The more complex a system is, the easier it is to overlook the small building blocks that hold everything together.
If the energy system is to become sustainable, it is clear that nothing works without wind turbines, solar collectors and batteries.
But what makes a functioning system out of many small and large systems, one that communicates, controls, regulates and distributes, are primarily semiconductors.
Anna-Lena Niemann
Editor in business.
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The energy transition is turning a centrally controlled system, with large power plants in the heart that shoot their electricity to the edges via increasingly fine veins, into something completely different. Tens of small producers are spread across the map. They produce when the weather permits. Sometimes there is excess electricity that needs to be intelligently distributed via the grid and storage system. Sometimes too little so that storage tanks have to be tapped or electricity does not flow from the roof into the grid, but from the grid into the house. Peter Wawer says: “You have to be able to move the current sometimes in one direction and sometimes in the other. For that you need more power semiconductors per se. "
Wawer also provides the reason why the division, which he heads at Germany's largest chip manufacturer Infineon, should continue to gain in importance in the future. The power electronics for wind power and solar systems, trains or power storage systems that are produced here under the name of "Industrial Power Control" have little to do with the chips that world market leaders such as Intel manufacture for computers or cell phones. Wawer's semiconductors may not have to be five nanometers in size, but they do have to face other extremes. In a modern wind turbine, the 60 watts of a notebook plug are compared to a hundred thousand times the electrical power. They have to be switched, converted from AC to DC and back, to synchronize speeds or to balance the frequencies between the system and the power grid.The more efficiently it all happens, the better.
New materials are slowly finding their way out of the technical niche
“Among other things, wind and solar systems obtain an important part of the added value from semiconductors,” says the division head.
Conversely, for Infineon's account books this means: “For each megawatt, sales with power semiconductors are between 2,000 and 3,000 euros.” But if he believes there are good reasons why his customers should soon be spending significantly more on the important power electronics.
For more than half a century, semiconductors have been based on silicon. The circuits are applied layer by layer to the wafers, which are roughly the size of a vinyl record. The work steps are so detailed and numerous that it takes three months for a power semiconductor to be finished. However, the increasing complexity has paid off. Fifteen years ago, of the energy that went into the power supply on the left, only 85 percent came out on the other side. The rest evaporated as warmth. There is always a little loss, even today, says electrical engineer Wawer. But modern semiconductors are now able to achieve efficiencies of up to 99 percent. But because even with this efficiency a wind turbine with six megawatts still loses 60 kilowatts,As soon as the power semiconductors switch, industry shakes the base of the silicon. A new generation of wafers made of gallium nitride or silicon carbide is slowly finding its way out of the technical niche.
Producing wafers on the basis of these connections is more complex - and more expensive. About a factor of two, as Wawer says. The advantages of both materials are on the system side: "These new semiconductors can be operated at significantly higher frequencies because they have fewer losses per switching process," he says and goes on to explain: "If you operate them at higher frequencies - and now it's time to start." the intricacies of electrical engineering - you can design completely new circuits that were previously not possible. ”They can withstand higher temperatures, field strengths and voltages. The passive components of power electronics, such as coils or capacitors, could be smaller or disappear entirely. In a central converter that works in the megawatt range, they usually take up more space than the semiconductors themselves.
Does the semiconductor shortage also threaten the energy transition?
Even the smallest building block counts for the big picture of the energy transition.
Whether ten or not eleven megawatts can be extracted from a wind turbine thanks to more efficient power electronics is not irrelevant.
Just as little as the question of what it means for the design of the systems if the same performance can be obtained with a much smaller system.
Installation space is valuable.
For example, if the nacelle becomes lighter, you can save yourself some steel and concrete when building the wind turbine.
Both costs.
And is responsible for a large part of the ecological baggage that a wind turbine first has to compensate for over four to 14 months.
"The market is currently still comparatively small in the mid to high three-digit million dollar range," says Wawer when he talks about power semiconductors made from silicon carbide. “However, growth is rapid.” The current shortage of chips, which is paralyzing many areas of the global economy, also affects Infineon. Just recently, its CEO Reinhard Ploss said in an interview with the FAZ that the shortage that is causing car manufacturers' production lines to stand still and causing delivery bottlenecks for cell phones, computers and game consoles could continue into 2023. Wawer emphasizes that this does not pose a threat to the major energy transition project, which has to pick up speed significantly. Not even if the demand continues to rise. If not only generated more volatile,renewable energy needs to be controlled, but also smart grids, heat pumps and electric cars.