Sunday, September 1, 2013

Green power the politics of hope

Around 60 countries around the world already get over 60% of their power from renewables, mostly hydro, some near 100%: And there are dozens of studies suggesting that it is credible to get 100% of electricity and perhaps all energy by 2050, across the EU and also possibly globally:

Yet another paper has emerged to add to the pile, although this new one, by US academics Mark Delucchi and Mark Jacobson in the Bulletin of the Atomic Scientists 69(4) pp30-40, mainly re-presents results from their earlier studies in summary form, with some extensions. But what it says, bluntly, is that ‘energy systems worldwide can be run entirely on wind, water, and solar power’ – without any nuclear.

These ‘100% renewables by 2050’ assessments certainly give a very positive view of the potential and costs of renewables. Some may be too optimistic. That was what Australian academic Ted Trainer argued last year in a critique of Delucchi and Jacobson’s earlier  ‘100% renewables’ paper in Energy Policy, claiming that they had not dealt with intermittency and costs sufficiently, although these authors came back with a fairly convincing rebuttal. Trainer had argued that renewable energy could supply the world only if the world ‘embraces frugal lifestyles, small and highly self-sufficient local economies, and participatory and co-operative ways in an overall economy that is not driven by growth or market forces’. Delucchi and Jacobson say ‘This vision may or may not be desirable, but it was found in our study not to be necessary in order to power the world economically with wind, water, and solar energy’.

Given that developers, promoters and enthusiasts can overstate their case, Trainer may be right to warn us not oversell what renewables can do. However he may also risk undermining them. Indeed, it is almost as if he does not want renewables to work, so we have to get on with the more important social changes. Certainly some see radical social and lifestyle changes as vital and as part of an urgent political and economic process of change. But most would include renewables as a central part of that transition.

Clearly there is plenty of room for debate, and to an extent, the various contrarians, from their various political viewpoints, make a contribution, even if it is not always a welcome one. There have been strong rebuttals of some contrarian views, but there is a healthy, if at times rather bilious, debate going on, much of it on the internet. Some of it is technical, some of it political.

Perhaps inevitably, there will always be some uncertainty, disagreement, prejudices and odd distortions, even when it comes to what might seem like purely technical issues. For example, those who are confident about the prospects for developing high temperature liquid sodium cooled fast breeders, or molten flouride salt thorium reactors, may sometimes a little oddly baulk at the technical difficulties they see as being associated with what are surely relatively much less complex wind, wave and tidal technology. More generally, it is possible to run energy scenarios with very different outcomes, based on differing assumptions about what is technically and economically credible. There is an element of judgement involved.

Objectivity, while very desirable, is sometimes quite hard to sustain, and indeed may not always be possible, especially when thinking about future systems and developments.
We may still need faith and hope, even in matters of technology.  That links to a current contention in policy circles that care has to be taken to avoid ‘optimism bias’. On balance, I think I would prefer to avoid ‘pessimism bias’.  For example, as REN21 has pointed out, in 2000 the International Energy Agency projected 34 GW of wind power globally by 2010, while the actual level reached was 200 GW. The World Bank in 1996 projected 9 GW of wind power and 0.5 GW of solar PV in China by 2020, while the actual levels reached in 2011, nine years early, were 62 GW of wind power and 3 GW of solar PV. Looking to the future, in 2012 REN21 interviewed 170 energy experts, and found that most industry experts believed that the world could reach at least 30–50% shares of renewables, while some experts advocated 100% or near-100% futures.

As I say in my new book on renewables, which is out next week, I support the latter view and I end it by quoting Bertrand Russell’s dictum that ‘Science may set limits to knowledge, but should not set limits to imagination’.


Trainer, T (2010) ‘Can renewables etc. solve the greenhouse problem? The negative case’, Energy Policy, Volume 38, Issue 8, August , pp4107–4114

Trainer, T (2012) ‘A critique of Jacobson and Delucchi's proposals for a world renewable energy supply’, Energy Policy, Volume 44, May, pp 476–481,

Delucchi, M  and Jacobson, M (2012) Response to ‘A critique of Jacobson and Delucchi’s proposals for a world renewable energy supply’, Energy Policy 44,  pp 482-484,
 For Trainers reaction see

My new book, ‘Renewables; a review of sustainable energy supply options’ is published by the Institute of Physics.
The above draws on its last chapter.

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