Archive for July, 2012

So, today’s ministerial statement from the Department of Energy and Climate Change (available here has confirmed that the subsidy available for onshore wind farms will drop by 10%.

Now, while I work in the wind industry, my expertise is on the measurement and analysis of the wind itself rather than the funding mechanisms used to support it. In their coverage, BBC News are grudgingly positive about this, and the tone of their article matches pretty closely my own appraisal of this. It is good that the funding has not been slashed 25% as was previously suggested as that would be a very steep climb in a very short time and such things tend to have strong impacts. I have far less concerns about a 90% subsidy.

The UK’s system for subsidising renewable electricity generation for large-scale projects is based on a ROC: a Renewables Obligations Certificate. This is an unusual scheme internationally, where the more common form is a simple feed-in tariff which pays a bit extra for every kilowatt hour from a particular source.

ROCs are distributed based on generated energy, and different sorts of generation earn different amounts; the amount of ROCs earned is loosely tied into how mature the technology is. The “renewable obligation” referred to in the title requires suppliers to generate a proportion of their electricity by means of renewables, a proportion which then increases year on year. Suppliers then have to present their ROCs as evidence that they have met their legal commitment. However, the certificates are not tied to the supplier themselves, but can be traded with other suppliers. While my understanding of the whole process is pretty sketchy it actually seems quite ingenious because of course from a government perspective they don’t care if individual suppliers meet an arbitrary percentage target: they care that the country as a whole meets that target.

Today’s announcement says that onshore wind will no longer earn one ROC but instead will earn 0.9 ROCs.

I first heard this suggested a few months ago, and I was rather surprised at the idea that the number of ROCs would drop below 1. (Which demonstrates my failing to pay attention as other technologies have earned less than 1 ROC per MWh before now.) After all, what is the certificate supposed to be saying? The whole point of the system was not so much to support emerging technology (although they worked that in), but rather to incentivise electricity suppliers to support the UK’s legally binding targets to reduce our CO2 emissions. I therefore assumed, wrongly as it turns out, that a non-thermal plant with no direct CO2 produced during operation would not earn less that one full certificate per megawatt hour, representing 100% renewable electricity.

The way the system is set up, there are knock-on effects from reducing the ROCs earned by onshore wind, above and beyond the financial implications (and my feeling is that the technology is now mature enough to weather this small loss of subsidy). Energy generated from onshore wind will now count less towards a supplier’s renewables obligation than their generated output would suggest. But the targets remain legally binding.

The reduction in subsidy is partially justified in the ministerial statement with the followeing text:

…delivering the best possible deal for consumers has been at the heart of the RO banding review. In considering the final shape of the banding package, we have focused on the need to balance cost-effectiveness with the range of objectives that the RO must deliver.

Any gap between current generation and the legal target, this year or in the years ahead as the target increases, will have to be met by some form of generation if we are to meet our legally binding targets. It may be more wind farms, or companies may risk more on offshore wind or emerging marine technology: all of which are more expensive than onshore wind and which will cost the consumer more in subsidies.

I think it is probably right, all in all, that the subsidy for onshore wind should decrease. I’m very interested to see how it plays out from here though.

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Every so often a company gets it so wrong you just have to sit back and enjoy the show. And laugh.

I give you Shell’s Arctic campaign.

Edited to add:

Well, it did always look a bit unbelievable that a company would get things so wrong on such a sensitive ground. Looking back, another red flag was that all of the posters, rather than just a majority of them, were green-type protests. Seems like the campaign was a Greenpeace stunt all along.

I discovered this through this New Statesman piece, which has the tag-line “Since when were Greenpeace the bad guys?” Um, I work in wind farms, and I’ve always been suspicious about Greenpeace: not just their tactics, which are often dubious, but their targets as well. But that’s perhaps an article for another time. More philosophically, there’s no such thing as bad people; just people who sometimes do bad things.

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Busy busy

Work — in general, I think, not just with wind farms — comes and goes in peaks and troughs. You get quiet weeks, where you can just putter on doing whatever it is you do. Sometimes you get almost to the end of your to-do list and wonder what you’ll do then! This week is not one of those weeks; not for me, anyway. I’ve been out at meetings a day and a half, this week, I’ve got management visiting from Down South, and New Starts needing training and support, and on top of all this I’ve got a list of things to Sort Out and three ongoing analysis tasks.

