual savings, shortening the payback period by roughly two years. The catch: batteries still degrade over time, and replacement after 10-12 years is not cheap.
The other risk is policy change. The Smart Export Guarantee pays a minimum of 5p per kWh exported, but that rate is set by individual suppliers, some pay as little as 4p, others up to 15p. If the export tariff were cut, the savings would shrink. Ofgem reviews the scheme periodically, but no major changes are expected before 2027.
Households on standard variable tariffs can apply through the Energy Saving Trust’s solar calculator from today. Eligibility for 0% VAT runs until March 2027. If your roof faces south, has minimal shading, and you plan to stay put for a decade, now is the moment to get three quotes from MCS-certified installers.
Frequently Asked Questions
For a typical 4 kW system costing £6,000, payback ranges from 7 to 12 years depending on orientation, shading, and how much power you use at home. South-facing roofs with low shading and high daytime usage pay back fastest.
There is no national grant for solar panels currently. The 0% VAT on installations runs until March 2027. Some local councils offer small schemes, check your council's website. The Boiler Upgrade Scheme does not cover solar.
