Under the plans, hot water and central heating for 500 new homes near the planned HS2 hub at Old Oak Common in northwest London would come from five air source heat pumps drawing warm air from the railway’s tunnels.
Waste heat from trains is usually extracted from tunnels by traditional ventilation systems and seeps into the ground surrounding the tunnels. But HS2 Ltd instead wants to capture and exploit it.
HS2 innovation manager Pablo García said: “HS2 is so much more than a railway. By taking a long term view of how the benefits of investing in the new high speed railway can be shared, we’re investigating how to provide sustainable, low-carbon heating and hot water to up to 500 new homes.
“Near Old Oak Common we’re building a crossover box. This is an underground hall that houses a points junction to enable trains to arrive and depart from any of the station’s platforms. Our plans would see warm air pushed into the crossover box by trains, in effect acting like pistons. It then rises to be harnessed by air source heat pumps, converted into hot water and transported to homes by insulated pipes.”
Based on current energy price forecasts, HS2 estimates that the investment in waste heat recycling system would pay for itself after four years.
Plans are at an early stage but the technology is proven, HS2 says.
Old Oak Common’s crossover box is the only place on HS2’s first section between London and Birmingham capable of supporting waste heat recovery technology but there may be further opportunities on Phase Two up to Leeds and Manchester.
“Our study focused on possible Phase One opportunities because its designs are most advanced,” Pablo García explained. “Designs for the second phase of the railway are at an earlier stage, and we hope to look at whether waste heat recovery technology could be deployed there too.”