Things I took for granted: when the blades of a windmill turn, it is saving fossil fuel somewhere else

In a strange way I do like windmills. They look majestic and the slow turning of the blades had something meditative. There also is that part of When the blades are turning, it is producing energy and therefor saving fossil fuels somewhere else. It is a nice thought, but is it also true? I didn’t gave it much thought until I experienced something that made me think.

Just before the Millennium I bought a house and renovated it, As someone green at heart I wanted some green technology in it. I thought a solar panel would be nice. When asking around I heard that solar panels that produce electricity were not efficient yet. I was advised to take a solar panel that heats water in a boiler. The principle was really straight forward. The sun heats the water that goes in that boiler. If I need warm water and the water isn’t warm enough, the central heating system would heat it up in stead. If the water was warm enough I had actually water heated by the sun. Simple as that.

It looked promising. Even when there wasn’t that much of sunlight the indicator light on the sun boiler was lighting up. My water was heated by the sun and it saved the gas that otherwise was needed to heat that same water. Nice, it worked!

But there were some problems too. The central heating system didn’t work that well. It took a looong time before the room was warm. This was a new system, so I feared that the capacity of the central heating system was not well calculated and my system was underpowered. Not really threatening, but quite an inconvenience. Probably my own mistake. What goes around comes around.

Other things made me think also. One summer I powered off my central heating. My assumption was that I only used warm water in summer. That shouldn’t be a problem when sun was shining. So no need for a central heating system for heating water. The sun boiler should be enough. That didn’t go well. Although the indicator light was on most of the time (and water was being heated) the water that came out of the system was only lukewarm.

Forward somewhat later. I heard strange noises in the solar system and I unplugged it. But this had quite some consequences. When I put on the heating, the room heated up in a jiffy … the system was not underpowered after all. It worked just fine. The problem seemed to be the solar installation or the link between the solar installation with the central heating system.

But if the central heating had problems to heat the room, then it was running longer, so needing more gas. Was this really true? To try this out I left the solar system off for a longer period. Then came the winter. The central heating wasn’t struggling, indeed less gas was needed to come to the desired room temperature and the room warmed up much faster than before.

I don’t know why the installation was faulty. Maybe there was a fault in production. Or it wasn’t properly installed. Or it didn’t work well with my central heating system. Or I couldn’t expect more from this early generation solar installation. Or my consumption pattern of warm water wasn’t compatible with the system. Or whatever.

The point I want to make is: when the alternative energy source is only a tiny portion of the total energy produced, it is really difficult to know if you are saving energy or not. I didn’t notice that it took more energy than it produced. My thought was that I was saving gas because the indicator light was on, but that was clearly not the case.

The same when generating electricity with wind/solar. Can we be sure that when the blades of a windmill are turning energy is saved somewhere? Wind energy as well as solar energy are intermittent and used in a system that needs a constant power production. This means the production of electricity will depend on the wind or the sun, not on our consumption. We can not trust wind and/or solar to produce energy when it is needed, so backup power needs to be provided. Which is using (fossil) fuel. But with only a few percent of solar and wind in the energy mix, nobody will ever notice if we are either saving fossil fuels, breaking even or using more of it in the process.

6 thoughts on “Things I took for granted: when the blades of a windmill turn, it is saving fossil fuel somewhere else

  1. eSell

    Nice post…sorry I’ve been away for a while–Real Life and all that. I’ve been seeing that you are writing up a storm!

    I would think there is a way to know. I’m sure there are stats on that kind of thing somewhere. Whether a person trusts the source of the numbers showing that energy is/is not being saved is a different issue. I’m inclined to believe that they DO save fossil/nuclear fuel somewhere else, but I haven’t looked at any numbers to prove it.

    Your water boiler and heating system sound strange. I have not heard of the water heating and the central heat being part of the same system. But that kind of thing isn’t my expert area so maybe I wouldn’t have. In Arizona, part of the desert in the US, that kind of roof-top water heater works very well. But, of course, it is almost always sunny and easily reaches 40-45C in the summer.

    Now, one thing I have HEARD, but have not verified, is that it takes more Carbon to make a giant wind turbine than is saved through the lifetime of the turbine–if the windmill really saves as much power as they say, it would still take the entire productive life of the windmill to offset the carbon footprint of its production. But I don’t know.


    1. trustyetverify Post author

      Welcome back eSell. Thanks for the compliment. Since September I got into a rhythm, this post is already number 70…

      I have seen stats of electricity production in other countries. Probably Belgium has them also. I don’t know how those could show how much fossil fuel was saved, unless the fossil fuel use numbers are also gathered somewhere.

      There were some attempts to calculate how much carbon dioxide could be saved (which is connected with the saving of fossil fuels). This is the reason why wind/solar are being used. It was done by mathematical modeling, so the result will be dependent on the assumptions that were or weren’t taken into account. A Belgian study said the carbon dioxide reduction from using wind energy would be maximum 4% in the best case scenario. Engineers from The Netherlands had less trust and calculated it was possible to have even more emissions than supposed will be produced (because of the suboptimal working of the back-up turbine).

      Problem with wind and solar is that these are intermittent sources. The production is depending on the availability of wind and sun, not on the demand. Therefor it is less reliable than fossil fuel. Plus the most power is needed in winter when wind as well as solar is at its minimum. Therefor it needs a backup plant running stand-by (which is using fossil fuel).

      This is the reasoning: integrating intermittent energy sources in a power grid has consequences: just adding intermittent power to an existing grid is just producing extra power above what is already there, so no saving of fossil fuel. When we want a reduction, this means we need to power off some fossil fuel turbines at the same time, otherwise there will be no reduction in fossil fuel use. But then what to do in case of a sudden peak and there is no wind or not much wind?

