No, more wind power doesn’t mean the lights will go out

October 16, 2020

“We believe that in 10 years’ time offshore wind will be powering every home in the country.” This was the Prime Minister’s positive vision for a low-carbon UK that he set out in his Conference speech last week. Rather predictably, this has led to questions about what happens when the wind stops blowing. Not all of this criticism will be in good faith, but there is also a serious point. As well as talking about low-carbon wind energy, the Government also needs to answer questions about its plan for keeping the lights on as we rely more on offshore wind farms. Some of these answers could come as part of the long-awaited Energy White Paper, which is expected to be published shortly.

The UK’s ambition on offshore wind is a monumental challenge that will see energy from offshore wind double by 2025 and quadruple by 2030. Critics of renewables are again claiming that wind power is unreliable and is a risk to the UK’s energy security. Last week’s headlines claimed that wind “will power EVERY home in Britain in ten years”. This is not a literal statement, as we’ll need a diverse range of energy sources, although it’s understandable why it might be confusing. So, what is the plan for powering Britain’s homes on a cold winter evening with little wind power?

Wind farms and power stations play different roles in the UK’s electricity system.

If you speak to an engineer building or operating the UK’s electricity system, you’ll find that they’re already aware that sometimes it’s windy and sometimes it’s not. The UK is already the world’s leader in offshore wind, so we have plenty of experience managing its ups and downs.

However, the engineers will tell you that there’s a difference between the power stations that provide ‘firm capacity’ (i.e. guaranteed electricity generation whatever the weather) and the offshore wind farms that provide clean energy when it’s windy. Offshore wind farms will increasingly power Britain’s homes, business and industrial facilities, but that doesn’t mean that we’re getting rid of ‘firm’ power stations any time soon.

The Government uses a scheme called the ‘Capacity Market’ to ensure that there is always sufficient firm capacity to cover those cold, windless winter evenings. It pays energy companies to provide that reliable back-up. Today, this firm capacity is dominated by gas power stations, although that will eventually need to change to hit Net Zero.

Despite the claims of the anti-renewables lobby, there is no gotcha moment, and there is actually a system in place to keep the lights on whilst powering more homes with clean wind energy more of the time. To address genuine concerns about the variability of wind power, the Government will increasingly need to talk about its plan. We need to start talking about the differences between the ‘clean energy’ generated by offshore wind and the ‘firm capacity’ provided by natural gas. The electricity system can only function with both, and the UK will have both.

New technology means that wind farms will increasingly power the UK.

Despite the opportunities of offshore wind farms, the UK’s ambition will pose genuine challenges for grid operators, who’ve traditionally relied on large gas- and coal-fired power stations to keep the system operating smoothly. We’ve seen this year that balancing a grid with more renewables – smoothing out peaks and troughs – costs money. Unless operators find new ways of keeping the grid secure, they will increasingly have to turn off wind turbines when it’s too windy, turning back on gas and other power stations. The good news is that Britain’s grid operator is already implementing new technologies, new monitoring equipment and new ways of working that mean, by 2025, there will be times that British grid will be able to operate with just low-carbon generators like nuclear, wind, biomass, solar and hydro. This will be a step change in our ability to power Britain’s homes with low-carbon energy.

The UK is already in the midst of a clean energy revolution built on offshore wind and the PM’s announcement last week puts us on an increasingly ambitious trajectory towards Net Zero. The Government is also committing to invest in the UK’s ports so that they can manufacture ever-taller wind turbines and, in future, can manufacture giant floating wind turbines that can be towed to the deepest seas to capture the strongest winds. However, as exciting as this abundant clean energy is, it must be balanced with firm capacity to ensure that people will never be left in the dark because the wind has stopped blowing.

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