Increasingly changeable weather in Britain could put net zero and the security of the electricity grid at risk according to a new report.
Produced by academics from Imperial College London for Drax Electric Insights, the report shows the country experienced its longest spell of low wind in more than ten years in the first quarter of 2021.
For example, on 3 March the UK’s 24.4GW wind turbine fleet fell to a low of 0.6GW in comparison with hitting 18.1 GW earlier in the month – high winds drove power prices down to a low of -£61/MWh towards the beginning of the month before these winds dropped away.
Dramatic weather was a key feature of the beginning of the year, with Britain going through periods when it was buffeted by storms and cold snaps that led to tight margins. This in turn led to grid operators overwhelmingly calling on gas-fired units to generate power to plug the gaps during periods of low winds.
In January, EDF was paid more in three days than in Q3 2020 as low winds and cold temperatures pushed the grid's security, for example. This included its West Burton B gas plant being called into the Balancing Market at the record breaking £4,000/MWh on Friday 8 January.
Strain caused by reduced generation due to the impact of weather on intermittent renewables is recognised in Germany as a Dunkelflaute – a dark wind lull phenomena, Imperial’s report explains. March’s Dunkelflaute lasted for 11 straight days, making it the longest in more than a decade.
“It’s time for Britain to get serious about the threat of extreme weather events to our electricity system,” Dr Iain Staffell of Imperial College London, and lead author of the quarterly Electric Insights report, said.
“Renewable power sources have made our country cleaner and greener, but as they rely on the ever-changing British weather, completing our transition away from fossil fuels comes with serious challenges.”
Britain can expect to experience a period of prolonged low-wind every two decades on average the report warns, and could threaten grid security. It further pointed to the recent widespread blackouts in the US State of Texas, which highlighted the cost of overlooking extreme weather risks to energy systems.
Dr Malte Jansen of Imperial College London, co-author of the report, added that “extreme events will become much more impactful” as wind and solar are set to supply half of the nation's electricity needs in the next five years. As such, the UK needs to invest in more “clean and flexible technologies, such as long duration energy storage” to bridge the gap.
The report goes on to say that pumped hydro acts as a key supporting pillar for intermittent generation, and during Q1 2021 set a new daily output average high of 409 MW.
Despite this, no new pumped storage plants have been built in Britain since 1984, but the Drax Group – who commissioned the independent report via Imperial Consultants – is currently progressing plans to develop a second power station at its Cruachan pumped hydro storage plant in Scotland.
But while pumped storage is useful, it is limited resource, argued Phil MacDonald, chief operating officer of Ember, in response to the report, saying real investments in research and development of novel long-term energy storage is needed.
“The Climate Change Committee is clear that it is possible for the UK grid to phase-out unabated gas by 2035 without new storage technology, but innovating now will make the transition cheaper and quicker.”
He added that biomass should not be relied on to fill low wind periods, “as the old assumption that it is carbon neutral to burn wood in power stations has been shown to be incorrect".