      So the problem is double: if no existing fossil fuel turbines are powered off, there is no gain in the form of a decrease in fossil fuel use, just adding extra power to the grid (hopefully not too much – electricity can not be stored in large quantities). And if a fossil fuel turbine is powered off there is a need for a system that can provide energy when energy production of renewables is lower than expected. In Belgium we only have a peak shaver with a very limited capacity (the shaver works for the complete grid, not only for the renewables) and we came several time to the brink of a brown/blackout in the last years.

      Belgium has an additional problem. Power plants were neglected in the past. No new plants were build and the current plants are rather old. And because the oversubsidizing of wind/solar, there was no money for investments in modern CCTG (gas) plants that could better function as backup than the older coal or gas plants.

      Does wind/solar save fossil fuel? I have not have exact figures either, but when I look at the reasoning above I really doubt it will be much. What I do know is that it is not the 100% the producers and providers say it is.


      1. jerrygraf

        I do not know of any specific reliable information regarding the amount of “carbon emissions” required to make a wind turbine, or the amount of energy required to make a wind turbine; as opposed to other forms of energy generation. What I do know is that it generally costs more to manufacture, install, operate, and maintain a wind turbine than the cost (value) of the electricity it can produce throughout its life. You can see various examples demonstrating this on my site.

        So, why does it cost more to make and install a wind turbine? One way to look at this is that cost is a basic measure of the effort (energy) required to make the wind turbine. It is reasonable to conclude that wind turbines cost more than they can produce because they take more effort/energy to manufacture and install than they can generate. Their energy return on investment (EROI) is very low, or even negative.


      2. eSell

        From my UNinformed personal view, I would say that having wind/solar on a Personal level would be more useful. In the States it is often the case that if you add solar to your house, you’re hooked into the grid in such a way that any over-production from YOU is sold back to the power company–so during the summer, especially, when you are running air conditioning (as everyone in the US does), you could almost be running for free!

        As for the over-supply of electricity on the grid in general, I thought that was all closely monitored and that production at the plant could be ramped up or down in Real Time; so, if everyone in Brussels had solar on their roof, and it is summer, and 3/4 of the electricity for the grid is being produced locally by each house, then the gas turbines at the plant can be turned down to Idle. If it gets cloudy, or sunset is coming and demand comes up, then they just turn the turbines up to normal operating speed. In that way it would save fossil fuel.

        Yes, solar/wind is intermittent and cannot replace reliable fossil fuel / nuclear, but it could be a start if done well.


      3. trustyetverify Post author

        eSell and Jerry, thanks for passing by and commenting.

        The question of eSell is a very good question indeed. I think we are mixing 3 different issues:

        • Is fuel being saved?
          That is anyone’s guess. First, there will always be a backup needed. If this is taken into account this will mean less fuel saved than producers/providers/media let us believe. Secondly, is this dependent on whether fuel needed for production, transport, installation and maintenance counted or not.

          • When wind/solar is plugged into the grid and nothing else is done, there is no fuel saved at all. If all needed fuel is counted, the saving would surely be negative.
          • The better they are integrated in the grid, the more chance of saving fuel.
          • When new investments were not done because the subsidizing of wind/solar makes new (more efficient) plants uneconomic and efficient power sources are partly disabled, then I fear the worst…

          But whatever is the case, with a that small portion of renewables in the mix in Belgium, would we even notice it? That was the spirit of the post.

        • Is less CO2 being emitted?
          This is connected with the previous point, but also CO2 emissions by production, transport, installation and maintenance is included. I saw a low number and some even think it is negative (more CO2 used than prevented).
        • Is it cheaper?
          It is definitely more expensive, therefor in need of subsidies.

        The example of the cheap summer price is in the last league. In the simple panel/consumer model the panel owner seem to have all the fun here. He will get his money for his excess energy, whether the netmanager was able to use it or not (electricity can not be stored).

        But the cheap energy for the panel owner has also be seen in a wider context. Solar energy is incredibly expensive (far the most expensive over other sources). A big part of it is paid by the government via f.e. subsidies, tax reductions for investors and so on and by the netmanager. So, the panel owner will also have to pay for these via taxes (as a taxpayer) and higher prices (as a consumer within the grid). So what he gained on one hand will be compensated with other costs that he would not had to pay if solar was not promoted. To give an idea: Flanders (about half the area of Belgium) pays more than 1 billion euro per year on subsidies for onshore wind, solar and biomass alone (and is increasing). For a small number of inhabitants that is huge, someone has to pay for it.

        Our grid is monitored, yes, but that doesn’t mean real time powering up/down of gas plants is possible. In Belgium our current power plants are outdated and not in line with modern standards anymore. New investments were not done because of the subsidizing of wind/solar, making fast cycling gas plants uneconomic. Ironically, those plants could compensate for the intermittent nature of wind/solar much better than the current old power plants (which can not do this in real time, therefor a near blackout so now and then). Maybe other countries can do it, but as far as I know we don’t have that ability (yet).


  2. eSell

    No upgrades to make the gas plants fast cycling…that would be a problem. Yeah, if they aren’t capable of that, then they would not be able to respond efficiently to the intermittent Green production, which makes that Green production nearly useless.

    You can store electricity…in batteries…but, of course, for a Grid, that would require a stupidly huge amount of very large batteries. What we really need is a breakthrough/revolution in battery technology.

    No, I was not counting in the “saving of fossil fuels” the costs in fuel for installing/transporting/etc the wind turbines. If they are as mechanically unreliable as an older post of yours was saying, then that would be a major consideration.



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