On January 3rd WWF issued a press release purporting to show how 2014 was a “massive year” for wind power in Scotland. Euan Mearns put this claim firmly into perspective here. Then two days later, on January 5th, WWF issued another report summarizing the results of a consultant study which purports to show how Scotland could generate 92% of its electricity requirements from renewables by 2030 without the need for any fossil fuel or nuclear backup. Here we will look briefly into the question of whether this proposal is in any way feasible.
WFF’s press release was, as usual, uncritically received by the press. Here’s what the Scotsman had to say:
SCOTLAND’S electricity system could be powered almost entirely by renewable energy by 2030, according to a report by an environmental charity.
WWF Scotland’s report uses independent analysis by an engineering and energy consultancy to test the Scottish Government’s policy to decarbonise the country’s electricity supply over the next 15 years. It found that an electricity system based on “proven renewables and increased energy efficiency” is a credible way of meeting the target. Lead author of the report for consultancy DNV GL, Paul Gardner, said: “Our technical analysis shows that a system with an extremely high proportion of renewable electricity generation located in Scotland can be secure and stable. There is no technical reason requiring conventional fossil and nuclear generation in Scotland.”
However, one key assumption wasn’t mentioned:
With the transmission capacity to the rest of GB currently existing or planned, there is little or no need for conventional generating capacity in Scotland to maintain security of supply, even in periods of low renewables production.
That’s right. WWF’s plan will work only if power can be imported from elsewhere in GB when the wind doesn’t blow in Scotland.
So what the Scotsman should have said was:
WWF Scotland’s report … found that an electricity system based on “proven renewables and increased energy efficiency” is a credible way of meeting the target only if power can be imported in sufficiently large quantities from elsewhere in Great Britain during periods when renewables generation is unable to meet demand in Scotland. Since the future availability of surplus power from elsewhere in Great Britain is subject to considerable uncertainty WWF’s system cannot be relied on to deliver the stable and secure power that Scotland needs.
To set the stage we will briefly review the situation regarding electricity generation and consumption in Scotland using the data contained in the annual generation statistics published by the UK government and the annual renewables generation statistics published by the Scottish government. The chart below summarizes these data. Since 2004 wind generation and electricity exports have increased substantially, conventional generation has gradually decreased and consumption has been reasonably constant except for the step-down after the 2008 recession. But conventional generation still supplied over two-thirds of Scotland’s electricity in 2013, and over three-quarters if hydro is included:
Generation by type, consumption and exports, Scotland 2004-2013
Now on to WWF’s vision for a secure renewable future. It’s what WWF calls its “Low Climate Risk” scenario, a title which implies that by generating 92% of its electricity from renewables in 2030 Scotland can save the world from climate change all by itself. Here are the details, reproduced from the WWF report, Note, incidentally, that the scenario doesn’t include any more rooftop solar, showing that even WWF doesn’t hold out much hope for Solar Scotland:
WWF’s 2030 “Low Climate Risk” scenario
According to DUKES Scotland presently has 12,099MW of installed capacity, 4,270MW of which is non-dispatchable wind and 7,829MW dispatchable coal, gas, nuclear and hydro. This much dispatchable capacity should be capable of meeting Scotland’s ~6,000MW peak winter demand when the wind isn’t blowing provided there are no major plant outages.
WWF’s 2030 generation mix, however, eliminates the coal and nuclear and most of the gas and cuts dispatchable capacity to only 3,340MW. A simple calculation shows that at ~6,000MW peak demand this will result in deficits of up to ~2,660MW during low-wind periods even when all the dispatchable capacity is running flat out. How does WWF propose to eliminate these deficits?
First by aggressive but “perfectly feasible” demand management:
…. the scenarios show that a perfectly feasible demand reduction of 1% annually will allow Scotland to hit the 2030 target well within the current renewables pipeline, even allowing for the electrification of heat and transport.
And second, by importing power “safely and securely” from somewhere else:
Where there is any shortfall between demand and supply, this can safely and securely be met by imports from the rest of Great Britain or Europe through interconnection.
Although WWF doesn’t think the need to import power will arise very often because the Scottish wind can be relied on to blow during most winter peak periods:
Maintaining system security during periods of high electricity demand and low renewable production is critical, even though this will be a relatively infrequent occurrence as high demand for electricity in winter often coincides with high wind output.
But the deficits won’t be limited just to high-demand periods. There are times when even Scotland is blessed with a prolonged period of fine weather during which wind output drops down close to zero and stays there. I discussed in an earlier post how the Island of Eigg ran out of renewable energy during such a period in the summer of 2010. A similar period of fine weather in the summer of 2030 could result in Scotland having to import power for more than just a few hours.
There are also problems with WWF’s dispatchable power assumptions. The existing 1,500MW of hydro, for example, is capable of delivering power at full output only for a few hours, and there are questions as to whether an additional 1,000MW of hydro could even be installed in Scotland. The 340MW of gas has CCS attached, and CCS is still unproven technology on the commercial scale. And WWF’s proposed addition of 360MW of biomass makes no sense at all if the goal is to reduce carbon emissions in the short-term . Biomass when burned emits about as much CO2 as coal. (There’s also the question of where the biomass will come from. It’s unlikely to be Scotland and there are limits as to how much virgin North American forest we can cut down.)
I could go on listing problems with the WWF proposal but I think I’ve gone far enough. I will just conclude by saying that it’s unwise to underestimate the influence that NGOs like WWF have on politicians and the public. If it wasn’t for Friends of the Earth and their “Big Ask” campaign the UK probably wouldn’t have the Climate Change Act of 2008.