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.