When fifteen 240-foot-long spinning fiberglass blades off the coast of Rhode Island finally start converting wind into power before the end of this year, history will be made. The Block Island wind project—five 560-foot-tall wind turbines attached to the seafloor via steel—will be the first offshore wind farm operating in U.S. waters.

Previous efforts to build wind farms off the East Coast have famously failed (Ted Kennedy helped torpedo one to protect the view from his Cape Cod estate), but there are now almost a dozen planned for the region.

What changed? Over the past six years the price of wind energy has plummeted, finally becoming cost-competitive with traditional power. And while offshore farms are still significantly more expensive, they have become increasingly appealing for coastal states with little open space, large urban populations, and soon-to-be-retired nuclear plants.

BRB.11.01.16.wind chart

In Europe, offshore wind already powers over a million homes. Denmark’s DONG Energy went public this summer in one of Europe’s largest IPOs of 2016. But to get to that level, the U.S. industry will still need government incentives, like the game-changing law Massachusetts passed this past summer that requires the state’s utilities to buy 1.6 gigawatts of energy from offshore wind farms over the next decade. Expect plenty more ocean views to feature turbines.

For more on the environment, watch this Fortune video:

A version of this article appears in the November 1, 2016 issue of Fortune with the headline “Wind Is Getting Really, Really Cheap.”