Technology

Londons underground rail upgrates for blackouts

What other rail operators do long, now also introduces Transport for London: The braking energy will no longer be converted into useless heat, but into usable energy. This benefits the environment and saves costs.

The first London Underground rolled, pulled by a steam locomotive, on 10 January 1863. the subsoil of the British capital. A world premiere. Now reclaims Transport for London, the operator of the third longest metro network in the world, another first for themselves: The recovery of electricity into the grid when braking.

“With this test, London takes a leading role,” says Matthew Pencharz, Councillor for the Environment and Energy. Five percent of the electricity consumed the London Underground are to be recovered this way. This means a savings of six million pounds a year, ie more than € 8 million.

Trains provide each other with electricity

Other railway companies have departed believes as Pencharz. So the German Railways wins 6% of their electricity consumption back during braking. It works like this: The driver switched on when a station comes into view, the power supply from. The DC motors driving the vehicle are, then, equipped according to generators that produce electricity. They are driven by the momentum of the heavy vehicles tonnes. The electricity is fed into the two conductor beside the tracks and by another train, which depends on the same circuit, consumes.

London is testing at a subway, the recovery of electricity into the grid.
London is testing at a subway, the recovery of electricity into the grid.

Since the braking action of the generators is becoming weaker, the slower the train, must take on the conventional mechanical brake at a certain speed. In rare cases, it has to bring to a halt the train alone, namely, when no other train can consume the braking power, which in the direct line of play the London Underground but hardly ever occurs.

Cooling costs less future

The recovery of braking energy has another positive effect. So far, it is converted into heat, which heats up the tunnel. The ventilation system ensures that the temperature remains bearable. In future it can be switched down a gear so that additional power is conserved.

London is testing at a subway, the recovery of electricity into the grid.
London is testing at a subway, the recovery of electricity into the grid.

Transport for London considers the retrofitting of underground as part of an environmental campaign, which continues above ground. Transportation by public transport should be clean and green, says Pencharz. “This includes our busses,” said the councilor. “We have already introduced hybrid and zero-emission vehicles.” In fact, roll over London’s streets already more than 1,200 buses with diesel and electric engine. Their braking energy is used to recharge the batteries on board.