A couple days ago I watched the Discovery Channel program “Incredible Engineering Blunders”, the episode that looked at the problem which the early Denmark offshore windmill suffer from. To summarize: the foundations of the early windmills were build on a monopile foundation, but because a windmill is very top-heavy, there are huge strains on the joints. If the grout in that connection cracks or grinds away, the windmill could sink down on the base pipe. Although there are stoppers in place that initially prevent this from happening, these were not designed to take the full load of the turbines on a permanent basis. If they crack under the pressure, the turbines could collapse into the sea.
But that was not the thing that got my interest. It was the typical way in which wind energy was described (my emphasis):
[…] I am heading out in the freezing North Sea to help to fix a blunder that threatens the lights switch off in Denmark. […]
[…] The wind that is churning up these waves and my stomach, is a free source of energy that is helping to meet Europe’s increasing power demands. […]
[…] On this site alone there are 80 turbines. Each one capable of powering 2000 households. This is a booming industry and it really is the future of power generation. […]
[…] Europe’s off shore wind turbines create a clean, unlimited power. […]
[…] They also work in deeper water, opening up more potential sites out at sea. That means cheaper, more abundant, clean power for everyone. […]
Basically, this is exactly the same what the media is tells us: wind energy is free, clean, unlimited, it can power x number of households, it already has an important share and it is the future of energy production. These are not exactly lies, but it is only part of the truth.
- It threatens the light switch off
It seems to have such an important share that it threatens the lights to switch off in Denmark. That is a bit over the top. While Danish wind mills produce on average 34% of the electricity supply, that is on average. Wind energy, being intermittent, it has sometimes a higher share (and then this fact is hyped all over the media) and sometimes has a smaller share (not reported in the media). I think their negative effect on the reliability of the grid is threatening much more the lights switching off than when their share would be declining for whatever reason.
How much less than average? Well, a lot less. When downloading the Denmark wind data from 2015, the minimum production was 1.1 MWh on October 4, 2015 at 08:00 (0.023% of the installed capacity)! The total load at that time was 3008 MWh. So something was able to take over to compensate for the other 3006.9 MWh that hour. That day the production was really low, a meager 634 kWh for the full day (about 0.5% of the installed capacity). Total load was 78625 MWh. So something took over for the 77991 MWh that day. Anybody heard about that in the media?
If the other sources could compensate for such a huge dip in production, then some windmills that stop working because of foundation problems would very unlikely threaten lights to switch off…
- It is free
Sure, the wind is blowing for free … but the machines that capture that “free” energy are expensive, very expensive. Just look at the subsidies that are needed to promote it and keep on promoting it. If wind energy would be profitable (which is what one expect from a source that is free), then there would not even be a need for subsidies.
- It is clean
True, there are indeed no direct emissions while working, but that doesn’t mean that there aren’t emissions involved. There are emissions in all stages: production, transport, construction, backup power when there is no(t much) wind/too much wind and scrapping.
- It is unlimited
I think there are many limitations like for example the intermittency, locations with enough wind and in a place where they don’t hinder for example human habitation, tourism, shipping traffic. Also, the airflow behind a windmill affects the next windmils. You can not just build an unlimited amount of windmills. Denmark has its seas, but for example Belgium has is very densely populated and has a very tiny coastline of about 70 km.
- It is the same as other (fossil fuel) energy sources
The “enough for x number of families” claim implies that the wind energy is basically the same as conventional energy sources. In a way that is true of course. Nobody can distinguish the electricity produced by wind or by fossil fuels. But the big difference is that wind energy is intermittent. Fossil fuel energy sources have a reliable output, while the output of wind energy is erratic. It is non dispatchable, it is in no way connected with actual consumption patterns, but depends on how much the wind is blowing. There is no guarantee that wind is blowing more at peak consumption or less at low consumption. Other sources have to fill in the gaps which uses them in a less than optimal way and makes them less economical.
- It is the future
That might well be true, but only if we come up with a solution for the intermittency. If we can store the energy that is produced at moments that we don’t need it and can bring it back online when we need it, then I think wind energy is viable. But the end result will be that it will be incredible expensive it we take all this into account.
But then, Denmark can get away with it. It is lucky with big neighbors like Norway and Sweden, that can absorb an over- or underproduction. In 2013, total load in Sweden was 137.5 TWh, in Norway it was 128.1 TWh and 34.0 TWh for Denmark. So compensating for that 34% of Denmark production would not be a big problem. There are also other measures been taken by the Danish.
If there is a lesson here, it is that you can’t just add an intermittent energy source into a continuous working grid without good backup or measure to support this. What if Denmark was not connected to two big grids, but to a grid that is increasingly turning to the same energy source? How representative is Denmark for most other countries?
That is the problem I have with such a one-sided view on wind and solar. If only the bright side is looked at and the dark side ignored, how could we expect engineers to find solutions for something that is not even acknowledged? How could we expect politicians to take well-grounded decisions in integrating alternative power sources into our society, if they ignore that there are issues involved that need be looked at? How could we expect scientists to look for better alternatives when we think we already have the ideal power source?