Electric Insights: Britain records its cleanest quarter ever

Getting to zero fossil fuel electricity

Back in 2016, Britain had its first ever zero-coal hour. Then, 8 years later, the last coal-fired power station shut forever. However, we are still heavily reliant on fossil fuels. Gas has been burnt to provide electricity every hour of every day since the 1980s. Phasing out gas is the next step on the road to clean power, and a major milestone may be just around the corner. Since 2019, NESO has been preparing the electricity system to be capable of running with zero fossil fuels when there is sufficient renewable output for short periods by 2025.

Getting to even short periods of zero-carbon electricity will require more than just new technology. It will mean upgrading the grid to handle higher peaks in renewables, expanding storage, and maximising flexibility from homes, businesses, and industry. It will also take faster connections for clean energy projects and investment in backup solutions that don’t rely on fossil fuels.

Power prices turned upside down

Ever since Britain had an electricity market, power prices have followed demand. High during the day when people are working, low overnight when they sleep. This summer, that logic has turned on its head, as supply of renewable electricity becomes a bigger factor than demand.

Over the second quarter of 2025, daytime power prices were lower than those overnight for the first time ever. The rapid rise in solar PV over the last two years means the grid is being flooded with clean power on sunny afternoons, helped by the sunniest Spring on record, with 40% more sunshine hours than average.

What do heat waves do to the power system?

The UK, Western Europe, Japan and parts of China saw their warmest June on record in 2025. Rising temperatures place growing strain on both public health and power systems. Across the world, 500,000 heat-related deaths occur each year, with 1,300 excess deaths in the UK alone last summer. The heat also lowers people’s productivity, with hot days (above 28°C) costing the UK economy an average of £1.2 billion per year.

Alleviating heat stress requires that homes and businesses are cooled to a comfortable temperature. Across the UK, rising temperatures mean the need for cooling is rising by 3% per year. In London, this is growing by 5% per year, faster than anywhere in the world.

Global LNG trade

Natural gas heats eight in ten UK homes and provides one third of our electricity. Half of the gas we consume is imported, one-quarter of which arrives by ship in the form of liquefied natural gas (LNG), primarily from the US. The colossal $750 billion US–EU energy pledge will reshape global gas markets, with implications for UK energy prices and security of supply The UK’s dependence on imported LNG is a relatively recent phenomenon. Globally, LNG has now overtaken pipelines as the main form of trade, quadrupling from 140 to 550 bcm between 2000 and 2024.

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