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How are we going to de-carbonise heating of buildings?

Two strategies considered in this presentation:

1. Now - Elec plus house heat pumps with ccgt , long term wind to electric to house heat pump, ccgt as back up and pumped hydro storage

2. Now - District Heat with ccgt as chp, long term wind to central heat pump to DH, ccgt chp as back up and thermal storage

Important question because building heating is the largest use of end use energy

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Costs

The Elec route needs extra power cables since existing ones are not big enough if all houses in a city had electric heat pumps. Must be ASP but these don’t work well when it is cold

The DH route needs expensive DH mains to be laid.

Both need digging up the streets Both need storage Maybe insulation

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Heat stores are an integral part of CHP and DH –20 times cheaper than elec storage per unit energy stored

6 hour store in Odense - Inter-seasonal have been designed

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CHP is a heat pump, but with COP (Z) of 11.45 compared to HP with 2.8 if you’re lucky

This Iron Diagram shows that Odense power station generates about 430 MW in electricity – only mode ( left axis) , and loses electrical output when 550 MW ( lower axis) of heat is produced as chp. Over the whole range, loss of 1 kWe of power creates 11.45 kWth of heat. A heat pump is much worse and only delivers about 3.2 kWth of heat, for the loss of 1 kWe of electricity over the year, down to 2.2 in winter

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Chpdh can readily cope with intermittency:

Heat stores store and forward at a later time, surplus wind energy

CHP can coast at low load with any spinning reserve losses captured as useable heat

CHP can switch to elec only mode with instantaneous increase in power, and vice verse

AND CHPDH can utilise: solar, geothermal,

industrial waste heat

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Double today’s energy costs, 10 day storage, €4.5k of insulation gives a 1/3 reduction of heat energy, COPs 3.2, 2.2

and 2.

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