In an effort to harness the power of wind, energy companies are going farther out to sea, which requires building taller and heavier components for wind towers. To support these larger structure, the traditional seabed bases (monopiles) will no longer suffice. Rather, floating bases are the future for many offshore wind energy developers establishing wind farms in deeper waters.
Anticipating this, Finnish-based Pemamek has dedicated more manpower to designing and building solutions for manufacturing floating platforms for wind towers in water deeper than 200 ft.
Torben Blaaholm, Pemamek’s director of sales and business development for the wind energy segment, says the company, which has made a name for itself producing turnkey solutions for wind tower and monopile production, shipbuilding, heavy equipment and power generation, is uniquely suited to provide a solution for the wind towers that will require a floating platform, which is referred to as a “floater.”
“We have really high activity on the floater side,” Blaaholm says, explaining that Pemamek has worked with wind energy companies for years on a turnkey solution for manufacturing floating platforms, and that recently, activity has ramped up. “Our focus is mainly on the industrialization of floater production.”
Current offshore wind farms rely on monopiles, which are “fixed bottom” foundations that secure the wind towers to the seabed. Monopiles are large, sturdy structures capable of holding towers up to 600-plus ft. tall, blades that span nearly 200 ft. and turbines weighing up to 500 tons. The onus on the floaters will likely be much more drastic as new towers and turbines are built larger.
Pemamek is no stranger to the wind energy sector, having developed roller beds, handling solutions and automated welding technology to allow manufacturers to produce the massive towers and monopiles for onshore and offshore wind farms.
State of wind energy
According to the U.S. Department of Energy (DOE), as of April 2024, an existing 250 megawatts (MW) of energy is being produced by current offshore wind farms. Additionally, wind farms under construction are slated to produce 5 gigawatts (GW) of energy. For reference, 1 GW, which is equal to 1,000 MW, is capable of powering a medium-size city.
DOE’s report, “Pathways to Commercial Liftoff: Offshore Wind,” says that “the U.S. offshore wind market is at an inflection point … In the next few years, an additional 5 to 10 GW of projects have a path to reach Final Investment Decision (FID) and begin construction.”
Looking into the future, DOE says offshore wind energy has the potential to deliver 100 GW of clean power by 2050, and that 50 GW worth of U.S. seabed has been leased to developers with other lease areas planned for auction, which means there is a “clear path to scaling deployment over the next several decades across the U.S.”
The bonus is that this clean energy provides “near-term and long-term decarbonization of the U.S. energy system,” the report says. “Offshore wind promises to help meet demand growth by providing near-term deployment at scale, particularly for land-constrained coastal demand centers that have limited clean electricity alternatives and might otherwise need to add new natural gas or delay fossil fuel retirement.”
Better by sea
While wind farms continue to pop up across the country at inland sites, the science says wind is better at sea. According to the DOE report, compared to wind over land, “wind over water is generally higher speed, more consistent and less turbulent.”
Furthermore, offshore wind allows for more efficient use of larger turbines than can be installed onshore.
“With a technical resource potential exceeding 4,200 GW in water depths up to 1,300 m,” the DOE report says, “offshore wind could theoretically meet today’s U.S. electricity demands by more than three times … Floating wind has long-term potential to serve electricity demand across the East and West Coasts, Great Lakes, Hawaii and the Gulf of Mexico.”
The report also says floating offshore wind can be an “essential tool to help decarbonize these regions, especially in areas where the potential for fixed-bottom offshore wind, onshore renewables or other clean sources (e.g., nuclear, out-of-state imports) is limited.”
DOE has also determined that globally, roughly 80 percent of offshore wind potential exists in water too deep for fixed-bottom foundations, which drives home the importance of developing floating technology. To prevent the wind towers from drifting out to sea, current designs call for the floating platforms to be anchored to the seabed with mooring lines.
“While pilot projects have already been deployed in Europe and Asia, with larger projects under development,” the DOE report says, “in the United States, planning for development is just beginning.”
Floating design
Pemamek specializes in designing and manufacturing automation solutions that are capable of working with massive pieces of material, improving the overall production capacity, safety and end-product quality. Blaaholm says the floating platforms for offshore wind towers can weigh between 3,000 and 5,000 tons.
“Offshore, where the tower gets higher, the blades get longer and the turbines get bigger, that means the floaters get bigger,” he says. “The strength of the construction needs to be there.”
Pemamek is working on a variety of solutions for different floating platform designs, which have similarities to the systems Pemamek produces for manufacturing offshore wind towers, monopiles, jackets, submarines, ships and oil rigs. One of the designs is a tubular floater that features a tubular section of the platform underwater, buoying the wind tower.
“It is in the family of monopile production,” Blaaholm says, “but it is more complex in some ways because the diameter gets very big while the plate thicknesses is quite thin. This adds to the complexity of the production.”
Fortunately, many of Pemamek’s welding automation solutions can be operated by one person, which helps to address the challenge that manufacturers in all industries face – the skilled worker shortage. This will also be the focus for manufacturing the floater systems.
“What is everyone’s struggle?” Blaaholm asks. “To have employees for their factories; to have the workforce in place – that’s always the struggle. That’s why we’re aiming for it to be as automated as possible, which helps to achieve predictable production and predictable high quality.”
