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Veteran
Posts: 275
 
| There's an Edinburgh company called Flexitricity that's come up with two interesting ways of helping to cope with the variable/ unpredictable nature of many renewable sources - which will become a major problem as the importance of renewables increases. One involves signing up companies with stand-by diesel generators, so that they can be remotely switched on when needed, and the other involves turning off applications like heating/ cooling/ pumping that can be postponed for a while. Switching on diesel generators may not sound like a good idea, but the alternative is to run fossil-fuel fired power stations below capacity. so they can be turned up when needed. The diesel generators are already there, and produce less greenhouse gases than running power stations inefficiently. They are one of three Scottish companies in the Barclays "Take One Small Step" competition for business ideas - and the only Scottish one helping reduce emissions. You can vote for them and see a video at https://www.takeonesmallstep.co.uk/Entry/View/5512 or you can see a longer version of the video at http://www.flexitricity.com/tv . I ought to say I have an interest in the company! - but I think it's a really useful idea, and one that deserves support, so have a look, and vote for them if you agree. |
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Extreme Veteran
Posts: 319
| Report in Guardian. So far wind generation is pretty much all replacing fossil fuels with no need for extra expensive gas to be built to back up supply. In fact conventional power stations which suddenly go off line or commercial breaks are said to be much more of a problem in balancing supply and demand. http://www.guardian.co.uk/environment/blog/2012/sep/26/myth-wind-tu... |
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Veteran
Posts: 275
| I think the Guardian article is probably correct as far as it goes - but it's looking at the levels of wind generation we had when the report was produced, rather than the levels anticipated in the future. The problem of intermittency and renewables increases rapidly as the proportion of renewables in the grid increases. That still isn't all that much of a problem provided we're happy to use fossil fuel power stations to balance the grid, but if we are to achieve climate change targets, we can't. (And as Anne has pointed put, this is as big a problem for nuclear generators as it is for renewables)
Finally the Westminster government is funding a small number of grid-scale electricity storage initiatives, and as noted above, there is also some good work being done on demand-side management, but all this is a long way behind the pace of renewables installation. |
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Extreme Veteran
Posts: 319
| The link to the Spanish system that the article mentions is 2009 but they did seem to be managing up to 53% of generation from wind without turning turbines off http://www.guardian.co.uk/environment/2009/nov/09/spain-national-re... They probably have more interconnectors with neighbouring countries but our proposed ones to Ireland and Norway could make quite a difference. French Dutch and Northern Irish ones already seem to be sending electricity both ways. http://www.nationalgrid.com/uk/Interconnectors/ |
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Extreme Veteran
Posts: 319
| Spanish renewable industry now seems to have ground to a halt as all the subsidies have been stopped but previous installations still mean up to 61% of generation has come from renewables. http://www.businessweek.com/news/2012-05-29/spain-ejects-clean-powe... The financial problems are said to be mainly down to consumers not being charged full price for electricity and the whole system getting into debt but it's being blamed on renewables. |
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Veteran
Posts: 275
| No doubt at all it's possible to have over 50% of generation from wind, but the 2009 article makes clear this was a one-off event due to particularly high winds. That means that there has to be some mechanism to deal with that scale of variability. Interconnectors will help (although it's debatable whether or not they contribute to local resilience!) but if all the big European countries are heading for a mixture of wind and nuclear, with smaller amounts of other renewables, we are going to need some mechanism for storing electricity when demand is low (e.g. in the middle of the night) and supply is high. |
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Dealing with the intermittency of renewables
