Clean Power by 2030!
Our electricity sector is trapped in a bewildering and dangerous paradox: taxpayers are being charged billions of pounds to curtail wind farms, while at the same time, millions of homes are freezing due to heat poverty. This market failure is only aggravating our existing social and economic woes while large volumes of precious clean energy are going to waste.
Without immediate action, there could be more pain on the way. According to Carbon Tracker, wind curtailment alone could increase household power bills by another £150 a year by 2026. Just take a moment to let that sink in: if it weren’t already expensive enough to buy electricity, now we’re also being charged to waste it.
Clearly, something has gone fundamentally wrong. The key to a greener and more prosperous UK is not merely generating more clean power, but being smarter with the resources we already have. This means closely integrating our power and heat systems, such as by deploying large-scale heat reservoirs.
The Unsung Heroes of the Clean Energy Revolution
For most people, the word ‘battery’ is synonymous with storing electricity. However, almost half of all energy consumed in the UK is for heating, meaning electrical storage is only one piece of our decarbonisation puzzle. And despite the UK having one of the world’s largest markets for utility-scale lithium batteries, they aren’t a panacea for our energy woes. While offering a means to store electricity, they’re also expensive, complex to build, and consume vast amounts of precious natural resources, many of which are mined in the third world. At the end of the day, what’s the point of advancing our clean energy goals if they come at the expense of people and the environment?
To affordably decarbonise UK homes and businesses, we must expand our thinking beyond electricity to include generating and storing green heat. This need is where heat reservoirs – huge, often stadiumsized thermal energy storage pits filled with hot water – are an ideal solution. These systems perfectly embody the ‘Danish Concept’, Henrik Stiesdal’s now near universal wind turbine design based on the fundamental principles of simplicity and economy. In the same way, heat reservoirs offer a practical, safe, and sustainable way to store clean energy, all at a far lower cost than traditional battery systems.
And ultimately, who really benefits from building all these giant lithium batteries? Our electrical system should provide the greatest public benefit at the lowest cost, not simply give large power companies even more control of the market.
“When connected to heat highways, these heat reservoirs can supply urban heat grids with affordable zero-carbon heat, exactly when it’s needed.”
Low-cost Green Heating for Urban Heat Grids
As heat reservoirs require considerable amounts of physical space, it is most practical to locate them on the outskirts of major cities. This raises an invariable question: how do we transport the green heat from where it’s stored to where it’s needed? The answer is connecting heat reservoirs to long-range ‘heat highways’, which form the vital link between regional energy stores and urban heat grids. Heat highways are underground piping systems that can deliver large volumes of hot water over long distances with only minimal temperature losses.
Deploying this green heat infrastructure can also help more UK communities benefit from the renewable energy stocks in their local region. For instance, much of the wind power generated in Scotland is transmitted south to England’s large population centres, and what can’t be used or stored is often curtailed at the taxpayer’s expense. However, by deploying power-to-heat systems connected to thermal energy storage, the Scottish wind power currently being wasted can become affordable heating for Scottish homes.
Electricity Market Reform: a Stark Choice
To achieve clean power by 2030, regulators need to make some fast and fundamental changes to our electricity market. This problem stems from having a power network designed to transmit electricity from a coal-fired power station to surrounding homes and businesses – not generate, store, or deliver intermittent renewables like solar and wind, let alone charge millions of EVs.
With clean energy generation and EV sales poised for rapid growth, our existing power system simply can’t keep pace with such a dramatic rate of change. Various industry experts project that we need at least four times as much demand flexibility as we have now, such as infrastructure like large-scale heat storage that can decouple demand from supply.
However, for heat reservoirs and heat batteries to deliver green heat at the lowest cost, we need electricity pricing reforms that allow them to utilise excess renewables. These reforms include introducing dynamic and zonal pricing models, in which electricity prices fluctuate in real time based on the supply and demand within specific areas. These changes would enable thermal storage, equipped with large-scale heat pumps and electric boilers, to convert cheap or even negatively priced electricity into large volumes of zero-carbon heat and store it for later use.
These dynamic pricing models have proven highly successful in Denmark, where heat battery and reservoir operators soak up excess renewables while providing valuable grid balancing services. Here in the UK, pricing reforms would enable renewable energy stored as heat to provide broad-scale demand flexibility, the foundation of a green, future-proof electricity market.
Clean Power by 2030? Only with Heat Batteries
If we’re serious about achieving clean power by 2030 – not to mention net zero beyond that – we must understand that electricity and heating are equal elements of the same equation. By utilising power-to heat technologies, large-scale heat batteries can efficiently and affordably streamline our transition from fossil fuels to cheaper, more sustainable forms of energy.
When connected to heat highways, these heat batteries can supply urban heat grids with affordable zero-carbon heat, exactly when it’s needed. This power-to-heat strategy, supported by electricity market reforms, is the key to lifting millions of homes out of fuel poverty, slashing our carbon emissions, and building a stronger, more efficient UK economy.
Did you know?
Dunkelflaute—a German term meaning “dark doldrums”—describes periods of low solar and wind energy production, typically occurring in winter when skies are overcast, wind is calm, and demand for heat and power is high. These conditions pose a significant challenge for energy systems that rely heavily on renewable energy, as generation drops while consumption peaks. Without sufficient backup systems, such as combined heat and power (CHP), energy storage, dispatchable renewable heat sources, or flexible demand management, a dunkelflaute can lead to energy shortfalls. The importance of developing resilient energy solutions, like thermal storage and grid-balancing technologies, to ensure stability during these extended lulls is essential. Addressing dunkelflaute is critical for achieving a secure and reliable renewable energy transition, particularly in regions prone to seasonal variability.
