The City of London Corporation is the local authority partner in the Citigen tri-generation CHP system which serves the City of London and the southern part of Islington.
The CHP system was originally a Corporation initiative in the late 1980s and has been operating since 1993. It comprises a central energy centre and district energy network supplying heating cooling to customer properties, and was one of the first tri-generation systems in the UK. It is owned and operated by Citigen, an Energy Services Company (ESCO) which is itself part of E.On CHP Ltd.
The central plant is constructed behind the retained façade of a former cold store in the Smithfield area. It underwent a major redevelopment between 2013 and 2015 with two new gas-fired CHP engines, thermal store and additional electric chillers, and a new control centre. The CHP engines provide 8.6 MW of power and 8.3MW of low-carbon heat. A further 25MW of heat is available from boilers around the network. Chilled water is generated by a combination of 4.4MW of electric chillers and a 5.6MW absorption chiller. Currently all electricity is exported to the UKPN local distribution grid.
The energy network is around 3.6 kilometres in length with a branch extending across the border north into Islington. It supplies 11 of the City Corporation’s properties with heat, including the Guildhall, Barbican Arts Centre, Smithfield Market and Museum of London, and four with chilled water for air conditioning. Several private customers, including residential properties, are also served and new connections are being added. Pipework and cables make use of existing subways, basements and car parks as far as possible with the rest buried under roads.
Extensions of the network are being planned south towards Central Criminal Court and St Paul’s Cathedral and east to the Moorgate area, where there is significant commercial interest. To increase the supply of heat a further two CHP engines may be added. The Corporation encourages 3rd parties to connect to the system in accordance with its Local Plan and provides advice on availability of supplies and method of connection.