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Are renewables enough?

By Dave Elliott

Richard Heinberg from the Post Carbon Institute raised some interesting issues in a lengthy paper at: http://www.postcarbon.org/our-renewable-future-essay/ For example, he says ‘renewable energy technologies currently require fossil fuels for their construction and deployment, so in effect they are functioning as a parasite on the back of the older energy infrastructure. The question is, can they survive the death of their host?’

There are certainly some who say not: http://sunweber.blogspot.co.uk/2011/12/machines-making-machines-making.html with the emphasis often put on the large material requirements – steel, aluminium etc. all of which require large amounts of energy to make: http://theenergycollective.com/robertwilson190/344771/can-you-make-wind-turbine-without-fossil-fuels

However, there are counter views. For example, a global life-cycle assessment of clean energy sources by an international team claimed that a renewable system could supply the world’s entire electricity needs by mid-century without major problems with material resource limits or other constraints: http://www.pnas.org/content/early/2014/10/02/1312753111.abstract   Since many material resource issues come down to energy, the resource scarcity issue is often discussed in terms of Energy Return on Energy Invested (EROEI). The EROEIs for fossil fuels were historically high but are falling rapidly as resources dwindle: http://classic.rsta.royalsocietypublishing.org/content/372/2006/20130126.short

By contrast they are rising for renewables, although there are methodological disgreements about how to make comparisons. Heinberg cites a study by Weissbach, which has nuclear, hydro, coal, and natural gas power systems (in this order) as one order of magnitude more effective than PV solar and wind power. www.sciencedirect.com/science/article/pii/S0360544213000492

This is a very different conclusion to those produced by many other studies e.g. see the review of EROEIs in Danny Harvey’s Earthscan book Carbon Free Energy Supply – modern wind turbines can get to 80:1 and that should rise as the technology improves, while nuclear is put at 16:1 and that will fall as reserves of high-grade uranium ore diminish. A key difference is that the Weissbach study does not include the energy content of the fuel that the technology concerned uses in its assessment – just the energy used in its construction. Hardly surprising then that fossil and nuclear get off lightly, while the renewables lose one of their key advantages – no fuel requirement. Heisenberg also adds a large carbon debt figure, assumed from the use of pumped hydro storage to balance variable renewables: that impacts heavily on renewables, perhaps overly so. There may be more efficient balancing options, some of which may offer economic and operational gains that offset their costse.g. smart grid and supergrid systems that can avoid wasted energy and use it to balance shortfalls. Certainly balancing will cost, but it may not be that significant. For example, in its report on ‘Renewable Power Generation Costs in 2014’, IRENA says ‘estimated values are in the range of $0.035-$0.05/kWh with variable renewable penetration of around 40%’. That has to be compared with the social, environmental and heath costs avoided by not using fossil fuels, which it puts at $0.07-$0.19/kWh. However Heinberg evidently fears the worst and seems to back the view that ‘the costs of enabling solar and wind to act like fossil fuels are so great as to virtually cancel out these renewables’ very real benefits’.

Heinberg also looks at the Google research on renewables in 2007. The aim of this well-funded work was to identify a set of technologies that could keep global temperatures below 2°C and cost less than using coal. http://spectrum.ieee.org/energy/renewables/what-it-would-really-take-to-reverse-climate-change However it was concluded that it was not possible to put together a complete package at that time – many of the technologies were too expensive to compete on the open market. Well that’s not surprising. Although costs are now falling, there is no fundamental reason why clean technologies should automatically be cheaper than dirty technology. They need financial support to get started and challenge the dominant set of options. That is what governments have been doing – though perhaps not fast enough and, of late, haltingly.

Heinberg is however not hopeful that it will be possible to deliver enough. He concludes ‘reluctantly but increasingly, we may have to adapt the ways we use energy to suit the quantities and inherent qualities of the energy available to us’. We may try to fix things to keep the show on the road: ‘where it is absolutely essential to maintain these systems in their current form, we will certainly make every effort to adapt our new energy sources to the job (using batteries, for example); where systems can themselves be adapted to using less energy or energy that is intermittently available, we will adapt those systems’. But he says ‘in many instances it may be unaffordable to adapt either the energy source or the usage system; in those cases, we will simply do without services we had become accustomed to’.

He concludes grimly, ‘the problem is, the gap between our current way of life and one that can be sustained with future energy supplies is likely to be significant. If energy declines, so will economic activity, and that will create severe political and geopolitical strains; arguably some of those are already becoming apparent.’ So prepare for ‘energy descent’…

It will be tough, but Heinberg sees no alternative and makes a strong case for attending to how we live, making lifestyle changes and all the rest of the transition movement package, including a shift from growth as an aim. It is certainly true that the industrial revolution benefited from cheap abundant energy sources with very high EROEIs (up to 100 :1). http://www.postcarbon.org/wp-content/uploads/2015/01/characteristics-of-energy-resources.png We won’t see that again. So yes it will be tough. And, if he is right, we will need more than just technology and technical fixes and a bit of market tweaking: radical social change too.

The new Global Calculator that DECC has helped produce does not adjudicate on just how much lifestyle change would be needed, when and by whom, and only looks at average figures for consumption globally. However, it is much more optimistic than Heinberg about the potential for meeting needs from the resources available. Its summary report ‘Prosperous living for the world in 2050’ says unequivocally that ‘it is physically possible to achieve both our economic development and climate change goals by 2050. The world has enough energy, land and food resources for us all to live well. The technology, fuels and land use methods already exist for us to meet our economic development goals, whilst tackling climate change’. It is claimed that with massive commitment to energy saving and non-fossil fuel use, ‘in our four plausible 2°C pathways, the global average carbon intensity of electricity generation reduces to near zero by 2050’, but ‘the total cost of a decarbonised energy system is only fractionally higher than one that stays fossil fuel dependent, and it could even be cheaper,’ when avoided external costs are taken into account. https://www.gov.uk/government/publications/the-global-calculator

* The debate continues over whether renewables can be more than just a technical fix, and on what else is needed as I explore in my next post and in my new book ‘Green Energy Futures’, available soon from Palgrave.  

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