DISTRICT HEATING LONDON HEAT MAP


Combined heat and power units at Bunhill and Dalston


homes are overheated and people throw open the vents to discharge the heat.’ E.ON is one energy services company


‘We struggle to make this viable on our smaller schemes,’ says Jake Lock. Affinity Sutton housing association hopes that small heat networks will eventually connect to neighbouring schemes, where they begin to make sense


those of individual boilers in each home.’ Certainly, the London Plan stresses the


need for lifecycle costing rather than capital costs to be considered when developing heat networks – a difficult tenet in cash-strapped times. ‘The biggest single evil is the curse of someone saying: “Build me a system at capital cost X,” regardless of performance. Corners are going to be cut,’ says Blackwell. Terry Keech, partner at consultant calfordseaden, is critical of the London Plan: ‘They are not thinking this through. Some of the 50-unit schemes don’t stack up economically and the charges end up being high for the consumer. Equally, you’ve got to question the CO2


savings. These are


highly-insulated homes with low heating requirements. With DH you are looking at 80/60°C flow and return temperatures –


54 CIBSE Journal February 2014


(ESCO) that is making DH schemes work, at least on a large scale (see box on page 56). Would it get involved on a 50-unit scheme? ‘We look at schemes with 300+ units,’ says Jeremy Bungey, head of community energy at E.ON Energy Solutions. ‘That way we can offer a price position for customers that will be cheaper than gas-fired boilers. We could look at 200+ if there was a large commercial load, otherwise it’s difficult for it to be viable because of the fixed costs.’ Planners hope that small heat networks


will eventually connect to neighbouring schemes where they begin to make sense. The reality is that there is little incentive for developers to look to do so. Affinity Sutton is one of the largest housing associations in England. It has a number of district heating schemes in operation, several of which have less than 100 units. ‘We struggle to make this viable on our smaller schemes,’ says Jake Lock, development manager. ‘Yet it’s hard to argue against the planners.’ Planning is not the only issue affecting


the viability of DH schemes. Problems such as poor pipework specification and layout, lack of insulation continuity, high


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