Rheinzink: grid stability with induction ovens

Zinc in induction ovens

Rheinzink is the market leader in the production of titanium zinc. The company has 670 employees in over 30 countries worldwide. Rheinzink specializes in accelerating the natural weathering of titanium zinc using a specific pickling process. This gives the basic material used in guttering, drainpipes and other construction components a distinctive blue-grey color. Fine zinc blocks with a purity of 99.995% are melted in five induction furnaces and then rolled to 0.5 to two millimeters thick, depending on individual requirements. As a large-scale industrial consumer of energy, Rheinzink was looking for a system to make the frequency containment reserve (FCR) available for grid stability. This was difficult because the ovens do not run continuously using the same power, meaning that the use of a permanent regulating power was not possible for pre-qualification.

Delivering energy together

Centrica Business Solutions established an initial reserve pool for large-scale industrial consumers in Germany. These companies usually have no opportunity to commercialize the frequency containment reserve, because they are unable to provide symmetrical supply. As part of the Demand Response solution, Centrica Business Solutions examined how and to what extent Rheinzink was able to make the frequency containment reserve available. In cooperation with other participants in the reserve pool, Centrica Business Solutions can now commercialize this capacity in bundled form. The frequency range is split within the frequency containment reserve of +/- 200 MHz. Algorithms manage this so that each installation delivers a certain amount of the needed capacity.

Central switching 

Rheinzink examined the extent to which the induction furnaces and their different configurations could be used for regulating capacity. To avoid additional network costs, the maximum power of 11.5 MW must not be exceeded. “The additional power is distributed across four of the five induction furnaces via a central switchboard,” says Wolfgang Beigel, Head of Maintenance, Rheinzink GmbH & Co. KG. A central power control system monitors take-up so that the defined maximum is not exceeded.

Results

“The reserve pool established by Centrica Business Solutions provided us with a solution. At Rheinzink, it was not possible for us to provide capacity on our own. This solution has made us flexible and allows us
to support grid stability,” says Beigel.

The frequency containment reserve is being used around 80 to 100 times a year, although this has gone unnoticed by the furnace workers over the last year and a half. The provider has autonomy over the installation at all times and also monitors the grid load management to rule out any risks. “We cannot afford any outages because this poses major problems for our production,” explains Beigel. “The implementation of the practical details and the cooperation with Centrica Business Solutions have been very good.” With 2 MW of power, Rheinzink can participate in the reserve pool, support grid stability and generate income without higher network costs.