The “thermos” that heats the city of Borås
Posted on April, 15th 2014.
In 1959, the municipality of Borås, in Sweden, decided to gradually reduce its dependency on fossil fuels. Heating, they decided, was the first step.
Welcome to Borås, a town in Sweden with 100,000 inhabitants, 37 miles from Göteborg. Borås has two claims to fame: a giant bronze statue of Pinocchio and the “thermos,” an 80-meter high energy storage reservoir with a capacity of 37,000 cubic meters that cuts the town’s greenhouse gas emissions by around 5,500 metric tons a year – that’s the amount that would be saved if the inhabitants of Borås stopped producing carbon dioxide for three days.
A little bit of historyUnhappy with the consumerist model of the post-war boom years, in 1959, the people of Borås decided to gradually reduce their dependency on fossil fuels and to find ways of recovering their waste. They started in the 1960s by installing a district heating network, supplied by the Ryaverket power station, which was then powered by oil. By 1984, the station had been converted to biomass (wood pellets) and coal. Then, in 1995, after installing the world’s biggest steam dryer, to dry out the wood prior to burning, it cut out coal entirely. Now, the Ryaverket site adapts its fuel mix (the different types of energy sources – fossil and renewable – used to supply the town with energy) to the seasons. When the outside temperature rises above two degrees Celsius, all of its energy is produced from biomass.
But Borås is cold. Very cold.
So the town’s heating is still partly produced from fossil fuels during winter cold snaps. To limit this dependency, the town put a new system in place in 2010: the “thermos,” a source of great pride for its inhabitants. It stores energy produced from biomass and waste in a giant tank in summer, when energy consumption is low, then uses this energy to supply the district heating network in winter.
In 1999, 40 years after starting down the road towards sustainable development, renewable energy represented 70% of the energy used in Borås. The municipality hopes to achieve zero fossil fuels by 2025. In a town where children learn to sort waste from an early age, they’re confident they’ll manage it.
Find out more:Town challenge: Borås, in Sweden
Main picture: Boras, ©Borås Energi och Miljö