With the rise of renewable energy technologies that produce power in the form of direct current (DC) – which can be used directly by industrial machines – plant-internal DC grids can play a key role in decarbonizing industrial production. This is especially true for energy-intensive steel plants.

In an energy industry that has long relied on large coal and nuclear power plants as electricity suppliers, public power grids are mainly AC grids. For use by consumers in industrial grids, alternating current from these grids must first be converted into direct current. This process offers just few opportunities for energy recovery. That is why plant-internal DC microgrids are met with great interest in the steel industry.

An energy-efficient plant infrastructure from a single source

The expansion of renewable energies, however, requires greater flexibility of the power supply system. The need for constant balancing of supply and demand for a secure power supply leads to a greater use of electricity storage when the share of wind and solar energy increases. Both short-term storage and long-term storage are absolutely essential for intelligent load management, e.g. to be able to handle peak loads. In particular where the load clearly exceeds the infeed from renewable energies or, vice versa, the infeed from renewable energies temporarily exceeds the load, shifts as well as switch-overs of non-critical power applications must be managed.

SMS group’s DC ECO GRID is able to connect all metallurgical plant units to an economical power grid. It comprises a central connection to the public AC grid, to the respectively available renewable energy sources, such as solar or wind energy, as well as energy storage units such as battery storage systems.

Green energy supply for plants in the metals industry with DC ECO GRID from SMS group
As a systems supplier and system integrator of large-scale steel production plants, we combine all electrical consumers and power producers. Our DC ECO GRID connects them to hybrid power distribution grids, AC & DC, thus improving the plant’s energy efficiency. It is the link between a green metals industry and new green energy supply systems. Combined with energy management consulting, business case definition and concept development as well as solution design and system integration, we provide an integrated solution – from a single source.

Key features at a glance

  • Cost advantages
    In the future, DC ECO GRID will connect large consumers in modern steelmaking plants, such as electric arc furnaces, rolling mills and strip processing lines, to the public power grid. With a plant-internal DC grid, production units can be connected to new hydrogen electrolysis units, powerful battery storage units and renewable energies. The connection is made via state-of-the-art power electronic rectifiers and inverters, which are connected to the DC grid. For example, frequency converters no longer require the rectifier components needed in an AC grid. In this way, savings are obtained as the infeed units can be omitted in the case of direct infeed from a DC grid. This also reduces the cost of cabling.
  • Reliability of production facilities
    The reliability of the entire production line or individual production areas can be increased by integrating battery storage units and local power generation plants into the production facilities’ power supply. In this way, production downtimes due to disturbances in the power grid are prevented. Supported by intelligent energy management systems, the production process can be optimized in terms of energy consumption.
  • The path to green steel production
    Today, conventional metallurgical plants are usually supplied with different voltage levels via three-phase AC grids. Electrical losses due to the apparent power and high investments in flicker compensation and adaptation of the power factor are accompanied by a large space requirement for such plants. The owners of such plants rarely use renewable energies.
    Since fewer rectifier components are required, DC ECO GRID allows for large energy savings. Unlike AC grids, in which the braking energy of the machines often goes to waste in the form of heat, DC grids allow for the energy to be recuperated and fed back into the grid. With renewable energy sources and energy storage units connected directly to the DC ECO GRID, the plant is not only more flexible and independent of overall variations or power outages that might occur in the public grid, but also relies on CO2-neutral resources for green steel production.

Know-how from SMS group for green power supply

As a systems integrator and supplier of large-scale metallurgical plants, SMS group can help to combine all consumers and power generators in order to operate distribution grids as DC ECO GRID or as a hybrid mix. These microgrids can be completely or partly converted into DC grids both for new plants and for modernization projects.

Major advantages

  • Higher energy and resource efficiency due to combination of power electronic as well as improved grid stability in the entirety of metallurgical plants connected to the DC ECO GRID bus technology
  • Improvement of energy efficiency thanks to lower conversion and transport losses, energy recovery, direct use of renewable energy sources and the handling of load peaks by means of storage systems
  • Reduction of copper use for cables and bus bars
  • Better resource efficiency due to lower equipment costs and less space requirements as, among other things, additional investments for adaptation of the power factor and flicker compensation are not required.
  • Connection of new plants to existing weak grids supported with the possibility of integrating battery storage and energy recovery systems to prevent production downtimes due to disturbances in the power grid
  • Control of the energy flows and optimization energy procurement costs as a result of an intelligent energy management system
SMS group is leading the way when it comes to Green Metals. We have made it our mission to achieve future-oriented green steel production and processing. With the numerous advantages of our DC ECO GRID, we motivate a change in systems and a shift of awareness in the energy supply of metallurgical plants.