Polish subway to recycle brake energy

Alex Blackburne looks into the idea of regenerative braking, and why the subway system in Poland’s capital is set to use it to power other trains.

Subway trains in Warsaw, the capital of the Eastern European state of Poland, are set to use an innovative brake energy capturing system to help power other, accelerating trains.

Regenerative braking is the process whereby energy is recovered when a vehicle brakes or slows down, essentially turning the electric motor into a generator, transforming the energy for immediate use, or storing it for the future.

In the case of Warsaw’s subway, regenerative braking is going to be used to power other trains on the city’s transit system. Enough energy is stored from one decelerating train to power a 60-watt light bulb for more than a week.

The project is part of a wider, $15m venture headed by multinational power and automation technology group, ABB, which has planned seven new substations to provide power to a new metro line in Warsaw.

“This is an innovative traction power supply solution incorporating an energy storage system”, said Oleg Aleinikov, head of ABB’s substations business, a part of the company’s power systems division.

“Utilizing braking energy from decelerating metro cars and feeding it back into the power supply system will help enhance the energy-efficiency of this metro line further.”

The installation of regenerative brakes would have no detrimental effects whatsoever on a vehicle’s performance. Instead, it would simply add to the cost-effectiveness because of the energy recycling capabilities it possesses.

One of the main issues, though, is the need for a back-up system – usually regular friction brakes – just so a vehicle has a way of slowing down if the regenerative ones don’t kick in.

Comedy actor and car enthusiast Robert Llewellyn explains how the energy-storing technique works in this video, and although his experiment takes place in a car, the concept is the same.

One thing we should add about it, though, is that Llewellyn concludes by labelling the experiment “utterly pointless”. He simply didn’t give the car enough time to regenerate new energy.

A variation of regenerative braking is dynamic braking, and this beautifully-created slow-motion video from General Electric gives a great visual explanation of the technology behind the system.  It’s worth a watch even if you have no interest in the actual science behind it.

Innovations like regenerative braking are being developed all the time, and they can only be positive towards the future of our planet. If you would like to find out more about investing in such technologies, ask your financial adviser, if you have one, or complete our online form and we’ll connect you with a specialist ethical adviser.

Picture source: ninasaurusrex