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Hiatus

I think I may put this blog on hold for a while.It’s been an interesting experiment and I’m glad I brought it this far: I feel as though I gave it a good run. Although obviously you need to do more than 7 months if you want to genuinely build popularity. Still, I only have a limited amount of free time, and it turns out that these posts aren’t really the way I want to spend my time at the moment.

I wish someone else was doing something similar so I could point you there. Perhaps Scottish Renewables, which have syndicated a fair number of these posts? It’s not a technical perspective, though, and that’s what I felt I could contribute.

Hopefully I’ll return to this in time when the propaganda and politics gets me irritated again!

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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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I think the people most impacted by the current government’s completely inexplicable austerity drive are the people who rely on state money, whether as benefits or because the state pays their wages. I am in the very fortunate position to be privately paid, and in a high-skill, high demand area.

Even so, I’ve found that the austerity measures are having an impact.

I guess the first thing I’ve noticed is that my money isn’t worth as much, and my time isn’t worth as much. Wage rises are very low, generally less than inflation; and the rate of interest you get on any money you can afford to save is actually laughable. (My “interest paying current account” was demoted to “current account” when it stopped paying interest, and I recently saw a poster advertising an actual ISA with 3% interest which only a few years ago would have been miserly for instant access savings.)

At the same time, the public discourse is highly demotivational and depressing. “Do more with less”. Services being cut at every turn. Tabloids turning on the unemployed, the sick, and the disabled, as though the tiny fraction of GDP which represents benefits for the genuinely needy is anything to do with the size of our defecit. On a personal level, individuals have to stretch their money to pay for their own higher education, their own retirement, childcare for any children, their day-to-day living expenses, the astronomical cost of housing… It’s depressing to feel like your time is not worth as much and at the same time to know that you have to pay for your past, present and future (and that of any dependants) out of a shrinking pool of income at a time of high inflation.

And of course by cutting benefits the government is telling me in no uncertain terms that if I fall sick or lose my job, I’m on my own. And I actually can’t save up for that possibility because I’m too busy saving for home repairs, pensions, student loans and you know, actual living expenses.

The thing is, if you’ve always had money you won’t see that. If you are in the fortunate position of having always had a little bit put by either by your parents or through some other means then you’ll never see cost as an ultimate problem. Similarly if you bought your house in the early days of the boom and sailed up the housing ladder on equity then you won’t appreciate how different it looks when you stretched yourself to the limit at the end of the boom to buy your house and watched its value fall through no fault of your own. The rich don’t see money as a problem, it’s always there when they need it. It’s more a way of keeping score.

Any household which covers its debts by letting its members starve and die is doing something wrong. That’s what this government’s austerity politics are doing, as disabled people are villified by their neighbours for the pittance we spare them. The government is letting us down; failing in its duty of care to its own citizens.

It sounds like socialism, and it is. Because how can it be bad for the resources of the many to be used to help those with nothing? You can only villify socialism if you genuinely believe we all have equal opportunity to be rich. And you can only believe that if you walk around with your eyes closed and your fingers in your ears.

(For context, I just read this. Alongside some other things I’ve read, the whole thing really worries me. I have worries about the independence debate, most notably regarding how little information seems to be available about what the former Great Britain might look like after independence, but this government would drive me to a YES vote on the grounds that at least Scotland might not have to face the worst. And if it’s impacting me, the picture of the squeezed middle, how much more must it be hitting the genuinely poor?)

Normal service will be resumed shortly…

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Wind farms are pretty different to prior large-scale generating technology. A big way that they’re different is that we, as users, can’t choose ourselves how much fuel they need to provide us with the energy we want to use; we simply have to accept as much of the available wind energy as we can.

For some this is an insurmountable problem with the very technology. If the energy isn’t there on tap you might as well pack up and go home. To me that seems crazy. If someone offered you a £20 voucher towards your weekly shop, you wouldn’t toss it in the bin on the grounds that it wouldn’t buy your whole week’s food, you’d use it and make up the rest other ways.

