Look-up any renewable energy website, and you'll be told the renewables are the answer to all of our energy needs. Not only that, but they will solve the issue of global warming or climate change, too. Much of this advertising copy is written in an ecstatic, almost starry-eyed tone. Either these guys are justifiably enthusiastic about the great potential of their products, or it's an attempt to conceal the inherent weaknesses of the scheme behind the marketing hype. Which, I leave to you to decide.
Let's look at a few of the claims made by windturbine manufacturers and sellers:
This was one of the early promotional claims. You don't hear it so often today, mainly because it's been discredited. It's worth reminding readers about, because it underlines just how inaccurate some of the early advertising spin was. The 'everybody' they mention in the ad copy doesn't seem to include weather forecasters, who will be quick to point out that high pressure regions are typically associated with very light winds, and such systems are often very large, covering not just the whole of the UK, but sometimes most of Europe.
Thus, Definitely not true. Yet, it was on the basis of this claim that mass deployment commenced, with great enthusiasm. Now that we have UK-wide deployment we can see that it was a completely false claim. The amazing thing is that no-one in government though to ask a met guy or two if the claim was realistic, or not.
July 2013 was a case in point, with UK wind output suffering a 20-day long continuous brownout. June and July 2014 have seen similar patterns.
If we look at the generation charts we see that winds typically fluctuate over a cycle of two to five days, and on average seem to be light for three days out of five, stronger for two. This is generalising, of course, patterns vary a lot. The point is though, that any system of wind power has to have backup capable of getting it through regular periods of 2-3 days of near-zero output, and occasional periods of up to a month with very low output. So, that brings us to the question of backup, which we'll look at further down.
Another early claim which was a brazen exaggeration. As we shall see, countries with large windturbine deployment typically have high electricity prices. The UK now has about 10% or wind capacity, and there is no indication whatsoever of this resulting in cheaper electricity. On the contrary, we see plans afoot to install Smart Meters in every UK home. If windpower is so cheap, why on earth are these Smart Meters needed? The answer of course, is that windpower isn't cheap, never was cheap. We were lied to about that.
Like any machine the turbines need maintenance, and the cost of that is hard to quantify. Earlier designs are already suffering gearbox and blade problems, calling for costly remedial work. There is also the cost of maintaining the transmission lines, often in remote areas where no lines would otherwise be run. By the same argument coal is also free as the material itself is plentiful and costs nothing. The cost of coal is that of the work required to extract it from the ground. Likewise, wind may be free but windturbines or the power they generate are not free.
There is presently some controversy of the life expectancy of turbines. The manufacturers quote twenty years, but some operators are already experiencing high rates of maintenance on turbines of 12-15 years age. Even if the 20-year figure is realistic, it has to be contrasted with the 40-60 year life expectancy of a conventional power station.
The best way to answer this one is to look at retail electricity prices in countries with large-scale wind deployment. Denmark, with the largest European investment in wind, also has the most expensive electricity in Europe. Germany, with extensive wind and solar deployment, has a much higher electricity price than the UK. The problem that both of these countries is hitting, and a serious one with wind, is the need for backup when the wind isn't blowing. Denmark has to rely on the goodwill of neighbouring countries for this backup power, especially Norway and Germany, and it doesn't come cheap. Germany, meanwhile, has started on an intensive programme of building coal power stations. This is partly to replace nuclear plant similar to that at Fukushima whose safety is questionable, but also due to the unexpected shortfall in output from renewables.
As environmentalists would be only too keen to point out about your washing machine or iPad, the total pollution throughout the cycle of manufacture, use and disposal of the product has to be considered, not just that involved in its use. Yet, with wind turbines the manufacture and disposal pollution costs are conveniently forgotten. In reality, wind turbine manufacture requires a number of exotic materials, especially rare earths (neodymium) for generator magnets, and advanced polymers for the blade aerofoil structure. The mounting base requires a very substantial amount of concrete. All of these involve pollution to some degree at manufacture, disposal or both. Much of this pollution is released in overseas locations such as China, so it's a case of out of sight, out of mind. Zero pollution? Sorry, no. No more so than your fridge is a zero pollution product. How much pollution? Hard to make a comparative estimate, but let us say that 2000 turbines equals one conventional power station. Materials-wise there's probably not a lot of difference.
