The two power plants were commissioned in 2007, reported Reuters.
Earlier in 2013, the company had shut down 510MW Robert Frank gas-fired power plant and the 450MW Emden gas-fired power plant in 2012.
In 2012, the company took $340m impairment charge on its gas power plants in Germany.
Statkraft investor relations vice-president Yngve Froeshaug said, "Short-term power prices have continued to fall (in Germany), worsening the margin between power and gas prices. Due to this, our gas power plants in Knapsack and Herdecke for the time being are out of production – that is in the wet reserve."
"Wet reserve" means the plants could be restarted in a relatively short time in case market conditions change," Froeshaug added.
