Electric steel moves
Demand for electrical energy is constantly growing. According to the latest forecast from British energy group BP, demand increases by 1.4 percent each year. By that estimate, the world will use roughly one third more energy than today in 2035. The World Energy Council predicts that by 2060 demand for electricity will even be double what it is today.
And renewable energy sources are expected to meet a majority of the rising demand. This is necessary, on the one hand, because fossil fuel supplies are finite. On the other hand, the use of oil, coal, and gas accelerate climate change, thereby making it absolutely essential to phase out conventional methods for generating energy.
Electrical steel from thyssenkrupp supports the energy revolution. The steel alloy contains iron and silicon and determines the efficiency level of generators, transformers, and motors, which should be as high as possible, as well as their energy loss, which should be as low as possible. Energy should be used efficiently, whether generated by a factory or a windturbine. “Wherever energy efficiency is required, you’ll find electrical steel from thyssenkrupp inside,” says Simon Stephan, Head of Sales Automotive, which is responsible for marketing non-oriented electrical steel in the company. His colleague Georgios Giovanakis , CEO of the Electrical Steel business unit, adds, “As legislators impose stricter standards, the requirements placed on our materials increase and the materials have to get even better.”
The two experts from thyssenkrupp are working with their teams from the Steel division in close cooperation with their customers to improve their products even further. And that includes products used in generating renewable energy, a sector in which a new generation of non-oriented electrical steels play an important role, for example, in state-of-the-art generators contained in hydropower plants and wind turbines.
The soft magnetic steel concentrates and amplifies the magnetic flux inside the generators, which allows the mechanical rotational energy generated by the turbines to be transformed into electrical current without significant losses. “The performance of the generators and the efficiency of the plants is largely determined by the material properties of the electrical steel,” says Stephan.
Transformers regulate voltage
Georgios Giovanakis continues: “In order to transport the electricity generated by the plants across large distances, it has to be raised to a higher voltage than it had when it was generated.”
This is a job for transformers, which have grain-oriented steel built into them. “Electricity is transported at voltages of up to a thousand times higher than those found in a household electrical socket. Before the electricity can be used, the voltage has to be reduced, and transformers are required for that, too.”
A major challenge for the Electrical Steel business unit and its grain-oriented electrical steel is that it has to fulfill the European Union’s Ecodesign Directive. Among other provisions, the Directive specifies which energy efficiency requirements have to be met by power transformers, distribution transformers, and generator transformers.
The first phase went into effect in July 2015. The requirements stipulated for transformer efficiency will become increasingly strict over time to ensure that the amount of energy lost during transport continues to decrease. “Half of Denmark’s annual consumption: That’s how much energy could be saved by Europe’s transformers alone by the time the second phase of the Ecodesign Directive is implemented in 2021,” says Giovanakis .
New high-grade varieties reduce noise levels
In Germany alone, the loss rate is still between two and three percent. “In the future, an even broader portfolio of electrical steel grades will be required if the goals are to be met. We are well-positioned today where the most important grades are concerned, and we’re supporting development with grain-oriented products of exceptionally high quality.”
It takes an enormous amount of technological expertise to produce grain-oriented electrical steel, and Electrical Steel has it in spades. Over the past 20 years, this business unit of thyssenkrupp’s Steel division has increased the energy efficiency of electrical steel by nearly 40 percent, and counting.
The top varieties are capable of reducing not only energy consumption, but also noise levels. “The electrical steel has been optimized down to a thickness of only 0.18 mm and makes transformers quieter,” says Giovanakis . “This is partly thanks to highly successful cooperation with our customers, who value the fact that we combine innovative product development with a high level of expertise in dealing with materials.”
Improved magnetic properties
The Energy Efficiency Act has much the same effect on non-oriented electrical steel from the Automotive business unit as the Ecodesign Directive has on grain-oriented electrical steel. Manufacturers of motors for industrial drives have to maintain a certain level of efficiency depending on drive classification. Household appliances, too, offer opportunities for savings.
PP grades come into play here; after stamping, the stamped parts are annealed, thereby removing the effects of processing and further improving the properties of the material. “They exhibit high magnetic conductivity with extremely low loses,” says Stephan. For no matter how perfect and highly efficient a grade of electrical steel may be, each mechanical influence on the material influences its magnetic properties in turn.
Furthermore, highly efficient electrical steel is an indispensable part of electromobility both now and in the future. “There is no electromobility without steel. Electrical steel is absolutely essential to the manufacture of e-motors,” says Stephan. For that reason, thyssenkrupp also offers high-strength types of electrical steel that make it possible to build drive motors capable of high rpms. Thanks to their improved magnetic properties, they make motors more efficient, thereby increasing the range of the vehicles. “And that is one of the main features that will lead to broader acceptance of electrical cars,” says Stephan.
Non-oriented grades of electrical steel designed for use in vehicle motors are tested in a thyssenkrupp e-mobility center built especially for that purpose. “We are testing how the product performs at various processing stages in the final application. This is important, because an electric motor designed to be used in a car has to meet a different set of requirements than an industrial motor,” says Head of Sales Automotive Stephan. It has to perform very different tasks, from driving on the highway at a constant speed to driving up a hill or suddenly accelerating when passing another car in stop-and-go traffic in a congested city.
Thanks to its long tradition and high level of technical expertise, the Automotive business unit cooperates intensively with every German automobile manufacturers. There is a lot happening in the areas of motors, electronics, batteries, and lightweight construction.
For years, the Steel division of thyssenkrupp has supported a variety of projects, for example, the StreetScooter project for Deutsche Post, where it primarily works to facilitate affordable lightweight steel construction and to ensure that e-car batteries are installed in the most crash-proof position. “The question is not whether electromobility can or should be implemented, but when,” says Stephan. “The market is still reacting cautiously, but the dynamic is recognizable. And we’re ready.”
The speed at which things will be done depends on the legal environment, the budgets provided for investment and development, and the available infrastructure.
Intelligent distribution networks are needed
Issues such as vehicle range and charging station availability play an important role for consumers. As the number of charging stations increases, so does the number of feed points or distribution transformers that are needed. “It’s very simple,” says Giovanakis . “As the number of electricity consumers rises, the capacity for distribution has to be increased, regardless of what the electricity is being used for.”
Electromobility exacerbates this situation, because the distribution networks in Germany and Europe would currently be unable to handle it. “Intelligent energy distribution is an integral part of the energy revolution.” Intelligent distribution networks, or ‘smart grids’, are required.
Now is the time to start managing and offsetting fluctuating demand for electricity. This task will become even more complex in the future as the use of renewable, sporadically available energy continues to increase. A data network operating in parallel to the power grid is therefore needed to coordinate the generation, storage, and distribution of energy with the help of innovative transformer concepts.
“The demand is there,” says Giovanakis . “We are already capable of supplying the grain-oriented electrical steel that these smart transformers require.” In other words, the energy revolution would be impossible without thyssenkrupp.
