Cost-Savings of Using Aluminum in the Solar Industry
Advantages of Aluminum in Solar
The benefits of using aluminum in rooftop solar installations have been widely documented. Aluminum is lightweight, very strong, resists corrosion and is highly recyclable – all of which combine to make it the material of choice for use with solar systems. Factoring in logistical considerations, ease of fabrication and low maintenance requirements, its benefits more than compensate for a lower initial expenditure with galvanized steel or other rolled materials. Aluminum often makes possible projects that are prohibitive with steel or other systems, as pointed out by Sapa customer, Advanced Racking Solutions, Inc.
"Often a rooftop photovoltaic project doesn't get built if the roof has limited structural capacity and the mounting system is heavy. The aluminum wind deflector and rails of our Advanced Racking Systems mounting solutions offer a considerable advantage over the competition as the system weight including solar module is less than 2psf."
Lisa Oelke, Manager Business Development North America, Advanced Racking Solutions Inc.
Another advantage of aluminum is its design flexibility. Through the extrusion process, aluminum can be formed into intricate designs and consistently manufactured to the specifications of complex mounting systems, module frames and other structural components, a process that would be impossible to replicate with steel. Extruded profiles also require minimal secondary processing and make for a speedier installation. Aluminum requires much less maintenance than steel, due to its corrosion-resistant properties.
Changes in the Industry
The solar industry has reached a point where differences between systems depend more on how they are installed rather than the solar panels themselves. "Over the years, the mass commoditization of crystalline panels has made the PV panels themselves fairly uniform," says Scott Condreay, senior manufacturing engineer in Sapa's North America Technical Center. "The truth is solar crystalline panels are now mostly the same. It's the mounting systems underneath that are more important, and those systems are critical."
Now many in the industry believe the time has come to make better use of aluminum in ground-mount systems as well, where steel has long been seen as the prime material.
Comparative Study Proves Aluminum is Cost Beneficial
An independent study conducted for the Aluminum Extruders Council by consulting firm IBIS Associates confirms aluminum's cost advantages over steel. The study shows that while steel is less expensive on a dollars-per-pound basis, aluminum offers significant cost savings over the life of a solar installation.
In order to compare the costs of aluminum to competing materials, the IBIS study established baselines for each category, including ground-mount systems. Researchers created designs by collecting information from a variety of sources, including racking component and system suppliers, PV integrators and acquisition costs, shipping costs and installation labor expenses. In addition, they obtained price quotes from a range of suppliers and estimated delivery and installation labor costs based on location-specific rates.
For its examination of ground-mount systems, the study considered three fixed-axis systems of different sizes (1MW, 5M and 50MW) to see whether volume affected pricing. IBIS based the design on the more common installation process calling for galvanized steel beams being pile driven into the soil (rather than attaching the mounting structure to a concrete foundation). While aluminum posts cannot withstand pile driving, they can be used as supporting posts.
In formulating a cost comparison, the IBIS consultants determined that although aluminum is a more expensive material on a per-pound basis, its overall cost is comparable to steel (see Figure 1 below). In addition, aluminum out-performs steel in both installation and shipping cost efficiency.
Figure 1: System Acquisition Cost Estimates
Recyclability Increases Aluminum Value
The advantages of aluminum are clearly most compelling in roof-top installations because of weight considerations; however, there are legitimate reasons, like recyclability, to consider aluminum extrusions for even the largest ground-mount installations.
The IBIS study used a ground-mount system to compare the recycling value of aluminum and steel. Based on scrap values for each material provided by the U.S. Geological Surveys, when decommissioned, the aluminum structure would be worth three times that of steel, according to the study.
"Some people look only at the cost of the product itself, but it's important to remember the total installed cost over the life of a project," says Jason Weber, manager of business development, renewable energy for Sapa Extrusions North America. "A steel mounting system may initially cost less than a comparable aluminum system, but when you look at the additional labor required by a steel system and added shipping costs, aluminum comes out ahead." Plus, when the system is ready to be decommissioned, scrap aluminum is vastly more valuable than steel.
As the Aluminum Association points out, recycled aluminum pays for its own cost of collection - and then some - compared to the recycling costs associated with other materials such as steel, glass, plastics, or paper, which come at a premium.
Weber also points out that recycling aluminum is far more energy efficient than recycling steel. "Recycling aluminum takes only five percent of the energy it takes to make new aluminum, whereas steel requires an equal amount," Weber states. "And keep in mind that aluminum can be recycled over and over without degrading."
One-stop Shop for Aluminum Needs
Supply logistics is an important differentiator for Sapa. With its large manufacturing footprint—16 manufacturing plants in North America—the company can ship directly to the customer from the nearest plant, cutting down freight costs. Rather than having to develop a supply chain with multiple suppliers, Sapa customers can enjoy one-stop shopping.
At the plant, Sapa fabricates the extrusions from machining, punching and cutting to anodizing and processing, delivering finished parts right to the job location.
Once at the installation site, crews save time because the systems are ready to go. "We are able to produce complicated, patented designs for mounting systems, and the crews in the field simply fit them together," Scott Condreay says. "It's like a gigantic Erector set." Condreay points out that for every pound of PV panel, there is between three-and-a-half to four pounds of supporting aluminum mounting structure underneath.
In addition, being a global company, Sapa can take advantage of knowledge-sharing around the world. Particularly in solar mounting systems, many of the design advances have traditionally come out of European companies with whom Sapa has technology sharing relationships. Additionally, through its Technical Center based at corporate headquarters in Sweden, Sapa collaborates with its North America counterpart in sharing these design solutions and best practices, enabling a truly global service offering for many of Sapa's customers who are based in multiple markets around the world.
This has resonated in North America particularly, where Sapa has seen strong growth in sales to the solar industry over the past few years. Weber states, "Sapa's offering has been enthusiastically received by our solar partners and we witnessed double digit growth in our market share in this application in each of the last three years."