50Hertz, a high-voltage operator in northeast Germany, said more wind and solar power plants could be integrated if the industry parted with the idea they must be synchronised with increased grid capacity.
"We must change our thinking from networks having to follow production capacity to renewables having to tap into where the networks are," Boris Schucht, 50Hertz' chief executive, said in an interview.
"I expect that, instead, there will be a new mix of measures, including installing more photovoltaics, more onshore wind also in the south and boosting networks with batteries," he said.
German Economy Minister Peter Altmaier is due to present a draft plan for changes to national grids before parliament breaks for summer.
Other transmission grid companies initially rebelled when Germany's ruling coalition in January set fresh challenges for their job, which is ensuring grid balance so power can flow from producers to consumers without disruption.
A near doubling of the current national share of a third of renewables to 65 percent by 2030 could multiply by many times their management costs of already well over 1 billion euros (896.66 million pounds) in 2017, they said.
New cables might be required, adding time pressure and triggering opposition by the public, which has already delayed thousands of kilometres of lines, 50Hertz peer TenneT warned on Tuesday.
This has resulted in the north of the country often throwing away excess wind power while the industrial south risks shortages when nuclear power is switched off by 2022, removing stable supply.
But Schucht said the measures he outlined could work.
"I am optimistic that we can get near the 65 percent target," he said.
Solar power, which accounted for 7 percent of total production last year against wind's 18.4 percent, has become inexpensive. Costs have fallen to under 5 cents per kilowatt-hour from over 50 cents 20 years ago.
"It can be handled more easily than wind and supplies electricity during the day, meeting peak demand," Schucht said.
It made sense for the south to build more wind turbines, because the region had no grid bottlenecks, he added.
50Hertz could also help the state of Bavaria by possibly doubling capacity on SuedOstLink, a 580-km line planned for the mid-2025s, to 4 gigawatts.
($1 = 0.8465 euros)
(Reporting by Vera Eckert; Editing by Dale Hudson)
By Vera Eckert