Find out how to supply heat to an additional 500 dwellings in central London. That was the task that Ramboll was commissioned with by Islington Borough Council. Now the results of this ground breaking study are available. They confirm that the 850 dwellings already connected to the district heating system in central London can be extended to 1350 dwellings by adding an innovative low-carbon heat source.
Client: Islington Borough Council
Using heat from the London Underground
The heat source is a London Underground ventilation shaft located on City Road where 18-28 degrees Celsius air is exhausted to the atmosphere as part of the Northern Line tunnel ventilation system. The feasibility study confirmed that this source of waste heat could be exploited by heat pumps, which can capture the waste heat and then upgrade it to approximately 80 degrees Celsius. This heat can then be fed directly into the district heating system.
“We believe that the use of large-scale heat in this way connected to urban district heating systems will play a major part in decarbonising the UK’s heating energy demand”, says Crispin Matson, head of Ramboll’s energy systems department in the UK. “The use of heat pumps utilising industrial waste heat sources is more carbon efficient than gas-fired CHP, the usual source of heat for district energy schemes. I am convinced that with the increasing use of renewable power sources, large-scale heat pumps connected to district heating systems will play a major role in the future heating of cities in the UK”, he says.
A financially and technically viable approach
The aim of the study was to prove viability of this heat pump concept both in terms of providing the supply of heat and matching it with the heat demands from the connected buildings. In particular the study explored the impact of supplying heat from the extended district heating system at a temperature of 80 deg as opposed to the original design temperature of 95 deg C. This involved looking at the impact of lower hot water temperatures for both the connected buildings’ heating load and domestic hot water load.
As well as being financed by the London Borough of Islington, this project is partly funded by the EU funded CELSIUS Partnership, and is supported by other London project partners including the GLA and UKPN.
January 2016 Update
Upon completion of the feasibility study, Ramboll were appointed to act as the Owner’s Engineer on the project. This role involved developing the design of the complete system to enable planning permission to be obtained and for it to be tendered in the summer of 2015.
As part of the design development, discussions were held with LUL with respect to the size and function of the heat pump serving their ventilation shaft. This resulted in the heat pump increasing in size to 1000 kWth.
The successful Contractor for the scheme has now been appointed and the scheme is now in construction with the intention that it will be operational in 2017.
“Ramboll have demonstrated they have excellent knowledge and experience of the developing district heating sector in the UK and have acted professionally and to a high standard since the start of the contract. This has included engaging in the innovative nature of Bunhill Phase 2 combining the use of large scale heat pumps from low grade heat sources with a district heating scheme serving both new and existing homes and council facilities,” says Lucy Padfield, Energy Services Manager at Islington Council.