The United Kingdom's energy landscape is grappling with a significant challenge as "dunkelflaute"—a period characterized by dull, windless winter weather—has led to a dramatic decline in renewable energy output. This weather phenomenon has plunged the nation into increased reliance on gas-fired power stations to meet electricity demands. On Wednesday evening, the system operator had to pay gas power stations more than £500 per megawatt-hour (MWh) to sustain operations, spotlighting the financial strain on the energy grid.
As the "dunkelflaute" continues, Britain's renewable energy output has hit near-zero levels this week. The market price for electricity surged to approximately £250 per MWh at auction—nearly seven times the average price before the pandemic. This surge has underscored the volatility and challenges in managing the UK's energy needs during periods of low renewable energy generation. Wind power output notably fell to just above zero on Wednesday, further exacerbating the situation.
Despite these challenges, renewable energy sources still accounted for over 70% of power generation at certain points on Wednesday, highlighting their integral role in the UK's energy mix. However, the current situation has forced the system operator to offer higher payments to gas power stations to ensure electricity supply remains stable.
Akshay Kaul, a director at Ofgem, commented on the situation:
“We’ve seen this winter that when you have a period of still, cold, cloudy weather [that] batteries on their own, and [power] interconnectors on their own, are not sufficient.” – Akshay Kaul
The UK's energy system operator forecasts a need to expand its capacity significantly, aiming for growth from 11GW to 15GW by 2030. This expansion is essential for managing fluctuations in renewable energy and ensuring stability during periods like the "dunkelflaute." Kaul further emphasized the challenge but remained optimistic:
“That is quite a considerable challenge to physically get things like big pumped hydro storage built. But we relish it, we’re up for the challenge,” – Akshay Kaul
Amid these challenges, a "weather bomb" is on the horizon, expected to alleviate the current surge in wholesale energy prices. However, it also poses risks of travel disruptions and potential damage from flying debris. This complex situation underscores the need for a robust and flexible energy system.
Barnaby Wharton, a director at RenewableUK, highlighted the importance of maximizing renewable energy sources:
“A modern energy system which maximises the use of wind and solar offers the best deal to consumers as they are our cheapest forms of new power and they protect us from spikes in international gas prices.” – Barnaby Wharton
Experts advocate for deploying 20GW of long-duration energy storage by 2050, which could save the electricity system £24 billion and reduce household energy bills significantly. Such measures could bolster the UK's resilience against future "dunkelflaute" events and similar challenges.