Flywheel-derived energy harvesting is fast becoming a real option

IDTechEx has said that many vehicle applications involve grabbing huge amounts of energy in only seconds, one increasingly popular form being use of 60,000rpm lightweight flywheels during braking. The energy is returned electro-dynamically, mechanically or both.

Known as High Power Energy Harvesting – regenerative braking of trains, buses, trams, cars and so on using generators and motors working backwards and also known as Torque Assist Reversing Alternators (TARA)- are being prepared in the UK for use in conventional cars. 

The humble bicycle dynamo has been followed by regenerative sailing, and other sea-going boats designed with thrust propellers that work backwards to generate electricity. 
 
On land, the market for remote power and microgrids is $US17 billion and high power energy harvesting is an increasing percentage of that. It is particularly in the form of small wind turbines with solar to be followed by the new airborne wind energy – mainly tethered multicopter kites. 

Water turbines in rivers and other options are gaining traction, most of them being electro-dynamic, the dominant form of HPEH from 10W to 100kW. 
 
Analysts IDTechEx advise that multi-mode energy harvesting will increase greatly in land vehicles, boats, ships and aircraft and in static off-grid applications on land, where harvesting typically employs hours of sunshine, wind or heat. 

In combination, the supply of electricity will sometimes be continuous leading to elimination of most of the troublesome expensive energy storage that has been holding things back.
 
Dr Peter Harrop, team leader of the IDTechEx research project has said, "We were interested to find that Europe is in the lead in flywheel adoption and research, with 500 London buses trialling GKN/Williams ones for example.”

“The technology derives from the $US9 billion British motor racing industry, which is rapidly moving to pure electric and hybrid racers. Europe has more organisations developing airborne wind energy (AWE) than the rest of the world put together, the power being typically 10kW to 100kW – that is also electro-dynamic harvesting.”