Britain’s energy operator is turning to centuries-old technology to address a modern challenge maintaining grid stability in an era dominated by renewable power. The solution lies in flywheels, spinning metal devices that have been used for hundreds of years to store and manage energy in everything from potter’s wheels to steam engines.
At the heart of the issue is inertia. Traditionally, coal and gas power stations provided the grid with inertia through their large spinning turbines. This inertia helped keep the system frequency stable by resisting sudden changes in electricity supply and demand. Without it, grids are more vulnerable to fluctuations that can lead to outages, like the blackout that struck Spain and Portugal earlier this year.
As Britain phases out fossil fuel plants and increases reliance on wind and solar energy, grid operators are grappling with the fact that renewables do not inherently provide inertia. Solar panels and wind turbines generate electricity through power electronics rather than rotating masses, which means they cannot automatically smooth out imbalances in the system. Moreover, renewables are less effective at addressing other technical challenges, such as voltage control.
Flywheels offer a promising workaround. By spinning at extremely high speeds, they can store kinetic energy and release it instantly when the grid needs support. Unlike batteries, which degrade over time and are better suited for long-term energy storage, flywheels excel at delivering rapid bursts of stability. This makes them particularly useful in renewable-heavy grids where supply can fluctuate dramatically with weather conditions.
Britain is not alone in exploring this option. Grid operators across Europe and beyond are testing flywheel projects to ensure that as clean energy grows, reliability does not suffer. In the UK, integrating flywheel systems into the grid could help smooth the transition away from fossil fuels while reducing the risk of blackouts.
As the country pushes toward its net-zero targets, the revival of flywheel technology illustrates how old innovations can be repurposed to solve new challenges. The future of energy may be renewable, but keeping the lights on could depend on a technology that predates the industrial revolution.
