A flywheel plant set to come up in Ireland holds the promise of almost unlimited storage of energy for both dirty and clean sources connected to the grid.
The plant will have an operating capacity of 20 MW and is expected to begin commercial operations in 2017.
European Commission and the Irish government are jointly funding the project that is coming up at Rhode in Offaly county.
Such a plant is particularly useful for clean energy sources whose production varies with climatic factors.
When climatic conditions cause excessive production from renewable energy projects, the flywheel plant can store the excess power in the form of kinetic energy and transmit it to turbines when the grid faces energy slumps.
Flywheels are able to completely absorb the energy supplied to them and return it with an efficiency of 85 to 90 percent. Conventional gas and coal generators at the same time have only an efficiency ratio of 35 to 40 percent.
The upcoming project is expected to have the capacity to absorb 75 percent of intermittent supply from renewable sources compared with 50 percent the current systems are capable of absorbing.
According to reports, the Irish transmissions systems operator Eirgrid is looking to attain such efficiency over the coming decades.
“The grid is designed to run at 50 hertz and when there is an imbalance between supply and demand, the frequency starts to change,” professor Noel Buckley a co-designer of the project from University of Limerick, said. The flywheel project helps stabilize such changes.
“By using back-up flow batteries that store electricity in tanks in a liquid form, you can scale up your power and storage capacities separately so that, in principle, the storage can be unlimited,” Buckley added.
Such projects have so far been experimented with largely in the US on a limited basis.
The Irish project is, therefore, drawing interest from national grids across Europe as it holds the promise of better storage and utilization of the variable energy produced.
The flywheel project is also expected to create 50 new jobs.
Ajith Kumar S
How the flywheel stores energy
The flywheel setup comprises carbon fibre tubes that are 3m tall and 1m wide floated on magnets in vacuum. This creates a nearly frictionless environment in the flywheel. When electricity is supplied to the arrangement, it spins the flywheel. The flywheel continues to spin in the friction free environment at speeds proportional to the energy it stores. When power is needed back in the grid, this kinetic energy is used to run turbines to generate power again.