Because most of the London Underground is ‘mostly’ underground, it’s not just transported by electricity, it also generates and uses a remarkable amount of energy. Below street level, the Tube’s ecosystem is a complicated dance of power, waste heat, and resource management.

Energy Consumption & Power Usage:

• The Underground consumes a massive amount of electricity daily. While precise daily figures vary, the scale is enormous, for some context, it takes enough power to light an entire city the size of York.
• Much of the energy is used not just for the trains themselves, but for station lighting, escalators, lifts, ventilation systems, and signaling.

Waste Heat Recovery:

• Some now-disused sections of the Underground are being repurposed to extract heat. For example, the City Road station, a long-closed station on the Northern line, has been converted so that its lift shaft is used as part of a waste heat recovery system.
• The Bunhill 2 Energy Centre uses the heat from the disused tunnels to help warm nearby residential buildings, turning otherwise wasted thermal energy into genuine community benefit.

Infrastructure for Power:

• The system is studded with substations and transformers to manage the flow of electricity to trains. Without these, the constant stop-start nature of Tube services would be inefficient and unsustainable.
• Vent shafts and cooling systems are vital; heat generated by trains and electric equipment needs ventilation, even deep underground.

Efficiency and Modernisation:

• Over time, older systems have been upgraded. For example, modern trains are more energy-efficient, regenerative braking is used in many newer models, and signalling upgrades reduce unnecessary acceleration and braking.
• TfL and other organisations continually evaluate how to make the Underground both power-hungry and environmentally responsible.

The London Underground is not just a train network, it’s a massive, subterranean power consumer and recycler. Between the electricity demands of millions of commuters and clever systems that recover heat from disused tunnels, the Tube stands as a case study in urban energy reuse and engineering innovation.