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Wind Turbines: really green?

Editorial Staff

They were claimed to be the solution to fossil fuels. Acres of land and sea have been devoted to the alien structures that make even power-grid towers seem inconspicuous. Now about two decades into what was the future, has the promise of Wind Turbines turned into reality? Are there unintended consequences and are they good or bad?

Although the UK Government has said, in a report, "Electricity Generation Costs," that wind generated power can be cost effective, it also says, in a report issued in 2016 "It is important to note there is a large amount of uncertainty when estimating current and future costs of electricity generation. For example: uncertainty over costs will be greater for more immature technologies; variation in capital and operating costs across sites; differences and uncertainty over load factors and hurdle rates. uncertainty over the fuel and carbon price trajectory for relevant technologies; and" .. and that's where the report leaves it, mid sentence and apparently mid list. See page 6 of the report. The report makes it clear: this is not only an industry that has immature technology, it also has immature data and everything is, largely, an unknown. To try to address this, various novel formulae have been adopted and new forms of costing and estimating created. That, so far as we can see, is little more than accounting guff designed for business presentation purposes rather then genuine financial analysis, more like economists making a range of assumptions and then saying that, by relying on them, they can produce accurate predictive modelling.

And the circle continues to turn: in April last year, an eight year old "state of the art" turbine at the Alpha Ventus wind farm in the North Sea suffered a catastrophic failure in which part of the turbine housing fell off and dropped some 90 metres into the sea. The concern was so great that the entire farm was taken off-line and even maintenance crews were not, initially, allowed to enter the area. Speculation at the time suggested metal fatigue in bolts which had last been inspected only two years earlier. Commentators spoke of "under-designed." More properly, it's under-engineered, if that's the case. The simple fact is that the North Sea is, and always has been, an extraordinarily hostile environment below, at and above sea level. That was supported by research by two academics at University College London who pointed out, in 2010, that, when an offshore turbine requires repair, there must be "an expedition." It is not, obviously, a question of sending out a couple of chaps in a Land Rover. The academics proposal was nothing novel: it was that the industry needed to move from a model of repairing to a system of routine maintenance to avoid failures. In this, they were following the public bus industry in the UK in the 1970s, when "crisis management" i.e. managing when there's a crisis and doing nothing before, fell out of fashion at leaders such as Teesside Municipal Transport. Considerable resistance was shown to the idea of planned maintenance, but eventually arguments of medium to long-term cost savings and public safety won and the industry followed.

It was by no means the only failure: in the UK some ten years ago, it was the talk of dinner tables that turbines were breaking down, on shore and off shore, and, even when they worked, were not generating the power expected or, importantly, paid for by the taxpayer.

This is the dilemma: is this "green tech" really that green? What are the environmental impacts of production of these giant devices and of their collapse and/or removal? In 2016, the responsible actions of company Nuon saw four 22 year old turbines being dismantled, just 600 metres of the Dutch coast. The turbines were reaching end-of-life and were no longer cost effective. There is, below, a time lapse video of the process. A second video is a documentary about the taking down and dismantling, by company DDM, of an on-shore turbine. It was a pretty dinky little thing compared to the enormous devices in place and planned for the near future. And it was still not a simple job. For the sake of completeness, a third video shows the erection of an on shore turbine by Juvent.

In 2017, magazine Maritime Executive reported that the world's first offshore wind farm was being dismantled. It took six months to take down what are, in today's terms, tiny windmills. There were just eleven of them. What is worse is that the blades in the new versions are of highly sophisticated composites that are difficult or impossible to recycle. Ideas for re-use are uncommon, it seems.

One possibility, an article in Politico says, is to take down the windmills, restore them, and sell them to developing markets. That begs the question, why replace them in toto if they can be updated for a longer life. New Zealand Wind Energy says that a modern wind turbine " annually produces roughly 180 times more electricity per year and at less than half the cost per kilowatt-hour (or "unit" of electricity) than its equivalent of 20 years ago." Again size matters: to quote Politico "A modern tower can stretch more than 100 metres tall, with blades that span 126 metres and a capacity of 7.5 megawatts — enough to power about 3,000 households. One of the world's largest rotors has a diameter of 164 metres. Its 82-metre blades correspond to the wingspan of an A380 aeroplane and it produces some 9.5 megawatts of power."

All those rotors have to go somewhere: Politico says that, in 2014, the most recent data available, "Germany had to deal with 54,000 tons of waste from rotor blades." None of the disposal options is at all environmentally friendly. By next year, on some estimates, some 28% of the current wind farm tech will be at the end of its designed lifetime. There are somewhere close to 80,000 windmills, on shore and off shore, in Europe alone. They all need an end of life plan. While the EU has measures in place they do not cover older devices.

And that's before one of the things falls down due to, of course, wind. In January last year a 260 tonne wind turbine was blown down by high winds. The windmill, at Bouin in France's western Loire region of Vendée, was only thirteen years old but had been battered by storms during that time. Storm Carmen, not a big blow by global standards, was the straw that broke it.

The sceptics are wrong to put out mis-information but there is sufficient reason for concern that wind turbines should, arguably, not be the first port of call for those looking to replace fossil-fuel power generation.

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