Kraftwerke Mainz-Wiesbaden

Kraftwerke Mainz-Wiesbaden AG (KMW) is a German municipal energy utility headquartered in Mainz. It generates and distributes electricity, process steam and district heating for the Mainz-Wiesbaden conurbation and the wider Rhine-Main region. The company traces its origins to the merger of the Wiesbaden and Mainz power stations in 1931, and its official history notes that it has been reliably supplying the region with power and district heating for over 90 years, with roots reaching back more than 120 years. KMW operates as a communal service provider (kommunaler Dienstleister) with a portfolio that includes gas and steam turbine plants, combined-cycle units, combined heat and power (CHP) plants, waste-to-energy, wind farms, solar parks, a wind-to-gas park, battery storage and district heating with heat storage. It is also involved in the energy supply consortium for the Opel site and operates a natural gas network. In recent years KMW has pursued a transformation from a traditional power plant site into an integrated energy hub, investing in renewable generation, hydrogen production and storage, and large-scale heat pumps. The company employs nearly 500 people and describes itself as modern, social and responsible, combining high technical availability and efficiency with a collegial working culture. Its ownership structure is municipal: it is a public industrial and commercial establishment (établissement public à caractère industriel et commercial) that has retained its status as a municipal régie, with financial autonomy, and its accounts are consolidated into those of the city of Mainz. The budget is voted by the administrative board and approved by the mayor. KMW's plants are among the more efficient generation assets internationally, and the use of cogeneration allows an energy efficiency of around 80%. The company continues to plan and build new capacity, including a highly modern engine power plant on the Ingelheimer Aue, and is positioning itself for the energy transition with projects such as a data centre, a large heat pump, a campus and battery storage.

Kraftwerke Mainz-Wiesbaden AG (KMW) traces its origins to the merger of the Wiesbaden and Mainz power stations in 1931. The company has since operated as a municipal energy utility for the Mainz-Wiesbaden conurbation, and its official history states that it has been reliably supplying the region with electricity and district heating for over 90 years, with roots reaching back more than 120 years. In the post-war decades, KMW expanded its thermal generation capacity. In 1958, 1963 and 1966, three coal-fired units with a capacity of 100 MW each were commissioned at a power plant. In 1977, two units were converted to combined-cycle operation, combining steam turbines with an upstream gas turbine. In 2000, the three coal-fired units were shut down and replaced by a single unit. In 2001, a 400 MW combined-cycle plant was commissioned on the Ingelheimer Aue. The facades of the power plant building were designed by Friedrich Ernst von Garnier. In August 2011, 'Power Plant 2' served as a 'cold reserve' and was designated by the Federal Network Agency as an essential component (1009 MW out of a total of 350 MW in southern Germany) of the reserve capacity for the phase-out of nuclear power following the moratorium. This was already based on the supply from a closed nuclear power plant being lifted as a reserve. In 2012, KMW made an investment in the future. In 2014, the company further increased the efficiency of its gas and steam power plant, modernising the facility for around 60 million euros to prepare it for the requirements of the coming years. In 2015, the first own KMW wind turbine went into operation near Biedesheim in Rhineland-Palatinate. In 2020, KMW took over Wind to Gas Energy GmbH & Co. KG, thereby opening up further business fields in hydrogen production and battery storage while expanding its wind power portfolio. Also in 2020, a new gas engine power plant went into operation; this combined heat and power plant complements the plant portfolio perfectly, providing flexibility to react to energy market developments on a minute-by-minute basis thanks to its short start-up time. KMW has also added district heating to its activities, achieving an energy efficiency of around 80% through cogeneration. The company is planning a coal-fired power plant on the Ingelheimer Aue with a capacity of 820 MW and an efficiency of 46 percent, with combined heat and power allowing up to 300 megawatts of additional heating to be decoupled from the coal plant. More recently, KMW has been transforming its site from a traditional power plant location into an integrated energy hub, with plans for a data centre, a large heat pump, an engine power plant campus and battery storage. The company remains a municipal establishment with financial autonomy, its accounts consolidated into those of the city of Mainz, and its budget approved by the mayor.

• 2020

  Takeover of Wind to Gas Energy GmbH & Co. KG, expanding into hydrogen production and battery storage.

• 2020

  New gas engine power plant (combined heat and power) goes into operation.

• 2015

  First own KMW wind turbine goes into operation near Biedesheim, Rhineland-Palatinate.

• 2014

  Modernisation of the gas and steam power plant for around 60 million euros to increase efficiency.

• 2012

  Investment in the future (details not specified in the source).

• 2011

  'Power Plant 2' designated by the Federal Network Agency as an essential component of reserve capacity for the nuclear phase-out.

• 2001

  Commissioning of a 400 MW combined-cycle plant on the Ingelheimer Aue.

• 2000

  The three coal-fired units were shut down and replaced by a single unit.

• 1977

  Two units converted to combined-cycle operation with steam turbines and an upstream gas turbine.

• 1966

  Commissioning of a third coal-fired unit with a capacity of 100 MW.

• 1963

  Commissioning of a second coal-fired unit with a capacity of 100 MW.

• 1958

  Commissioning of a coal-fired unit with a capacity of 100 MW.

• 1931

  Merger of the Wiesbaden and Mainz power stations to form Kraftwerke Mainz-Wiesbaden.

Municipal, regionally rooted energy provider combining high-efficiency conventional generation with growing renewable and storage assets.

• Electricity

  Generated from thermal, renewable and combined heat and power plants.

• District heating

  Supplied to the Mainz-Wiesbaden conurbation, with heat storage.

• Process steam

  For industrial customers.

• Natural gas distribution

  Operation of a natural gas network.

• Hydrogen

  Production via wind-to-gas park.

• Battery storage

  Grid-scale battery storage.

1. 1KMW: Energie für den Großraum Mainz-Wiesbadenkmw-ag.de
2. 2Über 120 Jahre : Das ist unsere Geschichtekmw-ag.de
3. 3Mehr über uns: Geschichte & Organisation von KMWkmw-ag.de
4. 4Kraftwerke Mainz-Wiesbadenwikidata.org
5. 5Kraftwerke Mainz-Wiesbadenfr.wikipedia.org