Research suggests we can use subway tunnels to generate heating and cooling for homes
Groundbreaking new research out of Lausanne, Switzerland suggests using subway tunnels to generate energy to heat and cool homes in cities around the world.
Heating and cooling is one of humanity’s top uses of energy, especially energy produced by fossil fuels. It’s also expensive and produces hundreds of millions of tons of carbon emissions every year that contribute to climate change.
But researchers at L’Ecole Polytechnique Fédérale de Lausanne (EPFL) have discovered that subway tunnels used to transport millions of people in cities around the world from place to place every day can act as a generator of geothermal energy that can heat homes in winter and cool them in the summer. And all for free or a very low cost because the equipment necessary would only need to be replaced every quarter century.
According to EPFL:
The system works in a similar way to a refrigerator, with plastic pipes containing heat-transfer fluid, or simply water, placed at regular intervals inside the concrete tunnel walls and connected to a heat pump. In winter, cold water will be pumped into the pipes, emerging hot at the surface. The opposite will happen in summer. According to the researchers, the system would be cheap and energy-efficient to install and would have a lifespan of between 50 and 100 years, with only the heat pumps having to be replaced every 25 years.
The research is based on a thesis authored by Margaux Peltier, who also worked on the project.
“Our research shows that fitting the heat-recovery system along 50–60% of the planned route – or 60,000 square meters of tunnel surface area – would cover the heating needs of 1,500 standard 80m2 apartments, or as many as 4,000 Minergie-certified energy-efficient units,” she said. “Switching from gas-fired heating would cut the city’s CO2 emissions by two million tons per year. The tunnel would act like a highly reliable, year-round heating and air-conditioning system.”
This definitely gives people a new excuse to use the subway.
If cities around the globe employed the same technology to their own subway systems, it would go a long way toward reducing carbon emissions and saving people a lot of money on their energy bills. Because the more the subway is used, the more energy is produced.It’s a win-win for the planet and humans.
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