There are people who go from one extreme to the other. Take, for example, the Utrecht-based entrepreneur Henk Arntz. In 2010 the former mechanical engineering student at the Technical University of Eindhoven (TU / e) developed a snow compressor at the University of Brabant. After graduating, he marketed his invention through the spin-off Snocom. Now, a few years later, he's focused on the completely opposite side of the spectrum with Suncom Energy. Solar energy at a competitive price.
The technology used is nothing new. The scale is new. Thanks to an ingenious idea by Arntz, the solar power plant can be made much smaller and cheaper. This makes it particularly attractive for use in countries with a lot of sunlight.
Arntz laughs briefly. “Yes, this snow compressor was really something. We developed it in the Finnish Arctic Circle and in the Swiss Alps. I then sold one to Schiphol Airport. And a year later I sold more machines to the airports of Paris and Helsinki. Then after 6 busy years I had to take a break. “
Now his attention is focused on his new company, Suncom Energy. This solar power plant works on the principle of concentrating solar energy (CSP). The best example of this type of solar power plant is the Gemasolar CSP power plant in southern Spain.
“It's exactly what little kids do with a magnifying glass. They focus the sunlight to set something on fire, ”explains Arntz. The same thing happens with a CSP generator. There are four different techniques: towers, parables, plates and dishes. The variant that I am developing works with parabolic mirrors. long parabolic discs arranged in rows in the desert. “
This principle has been around for at least a century. The sunlight reflected by the mirrors heats a liquid that flows through a pipe. It could be oil, but it could also be molten salt. The advantage of the latter medium is that your steam turbine is much more efficient, which you ultimately use to generate electricity.
“The nice thing about molten salt is that it's just incredibly cheap. The storage costs are only a fraction of the costs of storing electricity in lithium batteries. And you also have the residual product, heat, which can be used for all kinds of process purposes. The great thing is that you only generate electricity when you actually need it. So you have created a heat store. “
Competitive with fossil fuels
According to Arntz, the cost of electricity, including storage, is lower than a range of solar panels with lithium batteries. “It's also competitive with fossil fuels when it comes to generating electricity. IRENA, the International Renewable Energy Agency, has published a report confirming this. We're talking about facilities in sunny areas like Texas, southern Spain, Australia. In short, all sunny areas; and that's well over half the world. “
There is one problem, however. To achieve this level of profitability, the size of these plants must be enormous. This also includes investments in the billions. Another problem is limited network capacity. You can't add an infinite amount of electricity to the grid. Solutions for this network congestion cannot be found quickly. In addition, the place where people need energy storage is in and around cities and not in the middle of the desert.
Two major changes
“If you have a small ‘plant' that is close to energy consumers or even on the user's property, you no longer have this problem. My goal is to reduce this technology to the dimensions of a soccer field. And basically I succeeded. I made a setting on the receiver. Concentrate the sunlight on this pipe. This resulted in two major modifications to the system that suddenly made it profitable. Use the same specifications. I am currently developing this with my colleague Wout Gubbels, who was also involved in the Snocom spin-off of TU / e. We have now built a pilot plant in Italy to demonstrate this profitability. “
I would like to explain it to you. But not yet! “Henk Arntz, CEO of Suncom Energy
However, downsizing is easier said than done. As the mirrors get smaller, the tube that needs to be heated also needs to get thinner to get the same effect. “The pipe then becomes as thin as a straw. In this case the installation costs more energy than it generates. So the concept no longer works. However, we have found a solution to this problem using very cheap materials. This ultimately makes the small scale viable. I am happy to explain to you exactly what I have been doing in about a year. But not yet! “Arntz laughs. “Because once you know, you think – it's so easy!”
That means that even Arntz's plant has a certain natural basic size. The minimum dimensions depend on the equipment you will ultimately use. The steam turbine required to generate electricity, for example, easily takes up half a football pitch. There are smaller turbines, but they tend to be more expensive per kilowatt. Which inevitably comes at the expense of profitability.
Suncom's potential customers are often on tropical islands, where power consumption is already somewhat higher. “It's about parties that produce mostly fresh water. These are parties that work in hot areas where there is not much water and who need a lot of electricity to produce fresh water, which is often very expensive there. And they also like to use heat in their processes. So I can offer both with my system. “
“If you calculate how much energy it costs to build an installation with solar panels and store it in lithium batteries, the payback period is around 9 years. This is mainly due to the energy you need for silicon and lithium. It takes about a year for my setup. You can extract the salt you need from nature. But that is certainly not infinite either, which is why it is better to use synthetic salt. It's much more environmentally friendly than just using lithium in everything. This is much better suited for use in mobile applications like transportation. “
Cover photo: The parabolic mirror of the solar power plant developed by Arntz. Photo (c) Suncom Energy.
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