LOS ANGELES — California’s aggressive pursuit of an electric grid fully powered by renewable energy sources is heading in a new direction: offshore.

On Friday, the federal Interior Department took the first steps to enable companies to lease waters in Central and Northern California for wind projects. If all goes as the state’s regulators and utilities expect, floating windmills could begin producing power within six years.

Such ambitions were precluded until now because of the depths of the Pacific near its shore, which made it difficult to anchor the huge towers that support massive wind turbines. “They would be in much deeper water than anything that has been built in the world so far,” said Karen Douglas, a member of the California Energy Commission.

Several contenders are expected to enter the bidding, equipped with new technology that has already been tested in Europe.