Manufacturing costs and logistics are two challenges to rapidly integrating more renewable energy into the U.S. power system. This is especially true for tall land-based wind turbines, but Colorado-based Keystone Tower Systems is changing how wind turbines can be manufactured, transported, and installed.
Taller land-based wind turbines harness and generate more power than shorter ones, because they can access faster wind speeds at greater heights. But larger wind turbines are harder to construct and require more steel to build. They’re also difficult and costly to transport from the manufacturing plant to the wind farm, because the tower is often too large to fit under highway overpasses or across bridges.
With more than $7 million from the U.S. Department of Energy (DOE), Keystone Tower Systems has developed a solution: a spiral-welding technique, borrowed from the steel-pipeline industry, to build some of the largest turbine towers on the market. Spiral welding is when the steel used to make the tower is curled into a cylinder; essentially, these towers are built from meters-wide steel plates.
The technique requires only one machine to construct a tower section, and it can produce towers up to twice as tall and 10 times faster than conventional towers. These towers are produced using less steel, so they could be more affordable than conventional towers, too. They can even be manufactured on site at the wind farm, eliminating transportation issues.
Keystone’s cofounder and CEO, Eric Smith, an expert in machine design and the wind industry, and his 75 staff members are building Keystone’s first spiral-welded tower for a 2.98-megawatt GE wind turbine. Installation is expected to start later this year. This will be the first spiral-welded wind tower in commercial use, representing a significant advancement in overcoming key obstacles to bringing affordable wind energy to more locations throughout the United States.
Before the Keystone team could even dream of building tall wind turbine towers, they successfully competed for funding through the Small Business Innovation Research program. From 2012 to 2019, they were awarded $3.7 million to design the manufacturing process and show the company’s potential for cost-effective expansion.
Then, in 2019, DOE’s Wind Energy Technologies Office awarded Keystone $5 million to demonstrate its 160-meter spiral-welded tall wind turbine tower. Keystone worked with wind turbine manufacturing partners to design a commercial-scale tower ready for installation.
Smith says it hasn’t been easy being a small business in the wind industry: “There’s no way to be competitive unless your business is super large, so it’s difficult to start from nothing, which is why support from DOE has been integral.”
Keystone Tower Systems is just one example of the importance of funding innovative small businesses as the nation transitions to a clean energy economy.