By Dave Elliott
Several organizations have formulated proposals for transitioning to 100% renewable energy, nationally or globally. In one of the most recent, developing on their earlier 100% global scenario, US academics Mark Jacobson and Mark Delucchi and their team have spelt out how 139 countries can each generate all the energy they will need from wind, water and solar (WWS) technologies by 2050, in substantial detail.
It includes some cost estimates, broken down country by country and set alongside the environmental and heath costs avoided by using renewables for each of them. Along with saved energy costs (renewables being even cheaper by then), the total cost avoided globally is put at $4,982 per person per year, with the environmental costs ($1,930 pp/y) trumped by air pollution related costs at $2,882 pp/y – the latter avoiding up to 4.6 million premature deaths. It is all held together by a massive energy efficiency drive, keeping demand at around current levels. There is also a welcome section on grid balancing, though some of that is ‘work in progress’. Interestingly, it sees solar with heat storage as playing a key role.
The 139 countries have been divided into 20 groups of countries or individual island states, with time-dependent demand for and supply of WWS energy being modelled. The research team reported that ‘stable solutions have been obtained to date for all 20 regions and countries suggesting grid reliability is not a barrier to 100% clean, renewable WWS energy systems in the 139 countries considered’. Here is a draft: http://web.stanford.edu/group/efmh/jacobson/Articles/I/CountriesWWS.pdf
In parallel, David Fridley (from Lawrence Berkeley Laboratory) and Richard Heinberg (from the Post Carbon Institute) have been assessing many of these ‘100%’ proposals, and looking deeper into energy transition issues – particularly how our use of energy will need to adapt in a ~100% renewable future. They have a book, entitled Our Renewable Future, that examines the adjustments society will have to make in the transition to new energy: http://ourrenewablefuture.org. Heinberg has posted some ideas from it in a useful blog. Although keen to see a renewable future, he looks carefully at some of the key problems.
Solar and wind technologies are seen as key options, but they have a drawback: they provide energy intermittently. So he says ‘We’ll need substantial amounts of grid-level energy storage as well as a major grid overhaul to get the electricity sector to 80% renewables (thereby replacing natural gas in electricity generation). We’ll also need to start timing our energy usage to better coincide with the availability of sunlight and wind energy. That in itself will present both technological and behavioral hurdles’. Absolutely. But they are not insurmountable – using smart grids and demand side management.
Heinberg also says ‘The inherent intermittency of wind and solar power will pose increasing challenges as percentage levels of penetration into overall energy markets increase. Other renewable energy sources – hydropower, geothermal, and biomass – can more readily supply controllable baseload power, but they have much less opportunity for growth’. That depends on where you are talking about (his focus in this Blog is the USA). In some locations they, and highly predictable (although cyclic) tidal power, can be significant. And there are many balancing options, including storage and supergrid imports and exports.
He is also rightly concerned about basic resource scarcity – all these technologies need materials. Though many can be recycled from current uses. One that can’t is energy: once we have used fossil energy it is lost for ever. So we should prioritise its use, for example for building the renewable energy system. Once that has got going, it can hopefully provide a surplus for further construction, but that depend on how fast we want to make the transition and what competing energy uses there are meanwhile.
Heinberg says it’s even worse than that since ‘the fossil fuel industry will require ever-increasing levels of investment per unit of energy yielded’ so that ‘society’s available capital will have to be directed toward the deteriorating fossil fuel sector to maintain current services, just as much more capital is also needed to fund the build-out of renewables.’ He adds ‘Seemingly the only way to avoid this trap would be to push the energy transition as quickly as possible, so that we aren’t stuck two or three decades from now still dependent on fossil fuels that, by then, will be requiring so much investment to find and extract that society may not be able to afford the transition project. But there’s also a problem with accelerating the transition too much. Since we use fossil fuels to build the infrastructure for renewables, speeding up the transition could mean an overall increase in emissions – unless we reduce other current uses of fossil fuels. In other words, we may have to deprive some sectors of the economy of fossil fuels before adequate renewable substitutes are available, in order to fuel the transition without increasing overall greenhouse gas emissions. This would translate to a reduction in overall energy consumption and in the economic benefits of energy use (though money saved from conservation and efficiency would hopefully reduce the impact), and this would have to be done without producing a regressive impact on already vulnerable and economically disadvantaged communities.’
That sounds a bit fraught, and even though, as he suggests, we can aim for a future in which less energy is used, he may be right about the transition problems: ‘We may be entering a period of fossil fuel triage. Rather than allocating fossil fuels simply on a market basis (those who pay for them get them), it may be fairer, especially to lower-income citizens, for government (with wartime powers) to allocate fuels purposefully based on the strategic importance of the societal sectors that depend on them, and on the relative ease and timeliness of transitioning those sectors to renewable substitutes. Agriculture, for example, might be deemed the highest priority for continued fossil fuel allocations, with commercial air travel assuming a far lower priority. Perhaps we need not just a price on carbon, but different prices for different uses’. www.postcarbon.org/renewable-energy-after-cop21/
It’s a thoughtful analysis, though some of the problems may be reduced if renewables get cheap fast, as seems to be happening. Then they may see off increasingly expensive fossil fuel directly, that process being accelerated if the social and environmental costs of using fossil energy are included in the assessment. That may also dispel the rather gloomy view that emerged from Google after their major 2011 study of renewable options. They had concluded that none were cheap enough to be adopted widely: http://spectrum.ieee.org/energy/renewables/what-it-would-really-take-to-reverse-climate-change
They were actually quite positive about the technology: www.google.org/energyinnovation/learnmore.html But didn’t seem to think of eco-cost benefits being included. That may now change, especially after the COP21 agreement. Moreover, renewable generation costs have fallen dramatically since 2011, and that looks set to continue: a new IRENA report says that, by 2025, PV costs will fall by up to 59%, onshore wind by 26% and offshore wind by 35%: www.irena.org/menu/index.aspx?mnu=Subcat&PriMenuID=36&CatID=141&SubcatID=2733. So there’s hope yet.