by Dave Elliott
In its business leader column on August 25th The Observer, said “If there is a body of opinion that states that wind farms and energy efficiency can fill the looming energy gap, then it is small and deeply unrepresentative”. www.theguardian.com/business/2013/aug/25/anger-fracking-cant-manage-without-gas
Germany is aiming to get at least 80% of its electricity from renewables by 2050, with overall energy demand cut by 50%, so the Observer seems to have it wildly wrong, certainly long term. And in fact, far from being marginal, around 50 countries are already getting more than 60% of their electricity from renewables in the form of hydro, some of them near 100%. http://k.lenz.name/LB/?p=6525. Longer term, dozens of studies claim that renewables could supply 100% of the worlds electricity in many countries by around 2050. http://www.mng.org.uk/gh/scenarios.htm. That is what Denmark and New Zealand are aiming for and many others see renewable as their main future energy option- with China leading the way.
Globally, since 2000, the annual growth rates for onshore wind power have averaged 27% and for solar PV 42%, and Frost & Sullivan’s 2013 annual review sees renewables reaching 2252.3 GW (2.2TW!) globally in 2020, if current levels of financial and political backing are maintained. www.frost.com/c/10118/sublib/display-report.do?id=M8E1-01-00-00-00. That is around 7 times the currently operating global nuclear capacity.
However maybe the Observer was just talking about the UK, where things tend to move slowly? At present we get about 11% of our electricity from renewables, with wind beginning to take the lead (nearly 10 GW so far), and by 2020, on current plans, this should reach over 30%. But several scenarios have suggested that we could do much more and get to near 100% within a few decades. For example, the Centre for Alternative Technology’s Zero Carbon Britain says we could do this by 2030. http://zerocarbonbritain.com/
More conservatively, the Pugwash High Renewables Scenario says it could be done by 2050, at reasonable costs, and in both cases without nuclear. http://www.britishpugwash.org/recent_pubs.htm
Even if CATs study is discounted as too speculative, it does seem that, given proper support, renewables should be able to expand to quite high level rapidly. The new report from the cross party Carbon Connect group suggested that renewables could be accelerated to supply between 45 and 55% of UK electricity by 2030. www.policyconnect.org.uk/cc/research/report-future-electricity-series-part-2-power-renewables
They saw this as a ‘Plan B’, in case nuclear did not deliver as hoped, but it could also be seen as a more sensible option, making the UK’s already faltering attempt to re-expand nuclear unnecessary. That’s a view I put strongly in my new book for the Institute of Physics ‘Renewables: a review of sustainable energy supply options’, which as I mentioned in my last post, takes a positive, optimistic, line. It looks at all the renewable energy options for the UK and globally, and at how they might be integrated together in a sustainable and economically viable energy supply and demand system.
Certainly the overall resource is very large, and by definition renewable- the energy supply wont run out. Most renewables have no fuel costs and the technology costs are falling rapidly, for PV especially. So longer term, quite apart from the other issues associated with using fossil and fissile fuels, renewables will inevitably win out against fossil and nuclear options, the costs of which are bound to rise as reserves diminish. And even in the short term, costs are beginning to look competitive. For example, the Financial Times now sees PV solar as a relatively cheap option: www.ft.com/cms/s/0/a41d86b4-ff9c-11e2-a244-00144feab7de.html, and it has been claimed that UK power will cost $83/MWh by 2015, compared to $44/MWh in Germany, as Germany benefits from reduced fossil/nuclear use: www.bloomberg.com/news/2013-06-14/u-k-power-price-to-double-german-on-wind-solar-energy-markets.html
Now that cost issues are beginning to look less serious, environmental impact issues are often wheeled out to try to demonstrate that renewables are not much better, and in some cases worse, than fossil and nuclear. Although I note in my book that new large hydro projects are probably not the best option for the future, given their environmental impact. and I see large tidal barrages as similarly very invasive, by contrast most of the other renewable electricity supply options are much more environmentally benign. Land use issues are sometimes raised as possible limits, but I argue that they can be overstated: offshore wind, wave and tidal stream projects have no direct land use implications, on-land wind farm sites can be used for farming and most PV solar can be on roof tops, on marginal land, or in desert areas, of which there are plenty for both PV and focused-solar CSP thermal generation. I also see geothermal energy as promising for electricity supply in some locations, with low impacts, once established.
On the heat supply side, I am optimistic about the role of solar for space and water heating, given that there is already over 250GW in use around the world, mostly on roof tops, but with, in cold northern areas, large arrays increasingly being built to feed district heating networks, some with inter-seasonal heat stores to allow summer sun to provide winter heat. In the south there is the option of using solar heat powered absorption chillers to help out with air conditioning. I see biomass playing a role in heating as well as electricity production, with short rotation coppicing favoured, but I have concerns about the land-use issues associated with large-scale development, especially in relation to biofuel production for vehicle use, although I note that biogas production from bio-wastes avoids them, and some vehicles could use compressed biogas. In addition, I see storing biogas from AD waste conversion plants, as well as syngases produced using excess electricity from wind and PV, as a way to balance the variable output of wind, PV and other renewables. I also see imports and exports via long distance HVDC supergrids, coupled with smart grid demand side management and some storage capacity, offering a way to balance local variations in supply and demand, by linking up generation from a wide range of renewable sources over a wide geographical area.
Taken together then there are many viable options at a range of scales. The overall conclusion is that renewables are on their way, and given a chance could in time realistically replace all other energy sources in many if not all countries. Maybe then the Observer leader writer should rethink, especially given that the UK has the best renewables resources in Europe. The Observer thought shale gas was vital. It is true that we will need storable gas for balancing renewables as they expand, but rather than fossil/shale gas, biogas and syngas could play an increasing role, with much less environmental impact. And with no new inflexible nuclear on the grid, and supergrid links to the rest of the EU, balancing should in any case be easier, with wind curtailment being unnecessary. It may not all be easy, and will need vision, but, I argue, there is a viable 100% sustainable path available, should we want to take it.
My new book, ‘Renewables; a review of sustainable energy supply options’ will be out soon, published by the Institute of Physics. http://ioppublishing.org/publications/books