Chancellor Olaf Scholz voiced confidence Wednesday that Germany was well prepared to "survive" the winter despite turmoil in the energy markets in the wake of Russia's invasion of Ukraine.

In a speech heavily critical of his predecessor chancellor Angela Merkel's energy policies that left Germany dependent on Russia for power, Scholz said Germany will keep moving "at great speed" to shed the reliance in the wake of Moscow's invasion of Ukraine.

Germany has not only raced to fill up its gas storage tanks, but also sped up the building of terminals to receive liquefied natural gas, Scholz told parliament.

"Because we started so early, when it wasn't even such a big awareness of the problem in Germany, we are now in a situation that we can head into the winter courageously and bravely -- our country can survive," he said.

As Germany turns its back on Russian supplies, it was sealing new cooperation with its closest European partners, said Scholz.

"We have spoken with our friends on the west European coast, with the Netherlands and Belgium for them to expand (LNG) terminals and pipeline capacities with France which will for the first time deliver gas to us.

"What we have achieved with the terminals in the north and with those on the German west European coasts, we will guarantee a secure energy supply for Germany," he said.

Europe's biggest economy has also restarted mothballed coal power plants, and this week decided to keep two nuclear plants on stand-by through mid-April instead of completely ending the usage of atomic energy by the end of the year.

But Friedrich Merz, the leader of Merkel's CDU conservatives, said it was "insanity" to keep the atomic plants only on standby and not on the grid.

The power plants needed to be active "in order for us to bring down prices and costs for companies," he said.

Merz's criticisms earned a sharp rebuke from Scholz, who said it was under the conservatives leadership that Germany had failed to make the right decision for its future.

The conservatives, who were in power from 2005 to 2021, are "completely responsible for the fact that Germany made decisions to exit coal and nuclear but without engaging in anything else," said Scholz, who was finance minister in Merkel's coalition.

Rather, the conservatives "fought against every wind power installation," said Scholz, saying it was "irresponsible CDU policies that have brought us to our current situation".