CEEQUAL Excellent (82%) – Whole Project Award
Version 4, June 2012 | London, England
Assessor: Joanna Goodwin
The Olympic Park District Heating and District Cooling (DHDC) Network comprises 18km of distribution pipe work (16km heating and 2km cooling) to provide the London 2012 Olympic and Paralympic Games with efficient low-carbon heating and cooling.
The DHDC Network is connected to the newly constructed Olympic Park Energy Centres at Kings Yard and Stratford City. The Energy Centres use gas fired and biomass boilers for tri-generation Combined Cooling, Heating and Power (CCHP). A total of 48 heating and 23 cooling sub-stations are located within the Olympic Park venues, buildings, Athletes’ Village and Westfield Stratford City development. The system will be operated by Cofely.
The district-wide CCHP system is estimated to be approximately 30% more efficient than conventional heating and cooling systems and offer a significant reduction in carbon emissions. The system is also considered to be more reliable, resilient and offer security of supply with the ability to use a range of fuels such as gas, biomass or other renewables.
The DHDC Network serves the 2.5km2 area of the Olympic Park and Stratford City development. It carries hot water at 95°C, returning at 55°C, at a rate of up to 400 litres per second (l/s). The system has been designed for increased future capacity of up to 1000 l/s, this will ensure the system can serve the Olympic legacy and new buildings and communities that will be built after the Games. The system has been designed to enable future extension of the network beyond the Olympic Park and Stratford City developments.
Water is pumped through the distribution system using pumps with variable speed controls to maintain the required demand in the district heating and cooling return temperature fluctuations. Whilst only one pump is needed to meet demands, a standard pump set consists of two or three duty pumps to provide resilience.
The pipe work used to construct the DHDC Network is extremely specialised and sourcing the required volume of pipe work within the required time frame was a challenge for this project. The prefabricated and pre-insulated pipes used for district heating and cooling networks were sourced from specialists INPAL. Polyuretub 130 pipes were used that comprise welded black steel tubes manufactured in 12m lengths with polyurethane foam insulation and high-density polyethylene outer casing. A copper wire leak detection system is incorporated within the insulation layer and runs the length of the system to monitor the performance and locate faults.
The greatest challenge faced by this project was the need to deliver at the highest technical level for the ODA, whilst working to a demanding and relatively short deadline related to the London 2012 Olympic and Paralympic Games. The comprehensive suite of guidelines published by the ODA and the early consideration of aspects relevant to all elements of the Olympic Park ensured that these standards were achievable. The quality of early planning is reflected in the score achieved by the DHDC Network.
During design and construction, the DHDC Network scored particularly well in the following sections: Energy and Carbon, Materials Use and Waste Management.
The DHDC formed part of the wider scheme to provide efficient and low carbon cooling, heating and power to the London 2012 Olympic and Paralympic Games and subsequent Olympic legacy. The DHDC Network is pivotal in connecting the Kings Yard and Stratford City Energy Centres to the wider development.
Over 50% of all backfill material was sourced from within the site. The ‘soil hospital’ treated previously contaminated soils excavated from within the site in preparation for their reuse in all aspects of the development.
INPAL confirmed that approximately 28% of pipe work materials were sourced from recycled materials. At the end of the system design life, INPAL confirmed that approximately 12% of pipe work materials are recoverable (specifically insulation and junctions) and that approximately 82% of pipe work materials are recyclable (specifically the pipe work, protective sheath and leak detection system).
Very little waste associated with the DHDC Network left the site. The Site Waste Management Plan set out measures for waste minimisation, specifically stating that 100% of stone and soil will be recycled for use on site. Evidence was provided that confirmed that this target was achieved with no waste sent to landfill.