Nuclear power is a touchy political topic in Germany, even as energy shortages loom. AP
"The legal basis will be created to allow the operation of the nuclear power plants Isar 2, Neckarwestheim 2 and Emsland beyond December 31, 2022 until April 15, 2023," Scholz said in a letter to cabinet ministers seen by AFP.
The government had previously only agreed to keep two of the three plants going beyond their planned end-of-year phaseout, as Europe's top economy scrambles to reduce its reliance on Russian energy imports in the wake of the Ukraine war.
The fate of the Emsland plant in northern Germany had caused a rift between Scholz's two coalition partners, with the anti-nuclear Greens resisting calls by the liberal FDP to keep the Emsland plant online as well.
Repeated rounds of talks in recent days failed to resolve the row, and Scholz's statement on Monday evening indicates he pulled rank to break the impasse.
The letter says Scholz, from the centre-left Social Democrats, was invoking his authority as chancellor to issue a directive.
Germany had initially aimed to exit nuclear power by the end of 2022, completing the phase-out planned by former chancellor Angela Merkel.
But the Ukraine war has upended the energy landscape, forcing a dramatic rethink as power prices soar and Russia has shut off gas supplies through the crucial Nord Stream 1 pipeline.
Germany is now racing to secure enough energy supplies as the colder winter weather approaches, and is even restarting mothballed coal-fired power plants.
In a major U-turn, Economics Minister Robert Habeck recently announced that Germany would keep two of its last three nuclear power plants, Isar 2 and Neckarwestheim 2, on standby until the spring of 2023 as an emergency back-up.
But he had faced growing pressure from the FDP to keep all three plants running, with its head Finance Minister Christian Lindner saying all three were needed to "reduce prices and prevent blackouts".
Justice Minister Marco Buschmann from the FDP welcomed Scholz's decision on Twitter.
"Common sense prevails," he wrote. "This strengthens our country because it ensures more grid stability and lower electricity prices."