In his celebrated, recent book, Sustainable Energy — without the hot air , David MacKay shows what a zero-carbon energy system for the UK looks like. Whilst theoretically possible, it is daunting: the plan needs just about every option on the table, and in large quantities. A quick calculation for the rest of the world leads to the same conclusion. So how quickly can we build this new energy system?
In 2008, Shell presented two scenarios of how the world’s energy system could develop to 2050 . Blueprints was the more environmentally-conscious scenario. Yet one of the most frequent criticisms has been that “Blueprints isn’t good enough” because the rate at which the emissions profile turns round “is too slow”.*
Two colleagues of mine in the scenario team, Martin Haigh and Gert Jan Kramer, have written an opinion piece for Nature, looking at this question. It was published in early December (Click for the Nature Article).
In the paper, they have looked at humankind’s historical best efforts for deploying new energy technologies. There are some sobering conclusions. When things have gone well, it has taken around 30 years to move from the first pilot plants outside the laboratory, to reach a ‘material’ scale, which we define as delivering about 1% of the world’s energy supply. This still follows an exponential curve running at an average of 26% growth per year for those 30 years. It is simply that it has to climb three orders of magnitude in scale.
After that, growth slows down and runs on a linear course until the energy reaches its ultimate market share in the total energy mix.
They also explain why this historical evidence is something policymakers need to take seriously before aiming for overly ambitious targets. Their view is that these ‘laws’ are going to be a challenge to beat. Blueprints does look at conditions where we might be able to exceed them, but a good number of inputs in their modelling are stretching. Going even beyond these is going to be a herculean challenge.
Finally, what does this mean for policy? They argue it will need to be tailored for technologies at each stage of the deployment curve. Much discussion assumes that after a few pilot projects, the world will be ready to build the new energy technologies, competitively, at the large-scale, linear rate. However, CCS will not move beyond demonstrations if its cost must be recovered through a generic trading price. PV development will stall if it is treated on a par with wind. So whilst early-stage R&D and late-stage CO2 pricing will have critical roles to play, many technologies are going to need project and then later product support for some considerable time if they are not to lose their way on the path.
* Using IPCC’s yardsticks for emissions and atmospheric concentrations, Blueprints would have emerged as being around 500 ppm CO2-only and 550 ppm CO2e (all GHGs). MIT’s climate science team analysed the Shell scenarios, and incorporated the latest research since that considered by IPCC. Blueprints is assessed as a stabilisation pathway of 540 ppm CO2-only and 650 ppm CO2e (all GHGs).