I come home pretty tired with all that, and I don’t have a lot of spare energy for blogging or twittering at present.

Still, I do keep thinking one thing, and that’s about our approach to choosing a career. When I was at school, they asked what subjects you liked and were best at and then advised accordingly. Like English? Try teaching or writing. Chemistry? Become a forensic scientist. I am increasingly starting to feel that a better approach would be to ask what sort of tasks would make up a typical day, and work from there. Want independence? Freelance writing, or run your own business. Like solving problems? Engineering or science. Want an office job? Get good computer skills. Want to work outdoors? How about environmental science, zoo-keeping, gardening or building?

I’ve often wondered if that’s a better way to choose a career.

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Wind farms are still fairly new technology. In resource assessment, you see this when you look back at the sort of analysis that was done about 5-10 years ago, on older wind farms. To generalise, at the beginning of our industry we greatly underestimated the variability and complexity of the wind. This mostly resulted in an overestimation of the yield.

Differences compared to current best practice include having too few masts; making masts too small and then vertically extrapolating the wind flow to hub height; underestimating uncertainty on the whole procedure and the output prediction; a lack of understanding on how the landscape features would interact with the turbines.

The trouble is that this means that the wind farms which have been designed according to current best practice are pretty new. If it takes 4-5 years to get a wind farm from the stage of measuring the wind through all the technical and non-technical surveys, calculations and checks that have to be done and then through construction, then the best practice of 4 years ago is only just becoming operational. This makes it challenging to compare the actual output with the prediction and thus demonstrate that the current best practice works.

Of course, there are improvements that can be made, and there are several interesting developments of the last few years which are feeding back into best practice.

  • Lidar technology: This is based on radar technology and can measure wind speed using a laser pulse rather than a physical device actually sitting in the wind. That means you can put a lidar on the ground and measure up to 200m up (some models go further than this). While this technology has been around for decades and has been used in the wind industry for at least five years, it’s only relatively recently that the wind industry has really taken the opportunities this presents to heart. The reason for this, to my mind, is about understanding. Lidar measures the wind in a completely different way, averaging over a large area rather than at a tiny point the way previous anemometer technology did. This is a very fundamental difference on what the data are telling you, and frankly none of our tools really understand how to make best use of this. The difference gets most notable as the terrain gets more complicated — so hills and forestry; both of which are often found near proposed wind farms.
  • Computation Fluid Dynamics. Lay English considers a “fluid” to be a synonym for “liquid” but in fact gases are also fluid and therefore the movement of air is best described by fluid dynamics. Computational fluid dynamics or CFD is a way to solve the predictions for the movement of air in an environment which takes in as much information as we can manage about the complexity of the real world. This has become much more important with the rise of offshore, where, we discovered, the wakes of wind turbines behave very much differently than they do on land. Previous models, which were extrapolation and approximation to limit computing time (and which, I should add, do fairly well most of the time and are still both relevant and extensively used), couldn’t provide a reasonable approximation of wind farm wakes offshore. I don’t think CFD is being used much onshore at present, but given how complex the newest wind farms are it won’t surprise me if we begin to see CFD models being performed more often for onshore sites over the next few years.
  • Models: Virtual Met Masts created by meteorologists seem to be very popular at present. These use large scale climate measurements, such as satellite data, to feed into local models and provide detailed predictions of various aspects of the local climate such as wind speed and direction. What I’ve seen of these has been very positive, generally these predictions align well with mast measurements. Still, no scientist worth their salt would ever suggest that real world data could be removed in favour of model outputs: especially with weather and climate the world is complex and the only way to really see what happens out there is to be there measuring it. Where these models come into their own is in trying to establish what the long term climate is like. Anemometers degrade over time, and the landscape itself changes around a mast which has been there for decades. These two facts mean it’s hard to get long term wind measurements with the sort of accuracy the wind industry demands that can give confidence in how the wind at a particular site is likely to be over the lifetime of a proposed wind farm. Models have the potential to be perhaps more consistent.

I suspect that when we look back in five or ten years on the industry now we’ll still see it as a teething period when a lot of initial problems in analysis, measurement, modelling and prediction, let alone actually operating large scale wind farms, still had to be resolved. I don’t know which of these technologies, or perhaps something else entirely, will become the normal face of wind analysis in ten years time. And I find that uncertainty rather exciting.

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