Sheffield's steel plants could reduce the city's CO2 emissions by providing thermal energy to heat businesses and homes

The city’s traditional industry could help provide a green alternative for heating alongside other renewable energy sources, a study has found.


Experts from the University of Sheffield’s Faculty of Engineering believe that the many steel plants located just outside the city centre could be connected to Sheffield’s existing district heating network to provide an extra 20mW of thermal energy, enough to heat around 2,000 homes.


“It actually costs the steel plants to reduce the temperature of the flue gas and to cool the water used during steel manufacture,” said Professor Jim Swithenbank, who played a key role in developing the first phase of Sheffield’s district heating system in late 1970s.


“Recovering this heat and transferring it to the district heating network reduces the cost of heat production, improves energy efficiency and is beneficial to the environment, making a ‘win, win’ situation for the steelworks and the city.”


Sheffield has the largest district heating system in the UK, powered by an energy recovery facility that burns the city’s non-recyclable waste.


This generates 21mW of electricity per year, enough to power 22,000 homes, and 60mW of thermal energy in the form of super-heated steam, which is pumped around the city in a 44km network of underground pipes.


This provides space heating and hot water to over 140 public buildings and 3,000 homes across the city, reducing the city’s CO2 emissions by 21,000 tonnes a year.


Engineers from the University’s SUWIC Research Centre (Department of Chemical & Biological Engineering) have mapped out a possible expansion of the network which could reduce Sheffield’s annual CO2 emissions by a further 80,000 tonnes.


Funded by the UK Engineering and Physical Sciences Research Council (EPSRC), the researchers used digital mapping software (GIS) to identify areas of high energy demand against potential new energy sources, such as the steel works and a new biomass plant currently under construction on the site of a former coal-fired power station.


While some UK cities are now using their waste incineration plants to generate electricity, few connect such facilities to a district heating system to realise the full economic and environmental benefits.


“District heating is a good way to decarbonise the energy supply to meet national and international legislation on emission limits. And, importantly for local people, this form of energy can also be used to provide low-cost heating, especially to those in areas of fuel poverty.”