David MacKay : Heating London

I took some notes from remarks made by Professor David MacKay, the UK Government’s Chief Scientific Advisor, yesterday, 1st May 2014, at an event entitled “How Will We Heat London ?”, held by Max Fordhams as part of the Green Sky Thinking, Open City week. I don’t claim to have recorded his words perfectly, but I hope I’ve captured the gist.


[David MacKay] : [Agreeing with others on the panel – energy] demand reduction is really important. [We have to compensate for the] “rebound effect”, though [where people start spending money on new energy services if they reduce their demand for their current energy services].

SAP is an inaccurate tool and not suitable for the uses we put it too :-
http://www.eden.gov.uk/planning-and-development/building-control/building-control-guidance-notes/sap-calculations-explained/
http://www.dimplex.co.uk/products/renewable_solutions/building_regulations_part_l.htm

Things seem to be under-performing [for example, Combined Heat and Power and District Heating schemes]. It would be great to have data. A need for engineering expertise to get in.

I’m not a Chartered Engineer, but I’m able to talk to engineers. I know a kilowatt from a kilowatt hour [ (Laughter from the room) ]. We’ve [squeezed] a number of engineers into DECC [the Department of Energy and Climate Change].

I’m an advocate of Heat Pumps, but the data [we have received from demonstration projects] didn’t look very good. We hired two engineers and asked them to do the forensic analysis. The heat pumps were fine, but the systems were being wrongly installed or used.

Now we have a Heat Network team in DECC – led by an engineer. We’ve published a Heat Strategy. I got to write the first three pages and included an exergy graph.

[I say to colleagues] please don’t confuse electricity with energy – heat is different. We need not just a green fluffy solution, not just roll out CHP [Combined Heat and Power] [without guidance on design and operation].

Sources of optimism ? Hopefully some of the examples will be available – but they’re not in the shop at the moment.

For example, the SunUp Heat Battery – works by having a series of chambers of Phase Change Materials, about the size of a fridge that you would use to store heat, made by electricity during the day, for use at night, and meet the demand of one home. [Comment from Paul Clegg, Senior Partner at Feilden Clegg Bradley Studios : I first heard about Phase Change Materials back in the 1940s ? 1950s ? And nothing’s come of it yet. ] Why is that a good idea ? Well, if you have a heat pump and a good control system, you can use electricity when it’s cheapest… This is being trialled in 10 homes.

Micro-CHP – [of those already trialled] definitely some are hopeless, with low temperature and low electricity production they are just glorified boilers with a figleaf of power.

Maybe Fuel Cells are going to deliver – power at 50% efficiency [of conversion] – maybe we’ll see a Fuel Cell Micro-Combined Heat and Power unit ?

Maybe there will be hybrid systems – like the combination of a heat pump and a gas boiler – with suitable controls could lop off peaks of demand (both in power and gas).

We have designed the 2050 Pathways Calculator as a tool in DECC. It was to see how to meet the Carbon Budget. You can use it as an energy security calculator if you want. We have helped China, Korea and others to write their own calculators.

A lot of people think CHP is green and fluffy as it is decentralised, but if you’re using Natural Gas, that’s still a Fossil Fuel. If you want to run CHP on biomass, you will need laaaaaarge amounts of land. You can’t make it all add up with CHP. You would need many Wales’-worth of bioenergy or similar ways to make it work.

Maybe we should carry on using boilers and power with low carbon gas – perhaps with electrolysis [A “yay !” from the audience. Well, me, actually]. Hydrogen – the the 2050 Calculator there is no way to put it back into the beginning of the diagram – but it could provide low carbon heat, industry and transport. At the moment we can only put Hydrogen into Transport [in the 2050 Calculator. If we had staff in DECC to do that… It’s Open Source, so if any of you would like to volunteer…

Plan A of DECC was to convert the UK to using lots of electricity [from nuclear power and other low carbon technologies, to move to a low carbon economy], using heat pumps at the consumer end, but there’s a problem in winter [Bill Watts of Max Fordham had already shown a National Grid or Ofgem chart of electricity demand and gas demand over the year, day by day. Electricity demand (in blue) fluctuates a little, but it pretty regular over the year. Gas demand (in red) however, fluctuates a lot, and is perhaps 6 to 10 times larger in winter than in summer.]

If [you abandon Plan A – “electrification of everything”] and do it the other way, you will need a large amount of Hydrogen, and a large Hydrogen store. Electrolysers are expensive, but we are doing/have done a feasibility study with ITM Power – to show the cost of electrolysers versus the cost of your wind turbines [My comment : but you’re going to need your wind turbines to run your electrolysers with their “spare” or “curtailed” kilowatt hours.]

[David Mackay, in questions from the floor] We can glue together [some elements]. Maybe the coming smart controls will help…can help save a load of energy. PassivSystems – control such things as your return temperature [in your Communal or District Heating]…instead of suing your heat provider [a reference to James Gallagher who has problems with his communal heating system at Parkside SE10], maybe you could use smart controls…

[Question] Isn’t using smart controls like putting a Pirelli tyre on a Ford Cortina ? Legacy of poor CHP/DH systems…

[David MacKay in response to the question of insulation] If insulation were enormously expensve, we wouldn’t have to be so enthusastic about it…We need a well-targeted research programme looking at deep retrofitting, instead of letting it all [heat] out.

[Adrian Gault, Committee on Climate Change] We need an effective Government programme to deliver that. Don’t have it in the Green Deal. We did have it [in the previous programmes of CERT and CESP], but since they were cancelled in favour of the Green Deal, it’s gone off a cliff [levels of insulation installations]. We would like to see an initiative on low cost insulation expanded. The Green Deal is not producing a response.

[Bill Watts, Max Fordham] Agree that energy efficiency won’t run on its own. But it’s difficult to do. Not talking about automatons/automation. Need a lot of pressure on this.

[Adrian Gault] Maybe a street-by-street approach…

[Michael Trousdell, Arup] Maybe a rule like you can’t sell a house unless you’ve had the insulation done…

[Peter Clegg] … We can do heat recovery – scavenging the heat from power stations, but we must also de-carbonise the energy supply – this is a key part of the jigsaw.

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