UK's energy system wagers on flywheels to ensure continuous power supply

The British government is leading the charge in Europe towards a renewable-heavy energy grid, aiming to power the national grid with clean energy 95 percent of the time by 2030 and completely transitioning to renewables in the next decade. This ambitious goal has sparked a significant shift in the country's approach to grid stabilization, with flywheels and static compensators playing a pivotal role.

In an electricity grid, inertia is typically provided by large spinning generators found in coal-fired and gas power plants. However, renewable energy sources like solar and wind power do not add inertia to the grid, posing a challenge for grid operators. This issue was highlighted in the Spanish blackout in April 2023, when the Iberian Peninsula, which has a high share of renewables, experienced a blackout due to its grid's inability to absorb a sudden surge in voltage and deviations in frequency.

Grid operators are now looking to flywheels to add inertia to renewable-heavy electricity systems and prevent similar blackouts. Flywheels, which have been used for centuries to provide inertia to various machines, can mimic the rotational inertia of power plant generators, spinning quicker or slower to respond to fluctuations. The Norwegian company Statkraft commissioned the "Greener Grid Park" in Liverpool, UK, with two large flywheels operational since 2023. Each flywheel is attached to a synchronous compensator, which boosts inertia and provides voltage control services in the Liverpool region.

UK energy operator NESO launched a program to contract grid-stabilising projects following a 2019 blackout in Britain. As of 2023, 11 similar synchronous compensator and flywheel projects were operational in Britain, with several more contracted. The two giant flywheels at the Statkraft site weigh 40 tons each and provide one percent of the inertia for England, Scotland, and Wales' grid.

The British government is working with industry partners to develop world-leading technology, including flywheels and static and synchronous compensators, to overhaul the energy system. However, Guy Nicholson, Statkraft's zero-carbon grid solutions head, stated that Britain isn't building these technologies fast enough to decarbonize the grid. Nicholson suggested that the Spanish blackout will drive change in the European continent's approach to stabilizing renewable-heavy grids.

According to engineering professor Keith Pullen, steel flywheels can be more cost-effective and durable than lithium-ion batteries for adding synthetic inertia to the grid. In the coming years, Pullen warns that the grid will become more unstable due to greater, but spikier demand from electric cars, heat pumps, and energy-guzzling data centers. As traditional power plants are closed and replaced by renewable energy systems, the need for reliable grid stabilization technologies like flywheels and static compensators will become increasingly important.

These advancements in grid stabilization technology are not only crucial for Britain but could also have a significant impact on the European continent's approach to renewable energy integration. The Spanish blackout serves as a stark reminder of the challenges posed by renewable-heavy grids and the need for innovative solutions to ensure a stable and reliable energy supply.