Editorial - VGB PowerTech Journal 6/2015
GKM unit 9 – One of the most modern and most efficient hard coal-fired units worldwide
In May Grosskraftwerk Mannheim AG commissioned unit 9 – one of the most modern and most efficient coal-fired power plants in the world – and at the same time we celebrated another important milestone in more than 90 years of our company´s history. 10 years after planning and 6 years after construction, unit 9 sets new standards for hard coal firing with its output of 911 MW, district heating extraction of 500 MW, electrical efficiency of 46 % and fuel utilisation of 70 %. Being a highly efficient combined cycle power plant, unit 9 is making an important contribution to achieving the cogeneration target of the German Government and the climate and environmental protection policy with annual possible CO2 emission savings of up to 1.3 million tonnes. After old units and plants had been shut down simultaneously, GKM has now a total installed capacity of some 2,150 MW making it the largest power plant site in the German federal state of Baden-Württemberg. At the same time GKM is the only power plant that can feed in power in two control zones at different voltage levels.
It goes without saying that a new build power plant project of this magnitude involves a large number of small and also huge challenges. This issue of VGB PowerTech is devoted to the most important technical and safety related aspects as well as communicative problems which we would like to introduce to you in different papers.
In parallel to the construction of unit 9, the challenges of the “Energiewende” (turnaround in Germany energy policy), which had been initiated by German politics, were added on top. As a consequence of the new energy policy, the economic situation of conventional generation, and naturally of GKM, aggravated dramatically. The high amount of renewables feed in and the related decreasing utilisation periods of conventional power plants in connection with the downward trend at the energy exchange make it nearly impossible to generate cost-covering. However, at the same time conventional plants are to make up demand immediately and are to guarantee supply security when no renewable power at all or only small amounts of renewable energy are available. Lay people can hardly imagine which enormous endeavours have to be made by staff and equipment to instantly cover such demand. Apart from the erection of unit 9, we responded to the new general conditions by defining a totally new company strategy and increasing our plant flexibility and efficiency through different construction and saving measures. An example is one of the most effective district heating accumulators in Germany we have been running jointly with MVV Energie for roughly 2 years. With a capacity of 45,000 cubic metres the accumulator has an effective heat content of 1,500 MWh. Apart from flexibility of generation, the accumulator also contributes to supply security of the city of Mannheim and the surrounding region. Besides, we also erected new switchgear, quadrature booster and auxiliary boiler. Thanks to the intensive technical optimisation of processes of existing units and plants – mainly in the fields of firing, control and instrumentation and plant operation – our power plant units stand comparison with modern gas-fired power plants as regards load ramps and minimum load reduction.
We are convinced that these measures will not only secure our business site and jobs in the long term, but that we can give positive impetus to the entire German power industry, because Germany´s supply security is depending on highly efficient and flexible conventional generation. It is proven by all serious forecasts that power plants like the GKM will be needed for a number of decades to secure power supply in Germany. Finally such conventional plants are the reliable technology building the bridge for the extension of renewables.
We hope that you will gain valuable insight and information from our knowledge, experience and findings we have detailed in the papers published in the edition at hand.