The world’s oldest underground transit system, the London Underground has been undergoing some testing in recent months. While this is nothing new for our beloved Tube, given the amount of modernisation work that often besets this sprawling subterranean rail network, the new tests represent progression of a very different kind. For the first time, engineers are looking at ways of using the actual trains to generate energy.
Over a five-week period which began in September, engineers have been running a variety of tests to see if the force generated by braking trains can be used to create electricity. Cloudesley Road station on the Victoria line is being used exclusively for this purpose. As cars arrive at the station, a device known as an inverter is used to convert energy gathered from the force generated by decreasing momentum which then converts it into electricity. This is then transferred back to the electrified rail and into the Tube’s grid.
Initial results have been rather promising with trains able to recover enough power to run Holburn station for about two days per week. The estimated 1mwh which can be recaptured every day means that enough electricity could be saved to reduce the Tube’s energy bill by 5%. If this new technology changes was installed across the network, around £6 million would be saved each year.
With the widespread introduction of the new breaking technology, London Underground predicts that its carbon footprint will be substantially reduced. It claims that the new system reduces the amount of heat generated by braking in tunnels which means that less of a burden is placed on cooling systems. Currently, air-conditions systems are one of the biggest power saps on the network.
The brake system trials run hand-in-hand with other schemes run by Transport for London which are intended to make the Tube system greener. For instance, Greenwich Power Station is being converted into a low-carbon power generator – its boilers are being replaced by gas engines with waste heat being channelled into a new heat network.
The new tests are the first of their kind in the world and herald a breakthrough in how modern transit systems can be made more sustainable in their operation. The project is one of a number of proposals which have been put forth by architectural firm, NBBJ. One of their more radical ideas is to replace Circle Line Trains with electronic walkways known as travelators. These would run at different speeds, allowing commuters to travel as speeds ranging from a comfortable 2mph to a more hair-raising speed of 15mph. It is claimed that the system would allow pedestrians to travel the 17 mile faster than trains. This proposal remains on the drawing board.
However, if their new regenerative braking system proves successful, the methods of powering stations as well as the reduced costs have the potential to transform the London Underground service, allowing it to allocate more money for further improving a mass-transit network which is desperately underfunded.