Because of this intermittency problem, jobs like mine became available for the wind industry. Across the globe, whereever there are wind farms of any size, someone has to sit down with a computer and some wind measurements and try to assess what sort of production levels we can expect from them. In the early days, this was done based on some comparatively short measurement masts, using methods that were simplistic. Now, it’s a much better defined methodology, with larger masts, new technologies, and its own modelling tools to provide more accurate predictions of how the wind will vary in time and space.

The same sort of analysis techniques are used by the Energy Traders, who sell the generated energy under the system of the UK electricity market. Similarly, analysis of operational wind farms really benefits from that sort of detailed knowledge of the wind because it’s still key to understanding how far the wind farm is performing as expected.

So there are lots of benefits to the wind industry from this sort of work then. (Might be worth mentioning that these sorts of jobs are high skill, high demand and generally filled by people who live and work in the country in question.)

Even the most strident wind power advocate, though, doesn’t foresee a time when 100% of an electrical grid’s supply comes from wind power; not unless there’s a major leap forward in electricity storage. It is likely that other technologies like wave and tidal will start to mature to large-scale deployment.

When they do, those renewable resources will also need their resource assessed. And very similar techniques will be involved: make some measurements, assess their quality and representativeness, model where you have no measurements, and then feed through information about your machine and its output.

The national grid that was originally conceived to carry electricity from large-scale power plants to every home, factory and office was an astounding feat of engineering. However it was designed to match the supply to demand. The requirements of matching a variable supply with a variable demand are relatively new. Because wind power is the first renewable technology to get a substantial penetration into the generation market, the grid is learning to be more flexible. As we begin to use other renewable technologies — and we will — those lessons will transfer and we’ll have a system that can cope with the demands we ask of it.

Wind energy doesn’t have to be 100% of the answer to be a very important part of today’s and tomorrow’s technology mix.

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Transport is one of the cornerstones of the modern world. Fast, convenient transportation has allowed us to live and work at very different locations, offering us the ability to live where we want to with the minimum of compromise on our work and careers. It’s also one of the three main pillars which make up our energy use: electricity, heat, and transport. In the UK and in Scotland in particular, most of our efforts in reducing our carbon use has gone on the first of these: generating more low-carbon electricity. But that’s only part of the story.

When it comes to transport, walking, running and cycling are probably the most environmentally-friendly forms of transport you can choose. They all run on the food we consume and on the fat reserves we store. But walking is slow, and we’ve set up our road system in the UK so that cyclists share their road spaces with buses and for me, certainly, that makes cycling seem like a dangerous option.

Electric cars are starting to gain a foothold, though. A couple of years ago it was all about the hybrids, but more recently environmentally-friendly vehicles has meant fully electric cars. But they still have their limitations. We have petrol stations available at regular intervals the length and breadth of the country; we don’t yet have electric recharging points (As Top Gear pointed out). That means their range is limited to hopping from one known charging point to another. Similarly even a large petrol car can be fully refuelled after ten minutes at the pump, while electric cars generally require longer. Even their sheer quietness can be a point against them, as pedestrians and cyclists can’t hear them coming.

But every technology has to start somewhere. And it looks like electric cars are starting to get a real foothold, with the opening of the new Power of Now exhibition in Glasgow from Scottish Hydro. I had a look round it today, and it’s a bit of a strange mix between a science centre exhibit and an electric car hire and charging facility.

The exhibition space is smallish, about the size of a standard city centre retail unit, and is split into three displays, focussing on hydro power, wind power and energy savings at home. Then, next door, there’s a car hire and display unit which contains various models of electric vehicles. If I recall correctly, the staff said there’s charging available for up to six cars at a time, and that facility is free. They also had a DC charger which can charge a car in about half an hour, although apparently it only works on electric cars with Japanese engines (because they’re DC, apparently).

My car is a normal small petrol runabout. I don’t use it much because I live near a train station which gets me to work and back with minimal hassle, and those journeys it is used for tend to be short trips for the shopping and so on. I see no reason why an electric car wouldn’t do me, and thousands like me, almost all of the time. Until the technology and infrastructure catches up, it wouldn’t be hard or expensive to simply hire a petrol car for the occasional longer journey. And apparently Glasgow City Council has committed to free parking for electric vehicles within their jurisdiction.

