Until now, visions of Arizona homes powered by renewable energy have centered mostly on rooftop solar panels or huge solar power plants in the desert.
A Spanish company setting up operations in the Valley is promoting a new vision: developments built around generating stations providing solar power by day and generator power, preferably running on renewable fuels, after the sun goes down.
Aora Solar offers a community–scale power facility that can be built on a half acre and can generate 100 kilowatts, enough for between 60 and 100 homes. The centerpiece is a 100–foot–tall, tulip–shaped tower that an array of mirrors hits with sunlight to turn a turbine with superheated air.
Zev Rosenzweig, the company’s CEO, said the American Southwest is an ideal location for the technology because the plants use little water and can capitalize on the region’s abundant sunshine. The technology is in use at a plant in Israel and at a plant that is awaiting commissioning and certification in Spain.
“Today, we’ve been approached by quite a number of architects who want to design housing developments with our tower in the center because it’s aesthetically pleasing and it doesn’t dominate the neighborhood and it will create a sort of island of energy independence around it,” he said.
Rosenzweig expects a community–level system to sell for about $500,000, though the final price will depend on the quantity sold. His primary market is companies planning new developments, though he said the technology can provide power at a larger scale for industrial use, among other possibilities.
Aora is collaborating with Phoenix–based Sisener Engineering N.A., Corp., the U.S. branch of a Spanish firm that specializes in design engineering. The firms are seeking permits to build two solar towers in a research park near Sky Harbor International Airport and expect that to be completed within three months.
“It’s a very good location for this company,” said Michael Horner, CEO of Sisener Engineering. “The southwest United States has some of the best solar radiation in the world.”
Harvey Bryan, a senior sustainability scientist at Arizona State University’s Global Institute of Sustainability, said the companies are up against the increasing popularity and affordability of photovoltaic solar panels, which are now the dominant technology. It could be a tough sell to get firms to invest in such a complex technology when there are simpler and cheaper options available, he said.
“I’m not 100 percent sure this solar tulip will take off,” Bryan said. “The economics seem to be pushing us toward photovoltaic.”
Rosenzweig said his company’s design offers advantages over rooftop solar, including the ability to provide power at night.
“We have flexibility that other solar systems don’t have,” he said.
• Central feature: A 100-foot-tall tower shaped like a tulip.
• Function: Light focused by an array of mirrors superheats air in the tower, turning a turbine.
• Output: 100 kilowatts, enough to power up to 100 homes.
• At night: Offers a generator that can run on renewable fuel.
• Space: Can be built on a half acre.
• Cost: Around $500,000.
• Maker: Aora Solar of Spain.