As renewable energy continues to reshape the landscape of electricity generation, Britain finds itself at a pivotal juncture. Recent developments highlight both the potential and challenges of a grid increasingly reliant on wind and solar power. Last Wednesday, during a brief midday peak, wind turbines generated 24 gigawatts of power, contributing to a scenario where 55% of Britain’s electricity came from wind, 22% from solar, and 10% from nuclear, with fossil fuels providing a mere 2%. This resulted in a remarkably low wholesale electricity cost of £4.81 per megawatt hour.
However, this renewable energy success story contrasts sharply with the situation just 11 weeks earlier. On January 5, the price for electricity soared to £477/MWh as gas dominated the energy mix, with minimal contributions from wind and solar. This disparity highlights the grid’s vulnerability during periods of “Dunkelflaute”—a German term describing conditions of low wind and sunlight.
Following the decommissioning of Britain’s last coal power stations in 2024, gas became the sole flexible energy source. On January 8, 2024, a Dunkelflaute event drove electricity prices to an astronomical £2,900/MWh. When domestic renewable energy fails to meet demand, the grid resorts to costly imports, underscoring the challenge of managing an energy system transitioning away from fossil fuels.
Britain’s renewable capacity has grown from about 5GW in 2010 to over 30GW today, but managing this capacity within an evolving grid presents significant hurdles. With an average electricity demand of 33GW and capacity near 40GW, projections by the Royal Meteorological Society (RMetS) suggest future demand could rise to 52GW by 2035 due to increased adoption of electric vehicles, heat pumps, and data centers. By this time, wind and solar capacity is expected to reach 150GW, yet even this might not suffice during a Dunkelflaute.
RMetS analysis of January 2025 weather conditions indicates that while some days will see surplus electricity, others will bring near-zero production from renewables. The same pattern is expected in 2050, with Britain potentially producing twice the needed electricity on certain days and virtually none on others.
Nuclear power offers a potential solution, yet its future role remains uncertain. Current capacity of 6.5GW is set to decrease with the closure of Hartlepool and Heysham 1 in 2028, leaving Britain with less nuclear capacity in 2034 than it has today. Energy storage, including pumped hydroelectric storage and anticipated battery expansions by 2030, offers limited relief during prolonged Dunkelflaute periods.
Windy days pose their own challenges, as electricity cannot be efficiently transported to where it’s needed. This leads to “balancing payments” where wind turbines are paid to halt production while gas turbines are activated, a practice that cost £2.7 billion last year and reduced potential wind output by 13%.
The historical design of Britain’s national grid, developed in the 1920s and 1930s to connect coal power stations to urban centers, is ill-suited for the current energy landscape. As the focus shifts northwards to Scotland and offshore turbines, a £70 billion investment in new energy superhighways aims to address this imbalance, though many projects won’t be operational until about 2034.
Energy analyst Ben James projects that despite cheaper wholesale electricity from wind, the average household bill in 2030 could rise to £1,045, an increase attributed mainly to network costs. These include expenses related to transmitting electricity across the country and balancing payments. While wind and solar remain the most cost-effective electricity sources, the infrastructure necessary to support them—and handle periods of low production—remains a costly endeavor.
As Britain races towards a renewable future, the grid’s ability to keep pace will determine whether households face higher costs or reap the benefits of cleaner, cheaper energy.
Original Story at www.thetimes.com