An independent report by Lane Clark & Peacock (LCP) found that over the last two years, curtailing wind power added £806m (US $1.01 billion) to energy bills in Britain.

Rising gas prices made the practice of curtailment more expensive, as gas power stations were increasingly used to support the system when wind turbines had limits placed on their energy output.

What is curtailment?

Wind energy curtailment is the reduction in electricity generation below what a system of well-functioning wind turbines are capable of producing. It represents a significant loss in economic and energy efficiency. 

The LCP report further claims that enough renewable power to supply 800,000 UK homes went to waste in 2020 and 2021 as wind farms were routinely asked to switch off the renewable sources by the electric grid operator.

When and why does curtailment happen?

Curtailment happened as a result of constraints in the electricity transmission system and a lack of long-duration storage capacity, e.g. battery storage, which is needed to manage periods when there is excess power generation from renewable energy sources.

An extra two million tons of CO2 was emitted during 2020 and 2021 as a result of gas being used to replace reduced wind power, equivalent to putting almost half a million more cars on UK roads.

Britain’s wind turbines currently have the capacity to provide enough renewable power for almost 20 million homes.

“Increasing the output from wind power is essential for the UK to achieve its climate targets and ensure energy security. And yet because investment in the infrastructure needed to support this expansion has not kept pace, wind curtailment is costing the consumer and the environment”, said LCP’s Chris Matson.“Every Pound spent on curtailing wind power is a Pound wasted.”

Penny Small, Drax’s Group generation director, said: “This report underlines the need for a new regulatory framework to encourage private investment in long-duration storage technologies.”

“The UK is a world leader in offshore wind, but for the country’s green energy ambitions to be realised we need the right energy storage infrastructure to support this vital technology, make the system secure and reduce costs.”

“Drax’s plan to expand Cruachan will strengthen UK energy security, by enabling more homegrown renewable electricity to power British homes and businesses, reducing system costs and cutting carbon emissions.”

Source: Lane, Clark & Peacock