Renewable energy—or green power—has been receiving renewed and increased attention recently. Solar power is one of many power sources that have the potential to reduce our dependence on fossil fuels, thus reducing the harmful effects of greenhouse gas emissions. Today, aluminum extrusions are playing an integral role in making utility-scale solar energy a reality.

Aluminum extrusions play an integral role in the Solargenix xollector system for the Nevada Solar One project. Photo courtesy of Gossamer Space Frames.

Nevada Solar One—the mammoth 64-megawatt Solar Thermal Electric Generating Plant located in Boulder City, Nevada became operational in May 2007. Solargenix, the developer and lead for the 400-acre project, was looking for a new way to build solar collector frames—something that was more cost-effective, easier to assemble, and more precise. Enter Gossamer Space Frames of Long Beach, California and their new space frame technology called the Organic Connector made of aluminum extrusions.

Space frame was manufactured to extremely tight tolerances thanks to extruded aluminum. Photo courtesy of Gossamer Space Frames.

Collaborating with Hydro Aluminum, Gossamer fine-tuned the design and manufacturing processes to come up with a highly accurate space frame consisting of 36 components manufactured to extremely tight tolerances to support the solar mirrors. The design allows for fast, easy, and accurate assembly of all 9,120 space frames, which were assembled in record time. The design, which improved the way of connecting tubular elements at odd angles with the fewest components and fasteners, is so precise that the National Renewable Energy Laboratory concluded that the mirrors were 34-percent more accurate than the nearest competitive design—translating to a four percent increase in energy production. All thanks to aluminum extrusions!

Extruded aluminum use in solar rooftop panels, solar arrays, and solar power stations is increasing rapidly. Gossamer’s Glenn Reynolds, P.E. says, “For the rooftop mounting of photo voltaic modules, aluminum is both lighter and more corrosion-resistant than any other economically competitive material. Existing rooftops are usually not designed to handle more dead loads, so any additional structure installed on the roof must be as light as possible. For any type of solar power generating application, roof top or ground, some sort of supporting frame needs to be provided. Extruded aluminum frames bear the great advantage of the ability to be extruded with very thin walls. Our wall thicknesses have been down in the 0.058” range.”

Gossamer's president Glenn Reynolds along with partners Gary Curtis and Dean Hackbarth were winners of the ET Foundation's 2005 International Aluminum Extrusion Design Competition.* The team won in the structural category for their design of coaxial joint technology, which uses machine-threaded sleeves and couplings to connect round pipe to a joint resulting in a precise, rigid attachment without welding. Similar technology is used for the Nevada Solar One project.

For more technical information on designing to close tolerances using extruded aluminum, as well as standard dimensional tolerance tables, see the Tolerance section of this website.