The Mayor of London is committed to delivering 25% of London's energy supply by decentralised energy (DE) by 2025. To achieve this ambitious target, a DE programme has been developed to facilitate and accelerate the uptake of district heating. The programme initially focused on identifying opportunities for district heating networks through heat mapping and energy masterplanning as well as building capacity within local authorities to deliver DE projects and to secure planning policies that encourage and where appropriate require DE in new developments. This initial programme, which ran from 2008 to 2010 was called the Decentralised Energy Master Planning (DEMaP) programme. 

The DEMaP programme identified the stages of development required to progress a project from heat mapped opportunity, through feasibility and finally procurement to market. The Decentralised Energy for London programme was set €3.3m funding, 90% of which was secured from the European Investment Bank’s ELENA facility, and provides London boroughs and other project sponsors with technical, financial and commercial assistance to develop and bring decentralised energy projects to market.
The Decentralised Energy for London programme represents the next logical step in the Mayor’s vision to support the expansion of a more sustainable, secure, cost-effective and low to zero carbon energy supply in the capital. The GLA is committed to working with London boroughs and partners in the private sector to develop opportunities by providing assistance for commercialisation of large decentralised energy projects. The programme will predominantly look at district heating schemes supplied from combined heat and power (CHP) and sources of waste heat. It aims to facilitate over £95m of projects before summer 2014.

A new set of guidelines has been published by the Mayor of London, Boris Johnson, to support the delivery of decentralised energy schemes in the capital.

The 'District Heating Manual for London' provides practical guidance for developers, network designers and planners with the aim of creating a consistent framework for delivering efficient, interconnecting, district heating networks. It is also designed to help guide local planning authorities. The document, developed in collaboration with Arup, supports a range of initiatives provided by City Hall to promote the Mayor's target to achieve 25 per cent of London’s energy supply from decentralised energy sources by 2025.