The planning committee in Wealden gave the green light last week, solar panels will cover the roof of a supermarket in Hailsham. The decision is routine for a commercial building, but it carries a quiet signal for every homeowner who has wondered whether rooftop solar is worth the hassle.
As SussexWorld reported, the supermarket’s application sailed through with no objections, partly because the panels sit flat on an existing roof, partly because the energy savings are hard to argue against. That same logic applies to homes up and down the country.
Why a supermarket matters to your roof
Supermarkets do not install solar for the aesthetics. They do it because the numbers work. A typical large store draws 500,000–1,000,000 kWh a year. Panels covering even half that roof can slash electricity costs by 20–30%. For a household using 3,500 kWh annually, the maths is simpler: a 4 kW system costs £5,000–£7,000 installed, saves £200–£300 on bills each year, and pays back in 12–15 years, faster if energy prices keep climbing.
Ofgem’s latest price cap, announced in August, adds £63 to the typical household bill from October. Every kilowatt-hour you generate yourself is one you do not buy from the grid. The supermarket understands that. Your home can too.
Who qualifies, and who doesn’t
Most UK homes can install solar panels without planning permission, thanks to permitted development rights. The exceptions are listed buildings, homes in conservation areas, or flats above shops, where you may need a full application, just like the Hailsham store. Check your local authority’s website before ordering quotes.
Roof orientation matters. South-facing is ideal, but east-west arrays still generate 80–85% of the maximum. A typical 3-bed semi needs about 20 m² of unshaded roof. If your roof is north-facing or heavily shaded by trees, consider a smaller system or ground-mounted panels instead.
The Energy Saving Trust estimates that a well-sited 4 kW system in southern England generates 3,800–4,200 kWh per year, enough to cover most of a household’s daytime electricity use. Add a battery (another £2,000–£4,000) and you can store surplus for evenings, pushing self-sufficiency above 70%.
What it costs a typical 3-bed semi
Installation prices have fallen 40% in the last decade. A 4 kW system now runs £5,000–£7,000, including scaffolding, inverter, and labour. VAT is 0% until March 2027, a saving of £1,000–£1,400 compared to the old 20% rate.
You also earn money from exported electricity. The Smart Export Guarantee (SEG) pays 5–15p per kWh for power sent to the grid. A typical household exports 50–60% of its solar generation, earning £100–£150 annually. Some suppliers, like Octopus Energy, offer higher rates for customers who also have a heat pump or battery.
But the catch is timing. Installers are booked 8–12 weeks ahead in many regions, and the surge in demand after the 0% VAT announcement has stretched supply chains. Order quotes now if you want panels before spring 2025.
EPC rating: the hidden bonus
A solar array can lift your Energy Performance Certificate by 5–10 points, enough to move a D-rated home to a C. That matters for several reasons: higher EPC ratings increase property value by 1–3% (estate agents report), unlock cheaper mortgage rates from lenders like Nationwide and Barclays, and may be required for future rental properties under the government’s planned minimum EPC C target by 2030.
The ECO4 scheme, which runs until March 2026, provides free or heavily subsidised solar panels for low-income households and those on certain benefits. If you receive Pension Credit, Universal Credit, or Child Benefit (income-based), check your eligibility on gov.uk. The Great British Insulation Scheme also covers solar as part of a broader retrofit package.
Households on standard variable tariffs can apply through gov.uk from 4 November for the latest round of ECO4 funding. Eligibility closes on 31 March 2027. Do not wait, the scheme is oversubscribed in many areas.
Frequently Asked Questions
In most cases, no. Permitted development rights allow solar panels on domestic roofs without planning permission, provided they do not protrude more than 200mm from the roof plane. Exceptions include listed buildings, conservation areas, and flats above commercial premises, where a full application is required, similar to the Hailsham supermarket's approval.
A 4 kW system saves £200–£300 per year on electricity bills, plus £100–£150 annually from the Smart Export Guarantee. Total savings of £300–£450 per year, with a payback period of 12–15 years at current energy prices. Adding a battery increases upfront cost but boosts self-consumption and long-term savings.
