On 6th March 2014, David MacKay used the IET's Clerk Maxwell Lecture, on 'Climate, Energy Arithmetic, and 2050 Pathways' as an opportunity to engage the audience in a discussion about Britain's energy options. Using an approach developed last year in DECC's 'British Energy Challenge' Roadshows, the goal was to crowd-source a consensus pathway in the 2050 Calculator. In this blog, David discusses the interesting messages that came from those regional Roadshows and from the IET audience in London.

Reflections on the British Energy Challenge Roadshows

The British Energy Challenge roadshows were organised by DECC and a sequence of British host cities: Liverpool, Nottingham, Birmingham, Leeds, Sheffield, Manchester, Newcastle, and Bristol. (The Hay Festival had a special event too.) Each event featured a day-long exhibition by local and national energy-saving and energy-supplying organisations, and an interactive discussion using DECC’s 2050 Calculator, hosted by Mark Lynas and David MacKay or Tom Counsell.  The goal of these discussions was for the people of each city to choose a 2050 pathway for the UK that represented the consensus of their views and desires, and that met the goals of maintaining security of energy supply and achieving the UK’s climate change targets.

This note describes some of my reflections on these 2050 Calculator roadshows. What did each city say? What surprises were there? Did the roadshows work? Did they change people’s minds? What changes did the roadshows suggest we might make to DECC’s work?

In the time available, most cities managed to choose a pathway that came close to achieving the 2050 emissions target, but only a couple actually got there.  Many of the cities were enthusiastic about building-insulation and local energy systems such as combined heat and power, waste-to-energy, and solar; most of them were comfortable to build large amounts of large-scale wind power too, especially offshore wind.  But, as you’ll know if you’ve played with the calculator, those levers are not sufficient to meet the target.

The table below shows some of the choices made by the cities, compared with the government's four Carbon Plan pathways, and shows some consequences of those choices (emissions and back-up generation required).

Results from British Energy Challenge


  1. I have highlighted in bright green the cities that chose to set "Growth in industry" to "A", a choice which makes the decarbonization challenge significantly harder.
  2. in many of the discussions, some of the levers were not touched by the audience. So the fact that a city left a lever on "1" does not necessarily mean that they discussed that option and made that choice.
Levers CITY:  (IET) Carbon Plan
Liv'p'l Hay   Nott'm Sheff'd Leeds Birm'm Manc'r Newc'le Bristol London "M" "R" "N" "C"
Domestic transport behaviour 4 4 4 4 4 4 4 4 4 4 4 4 2 3
Shift to zero emission transport 4 4 4 4 3 4 4 4 4 3 3 4 3 2
Choice of electric or hydrogen cars and vans C A B A B C B C B B A B B B
Average temperature of homes 2 2 4 4 3 3 3 4 4 3 4 4 2 3
Home insulation 4 4 4 4 4 4 4 4 3 3 3 4 3 3
Home heating choiceDDDD DB DD BD CB CD BC DB CD* CC DD CC CB
Growth in industry A A B A B B B A B B B B B B
Energy intensity of industry 3 3 3 3 3 2 2 3 3 3 3 3 1 3
Nuclear power stations 2 3 1 2 2 2.5 2 2.6 1.5 2.5 1.8 1.4 2.7 1.5
CCS power stations 2 2 1 1 2 1 1 2 1 1.7 1.6 1.3 1 2
Offshore wind 3 1 3 3 2.2 2 2.7 3 3 2 1.3 1.9 1.2 1.3
Onshore wind 3 1 2.5 4 2.4 3 3 3 3 2 1.3 2.7 1.4 1.5
Solar panels for electricity 2 4 4 3 4 3.4 3 2 2.2 2.5 1 1.2 1 1
Land dedicated to bioenergy 2 3 2 1 2 1 2 2 2 2 3 2 4 3
Bioenergy imports 2 1 1 1 1 1 1 1 1 2 2.5 2 3.7 3
Geosequestration 1 1 3 1 1 1 1 3 2 2 1 1 1 2

emissions in 2050 (Mt CO2) 158 153 157 201 362 250 250 169 159178 138154153150
percentage reduction on 1990 80 80 80 74 54 68 68 78 80 77 82 80 80 81
backup required (GW) 54 0 35 42 0 0 0 0 51 0 7 24 11 0

I think it's true to say that all the audiences struggled to reach the emissions target; I think some of the main reasons that they found it hard were:

1.       First, the emissions target is indeed hard to achieve, and requires many actions, not all of which are universally popular.  Sadly we didn’t have quite enough time in our roadshows to fully explore the trade-offs between the tougher options and to revisit the audience’s initial choices.

