Grid constraints could cost consumers £3.5 billion by the end of this decade, but while we wait for HVDC infrastructure buildout, let’s build batteries too, writes Chris Wickins, technical director at developer Field.
Last year alone, a grid capacity constraint across the Scotland-England border added £920 million of curtailment costs to consumers’ electricity bills. Bill payers paid to ‘turn off’ wind farms, effectively wasting cheaper, cleaner energy supplies, and fire up more expensive and carbon-intensive gas power plants in England and Wales.
This comes at a time when high energy costs have become the new norm. Since soaring gas prices first caused a steep rise in bills in 2021, the energy crisis has seen consumers struggle with higher bills – with some forced to extreme choices between clothing or food and paying for heating.
Last month, Citizens Advice data showed the number of households seeking help over energy debt doubled, suggesting high bills are likely to remain the norm for the foreseeable future.
The problem of curtailment is unlikely to go away soon. Across Britain, we lack the network infrastructure our energy system needs to make the most of clean energy supplies. This is particularly a problem across the B6 boundary, a pinch point in the electricity grid running between Scotland and England.
Renewable generation capacity in Great Britain rose to around 56GW in 2023, up from less than 10GW in 2010. This makes it all the more perverse that about 25% of last year’s curtailment costs were to ‘turn off’ available renewable energy and about 75% was paid to fire up fossil fuel power plants in England and Wales or import energy from the continent via interconnectors.
For now, Field analysis shows the problem looks set to get worse as the rate of installation of new offshore wind outpaces the growth of network infrastructure needed to transport this energy to where it is needed.
By 2030, constraints payments along the B6 boundary could cost bill payers as much as £2.2 billion. Some think this could rise to £3.5 billion across Britain in the same year.
Growing renewable energy capacity in itself will not resolve the problem. We need solutions to transport clean abundant supplies to centres of demand – something our electricity grid cannot do now.
The National Energy System Operator (NESO) has recommended a course of action. In the 2030s, they estimate nearly £60 billion needs to be spent to connect around 20GW of new offshore wind. However, delivering new infrastructure, which is subject to a lengthy planning process, takes time and the industry has an ambitious electricity decarbonisation target to achieve by 2035.
While billions are rightly used to upgrade transmission infrastructure, Field’s analysis suggests there is a better route that should be considered as a priority. Deploying more battery storage systems across the energy system could bring down curtailment costs dramatically.
In fact, Field’s analysis shows batteries could cut current costs to bill payers by around 80%, if used efficiently across the network infrastructure we already have. However, two important things must happen if we are to enable them to play their part in a reliable, greener and more efficient grid:
- We need to increase the number and capacity of ‘intertrip services’ the NESO can buy. To protect the system when it faces disruption, the NESO’s control room acts fast to deploy these services when and where overhead lines are in danger of being overloaded – the perfect fit for the country’s fast-acting batteries. Batteries can provide inertia, frequency response and reserve services, enabling adequate capacity for each service when the NESO needs it.
- We also need to use batteries in new and innovative ways, in step with our peers across Europe. An important market mechanism in Europe and Australia, Grid Booster projects involve setting up large battery storage systems on either side of a high-voltage transmission line. If the line faces disruption, both sites respond almost instantly to mimic the line’s power flow and reduce the need for a second, expensive backup line to meet the shortfall in supplies.
With 1GW more intertrip services in Scotland and 1GW of Grid Booster capacity in England, for example, the NESO would not need to turn off – and waste – that same volume on a windy day as it would have to today.
By 2030, Field estimates that using up to 2.3GW of Grid Booster projects in key locations across the energy system would reduce current curtailment costs across the B6 boundary by nearly 90%. Britain would then be able to use almost the full potential of its clean energy generation capacity, transporting supplies to power homes and businesses across the country.
It is absolutely vital that we build new network infrastructure. However, growing the role of storage through new marketplaces, such as Grid Boosters, or flexibility services must also be a priority. They maximise use of the storage and grid infrastructure we already have, buying the industry, Government, NESO and regulator much-needed time to build the infrastructure needed to achieve net zero.
About the Author
Chris Wickins is Technical Director at Field, a renewable energy infrastructure business operating in the UK and EU, where he leads development, construction and commercial operation of BESS projects in GB. He previously worked for Welsh Power and was responsible for some of their most innovative national infrastructure projects including a portfolio of synchronous condensers across the UK, part of the company’s efforts to drive the transition away from fossil fuels.