The California Energy Commission has approved a sweeping plan to develop a massive floating offshore wind industry in the Pacific Ocean, a first-of-its-kind undertaking that will require billions in public and private investments and could transform parts of the coast.

The new state plan sets the path for harnessing wind power from hundreds of giant turbines, each as tall as a 70-story building, floating in the ocean about 20 miles off Humboldt Bay and Morro Bay.

The untapped energy is expected to become a major power source as California electrifies vehicles and switches to clean energy.

California's wind farms represent a giant experiment.

No other place in the world has floating wind operations in such deep waters-- more than a half-mile deep-- so far from shore.

State and federal officials use the word urgency to describe the frenetic pace needed to lay the groundwork for development of the five areas that the federal government has leased to offshore wind companies.

Those companies are now assessing sites within the leasing areas 583 square miles, study that is expected to take five years.

That will be followed by about two years of design, construction, environmental and technical reviews, and approvals.

The Energy Commission's plan estimates that just the work to upgrade California's ports will cost $11 to $12 billion, much of it publicly funded.

By 2045, 16 large and 10 smaller ports will be needed along California's coast to support various aspects of wind development.

The plan identifies the large ports of Humboldt, Long Beach, and Los Angeles as viable for storing, staging, and assembling parts needed for offshore wind operations.

Meanwhile, Californians are expected to vote on a climate bond measure on the November ballot.

If approved by voters, an estimated $475 million would be set aside for offshore wind-related port infrastructure.

For CalMatters, I'm Julie Cart.