A site steeped in tradition
Electricity has been generated at the Gersteinwerk power plant since 1917. In the early years, coal from the nearby collieries was used to produce electricity. In the 1970s, the natural-gas-fired units were installed at the site. All power plant units installed today are based on the combined-cycle principle. The generators feed the electricity into the high and ultra-high voltage grids. The site thus plays an important role in electricity supply in all load ranges.
Unit K – nothing but topping gas turbine since March 2019
After 34 years in operation, the coal-fired part of unit K was decommissioned at the end of March 2019 – the last coal unit at the Gersteinwerk in Werne. The 112 MW topping gas turbine of unit K will continue to operate until at least end of 2022. The gas turbines can generate electricity in solo operation for a short time as required.
Units F and G – equipped with efficiency-enhancing combined-cycle technology
The four natural gas units at the Gersteinwerk site were put into operation in 1972 and 1973. The units are equipped with efficiency-enhancing combination technology and are thus precursors to modern combined-cycle gas turbine power plants. Each unit can feed 410 MW into the public electricity grid; gas turbines account for 55 MW and the steam turbine process for 355 MW. The remaining natural gas combined-cycle units F and G as well as topping gas turbines I1 and K1 will remain in operation until at least the end of 2022. Gersteinwerk therefore has a total generation capacity of more than 1,000 megawatts.
Special features of power plant technology
The gas turbines are quick to start and can be connected to the electricity grid within a quarter of an hour. Fluctuations in the grid can be offset for a short period, for example in the event of power plant outages or unforeseen failure of supply from renewable sources.
Improvements in flexibility
Improvements have been made consistently over time to better satisfy the requirements of environmental protection and the market. In addition, a 9 kilometre optimisation pipeline was installed at the site in which around 1 million cubic metres of natural gas can be temporarily stored. The pipeline is connected to the high-pressure natural gas grid.
What’s more, the control technology was updated and the production process equipped with state-of-the-art technology for controlling and monitoring plants from a central control station. The process control is therefore always optimal, the gas turbines can be controlled remotely and the load distributor has a highly flexible, market-based generation unit.
Decommissioning
Unit H was decommissioned in August 2018.
Use of the combined-cycle units converted
In light of the huge growth in renewable energy (wind energy and photovoltaics), the use of the combined-cycle units has been converted. In solo operation (open cycle), the gas turbines act as a rapid reserve for outages in the event of brief bottlenecks.
Optimisation pipeline
Gersteinwerk is supplied via its own high-pressure gas pipeline that runs from the central distribution station in Werne to the power plant. This supply pipeline flows into a so-called optimisation pipeline in close proximity of the power plant. This underground line, around nine kilometres in length with a diameter of approximately 1.40 metres, can accommodate around 1 million cubic metres of natural gas. This is equivalent to the quantity a natural gas unit requires for ten hours of full-load operation. This gas supply makes the fuel procurement on the international gas market more flexible as the price fluctuations cannot go unchecked. The optimisation pipeline acts as a buffer in both logistic and financial terms.
