High-profile infrastructure project High Speed Two (HS2) could use its trains to power up to 500 new homes.
Engineers on the project are proposing plans to use the heat from brakes and engines of high-speed trains to power homes and heat water in the homes.
Waste heat from trains in tunnels is typically extracted by regular ventilation systems and is lost to the ground surrounding the tunnels.
But the project would pump this hot air from HS2 tunnels into a ‘local district heating system’ that would then be recycled to power newly-built homes.
The new homes would be located new HS2 station Old Oak Common in North West London. HS2 estimates that 250,000 people will pass through the station every day once up and running.
HS2 innovation manager, Pablo García, says: “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.”
The plans by HS2 come after Chancellor announced in his Spring Statement last week that the government intends to ban the use of gas boilers in all newly-built homes by 2025.
How much would it cost?
HS2 estimates that the cost of building such a recycling system would pay for itself in four years, as homeowners pick up the tab through their energy bills.
It estimates the outlay for five pumps would be around £57,000. How much households would pay for their energy depends somewhat on how the housing developer chose to feed the cost of the investment back.
But paying for the energy at cost, HS2 says conservatively it would cost 500 homes around £32 a year, a fraction of typical energy bills.
However, depending on usage, as some pumps wouldn't work overnight or when no trains were running, this cost could increase to £43 per year per household.
It says recycled heat generated by train engines and brakes would reduce the carbon footprint of the homes by 22%, compared to typical gas boiler usage.
However, HS2 concedes plans are at an "early stage" despite proven technology.
While Old Oak Common is the only place this system could be implemented between London and Birmingham, Mr Garcia says that similar projects could be implemented around Leeds and Manchester.
He adds: “Our study focused on possible Phase One [London to Birmingham] opportunities because its designs are most advanced. 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.”