2.       Second,
Heating technologies in the calculator
Gas boiler
Solid-fuel boiler
Gas micro-CHP - Stirling engine
Gas micro-CHP - fuel cell
Resistive heating
Air-source heat pump
Ground-source heat pump
Community-scale gas CHP
Community-scale solid-fuel CHP
District heating from large power stations
the urge to have lot of district heating supplied by combined heat and power may have actually made it harder to achieve the target: all the heating options have difficulties – ordinary gas boilers or micro-combined-heat-and-power boilers require gas, which is likely to be a fossil fuel (unless sufficient bioenergy is created and turned into methane); biomass boilers require wood, which has to come from somewhere; heat pumps require extra electricity, especially in mid-winter; and district heating requires a heat source, which, if local, is likely to be fuelled by wood or gas, and, as I just said, gas can only be low carbon if it is made from bioenergy. The amounts of bioenergy required to deliver a significant share of the nation’s space heating are very large. This brings us to the third point: 

3.       Most of the audiences had a strong reluctance to devote a large land area to bioenergy production, whether in the UK or overseas.  This was a strong and unexpected message I took from these roadshows: while in every city there were some people who didn’t want, say, onshore wind farms or nuclear power, I’d estimate that in all the audiences there was a majority who came to the discussion with strong reservations about bioenergy. None except Liverpool and London (the IET audience) voted to import bioenergy at any scale from other countries.  

4.       Most of the audiences were also reluctant to make use of the “geosequestration” lever, which, at level 3 or 4, would imply the deployment of thousands of artificial trees that suck carbon dioxide out of thin air, along with a network of pipes supporting the burial of millions of tonnes of CO2 per year in rocks under the north sea and elsewhere.  In some cases, setting this lever to level 3 or 4 would have made the target achievable, but the audiences did not vote for such a plan. 

So, what changes do I think we should consider making to DECC’s work, in the light of these deliberative interactions? I’ll discuss two things: enhancements to the 2050 Calculator, and possible changes to some of our long-term policy options.


Heating choices in the calculator

The calculator offers 16 different heating mixes for buildings (visualized by the 16 green dots in the diagram to the right), some of which have high amounts of district heating, and some low amounts. To help people find choices that work and that align with their values, maybe we should revise the menu of heating choices to give the user access to a greater range of diverse heating options.  We could also try to enhance the immediacy with which the consequences of the user’s choices are displayed in the calculator, so that it is clearer how each heating choice creates a fuel demand that must be satisfied mainly by either natural gas, electricity, or bioenergy.   Another heating technology option that could be added into the Calculator is large-scale heat pumps to deliver district heating. These already exist in a few Scandinavian cities. This option might be helpful to satisfy a desire for district heating in a low-carbon, low-bioenergy way.

Increases in ambition in some sectors

Many of the audiences felt that a few of the Calculator’s levers didn’t represent the full range of technically-achievable options.  For example, in transport behaviour, almost all audiences believe that higher levels of public transport and cycling could be delivered in 2050 than are represented in the Calculator’s “level 4”; some people also felt that higher levels of building insulation and waste-to-energy were possible. I definitely think we should revisit these options in the next update of the calculator.

Alternatives to bioenergy: hydrogen and air-fuel synthesis

In response to the apparent public resistance to high-bioenergy pathways, I would like us to enhance the range of technical possibilities that are available in the Calculator. For example, we could allow hydrogen to be used as a fuel for heating. At present, the user can choose to use electricity to make hydrogen and can choose to put that hydrogen into fuel-cell vehicles, but that's all. We could add the option to put hydrogen into a gas network so that domestic boilers and combined-heat-and-power stations could be fuelled by hydrogen. This would perhaps enable users to replace a bioenergy demand by a demand for extra low-carbon electricity.  Another technical possibility would be to combine hydrogen (made from electricity) with CO2 that has been captured from the air (again, using electricity) to make climate-neutral fuels that could replace fossil fuels in freight, aviation, and shipping.       

A related policy response could be to increase our investments in research and development and innovation support to improve our understanding of these hydrogen and air-fuel synthesis options, and to drive down their costs.

So, overall, did the Energy Challenge Roadshows work?

From the British Energy Challenge evaluation:

If we run similar events in the future, I think we need to make them longer so that there is a chance for proper deliberation and discussion of tradeoffs. I’d also like us to do a bit of before-and-after comparisons, to find out what people are changing their minds about.

What I’d really like to try is a similar deliberative event with a small number of high-profile opinion-formers, who would be asked to arrive at a consensus pathway, and report on what they learned.