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General Category => General Discussion => Topic started by: CrashCash on October 02, 2015, 11:21:19 PM

Title: Regen on London Underground train captures 1MW/hr per day
Post by: CrashCash on October 02, 2015, 11:21:19 PM

It's not a motorcycle, but pulling a megawatt-hour of regen deserves some respect.

Quote

In the first experiment of its kind, the London Underground has installed an inverter system that converts braking energy into power. For each day of the five-week test, the system captured a full megawatt hour

http://www.bbc.com/autos/story/20151002-the-train-that-powers-its-station (http://www.bbc.com/autos/story/20151002-the-train-that-powers-its-station)

Title: Re: Regen on London Underground train captures 1MW/hr per day
Post by: Doug S on October 03, 2015, 01:11:39 AM

Unfortunately they don't mention how much power the trains use overall. I'd bet that the amount recovered by regen is a pretty small fraction, just like it is on our vehicles. Not that they shouldn't be using regen, every little bit helps, but they'd probably save more energy by reducing the top speed of the trains by 2 mph.

Regen is overrated.

Title: Re: Regen on London Underground train captures 1MW/hr per day
Post by: protomech on October 03, 2015, 07:56:35 PM

The trains are far heavier than our vehicles and have far more mass behind their aero shadow than we do. Regen should be very effective - if they can handle the power levels.

I don't know what industrial power costs in the UK, but assuming 10 kWh per pound, they're saving £100/day. £36k/year. Not sure how they get to "millions of pounds saved per year" unless this is a small fraction of the system.

Good point about less energy required to cool the tubes as well with less kinetic energy turning into heat via friction braking.