Overhauling how Manchester City Council heats its social housing portfolio

Albion Towers is a 17-storey, 46-metre-high tower block that soars over Salford in Greater Manchester. Completed in 1970, the tower block is managed by Salix Homes, a not-for-profit social housing provider. As part of a multimillion-pound renovation scheme, Salix Homes contracted Ground Heat to remove the combination boilers and radiators and install a new system that would reduce residents’ fuel bills and the housing association’s CO2 emissions. Our system would use innovative heat pumps and natural energy collectors, thereby delivering a unique solution. The combination of multiple innovative products made this project possible where traditional methods and products failed at the feasibility assessment stage. Those failures were because of either a lack of land to recover naturally occurring energy to run the heat pumps or the inability of other heat pumps to adapt to changing electricity demands.

Since its inception, Ground Heat has pioneered developing ground source heat pump systems (GSHP). The company has been collaborating for years with Austrian manufacturer Heliotherm on engineering innovative systems. We designed a custom 1–6 kW inverter-driven GSHP to replace Albion Towers’ traditional gas boilers. The Smart Module Solution unit uses a heat pump specified to the client’s criteria with the addition of advanced control and monitoring software. The unit has real-time monitoring that transmits data via our web portal every ten seconds. The units are powered directly by photovoltaic arrays, batteries or from the national grid. We designed the system to reduce energy consumption by up to 70% during periods of load response rather than blocking the power supply. Thus, residents can continue heating their homes.

The system also enables our engineers to speed up or slow down the compressor, thereby enabling us to size each heat pump to the demand of the apartment. This also reduces the necessity to oversize a borefield, which reduces both installation and running costs.

A revolution beginning underground

The system Ground Heat delivered was the culmination of three years of working with housing providers, residents, electrical district network operators and Heliotherm. In the system supplying the 100 apartments at Albion Towers, the heat pumps are all connected to a shared ground loop array connecting all heat pumps to the same collector field, the first coaxial bore system in the UK. Previously, annual gas bills ranged from £300 to £400; our system reduced costs substantially, to between £250 and £300. The new system produces 843 kg of CO2 per apartment per year, equalling 113.8 tonnes for the 135 apartments. The total CO2 saving over the 20-year life of the ground source heating system is 8,903 tonnes.

The unassuming tower block in Salford is the recipient of some of the most advanced renewable heating technology in the UK and a showcase for the future possibilities of ground source heating. EURAC, a European research facility based in Italy, is working with Salford University to monitor progress. The data will provide new insights into shared ground loop collector technology and help move industry standards forward.