‘Sunlight salary’: Exactly how much solar panels knock off your energy bills – even under grey skies

Published on 25/09/2026 - 15:20 GMT+2 Britain may be famous for grey skies and rainy days, but its sunshine could still help residents shave more than €1,000 a year off household electricity bills. ADVERTISEMENT ADVERTISEMENT An analysis of more than 15 million UK homes by solar software company GreenSketch estimates that an optimised rooftop solar and battery system could save the average household around €1,100 a year – what the company calls a ‘sunlight salary’. Even in Scotland, Wales and Northern Ireland, the average savings topped €930. The findings show that household savings depend on more than sunshine alone. Electricity prices, the angle of your roof, when you use power, battery storage and payments for electricity sent back to the grid are all important factors. Grey skies aren’t a barrier to solar power Researchers used satellite imagery to model individual homes, accounting for the slope of rooftops as well as their orientation, local electricity use and hourly solar generation. Southwest Wales had the highest average estimated savings at around €1,160 a year, followed by southeast England at about €1,150. In Northern Ireland, the best returns were found in the east rather than the south, which GreenSketch says shows that local weather and geography can affect solar generation as much as geolocation. Those figures challenge the idea that solar panels only make financial sense in sunnier places. Although they generate more electricity in direct sunlight, solar panels still produce power on overcast days – good news for Europe’s less sunny stretches. Solar can also cover the cost of installment relatively quickly. The Energy Saving Trust – an independent UK energy advice organisation – estimates that a typical system can pay for itself in 10 to 12 years. Europe has barely tapped its rooftop potential The UK findings point to similar potential elsewhere around Europe. If solar panels don’t need Mediterranean sunshine to cut electricity bills – especially when paired with batteries that let households store power generated during the day and use it later – they could make financial sense far beyond southern Europe. A Joint Research Centre (JRC) study published earlier this year found that solar panels on rooftops could meet 40 per cent of the EU’s long-term electricity needs by 2050. In Finland and Denmark, non-residential roofs alone could provide at least 95 per cent of the solar capacity targeted for 2030. Still, just one in ten European rooftops has solar panels, according to the JRC, leaving enormous room for further expansion.