The sunniest start to spring increases solar power 40%
Solar PV has raced from a green fringe technology to a global front-runner. The world spent close to half a trillion dollars on solar panels last year, more than every other generating technology combined. Since 2010, solar PV has leapt from just 7% to over 70% of all new power capacity added globally. Even Britain, more famous for drizzle and fog than blue skies, has ridden this wave. Installed capacity as of March exceeded 18 GW, with Government policy aiming to expand this to 45 GW by the end of the decade.
Demand for rooftop PV systems has roared back to life, with 57,000 systems installed in the first quarter of 2025, the best start to the year since 2012. With Ofgem’s price cap for electricity now almost 28 p/kWh, Which Magazine estimates that home solar systems can pay back their original cost in as little as 10 years.
Cuts to red tape now mean more businesses can install solar PV without planning permission, and the New Homes Bill aims to make rooftop PV standard on all new builds from 2027. Larger utility-scale solar farms are also coming online after they started receiving approvals from the Energy Secretary.
Global investment in new power generating capacity, split by main technology groups. Data from BloombergNEF and IRENA.
Cumulative electricity production from solar PV over each year of the past decade. Output so far in 2025 has been 40% higher than any year on record.
Britain has also enjoyed the sunniest start to spring on record. The Met Office confirmed that England enjoyed its sunniest ever March and April back to back. This all adds up to make 2025 a record year for solar power. Britain broke its record PV output twice at the start of April, hitting a peak of 12.2 GW on 1 April, and then 12.7 GW on 6 April. This year, cumulative generation to the end of April has been 40% higher than any other year.
Every silver lining has its cloud though. This rapid increase in solar generation raises concerns over how to manage the system on sunny summer afternoons. The National Energy System Operator (NESO)’s Summer Outlook warns that transmission-level demand could fall below 13.4 GW, eclipsing the COVID-era lows. This might leave the operator no choice but to issue unprecedented “negative reserve” notices, forcing inflexible plants, such as nuclear reactors, to back off when solar floods the grid.
Greater investment in large-scale energy storage, such as batteries and pumped hydro, alongside other sources of flexibility will be essential to managing this new wave of solar PV plants. Britain’s challenge may soon shift from making clean electricity to making room for it.