US engineering firm Keystone Tower Systems aims to reduce costs and manufacturing time with a new way of producing onshore and offshore wind turbine towers.
The Denver-based company claims its spiral-welded steel towers could be built ten times faster than traditional can-welded towers — and at a lower cost.
Spiral welding is a process where a single machine completes the joining, rolling, fitting, welding and severing of a tower section, resulting in the continuous production of steel tower shells.
It has been proven for producing cylindrical pipe and pilings, and should increase strength and save steel compared with traditional can-welded wind turbine towers, Keystone claimed.
The firm aims to offer on-site tower fabrication for wind farms across the US by 2023.
Keystone CEO Eric Smith said: “Spiral welding makes possible a new level of automation, resulting in faster production and higher quality.
“The result is a tower that can be built ten times faster than conventional towers, cost-effectively reach heights of 160 metres and beyond, and can still be installed with existing cranes and identical interfacing with turbine hubs.”
Keystone produced a sub-scale demonstration project – a wind turbine tower manufactured using the spiral-welding method – that has been in operation since 2015.
In 2019 the company secured financing to take it beyond the development phase. It is close to completing its first factory in Texas.
Keystone has also secured a $5 million grant from the US Department of Energy to develop mobile manufacturing equipment to make spiral wind towers on-site. This will avoid transportation constraints that limit can-welded towers to sizes that can be moved on a highway, the engineering firm explained.
Keystone is chaired by wind industry veteran Steve Lockard, who had previously served as CEO of blade manufacturer TPI Composites and chairman of the American Wind Energy Association.
Meanwhile, former GE senior executive Peter Bierden, who had previously held leadership roles in GE’s former energy division, including a stint as general manager for renewable energy projects between 2003 and 2009, will be responsible for growing Keystone.
And Larry Oglesby, who had served in leadership roles at manufacturing firms Pratt & Whitney and Danaher, will be the firm’s chief operating officer.
Eric Smith, Keystone’s co-founder, and CEO, added: “By bringing together experts in tower design, technology development, and manufacturing execution, we’re rewriting the book on how wind towers are designed and built.”