Power Play

Solar synergies developed for tubular goods

Above: Nucor’s Econiq steel is produced from 100 percent renewable energy to offset Scope 2 emissions, while the Scope 1 emissions are countered through the purchase of carbon offsets. This sheet is used to make Nucor tubular products.

Solar synergies developed for tubular goods

September 2022-  Construction is in full swing at the Nucor Tubular Products (NTP) mill in Gallatin County, Kentucky. The new $164 million mill, announced in March 2021, will be able to produce 250,000 tons of steel tubing a year. In addition to serving construction and infrastructure markets, the site is expected to support the expanding solar energy market.

“Galvanized solar torque tubes are currently being produced at NTP’s Birmingham, Alabama, mill, which supplies America’s expanding solar energy market. In the future, the Gallatin tube mill will supply these products. Serving the solar energy market is one of the primary reasons for the investment in the Gallatin tube mill,” says Kim Olson, an engineer and construction solutions manager of technical initiatives for Nucor.

The steelmaker’s timing is well planned. “Nucor recognizes tremendous growth in the build out of large-scale solar projects over the next couple of decades as the United States strives for a more robust and greener grid,” notes Frank Fisher, general manager for energy solutions at Nucor. This growth is reflected in projections like those from the Solar Energy Industries Association (SEIA), which cites more than 71 gigawatts of large-scale solar projects either under construction or under development in the U.S. While a number of solar field projects are already operating along both coasts, in Texas and Florida, pending projects cover a broader area, extending up into the Midwest.

PRODUCT LINE

Torque tubes play an important role in solar field projects, supporting the solar panel array in a single-axis tracking panel system. The tube essentially acts as the drive shaft that is motorized and controls the angularity of the panel to follow the sun across the sky and optimize energy capture. Supported at each end by vertical posts forced into the ground, the torque tubes are typically closed sections to efficiently carry the weight of the photovoltaic (PV) panels and resist wind loads. The sections are commonly round, square or rectangular in shape. Due to their exposure to the elements, especially moisture from rain and snow, torque tubes are galvanized to ensure the longevity of the system. Higher strength grades can be used to minimize weight and reduce the amount of steel required,” explains Fisher.

Once the Gallatin tube mill comes on line next summer, galvanized torque tubes will be produced on the same campus as the Gallatin sheet mill, which produces the galvanized sheet used to form the tubes. “We will be able to produce custom orders even more efficiently and quickly for a variety of solar energy customers. We expect our torque tube business to grow greater than 20 percent year over year across the enterprise for the foreseeable future,” adds Fisher.

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       The torque tube business at NTP, including products for the solar energy market, is expected to grow greater than 20 percent year over year across the enterprise for the foreseeable future.

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     Once the Gallatin tube mill comes on line next summer, galvanized torque tubes will be produced on the same campus as the Gallatin sheet mill.

BUILT FOR SUSTAINABILITY

While production within the Gallatin tube mill will provide material for green energy, the mill itself is being built to environmental sustainability standards. Both the manufacturing plant and the administrative offices are being constructed for LEED certification (a U. S. Green Building Council rating system).

“As such, we are including water and energy reduction in our building and equipment design. We are incorporating sustainability features in building materials, such as utilizing Nucor’s sustainable building products, and site development to minimize light pollution and control storm water,” says Edye Raymond, NTP group environmental manager.

All NTP mills, including the Gallatin tube mill, source coil from Nucor’s sheet mills. Every Nucor sheet mill uses an electric arc furnace (EAF) that melts recycled scrap and turns it into new steel.

“EAFs are far less carbon-intensive and more energy efficient than traditional blast furnace steelmaking, which makes steel by burning iron ore and coking coal. These sheet mills are part of the efforts described in our sustainability goals. So, in turn, NTP customers will continue to receive tubular products with the lowest greenhouse gas (GHG) intensity available domestically,” according to Olson.

ECONIQ

Certain steels from Nucor’s EAF can be offered as Econiq, certifying that “the steel is produced from 100 percent renewable energy to offset Scope 2 emissions and that the Scope 1 emissions are countered through the purchase of carbon offsets,” reports Olson. Scope 1 and Scope 2 are key aspects of the Greenhouse Gas Protocol, a joint initiative of the World Resources Institute and the World Business Council for Sustainable Development. These protocols were established following the December 2015 adoption of the Paris Agreement, a global treaty to limit global warming.

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      Nucor Tubular Products support a range of applications in the construction, infrastructure and solar energy markets.

Nucor recently announced a commitment to a 35 percent reduction in GHG intensity by 2030, a move in line with leading manufacturers around the world and ahead of some steelmaking peers.

According to Nucor’s website, its business is 75 percent less GHG intensive than today’s global steelmaking average. The 2030 target will improve this number with an eye toward further reducing carbon intensity to net zero emission steel at scale. “This means Nucor is striving toward being able to produce net zero steel at its sheet mills, which could then be used to create tubular products with net zero GHG emissions,” says Olson.

Making Nucor’s view toward solar energy a synergistic one, the company is investing in renewable energy through virtual power purchase agreements (VPPAs) to achieve its net zero emissions commitment. “Nucor is supporting the development of more than 350 megawatts of new clean energy infrastructure through VPPAs. These agreements enable the construction of both new wind and solar energy projects. So not only is Nucor providing steel to build out our nation’s renewable energy infrastructure, but the company is also investing in the development of solar and wind energy projects across the country,” Fisher says. MM

Sources

Nucor Tubular Products, Birmingham, Alabama, 205/251-1884, http://nucortubular.com/

Solar Energy Industries Association, Washington, D.C., 202/682-0556, http://seia.org/