With free car tax, petrol prices through the roof (didn’t you just know that once the £1 a litre barrier had been broached it’d never really go below it again?), and now free parking, it’s beginning to look feasible. To really take off, it does need corporations with a vision to invest in the technology, and the Big 6 energy companies do have both the incentive and the profits to help us get the infrastructure in place.

Of course, most of our electricity isn’t carbon free at the moment. But then, none of our petrol is either.

It feels like a turning point to me. But we’ll have to wait and see what will happen next.

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I talked here about the job that myself and my colleagues actually do, in terms of why it would be complex to predict how the wind will flow across a potential site. I’d like to continue that topic a little and talk about how we actually measure the wind.

The first rule of good science is to make good measurements. In the wind industry, that means we want to know as much as possible about the wind which will encounter the rotors of the planned turbines. The most common instrument to use for this is a cup anemometer, which is actually a fairly simple mechanical device. Most commonly it’s made up of three cup-shaped objects which sit horizontally in the wind and spin round a central axis. By counting the number of spins we get a measurement of the wind speed. You’ll most likely have seen them; you see small ones quite commonly by the roadside, near small wind vanes.

Of course, a cup anemometer can only measure the wind speed that it’s actually sitting in. To measure at the heights of a wind turbine we need to mount it on a mast, preferably one which reaches to the turbine hub height. We also need several instruments at different heights, so that we can see how the wind flow changes with height. Then there’s the wind vanes, which give the wind direction, generally we want two of them. Multiple instruments have several advantages: they provide measurements at different locations, they can be used to sanity check measurements, and there is redundancy built in if something fails.

In fact the wind industry has generally had far higher requirements for measurement accuracy than the Met Office when it comes to wind speeds. There are wind industry professionals who visit masts in various locations and assess how accurate the measurements are, how consistent across the dataset and whether the data could be used as a reliable indication of how the wind behaves. The accuracy of the eventual dataset will depend on whether the mast is correctly sited, how the instruments are mounted on the mast, what sort of instruments are used and at what height, and whether the data are regularly checked and maintained.

Recently, lidar and sodar technology have started to really take off in the wind industry. These are alternatives to a mast, to an extent, and they work in a similar way to radar: by bouncing a wave off a moving target and looking for the reflection. Lidar units use light, generally infrared wavelengths, and sodar units use a sound-based wave. They’re collectively termed “remote sensing”, because they can sense the wind speed without sitting in the wind flow.

As it turns out, met masts with their instruments and the less intrusive remote sensing units are complementary technology rather than competitors. Met masts are large and unwieldy and cost a lot to install, but once they’re properly installed they continue to take data and require very little maintenance or additional expense. Temporary met masts which are installed for a wind project often take data for three years or even longer. Lidar and sodar can be bought outright or hired. Their huge strength is that they’re comparatively portable: lidar units in particular can generally be moved across a muddy field by two people, and they are not generally mentioned in planning requirements. A resource analyst might have two or three places on a site where the wind will be challenging to model or which are a long way from the mast but a mast can’t be installed there — in this case a short lidar deployment can really help in forming a full overview of how the wind is behaving.

Met masts are relatively simple things. Wind industry met masts are generally much smaller and less intrusive than the big telecommunications masts you see. However they have their challenges. They can be deployed in incredibly remote locations, which can make getting the required construction vehicles to the required location challenging; sometimes helicopters are required to transport the mast to site. (Note that one of the first things done when constructing the wind farm itself is building the roads. The turbines can then go along the roads. The met mast pre-dates this step, though.)

Remote sensing is obviously also a huge advantage offshore — the wind can be measured from the surface of an oil rig or even on a nearby shore rather than expensive and time consuming offshore met masts being required. The taller wind turbines of today, and the challenging terrain they’re sited in onshore, also benefit from remote sensing measurements which can be made far higher than a mast would support without any increase in cost.

There are technical differences between met masts measurements and remote sensing measurements which the wind industry as a whole are starting to get a handle on. It’s one of the more interesting elements of my job, watching the techniques and the technology changing and evolving. In many respects the wind remains something of a mystery to us.

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