Are offshore wind turbines in Washington’s future?

The cap-and-invest system aims to decrease carbon emissions and finance climate change mitigation measures across the state. Under the program, carbon-emitting corporations – like oil and gas companies and utilities – bid on state allowances for the pollution emitted by their facilities. The money raised in the auction is earmarked for projects and programs aimed at lowering the carbon footprint.

If the repeal vote is successful, the $625,000 in this appropriation disappears. It is not scheduled to go into effect until Jan. 1, 2025.

Fisher estimated that the studies could take a year to a year and a half to complete, depending on the scope of the research contract.

While the United States’ existing commercial-sized offshore wind farms produce 42 megawatts, projects on the drawing board total 52,687 megawatts for 2023 — up 15% from 2022 with the addition of proposed Gulf of Mexico projects. Thirteen states have plans to install more than 112,000 megawatts of offshore wind capacity by 2050.

Offshore wind turbines have been around since 1991. Chinese, British and German ventures account for at least 75% of the world’s offshore turbine power.

Offshore winds are usually faster and more consistent than land breezes. Offshore turbines have traditionally faced less public opposition than land windmills.

The downside is that offshore turbines are more expensive to install than land turbines — American offshore wind projects cost $4,000 per kilowatt to build in 2023, compared to $1,363 per kilowatt for land wind farms, according to the U.S. Department of Energy’s 2023 Offshore Wind Market Report. 

Land wind development typically takes two to three years from inception to commissioning, with development costs ranging from $1 million to $2 million per project. An offshore wind farm typically takes five to ten years to develop, requiring $10 million to $50 million in costs, said a 2019 World Bank Group report. 

That same report said: “Over time, offshore wind evolved into a distinct, specialized technology. Offshore turbines are now specifically designed to reduce maintenance requirements given the relatively high cost of marine access. At the same time, offshore wind farms are subject to fewer limitations faced by onshore wind, including land use pressures, concerns about views, and transportation/infrastructure constraints. As such, they have evolved to become the largest pieces of rotating machinery on the planet, capable of generating much higher capacity factors than their onshore cousins.”

The Department of Energy also expects costs to increase. “Supply chain constraints, high inflation, and rising interest rates have resulted in significant project cost increases of 11%–30% during 2022,” the department said in a 2023 report.

There are two basic types of offshore turbines — those with their foundations placed on the ocean floor up to 160 feet deep, and those that float, attached to the ocean floor by cables that can reach to 3,280 feet deep. A state’s control over the ocean extends 12 nautical miles from the coast. The West Coast has much deeper waters than those off the Eastern United States and Europe, which would make floating turbines more likely.