Asnæs Power Station near Kalundborg is Denmark's largest power station, with three active units able to supply a total of 1,057 MW of electricity and up to 502 MJ/s of heat. The first production plant, Asnæs Power Station’s Unit 1, was commissioned in 1959, and in 1981 Asnæs Power Station’s Unit 5 was put into operation. In addition to electricity, the Asnæs Power Station produces district heating for the Municipality of Kalundborg and process steam for the neighbouring enterprises Statoil, Novo Nordisk and Novozymes. 

In 2003-2004 Unit 5 of the power station, supplying 640 MW, underwent a major renovation extending its life by 15 years. Asnæs has a DeNOx facility, which will make the power station even more eco-friendly.

Asnæs Power Station uses coal as its main fuel. Oil is the reserve fuel at all three active units.