Building a heat map for London
Pinpointing areas of the capital suitable for community heating systems
Project duration: February 2009 to September 2009
The aim of this project was to ‘prospect’ for areas and/or sites of London where community heating systems would be viable (for an overview of this kind of decentralised heating network, see below).
The client for this project, the Greater London Authority, recognises that community heating can help achieve the carbon reductions in the capital that it is committed to*. However because this kind of decentralised energy network represents a significant infrastructural challenge (not to mention a long-term investment with a payback period measured in decades) the siting of any community heating network is critical.
CSE’s solution was the development of the London Heat Map, which is available on line at www.londonheatmap.org.uk
The London Heat Map allows users to identify opportunities for decentralised energy projects in London by providing spatial intelligence on factors such as major energy consumers, fuel consumption and CO2 emissions, energy supply plants, heat density etc. It is publicly accessible to anyone with an interest in decentralised energy, and London boroughs can use the map as the starting point to developing the ‘energy master plans’ that feed into their local development frameworks and climate change strategies.
The London Heat Map will be regularly updated and fully interactive by allowing users to upload and share energy data.
What is a community heating system?
A community (or ‘district’) heating system replaces the 100s or 1,000s of individual heating systems within a neighbourhood’s homes, commercial and public buildings with a large-scale heat distribution network, typically drawing on a nearby high-efficiency Combined Heat and Power plant. Hot water from the CHP unit (and other heat sources that may be available) is pumped to homes and other buildings using a system of highly insulated pipework. Heat is then transferred using a small heat exchanger, to radiators and water heating cylinders just as in conventional heating systems.
Community heating systems can be adapted to cover a wide area such as a city or a concentrated location such as a town centre, housing estate, university campus or hospital.
The benefits of community heating can be summarised as:
- Allowing the use of larger scale, higher efficiency, lower unit cost, and lower carbon heat sources
- Fuel flexibility: while hot water is the energy carrier, the heat itself can be derived from a wide range of fuel, plant and conversion process types, including traditional gas boilers, biomass boilers, gas or biomass CHP systems, and importantly, waste heat from existing processes such as power generation and waste incineration
- Systems serving diverse types of customer (i.e. both housing and public buildings) are likely to have a greater return on investment than those focused on, for example, housing alone. This is because when the heat demand for one customer is high, for others it is low, meaning, in the language of energy economists, ‘lower peak-to-base-load ratios’, and hence require less network capacity to deliver a given volume of heat over the year
- Long lifetime (decades) and low maintenance costs
As a result of these advantages, community heating has a key role to play in facilitating a shift from the current predominant use of gas and electricity for space heating, towards lower carbon heat sources and CHP, in both new and, importantly, existing buildings.
However, community heating systems are long-term investments with long payback periods. Their realisation requires extensive planning and a supportive regulatory environment. National differences in the latter factors are the main reason why community heating is prevalent in a number of Scandinavian countries, but has yet to be fully exploited in the UK. There are, however, examples of large-scale community heating schemes in Sheffield, Nottingham and Southampton, while smaller schemes typically serving individual housing estates can be found in most London Boroughs, Bristol, Doncaster, Manchester and other urban areas.
* The GLA has been at the forefront of the development of urban sustainable energy policy and planning in the UK since its foundation in 2000. This has lead to an increasingly sophisticated set of sustainable energy policies and targets, culminating in the Climate Change Action Plan (2007) and alterations to the London Plan (2008).
CSE worked with the Mayor of London to produce the report ‘Towards Zero Carbon Developments' which aimed to take the capital a step closer to having a ‘zero-carbon' development in every borough by 2010.
** © Vital Energi | www.vitalenergi.co.uk