It does, unfortunately most of those jobs and dividends go to foreign firms and investors. Conventional power creates British jobs. It gets worse though. A recent report suggest that each wind-related job costs the taxpayer around £100,000. If we assume a salary of £25,000 then we could fund four other jobs from the same tax burden, instead of one wind industry job.
Installation and maintenance involves a great deal of work at height, often in hostile weather conditions. Unsurprisingly, accidents do happen. The safety record of the wind industry is nothing to shout about. An incident in Denmark in which an ageing turbine ran out of control and broke up, scattering debris about half a mile, indicates that the risk to householders living in close proximity, whilst low, is not zero.
Renewables guys love this energy unit they call 'Homes.' I guess the advantage over Watts or BTU/hour is that, unlike the standard engineering units, there is no fixed definition of a 'Home' as a unit of power. So, the scope for claiming whatever you want without actually being accused of lying is always there.
Manufacturers quote a 'nameplate rating' for a given model of turbine. This is the absolute maximum output under conditions of ideal wind strength. In reality this nameplate rating is seldom achieved. They may then take what they consider to be an average output -often a very arbitrary figure- and calculate how many homes that would power, IF it were a continuous flow of power as from a conventional power station. The reality is that at some times the turbine will power perhaps double the claimed number of homes, but at other times it will power fewer. Often the average of the two extremes is well below half, more like 25-30%. Is this a realistic claim? Depends on your viewpoint, I guess.
The UK currently has about 7GW of installed windpower, and demand ranges from about 25GW on a summer night to 55GW on a winter's working day. Consequently there are bound to be times when wind output is a substantial fraction of total demand. The statistic is largely meaningless, though. It is an example of 'cherry picking' - choosing data that you like the look of, and discarding that which you don't want to see. A more meaningful comparison would be the average output over, say, a day or two.
Yes. Gas turbines can respond very quickly to changes in demand, thus they are ideal as a backup for wind capacity. Downside is that gas is expensive compared to coal, and supplies currently have to be imported from Russia. This situation could change if shale gas is exploited, which would make gas the cheapest energy source. But, the Greens vehemently oppose shale gas development. Paradoxically, in opposing shale gas they are opposing the one option that would make large-scale windpower a realistic proposition.
No. Both coal and nuclear stations are relatively slow to alter their output. Plus, with nuclear there is no real cost saving in running at reduced power, thus 100% output gives best financial return.
No. Hydro is one of the few renewables that can pay its way. Once installed, it is economic to operate and relatively trouble-free. The limitation is that in the UK we just don't have the geography to construct the number and size of hydro stations we'd need to back-up multiple gigawatts of wind capacity. Scotland has a good few hydro stations, but even there the total output is a only small part of Scottish electricity consumption.
Battery banks are a feasible option for small off-grid wind installations. As such, a windturbine and battery bank may be a far preferable arrangement to a diesel generator. For supplies on a national scale the sheer size and cost of such battery banks would render them impractical. Not to mention the fire risk, should a short develop.
A clever idea, but it overlooks the issue that people rely on their cars to get to work on time, and the required daily range of those cars is bound to vary a lot from one driver to another. I somehow don't think an employer would buy the excuse that I didn't turn up till 10am today because there was no wind last night so I had to call the AA to tow my car home from where it ran out of juice, and take a bus the rest of the way. No. When you think about that aspect, it is not a sensible solution. If I choose an electric car, then I need to be able to rely on it, in terms of it being charged and ready for use. If I cannot rely on it because the Grid operators might have drained the battery to make up for a lack of wind, then I will buy a fossil fuel car instead.
No. Smart meters will allow supply companies to turn off consumers' appliances when total demand exceeds supply. This might help in some circumstances. But, it can do little to help during nil wind times, which happen quite regularly.
No. Same answer as for hydro, basically. International connectors are a useful way of sharing power when peak load times differ. But, they are limited to a gigawatt or two in most cases. Simply not enough to back-up multiple gigawatts of wind capacity.
No kidding. The government is presently negotiating with owners of backup generators to have them supply power to the Grid when windpower cannot meet demand. That is a signal of how desperate they are to find a solution to the intermittency issue.