Large graphite furnaces are playing a key role in a joint pilot project undertaken by Lechwerke (LEW) and SGL Group. Part of the energy-intensive production of graphite components at the SGL site in Meitingen can be flexibly controlled and so used to stabilize the power grid. This “responsive power demand” is offered by Lechwerke as a service for SGL Group: LEW places the available flexibility daily on an auction platform. This so-called minute reserve is used to balance possible oversupply of power in the grids. The operators of the national power transmission grids compensate the suppliers for the provision of these capacities. Franz Josef Pschierer, state secretary in the Bavarian Ministry of Economic Affairs, visited the SGL Group site today to find out about the pilot project and the FOREnergy research alliance project.
“We want to switch our energy system to one based on renewable energies. This involves fundamental changes. In order to do this, we must question established structures and processes and adopt new approaches,” said state secretary Franz Josef Pschierer on his visit to Meitingen. “The project here in Meitingen is an example of how companies are tackling the challenges of the energy revolution and developing them into models for the future.”
At the Meitingen site, SGL Group produces connecting pins for graphite electrodes used in electrosteel recycling. To withstand the high temperatures in the electric arc furnace, electrodes and connecting pins must be graphitized at about 3000°C. This takes between half a day and a week. However, the period during which energy-intensive heating of the furnaces is carried out can be shifted within a certain time window. SGL Group now exploits this flexibility in cooperation with Lechwerke.
“Previously, electricity generation in power stations was driven primarily by consumption. This is going to change: in future, substantial amounts of electricity will be available from photovoltaic and wind power stations when weather conditions are favorable for generation. For this reason, we should use every opportunity to organize consumption more flexibly. This is important for our energy supply of the future based on renewable resources. In the project with SGL Group, we are putting into practice the idea of an energy-flexible factory,” said LEW Board Member, Norbert Schürmann.
“This is opening up interesting prospects for us,” said Dr Thomas Müller, Director Energy Purchasing Europe for SGL Group. “It’s no longer just a question of finding the most favorable time to purchase power from the markets but is also about marketing the flexibility of production profitably. In the energy system of the future, the traditional roles of energy supplier and energy consumer will change. Both will also contribute in future to stabilizing our power grids.” After successfully launching the project at the Meitingen site, SGL Group has now introduced the model at the Griesheim site and is currently examining whether other sites and production processes could also be suitable candidates for the model.
The “responsive power demand” of SGL Group’s graphite furnaces is marketed by the Lechwerke purchasing team. The specialists offer the flexible demand capacities on the nation-wide auction held by the power grid operators for the minute reserve. Here, in daily bid invitations, the four large German transmission grid operators award reserve capacities for the following day. The winning bidders undertake to hold in readiness the minute reserve they offered within a specified time window of four hours. In addition, they must be able to activate the reserve within 15 minutes when requested by the grid operator. “In a qualification procedure we had to verify that the technology functioned reliably and that production processes were really being deferred,” reported Thomas Reitemann, LEW Purchasing Director. “Only after this successful pre-qualification, were we able to market the reserve capacities on the platform.”
Planning and implementation of this pilot project are the result of cooperation between SGL Group and LEW in the collaborative FOREnergy project. The aim of this innovative cooperation between scientists and industrial companies is to realize the idea of an energy-flexible factory in practice. The Free State of Bavaria is funding this joint project to the tune of 2 million euros through the Bavarian Research Foundation (Bayerische Forschungsstiftung).
Lechwerke has been taking part in the auctions for so-called control energy since 2007. Its reserve pool includes flexible capacities for both power demand and power supply. In its cooperation with SGL Group, Lechwerke has now extended this service to industrial processes as well.