Researchers in Switzerland have calculated how the heat that is produced in metro tunnels can be captured and used to heat and cool neighbouring residences.
Researchers at the Ecole polytechnique fédérale de Lausanne (EPFL) have first the first time ever accurately calculated the amount of heat that tunnel air contains. According to the Swiss institute, this paves the way for innovative applications involving what are called energy tunnels, which can supply energy to built environments. The team has already tested its model on Lausanne’s future M3 metro line.
“Our research shows that fitting the heat-recovery system along 50 to 60 per cent of the planned route – or 60,000 square metres of tunnel surface area – would cover the heating needs of 1,500 standard 80 square metre apartments, or as many as 4,000 Minergie-certified energy-efficient units,” said Margaux Peltier, whose Master’s research forms the basis of the now-published article.
The system would allow heat to be stored so it can be supplied to homes when needed and could cover up to 80 per cent of the heating needs of local apartments throughout the winter. In the summer, the tunnel would act as an air-conditioning system.
According to the researchers, the system could cut the city’s carbon emissions by two million tons per year. It would also be inexpensive and energy-efficient to install, with a lifespan of between 50 and 100 years.
The researchers have now presented their findings to the city’s utility agency, the local public transport operator, the canton of Vaud, the city of Lausanne and the lead contractor working on the new metro line.
Image credit: LMS / 2019 EPFL