Bringing grid stability to Germany

Above: Biblis grid stability plant (source: GE Vernova)

LEAG has commissioned its first gas-fired power plant in southern Germany, at the site of a former military air base at Leipheim, to the north east of Ulm. The new power plant is one of four 300 MW fast-start-up open-cycle gas turbine based plants put out to tender by TSOs (transmission system operators) in 2018 (as part of a Bundesnetzagentur (Federal Network Agency) initiative), the sole purpose of which is to help provide grid stability in southern Germany in support of the energy transition, in the context of closing nuclear and coal/lignite fired power plants and expanding renewables. The contract for construction and operation of Leipheim was awarded to LEAG by Amprion. The power plant is owned by LEAG and employs a Siemens Energy SGT5-4000F gas turbine.

The other three grid stability plants, Biblis (constructed/owned/operated by RWE, with 11 GE LM2500XPRESS gas turbines), Irsching 6 (constructed/owned/operated by Uniper, with an Ansaldo AE94.3A gas turbine) and Marbach 4 (constructed/ owned/operated by EnBW, also employing an Ansaldo AE94.3A machine) are under contract to TSOs Amprion, TenneT and TransnetBW, respectively.

The new plants are not intended to be in continuous operation or to participate in the electricity market. They will only be ramped up, typically within about 30 minutes, when called upon by their TSO.

The Leipheim power plant is operated entirely from Siemens Energy’s central control room (ROMSC) in Erlangen, Bavaria, and, like LEAG’s two other grid-stabilising gas-fired power plants – Thyrow and Ahrensfelde near Berlin – it is monitored by LEAG’s Schwarze Pumpe power plant and integrated into that plant’s control system.

At the Leipheim commissioning ceremony, LEAG CEO Thorsten Kramer announced that the company was already planning another gas-fired power plant on the site. This will be H2-ready and gradually converted to full operation with green hydrogen.

LEAG became involved in the Leiphem project with its acquisition, in 2021, of Gaskraftwerk Leipheim (GKL), a special purpose company of Stadtwerke Ulm/Neu-Ulm, which had developed the project together with Siemens Energy and STEAG.

LEAG (Lausitz Energie), 50:50 co-owned by EPH (through its subsidiary EP Power Europe) and PPF Investments, is the largest energy company and the largest private employer in eastern Germany.

The Irsching 6 grid stability plant is also now operational. It is the first time that Ansaldo Energia has installed and taken into service one its gas turbines in Germany (although it is worth recalling that the AE94.3A gas turbine derives from Siemens designs).

Uniper’s Irsching site, the largest power plant site in Bavaria, hosts six units. The oldest two, Irsching 1 and 2, are permanently shut down, while unit 3 (gas fired steam plant) has been classified as “system-relevant” by Bundesnetzagentur and is available to the network operator as a reserve to ensure network stability. The advanced combined cycle plants, Irsching 4 (“Ulrich Hartmann”) and joint-venture Irsching 5 (Uniper share: 50.2%), are in commercial operation and are sometimes started up and shut down several times a day. The plants are also regularly used by TenneT for so-called “redispatch”.

An Ansaldo Energia AE94.3A gas turbine is also being deployed at the Marbach 4 grid stability power plant, with commissioning targeted for 2023. The planned date had been October 2022, but “global delivery problems, material supply bottlenecks, plant closures and staff shortages have led to delays in construction work”, says EnBW and “the buffer time built in as a precaution has now been used up.”

Remarkably, Marbach 4 will run on light fuel oil, rather than gas. “This will avoid any potential difficulties in obtaining the fuel supply”, says EnBW. “That’s because the large oil storage facility on the power plant site (with a total capacity of approx. 70 000 m3) ensures that the fuel is available all year round. This is especially important in winter, because any threat to grid stability is most likely to occur during cold periods.”

One relatively late design alteration at Marbach 4 was an increase in the chimney diameter by about 3 m to 10.5 m. This was found to be necessary during the plant supplier’s detailed planning activities, in order to achieve the low noise levels required for the plant.

RWE’s Biblis GE Vernova powered grid stability plant was inaugurated in May 2023, having started operation in early March.