September 2010- As consumer and government interest in renewable energy grows so does the need for metals and alloys with which to build new energy structures.
"The market is almost being legislated into existence," says Allan Bennett, vice president of solar market development with Hydro Aluminum Extrusion Americas, Baltimore, Md. Many states have Renewable Portfolio Standards that mandate they must get specific amounts of their electricity from renewable sources by certain dates, he says.
Such standards create demand for renewable energy and clean energy supplies, according to the Environmental Protection Agency. As of March 2009, 33 states and Washington, D.C., have established energy guidelines, according to the EPA. Standards differ across states, with some states choosing to specify types of renewable energy. For example, Delaware has mandated 20 percent of electricity sales will come from renewable sources by 2019, with 2.005 percent coming from solar energy, according to the EPA.
This is good news for the aluminum market, which sees the solar market as a growth opportunity, says Bennett. Hydro currently is supplying extruded frames for photovoltaic arrays in a 1-megawatt solar field. The installation is one of eight solar projects a major computer chip manufacturer in California is building, according to Hydro.
The eight solar fields, which should be completed later this year, will generate roughly 2.5 megawatts of power. The installation is using roughly 40,000 pounds of aluminum, says Bennett. It will cover nearly six acres of land, making it one of the largest non-utility ground-mounted solar installations in the state, notes Hydro. It is the only installation of the eight that will be mounted on the ground instead of on a rooftop.
Hydro is working with Terrafix Solarpark[www.terrafixsolarpark.com], San Leandro, Calif., on the project and has been working with the company since last year. Terrafix has developed an earth screw that anchors solar installations to the ground.
Previously, Hydro had supplied more than 7 million pounds of extruded tubing and connectors for a solar project known as Nevada Solar One. Located near Las Vegas, the installation generates 64 megawatts of power, says Bennett. In addition, Hydro has supplied material for three fields in Spain and one in Florida, totaling nearly 300 megawatts of power.
Aluminum is a good fit for solar-energy installations because the carbon footprint of the material is low, says Bennett. "One of our advantages is that the metal in the aluminum in our extrusions is 75 percent post-industrial recycled content," he says. "And aluminum has the quirky little characteristic that recycling it takes only 5 percent of the energy of creating it from a primary standpoint."
Hydro's recycled aluminum has a carbon foot print less than half of recycled steel, says Bennett. "You add in the recycled content and the fact that it takes relatively little power to recycle it, and that gives us a lower carbon footprint," he says.
Additionally, using galvanized steel posts in solar installations creates potential leaching problems in the soil, says Bennett. The zinc from the galvanization process "is leaching off into the soil almost immediately and essentially almost poisoning the ground around it," he says. It is necessary, however, to galvanize the steel to keep it from corroding. Aluminum does not corrode or leach, which makes it a good fit for solar installations. Aluminum also is lighter weight than some materials, which aids in handling and assembly, notes Bennett. Some of the frames with which Hydro has worked "have gone together in less than half the time of an equivalent steel frame, meaning less labor cost," he says. MM