A Denver company has tapped a construction technique used in the oil and gas industry to make bigger and cheaper wind-turbine towers faster, setting the stage to help expand wind power on the East Coast and offshore.
The Department of Energy has awarded Keystone Tower Systems grants to help develop equipment to manufacture its spiral-welded, tapered wind towers. The company is opening its first tower production plant in Pampa, Texas, later this summer.
The company won an $800,000 grant in March from the National Offshore Wind Research and Development Consortium, established by the Energy Department. The award dovetails with President Joe Biden’s plan to accelerate development of the nation’s offshore wind industry to reduce the use of fossil fuels and address climate change.
In Denver, Keystone Tower will continue to produce the custom manufacturing equipment it uses to make its towers. The equipment will be mobile, allowing the company to produce the much taller towers that are needed on the East Coast and offshore but would be too big to ship by truck.
“In the U.S., the wind industry is almost entirely onshore today there’s a huge pipeline of projects being developed and will be starting construction in the coming years on the East Coast,” said Eric Smith, Keystone Tower CEO and co-founder.
Key to tapping that market is building taller towers to reach the strong winds. The towers that will be produced in Texas will be the conventional height, from about 260 feet to 328 feet and will be installed in Texas, Oklahoma and New Mexico, where strong, consistent winds can be reached at a lower height in the wide, open spaces
The company will use its technology to build towers roughly twice the usual height, around 525 feet, for the Southeast, where the stronger winds are found higher, above the tree cover, and for off-shore projects.
For both sizes, Keystone Tower will use its process of welding the steel in a spiral, similar to the core of a paper towel roll. Other towers are built by mounting sections of steel on top of each other. But Keystone’s custom-made mill joins, rolls and welds the steel to create the tower.
“It’s essentially one giant machine that you feed steel into on one side and towers pop out the other side,” Smith said.
Jocelyn Brown-Saracino, the lead for the Department of Energy’s offshore wind program, said Keystone Tower has adapted construction used by the oil and gas industry and is an example of how the domestic supply chain for offshore wind can be developed. Keystone has worked with scientists at the National Renewable Energy Laboratory in Golden.
The Golden lab produced a federal analysis showing that adding 30 gigawatts of offshore wind by 2030, enough power for 10 million homes annually, would create 44,000 industry jobs and nearly 33,000 additional jobs in communities.
Smith and co-founder Rosalind Takata started the company with a grant from the DOE. Smith studied mechanical and electric engineering at the Massachusetts Institute of Technology and taught wind-turbine engineering at MIT.
“What the administration is pushing for here really enables us to quickly scale up and to decarbonize the grid at a much faster rate, which is critical for climate change,” Smith said.
Keystone can produce a tower section about 10 times faster than the conventional process, Smith said. The base of a typical wind-turbine tower is about 15 feet, compared to a 30-foot base for the taller towers Keystone plans to start producing in the next few years.
Smith said the larger base makes the tower stronger and allows for thinner walls, saving about 250 tons of steel per tower and cutting costs. The catch is a tower that big can’t be trucked. Keystone will manufacture the towers at the project site with its mobile mill.
The company, which expects to double its workforce of 50 by the end of the year, recently added a board member and staffers with years of experience in manufacturing and the wind industry.