ABB’s Medium‑Voltage Drives Cut Pump Energy Use by 25% at German Coal Plant

ABB’s high‑efficiency medium‑voltage drives have cut the energy use of two boiler‑feed pumps at the GKM coal‑fired plant in Mannheim, Germany, by 25%. The upgrade boosts annual revenue by $800,000 and reduces CO₂ emissions by 10,200 t.

The drives—ABB’s ACS 1000 medium‑voltage variable‑speed units—manage the two 5.8 MW boiler‑feed pumps on Unit 6 of the 1,675‑MW GKM plant.

Each pump was originally rated at 5.8 MW and installed in the 1970s. Before the upgrade, they were driven by hydraulic clutches operating at only 72 % efficiency, wasting over 1 MW of power per pump.

In 2006, during a major refurbishment of Unit 6, GKM determined that the pumps’ low efficiency was unsustainable and sought a modern solution from ABB.

ABB’s modernization package combined an ACS 1000 variable‑speed drive, an ABB RESIBLOC dry‑type transformer, and a comprehensive pump overhaul.

The water‑cooled ACS 1000 medium‑voltage AC drives are housed in air‑conditioned containers and on stilts to provide a safe and controlled environment and protect the drives from flooding by the nearby Rhine River.

Following two years of seamless operation, GKM confirmed a 25 % reduction in pump energy use—freeing energy that can be sold back to the grid, worth $400,000 per pump annually.

The energy savings translate into a 10,200‑t annual cut in CO₂ emissions, a noteworthy achievement for a fossil‑fuel plant.

The new drive system operates at an impressive 98.5 % efficiency, up from the former 72 %.

The success prompted GKM to award ABB two further contracts for medium‑voltage drives on feeder and circulation pumps in two additional generating and district‑heating units.

Coal plants generally consume 7–15 % of the electricity they produce, with pumps accounting for roughly 80 % of that parasitic load.

Click here to learn more about the medium‑voltage drive solution at GKM.

For more information, visit ABB’s website at www.abb.com.