Flywheels and small mechanical stores: Impact and additionality

Stability helpers for renewable grids, not fossil replacements

What this tab covers The impact and additionality lens: what it displaces on the grid, who gains and who bears the burden along the supply chain, and what happens at end of life.

Flywheels help grids absorb more renewables by providing fast stability services, but they do not replace fossil plants for hours of supply.

Grid decarbonisation versus fossil displacement

Mixed

With minutes of storage, flywheels do not displace gas peakers for evening demand. Their contribution is indirect: providing fast frequency response and inertia-like services that otherwise keep fossil units spinning part-loaded. Global deployment is small; the world's largest plant is 30 MW.¹

Largest plant 30 MW (Dinglun, 2024)¹ Previous largest two 20 MW US plants¹

Just transition and local community impact

Mixed

Manufacturing uses steel, composites and power electronics without mining-intensive inputs, and the hazard profile near communities is low. The largest recent project used a Chinese supplier, BC New Energy, suggesting the supply base is shifting to China.¹

Dinglun units 120 maglev flywheels¹

Circular economy and end of life

Mixed

Steel rotors, copper and housings are readily recyclable. Carbon-fibre rotors are harder: composite recycling is immature, so end of life may mean landfill or downcycling.²³

Sources

'World's largest' 30MW flywheel energy storage project connects to grid in China Energy-Storage.news, 2024
Milestones for flywheel, lithium battery grid-scale projects POWER Magazine, 2011
A review of flywheel energy storage systems: state of the art and opportunities (Li and Palazzolo, Journal of Energy Storage 46, 103576) Elsevier (Journal of Energy Storage), 2022