UK Renewables, System Balancing, and a More Technology-Focused Future

Where and when wind power is produced has a significant impact on the UK power network. Of the country’s 20 GW of wind capacity, 40% is offshore. However, wind generation’s intermittency and location far from where it is consumed create significant constraints on the grid. The 3Q 2018 issue of Drax’s Electric Insights Quarterly shines a light on the increasing cost of balancing the UK electricity network with increasing penetration of wind power:

“Balancing the power system cost £3.8 million per day over the quarter, adding 6% to wholesale prices. On 3 days this quarter, the cost of keeping the system stable exceeded £10 million per day. This daily cost has been gradually increasing since 2010, but the cost this quarter was one-sixth higher than the previous record
(3Q 2017).”

There is up to 16 GW of new offshore capacity either in the pipeline or predicted. This new capacity could generate 20% of UK power, compared to offshore wind’s current 6% contribution. It does not take an expert to realize that National Grid, the UK’s transmission system operator, will face significant issues trying to incorporate this huge increase in offshore wind generation.

Intermittent Renewables Increase the UK’s System Balancing Costs

Balancing costs are mostly caused by calling on flexible sources for short-term dispatch, and Drax’s data shows that balancing costs are significantly higher when the output from flexible generation is below 10 GW or when (both offshore and onshore) wind supplies more than 30% of the UK’s electricity. The UK’s predicted path of more offshore wind will bring balancing costs into sharper perspective because more generation will not only be intermittent, but also will be reliant on the transmission system to transport it hundreds of miles to consumers.

System Balancing Must Move Away from Fossil Generation 

The UK network will rely on increased flexible capacity to keep balancing costs down. To date, the UK has relied on its capacity market to deliver flexibility, but this was dealt a minor blow recently when the European Court of Justice ruled that the market—which favored coal, gas, and diesel generators—breached European state aid rules. However, this judgment should be welcomed. It should pave the way for alternative flexible sources to participate in the market, including distributed energy resources, storage, and demand response.

It may also accelerate the adoption of other technologies that can solve capacity issues cause by intermittent generation. In a recent conversation with Guidehouse Insights, Faraday Grid discussed how its Faraday Exchangers can dynamically control voltage, frequency, and power flow, and minimize harmonics to improve the efficiency of power distribution. The company has also developed software to support a distributed, transactive solution to improve system flexibility.

While it is unclear exactly how much wind will be deployed in the UK in the future, what is clear is that new technologies will play a much bigger role in balancing the system.