Steel plants located just outside Sheffield’s city center could be connected to the UK city’s existing district heating network (pictured) to provide an extra 20 MW of thermal energy, Phys.org reports.
Steel companies actually spend money to cool flue gas and the water used during manufacturing, so heat recovery helps them to save money while benefiting the environment, professor Jim Swithenbank of the University of Sheffield told the science news service. The initiative should also reduce heat production costs for the city, while improving energy efficiency.
Swithenbank played a key role in developing the first phase of Sheffield’s district heating system in the late 1970s.
Sheffield has the largest district heating system in the UK, powered by a waste-to-energy facility that burns the city’s non-recyclable waste. It converts 225,000 tons of waste into energy, producing up to 60 MW of thermal energy and up to 19 MW of electrical energy a year, the Combined Heat and Power Association says. Around 44km of underground pipes deliver energy to more than 140 buildings connected to the district heating network.
In an average year the district heating network prevents more than 21,000 tons of CO2 from being released in Sheffield, according to the city council.
Some companies are already capturing waste heat and using it to cut electricity use. For example, at Mansfield, Nottinghamshire in the UK, Crown Holding’s plant design allowed the metal packaging products company to recover 80 percent of waste heat from compressed air production, and use it for space heating.
According to University of Sheffield researchers, heating is responsible for half the energy use in the UK. Government estimates suggest that in areas of the UK with high heat demand, district heating could supply around 5.5 million properties and contribute a fifth of the UK’s heating needs, professor Vida Sharifi told Phys.org.