Find out more about Energiestro
André Gennesseaux co-founded d'Energiestro, a start-up that has developed a new method for storing solar energy. To even out fluctuations in production at a solar power station over a 24-hour period, electricity must be stored overnight. The traditional solution has been to use batteries. The flywheel is one possible alternative. The first is costly, but the second... is as well.
So Energiestro decided to use concrete to create a flywheel with a nearly unlimited lifespan, keeping storage costs low. The flywheel will run for over 20 years, performing more than one million cycles in that time. Batteries, on the other hand, last only a few years and a few thousand cycles. The 'VOSS' (from the French for 'solar storage flywheel') costs around 1 or 2 cents per kilowatt-hour, compared with around 10 cents for batteries.