A record amount of wind power capacity entered U.S. transmission interconnection queues in 2018, and wind represented 36% of total generating capacity in those queues, according to the U.S. Department of Energy's annual market report on wind technologies. Continued growth is uncertain, however, if Congress allows tax credits to expire.
A total of 92 GW reached states' interconnection queues in 2018, the report found.
The DOE conclusions are in line with findings of other recent reports, such as a National Renewable Energy Laboratory study that said annual wind capacity additions will fall dramatically following the expiration of the federal production tax credit. Congress is considering multiple bills extending the credits.
"Wind power capacity in the United States continued to grow robustly in 2018, supported by the industry's primary federal incentive — the production tax credit (PTC)—as well as a myriad of state-level policies," the report said. "Improvements in the cost and performance of wind power technologies have also driven wind capacity additions, yielding low-priced wind energy for utility, corporate, and other power purchasers. The magnitude of growth beyond the current PTC cycle remains uncertain, however, given declining tax support, expectations for low natural gas prices, and modest electricity demand growth."
The Southwest Power Pool, Mountain and Midwest regions had the greatest quantity of wind in their queues at the end of 2018, the report said. Texas installed the most capacity in 2018, with 2,359 MW. There were 14 states that exceeded 10% wind energy penetration as a percentage of total in-state generation, with Kansas leading the way at 36.4%, according to the report.
But solar and natural gas still beat out wind power in terms of capacity additions.
"The once-wide gap between wind and solar (power purchase agreement) prices has narrowed considerably in recent years, as solar prices have fallen more rapidly than wind prices," the report said. "With the support of federal tax incentives, both wind and solar PPA prices are now below the projected cost of burning natural gas in existing gas-fired combined-cycle units."
According to the report, General Electric Co. and Vestas Wind Systems A/S accounted for 78% of the U.S. wind power market in 2018, with GE capturing 40% of the market for turbine installations, and Vestas in a close second at 38%. Nordex SE captured 11% and Siemens AG captured 8%.
The report called the domestic wind industry supply chain "reasonably stable," though it faces challenges meeting short-term demand and rising competitive pressures. U.S. wind developers still import the majority of equipment for wind farms including turbines, blades and towers.
As of May 2019, renewables portfolio standards existed in 29 states and Washington, D.C., the report said, and wind power growth is outpacing state targets. Electric utilities were the largest off-takers of wind power in 2018. They owned 20% of wind projects and purchased 27%. Direct retail purchasers account for 24% as corporate wind energy purchases increase.