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Margaret Reynolds of AC Architects reports

Prof David MacKay,  chief scientific adviser to DECC, gave a talk at the Cambridge Energy Forum this week, looking at UK energy strategy on a huge scale.

‘The future is electricty,’  says the Cambridge physics professor. Over 90% of our energy comes from fossil fuels. Within 40 years, transport, heating and industry need to be electrified, electricity supply may need to double, and the grid must be decarbonised and able to cope with intermittent renewable generation.

MacKay presented the new DECC 2050 Pathways  Calculator online tool.  Here MacKay’s  ’back of an envelope’ estimates  for energy demand and supply, from his widely-acclaimed book Sustainable Energy: without the hot air, are ‘glued all together’ in a model with data from experts set out in 36 sectors. Each sector includes trajectories rated from 1 to 4 depending on how big a stretch they would be from where we are now.

2050 pathway calculator

You can fiddle around with this tool using your own preferences to try to meet 2050 energy targets – everyone attending the talk had been asked to try it. This is well worth the time for any architects concerned for the future – and for their clients; in fact, DECC’s Call for Evidence welcomes comment before the report is finalised in February. If you want to understand the summarised proposals or, like me, you are unsure about terms such as ‘geosequestration’ and CCS (both critical to current government thinking) you can browse the downloadable explanatory report , 2050 Pathway Analysis .

MacKay says the essential question is: “Do the lights stay on in 2050, after five successive winter days with no wind?”  What is the demand going to be, when will the worst cases occur, and how are we to supply them? MacKay divides today’s demand into three, transport, electricity and heating.  With characteristic clarity, he says that on the supply side the 5 ‘biggest fish’ now available are:  wind, nuclear, CCS, biomass/waste, and demand reduction. He then offers six ready-made pathways which achieve the required 80% reduction in emissions over 1990 levels: ‘Pathway Alpha’ which is ‘largely balanced effort across all sectors’, along with Pathways B,C,D E, F, each of which omits one of the five ‘big fish’ above, eg the non-wind scenario, the non-nuclear scenario, etc.

The model explores practical and physical limits, not cost optimisation. It isn’t designed to confirm a preferred route – too many future unknowns still have to be factored in – but to manage significant long term uncertainties and avoid making long term decisions that are incompatible with targets.

Here are seven messages emerging so far (note four of these concern electricity):
- Ambitious per capita energy demand reduction is needed.
- A substantial level of electrification of heating, transport and industry is needed.
- Electricity supply may need to double, and will need to be decarbonised.
- A growing level of variable renewable generation increases the challenge of balancing the electricity grid.
- Sustainable bioenergy is a vital part of the low carbon energy system in sectors where electrification is unlikely to be practical, such as long haul freight transport and aviation and some industrial high-grade heating processes.
- The pathways also show an ongoing need for fossil fuels in our energy mix, although their precise long term role will depend on a range of issues such as the development of carbon capture and storage.
- Emissions from agriculture, waste, industrial processes and international transport make up a small proportion of emissions today, but by 2050, if no action were taken, emissions from these sectors alone would exceed the maximum level of emissions permitted for the whole economy.

Of course all this has implications for the architectural profession. Broadly speaking, architecture  reduces the demand for energy through new-build and refurbishment, and supplies energy through the integration of renewable energy production into buildings and sites.  To some extent we can also help define lifestyles, where big changes will be needed. A third of today’s demand is heating, heating means cold outside, ‘inside’ is mostly buildings. MacKay challenged the Cambridge audience (mainly engineers) to come up with innovations: we need cheap building retrofit, as well as cheap electric vehicles, batteries, smart meters, energy controls that give incentives, and low-risk nuclear storage.

If the Japanese can install half a million well-performing heat pumps a year, then we must analyse this strategy and sort out the 75% crap heat pump installations recently carried out in the UK. See this Guardian article and CIBSE report.

The vast overview provided by the Pathways tool highlights fluctuations of key factors: it’s joined up thinking. You analyse simultaneously the variations in:
-    seasonal temperature
-    wind speeds winter and summer
-    known patterns of electricity demand day and night
-    transport needs day and night

This then forecasts the critical points:  eg that worst case of five successive winter days with no wind. Clearly we need to store power and heat when the going is good.  We must sort out heat demand, identifying the peaks and targeting them.  Logically for buildings, seasonal heat storage technology could be further developed, as this releases summer-stored energy in winter when most needed.  Examples are the heat store at Beaufort Court by Studio E and Max Fordham and in borehole storage at Drake Landing in Alberta, Canada. MacKay wondered if heat store technology offers a strategic alternative to high-effort, super-insulation and air-tightness retrofitting of existing buildings.

Beaufort Court by Studio E architects and Max Fordham engineers

Borehole storage by Drake Landing

The next step after the DECC February launch of 2050 Pathways is to assign costs and land areas to the various trajectories. Like it or not, this is the way government policy is moving, and the process is immensely complex. Clearly the strategy is to see the biggest picture, identify key constraints and opportunities, zero in on highly inventive possibilities and respond quickly to results. Architects can usefully provide feedback on low-carbon design, especially retrofit, and on our increasing experience with components like heat recovery, heat pumps and solar panels. Maybe you have strong opinions about waste incineration, land use, planning or upgrading Listed Buildings. Read this stuff, check out the possibilities, exercise your civic responsibility and register your views.

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