Germany on Saturday shut down its three remaining nuclear power plants as part of a long-planned transition to renewable energy.

The closure of Emsland, Neckarwestheim 2 and Essar stations came just before midnight.

"The end of an era," energy company RWE said in a statement, confirming that the three reactors had been taken off the grid.

Critics assert that the technology is unsafe and unsustainable, citing the disasters at Three Mile Island, Chernobyl, and Fukushima.

However, advocates of atomic energy say fossil fuels must be phased out first amid global efforts to tackle climate change, pointing out that nuclear power generates far fewer greenhouse gas emissions and can be a safe source of energy when managed properly.

The exit plan was accelerated by former chancellor Angela Merkel in 2011 after the Fukushima nuclear disaster in Japan.