VESTOLIT: grid stability with chlorine electrolysis

The chemical company VESTOLIT operates the largest fully integrated PVC production facility in Europe. The installations for chlor-alkali electrolysis can be used flexibly only up to a certain level. VESTOLIT was therefore looking for an appropriate system to offer this flexible energy source on the market and increase additional revenue. Centrica Business Solutions approached the company and proposed a bespoke Demand Response solution.

Initially, the production department at VESTOLIT was sceptical about an external intervention in its own facilities. However, a similar Centrica Business Solutions system installed in Belgium convinced them of the benefits. In addition to demonstrating that the approach had no negative impact on production, it also provided a good example of Centrica Business Solutions' extensive experience in this field.

Another decisive factor was that Centrica Business Solutions is the only aggregator to commercialize the frequency containment reserve in a pool of different industrial customers, which enables it to respond to the individual power capacity of each installation.

Power capacity proven without problems

VESTOLIT was the first chemical company in Germany to choose Centrica Business Solutions' Demand Response solution within a company pool at the end of 2016. Despite a certain level of complexity, only six months were required from initial contact to full technical implementation.

The pre-qualification process proved slightly more complicated as it included elements new to the German market. VESTOLIT was nonetheless able to demonstrate to the operators of the transmission system that the plant can increase power from -3 to 3 MW, maintain this level, and reduce it again within 30 seconds. This represents the required power to be supplied consistently during subsequent operation.

Installation of control box

Centrica Business Solutions had to explain to VESTOLIT how it would integrate the system that regulates the commercialization of flexible energy into the plant. Centrica Business Solutions therefore investigated situations in which the operation of the automated control system would be limited or in which it could not be operated at all. Corresponding rules were then defined in the automation system to reflect such instances.

Finally, a small local control box was installed, connecting the intelligent control system to the controller at the facility. The reference value for electrolysis is changed in small increments every time the grid frequency deviates from 50 hertz.

No measurable additional wear

Another question mark for VESTOLIT was the level of wear on its installation. Normally, the factory runs at a constant load to minimize wear. VESTOLIT was concerned that the service life of the various components would be shortened by constant variations in the load. However, no extra wear has been found, despite the flexible approach.

Extra income

The commercialization of the frequency containment reserve has enabled VESTOLIT to post extra euro revenue in the range of six-digits, without the need for additional investments. Centrica Business Solutions only needed the facility itself and the VESTOLIT staff to implement a successful project.

As a large-scale consumer, VESTOLIT now contributes to the safe, stable and sustainable operation of the grid. This system service provision reduces the dependency on power plants, many of which burn fossil fuels, and thus contributes to the reduction of CO2 emissions. As a result, the Demand Response system also has a positive effect on the image of energy-intensive industrial companies.