In Europe, the Dunkelflaute season cometh

On Friday (January 7) the French electricity grid operator RTE asked consumers to reduce their power consumption because things were getting tight. French citizens were asked to put off running the dishwasher or doing a load of washing that evening because there might not be enough electricity.

That day total electricity demand in France reached a new record 88GW driven by a cold snap around four degrees lower than the average for January. Parts of central Spain received heavy snow as cold weather combined with weak solar and still conditions to drive wholesale electricity prices up across Europe.

Northern hemisphere temperatures are expected to stay low for the rest of January driving up demand for energy – gas and electricity. Spot gas prices have skyrocketed to record highs in Asia as northern hemisphere consumers scramble to increase supplies. Prices for coal and oil are up sharply too.

Demand for energy spikes in the northern hemisphere when the weather is coldest. Electricity demand increases by around 50 per cent over winter, while solar PV generation falls off a cliff (short dark days). In winter German solar PV is regularly generating at around 3-4 per cent of its capacity, and obviously only during the middle of the day.

Offsetting this to some degree is that winters are windier in Europe , with gas generation and wind replacing each other through the days and nights.

Last Friday (January 7) was a Dunkelflaute day – dark and still – while much colder than average increased demand for many of the fuels that power  dispatchable generation: nuclear, coal, hydro and gas. In Germany up to 90 per cent of electricity demand is met by these sources on still evenings. The UK over the past month has relied on nuclear and fossil fuels for around 68 per cent of its electricity.

Yet the German Government policy, the Energiewende, intends to close nuclear generation by 2022 and coal by 2038. Nuclear is around 12 per cent of winter generation in Germany, coal more than 40 per cent. Building more renewables won’t help much during Dunkelflaute conditions. It’s a big hole to fill.

The sharp demand spikes for conventional energy sources puts europe’s climate ambitions into some context. It will need to replace thousands of petajoules of conventional energy each year with clean sources, which will mean a dramatic increase in renewables generation and the hope that energy storage and transport technologies like batteries and hydrogen can accelerate quickly to cut costs and increase capacity.

China has discovered how fragile energy can be, with reports that its unofficial boycott of Australian coal has resulted in widespread blackouts. Announcing bans on conventional generation types is easy. Replacing them is the hard part.