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France agrees new contracts for offshore wind farms to reduce output when prices go south.
Seems like a good idea.
But then we're constantly told curtailment is a bad thing.

Guess it depends on what's going on on your grid - and in France's case, it's so heavily dominated by nuclear which they'd rather keep going, and you can always save the hydro water for later.

https://renews.biz/100946/french-offsho ... e-pricing/

UK Allocation Rounds 2 and 3 CfDs don't make difference payments if day ahead prices are negative for more than 6 hours. From AR4 onwards, difference payments are not made for any hour of negative pricing.

dan_b wrote: ↑Tue Jun 03, 2025 9:44 am France agrees new contracts for offshore wind farms to reduce output when prices go south.
Seems like a good idea.
But then we're constantly told curtailment is a bad thing.

Guess it depends on what's going on on your grid - and in France's case, it's so heavily dominated by nuclear which they'd rather keep going, and you can always save the hydro water for later.

https://renews.biz/100946/french-offsho ... e-pricing/

Curtailment is neither good nor bad in and of itself. For all power generation you need the capacity to generate more than you need. This is because demand varies and also to cover outages (planned or unplanned) at other generating sites. You obviously need a pricing mechanism to encourage plants to generate more or less as and when the demand/supply requires it. Nothing new or exciting about that.

In my opinion wind curtailment contracts have been poorly designed in the past. The result is: wind turbine operators have benefited from vast remuneration for turning off when it might have been better to incentivise consumers to use more at those times. This would have reduced bills and fossil fuel consumption. Therefore curtailment contracts have both harmed the environment and increased bills. Additionally there is an inherent human distaste for “paying people to do nothing” and the billionaire spivs these curtailment contracts have enriched *cough* Dale Vince *cough* are frequently very objectionable characters.

If you want a reliable energy system capable of dealing with a 1 in 10yr peak event then you have spare capacity and that equates to curtailment at EVERY level even the gas and it has been known for even the nuclear. I guess its the money that people focus on not the act.

Curtailment as measured for the wind farms and transmission is actually only of the order of 2.1% and quite frankly sometimes it will not make sense to invest billions £ to save millions. The grid needs to see the future commitment to building new leccy production and its need before it commits to the billions£ Its just chicken and egg.

The curtailment last yr was c 6TWh when the yrs production was 281 TWh = 2.1%

Thanks for the numbers Ken. And I totally agree that some level of curtailment is entirely acceptable for as you say a reliable system.

With the new CfD rules, and existing CfD schemes falling out of subsidy once their 15yrs are up, then I assume that whilst curtailment may increase, curtailment costs should stabilise, maybe even fall.

Your comment prompted to me to have a think about storage costs (v's SZC) on another thread.

I know the numbers for curtailment are large, both the amounts of energy and the costs, but when considered in scale, I truly believe they are fine, and can be described partially as growing pains whilst we develop the new energy revolution.