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Northern Powerhouse European Union

Historic buildings generate low carbon energy

Two of Manchester’s finest public buildings are now generating their own low carbon energy supply with combined heat and power (CHP) technology.

Two of Manchester’s finest public buildings are now generating their own low carbon energy supply with combined heat and power (CHP) technology.

As part of a multi-million pound refurbishment of the historic grade two-star listed Manchester Town Hall Extension and adjacent Central Library in Manchester city centre, local CHP specialist, ENER-G, has worked with contractors to design and install energy efficient CHP technology on the site.

By simultaneously generating heat and power on-site, CHP can be up to twice as efficient as conventional power generation and can cut energy costs by up to 40 per cent over grid-sourced electricity supply. 

Cutting energy

The two 230kWe tri-generation engines installed by ENER-G produce the majority of heat, cooling and electricity required by the buildings, making a significant contribution to reducing Manchester City Council’s energy consumption and utility bills. 

As well as helping the buildings achieve a BREEAM excellent rating, it will also reduce their CO2 emissions by 710 tonnes per year – the same as taking 237 cars off the road.

The Council is able to alter usage of the two tri-generation engines to maximise operating hours of the system overnight when electrical demand is lower. Thermal stores have also been installed into chilled and hot water systems to allow night-time charging, while the cooling potential of the system is being used to provide 24 hour chilling to ICT communications rooms.

Retrofit design

In addition, the system has been designed to operate in ‘island mode’, so in the event of an electrical network failure it can be switched to operate independently from the main grid, providing emergency power to maintain critical public services. 

To operate this way, the system would normally require a ‘heat rejection’ radiator. However, space constraints in the buildings made this impossible, and instead the heat rejection facility has been linked to an existing absorption chiller radiator, thereby making smart use of limited space. 

Alan Barlow, managing director of ENER-G Combined Power, said: “As a local business we are pleased to help Manchester City Council deliver on its carbon reduction programme.

“The [CHP] units are operating at around 90 per cent efficiency, helping to create cleaner and affordable energy for the city. This project demonstrates the suitability of CHP for retrofit projects.”

Heat Networks

The project is the first phase of the proposed Greater Manchester Heat Network programme, which will provide a low carbon district heating supply for four city districts: Manchester, Bury, Oldham and Stockport.