Wednesday, January 5, 2022
Global efforts to protect the climate show how complex the challenges of saving our climate are and how multi-layered the political and social discussions are in this regard. In science and technology, the solution is less controversial: We need energy to live today. Electricity is our most flexible form of energy. It can be easily converted and therefore used everywhere. To achieve this, we essentially need to replace climate-damaging power generation based on fossil fuels with solar and wind power. Semiconductors play a key role in this process.
Anyone who has ever been sailing in a light breeze knows the feeling of gliding almost silently over the water, without exhaust fumes, in the fresh air—it’s a fascinating feeling. You are moving in harmony with nature, using natural forces to get around. CO2-free.
We have more than enough energy on our planet, and not only for sailing. The sun provides us with more than enough light and heat, and as a consequence it also provides wind. We don’t have to worry about a lack of energy. What matters is how we convert energy so that we can use it. With sails, this has worked very well for a few millennia, albeit with a limited scope of utility. Windmills are far more flexible. They have been powering many tools and machines for thousands of years. And modern windmills convert wind most efficiently into our most flexible form of energy, electricity. The technical progress of the past decades and the increasing demand for green electricity have long since made wind energy competitive. The situation is even better for solar power. Photovoltaics has established itself in widespread use and is economically attractive, all the more so given the comparatively high electricity prices in Germany.
Of course, wind turbine design and solar cell construction have played a very large role in increasing efficiency. And the progress made possible by microelectronics is decisive: without conversion conversion of direct current from solar cells and alternating current from wind power as well as adapting to the requirements of our power grids are all prerequisites for the contributions of sunlight and wind to our power supply. This contribution requires semiconductors that turn direct current into alternating current and adjust the frequency of the alternating current. But with every conversion, some of the energy is lost as heat. The same is true for electricity generation and electricity use. Anyone who has ever held the power supply of a switched-on notebook in their hand knows this. Modern semiconductors make sure that these heat losses are reduced. Whereas perhaps 20 years ago people were satisfied if a power supply unit operated with an efficiency of 85 percent, today we can achieve efficiency levels of up to 99 percent with modern microchips. That’s tremendous progress. Semiconductors for power conversion in solar and wind power systems have made similar efficiency gains possible.
But we need more progress: Our world’s hunger for energy is great, and it’s getting greater. For many decades, petroleum consumption was seen as a measure of economic growth. This was accompanied by an ever-increasing burden on our climate. We can no longer afford this, nor do we want to. Electricity generated from renewable sources and produced in a climate-neutral manner should and must replace fossil fuels. The special challenge: Green power generation will not only have to replace the share of climate-damaging energy sources, it will also have to enable continued growth. And it will have to do so on a global scale, because people everywhere in the world should have the opportunity to strive for a life of prosperity.
That’s why it’s so important to increase efficiency in everything from power generation to power transmission and power consumption. Every additional percentage point we can achieve counts.
I am very confident that we will make further progress here. New semiconductor materials, for example, represent a major and important advance. Silicon carbide and gallium nitride have now made it from research to practical application, enabling a major leap in efficiency of up to 50 percent. These new materials allow higher currents than traditional silicon semiconductors, they reduce heat loss and enable faster switching. This makes them predestined for our increasingly complex supply of power. The new materials reduce energy requirements in generation and consumption as well as in power grids with different network and voltage levels. The structure of these new materials is becoming more and more complicated. Whereas a few decades ago an economy like that of the Federal Republic of Germany had a reasonably manageable number of large power plants that were comparatively easy to coordinate in order to ensure a reliable supply of electricity, today millions of small power generators have to be coordinated. Even the direction in which electricity flows is no longer as simple and unambiguous as it once was: Many consumers have also become electricity producers. Sometimes they need electricity from the grid, sometimes they use the electricity generated in the solar array on the roof themselves, and other times they feed the electricity into the public grid.
Semiconductors are used at every point in the conversion of power. The new materials not only increase efficiency, they also enable new designs at the switching points of our power supply. They eliminate the need for many passive components such as capacitors and coils. This allows for smaller control units, which in turn helps make wind turbine generators, for example, smaller and simpler – which also contributes to greater efficiency and lower costs. Smaller designs also make it easier to bring high-efficiency power conversion to applications in mobility. So, not least in electric mobility, we are benefiting from advances in material sciences and semiconductor technology.
We will enable further progress because our intellect and curiosity continue to drive research, development and innovation. They fuel progress and carry it further into the future, into a CO2-balanced world that supplies us humans with sufficient energy even in a highly engineered environment and allows us to advance and live sustainably in harmony with our earth.
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