- The Greater London Authority (GLA) has published a report into the scope and opportunity for ‘Low Carbon Heat: Heat Pumps in London’.
- The report compares various air source, direct electric, gas and CHP configurations in new build houses, and concludes that shared ground loop arrays are the most efficient, lowest carbon, and lowest cost solution.
- Kensa’s work with ENGIE and Enfield Council features as the report’s case study for the shared ground loop array solution.
In light of London’s drive to become a zero-carbon city by 2050, the GLA’s report is well-timed to provide an invaluable resource to guide the specification of low-carbon heating in London’s new builds.
The report concludes that:
The communal ground loop with individual heat pumps appears to be the most economic solution of all (at approximately £500/yr) and is also compliant with London’s key objectives in terms of air quality and carbon emissions. It combines several advantages: it is very energy efficient and does not require dedicated heat metering and billing.
Heat pump systems provide the lowest carbon heat for all case studies, though significant differences exist between the various types of heat pump. The lowest carbon heat is achieved by the residential block using ground source heat pumps coupled to a communal ground loop. This system benefits from very small distribution losses due to the ambient flow temperature and relatively high efficiencies of 380% for space heating at 35˚C and 290% for DHW at 60˚C offered by ground source heat pumps.
Kensa has published a comprehensive review of the report highlighting some of its key observations, including:
- The mechanical design of building services must evolve;
- SAP2012 is out-of-date;
- Decarbonisation of the grid will further enhance the efficiency gap;
- A cohesive approach will deliver optimal results;
- Demand for electricity in the most ambitious heat pump deployment scenario decreases;
- Ground source heat pumps are as cheap to run for end users as gas boilers;
- Scale and optimised design and procurement reduce costs