A lack of wind in the UK this weekend coinciding with greater winter demand for power amid a cold snap and squeezed gas supplies from Russia will present a rare test for the grid - especially if there is a spike in demand connected to England's World Cup game against France.
National Grid PLC (LSE:NG.) said this week that "margins" - the buffers that it maintains to cope with imbalances in supply and demand - are "expected to be tighter this week".
National Grid's Electricity System Operator (ESO) revealed its winter outlook base case shows margins of 3.7GW or 6.3%, which it said is similar to recent winters and should be "adequate".
But with Russia’s invasion of Ukraine leading to a more challenging energy supply throughout Europe than before, ESO said it expects there might be some days where it may need to use system notices, where it pays coal and gas power suppliers to generate more power to make sure electricity generation is available during high demand.
ESO also said it has developed "additional tools to manage risk", including contingency contracts and its Demand Flexibility Service that allows businesses and the public to be paid to move their electricity use out of peak hours.
Moreover, low levels of wind are not likely to persist, with this form of energy the most productive during winter months when demand is highest, as well as being the UK’s largest low-carbon energy source.
The latest Government figures show that renewables generated 40% of the UK's electricity last year - and over half of that came from wind alone, as our biggest source of clean power.
Even so, it said it is "highly likely" that the wholesale price of gas and electricity will remain very high throughout the winter.
More challenging scenarios were also noted, if electricity was not able to be imported from continental Europe, such as during a shortage of gas or if there are high levels of outages in other countries, or days when demand was high due to cold, with low levels of wind generation.
This would require the use of back-up coal power and the Demand Flexibility Service, which the ESO said could secure up to 4GW and should be enough that customers would not notice.
Although "unlikely", it a combination of these factors might result in the "need to interrupt supply to some customers for limited periods of time in a managed and controlled manner" - rolling blackouts, in other words.
ESO executive director Fintan Slye said, "we are cautiously confident that there will be adequate margins through the winter period" under the base-case scenario, while the other measures reflected its "prudent action" in case of the worst.
Industry analysts Cornwall Insight told the Telegraph: “The system is probably going to be tested this winter. But at the moment, it's showing good signs of being fairly resilient. We'll have to see what happens in the coming days and weeks. But this cold period over the winter with low sun and low wind will be a test.”
With National Grid highlighting the risk of gas shortages this winter, the renewables body Renewables UK pointed out that every unit of power generated from wind, hydro and other clean fuel meant one less was needed from gas or coal.
Last year, power from renewables avoided burning the equivalent of 21 billion cubic metres of gas and as well as reducing reliance on imported fossil fuels, these forms of energy are also sources of low-cost power.
RenewablesUK, which has been highlighting on Twitter every fortnight how much energy the sub-sector is generating, called for urgent upgraded to grid infrastructure to make the most of cheap renewables, with investment in new power and storage technologies to ensure the system is more secure and help make energy more affordable.https://twitter.com/RenewableUK/status/1597632203311419392
Our first #WinterPowerUpdate shows low carbon made up 63% of generation in first 2 weeks of Nov - avoiding 1.2 billion cubic metres of gas, or 5% of annual LNG imports. That's enough power to meet the annual needs of 1.7m homes.
Generation data from Electric Insights @DraxGroup pic.twitter.com/1H8JNLUqk6
— RenewableUK (@RenewableUK) November 16, 2022
"It's important to look at wind generation over a meaningful period of time such as a year, rather than cherry-picking individual days," a spokesman for RenewableUK said.
"All power sources, including gas and nuclear, fluctuate on a daily and weekly basis."