Transport for London has been testing a new inverter technology, which recycles unused energy from the brakes on trains, and results suggest it could save London enough electricity to reduce the Tube's energy bill by 5%.
The test took place at the Cloudesley Road substation on the Victoria Line over five weeks, and saw the new technology apparently recover enough power equivalent to running Holborn for two days per week.
TfL points out that by saving the energy, it also reduces the heat generated by trains braking, which in turn reduces the energy needed to cool them again. Apparently the saved energy adds up to 1 Megawatt hour per day - which is enough to power 104 homes. It sounds a bit like regenerative braking in cars, basically.
Matthew Pencharz, Deputy Mayor for Environment and Energy, said: “The results of this project are really exciting and show huge potential for harnessing some of the immense energy in our Tube trains. The trial puts London at the cutting edge of this kind of technology and clearly demonstrates how energy from trains can be recovered to power Tube stations, making the network more environmentally friendly and cost effective. This complements our wider work to make other forms of public transport cleaner and greener, including our buses, where we have introduced hybrid and zero-emission technology.”
The other upshot is that if rolled out, the technology could save TfL a whopping £6m each year - which could then be either spent on improving other parts of the Tube, or pissed away on a stupid cable car, depending on what the Mayor wants.