The part of the planet’s population who have access to electricity are used to being able to flip a switch and have light, heat or their favourite TV show available instantly – whether that’s at 3am or 3pm.
“We’ve discussed the intermittency problem that renewable energy sources have before [LINK TO TOM VIDEO] – in essence, it means that solar PV panels aren’t producing electricity when the sun isn’t shining and wind turbines aren’t spinning to produce energy on a still day,” explains Thomas Gebauer, Chief Executive Officer: Redox One. “If renewables are to be the way forward – and they really should be – energy providers need to find a way to store energy generated by renewables and make it accessible when it’s needed, 24/7/365”.
Gebauer explains that if renewable energy isn’t used exactly when it’s generated, it’s wasted. That’s why energy storage is key “When the sun is shining, and solar PV panels are providing energy – and there’s a demand for it – that’s great. When there’s no or low demand, all that energy isn’t used and if there’s nowhere to store it, it can’t be harnessed later when it may be needed,” he says. “Effectively, solar and wind without battery storage means you have to use those electrons that are generated, immediately.”
Peak generation is a challenge for renewables too – when the sun is at its height during the day, people aren’t necessarily cooking or watching TV. That happens at the beginning or end of the day, when the sun is rising or setting and there’s less solar PV power up for grabs. While not entirely true for wind or hydro, demand and supply for energy generated by solar PV are mismatched. Midnight in one place is lunchtime in another, so it’s hypothetically possible to harness solar PV power from the other side of the world – but imagine the expense of establishing and maintaining a transmission network that could manage global energy supply?
The implementation of renewables is certainly making a global impact – in September this year, Britain made a vital step towards decarbonising its electricity supply when it closed its final coal-fired power plant, becoming the first G7 country to stop using coal for electricity generation. As recently as 1990, coal supplied 80% of the country’s electricity – but in 2023, it supplied just 1%. About one third of Britain’s electricity now comes from gas, another third from wind and solar, with bioenergy and nuclear making up the rest.
Along with that, benchmark crude oil prices have fallen sharply, which Reuters reports is amid concerns about a weaker global economy and oil demand. Permits for coal-fired power plants in China have dropped by more than 80% and jobs in the US clean energy sector grew at more than double the rate of the country’s overall job market, according to the US Energy Department.
“What we need more of, then, are batteries that can store energy produced by renewable – or any other sources – and make it available, on-demand, at a sufficient scale and magnitude,” says Gebauer. “The ideal battery for storing energy at industrial – thinking in Megawatts and Gigawatts – requires sufficient capacity to store all that generated energy, retain it for long periods to cover the times new energy isn’t being generated, and discharge it quickly, efficiently and safely when it is needed.”
Long-Duration Energy Storage (LDES) Solutions are the answer to this challenge. The emerging market for LDES is driven by the need to replace fossil fuel generation with renewables while minimising costs, improving reliability and managing the environmental issues around building new transmission infrastructure. These large-scale storage systems need to be capable of performing peaking services, grid congestion management and time-shifting of renewable energy generation.
“To have one charge and discharge cycle per day, you need to have a battery that can store enough energy to offset renewable generation for that day – so you’re targeting a 4–12-hour interval,” says Gebauer. “That will allow, say, a system with a combination of solar PV panels and an LDES battery to draw energy from the battery in the evening, through to the morning when the sun shines enough for the threshold to be crossed, then the solar panels provide power and charge the battery during the day, making energy available for that nighttime period again”.