A new report by UKERC defines the cost of intermittency of wind power in the UK electricity system for penetration levels that can be foreseen in the next 20 years (expected to be up to 20% of electricity generation). Based on a review of 200 studies on the subject, and written/reviewed by leading academics on power engineering in Europe, the report provides a snapshot of current knowledge on the subject.
A complex subject such as the intermittency of wind power, and its impact on the electricity system remains a communication challenge. Therefore, it's good to be conscious of the context of the report, to which its findings can be applied:
Under these conditions, the report concludes a cost of intermittency of 0.5 - 0.8 p/kWh (0.8 - 1.2 cEuro/kWh), subdivided in 0.2 - 0.3 p/kWh balancing costs and 0.3 - 0.5 p/kWh for maintaining a higher system margin. Additional reserve requirements needed for system balancing amount to 5-10% of installed wind capacity.
Capacity credit is reported in 29 studies, with values of 15-20% of installed intermittent capacity at the 20% penetration level. All studies find a positive capacity credit, which declines as penetration level increases.
On emissions & fuel savings, the argument is sometimes made that intermittency reduces these savings, for example through the increased variability of thermal power operation to compensate for wind's variability. The study finds this effect to be negligible to small (up to 7% of emissions saved). Overall, when carefully read and understood, this study provides a substantial contribution to the debate. The cost of intermittency is significant, but affordable. When spread over all electricity users at the 20% penetration level, it adds 0.1 - 0.15 p/kWh to the cost of electricity.Log in to post comments