French utility EDF and German energy storage company STORNETIC have embarked on a joint project that seeks to advance the position of flywheel energy storage technology in meeting the needs of the modern grid.
STORNETIC will supply one of its DuraStor Energy Storage systems to EDF by June 2017 for installment at the experimental ‘Concept Grid’ facility of EDF, located in Moret-sur-Loing, south of Paris.
The project will assess the performance of flywheel energy storage technology under a variety of simulation conditions and accelerated test campaigns.
In particular, the developers hope to demonstrate the validity of the system as a means to provide grid ancillary services, as well as function in an off-grid island mode
Thilo Engelmann, project manager at STORNETIC, and Tobias Gottwald, spokesperson at STORNETIC, spoke to Renewable Energy World about the project.
“Flywheel energy storage is clearly quite different from what many others are putting into the energy storage market with batteries or super capacitors,” Engelmann said. “STORNETIC technology transforms electrical energy into rotational energy, and stores it as such. In certain instances, this method of energy storage has several advantages over batteries.”
Within the device, a motor spins a carbon fiber rotor up to a frequency of 45,000 revolutions per minute — this means the surface is moving at about 3000 kilometers per hour. Because of the high speed, the rotor is levitating in vacuum and held by active magnetic bearings, noted Engelmann.
STORNETIC’s DuraStor device finds flexibility in being a modular concept — a single cylindrical machine that can be stacked up to several megawatts in scale.
“Being highly scalable in this respect is a very advantageous aspect to the STORNETIC solution,” Gottwald said, explaining that microgrids of varying scales and business needs may be accommodated.
Commenting on the venture with EDF, Engelmann said: “This will be an important test of STORNETIC in a microgrid. Extensively, we’ll be investigating power electronics and aspects of performance in relation to different modes of operation.”
In particular, he said, STORNETIC wants to demonstrate the system’s performance as it switches from island mode to grid mode — a critical aspect to effective operations within microgrids.
Tweet this: “Flywheel energy storage is quite different from what others are putting into the storage market.”
He added that, “the focus of our other current storage project is to support the virtual power plant of Munich Municipal Utilities, Stadtwerke München. The system has been in operation since 2015.”
Around six months of testing is expected to take place at the EDF Concept Grid next year.
Full Capacity Throughout the Whole Lifetime
Energy storage is rapidly becoming a competitive market, but STORNETIC is confident that its technology is valuable, with a particular role to play within the sector.
“The strength of the flywheel technology is to deliver many charging cycles per day without degradation. Ideal are applications requiring power for a duration of seconds up to approximately several minutes,” Engelmann said.
While batteries aren’t ideal for delivering power over highly fluctuating load profiles, flywheel technology handles this kind of operation very well — retaining full capacity throughout their whole lifetime.
Engelmann explained: “Flywheel storage is not the appropriate technology for storing renewable energy over many hours or days. But over short delivery timescales, seconds to a few minutes, flywheel technology is a highly reliable, cost-effective and long-life solution. The sweet spot for flywheels is between super capacitors and batteries, where a reliable delivery of a high number of cycles at high power is necessary.”
Optimistic for the future of flywheel solutions, and STORNETIC, Engelmann concluded: “Alongside this project, we have a lot of exciting market project on going. We’re certainly working hard to see flywheel technology reach its full potential.”
Images credit: STORNETIC