On the EarthTechling Utterly Cool Projects Scale™, the EnviroMission Solar Tower project might be unrivaled. More than 2,600 feet tall, with a mile-in-diameter greenhouse canopy at its base creating hot air that is sucked up into the tower, spinning electricity-creating turbines along the way – it’s like something a kid would build in Minecraft.
You can’t help but hope this thing rises, as planned, in the western Arizona county of La Paz, just to see if something so brash might actually work. So here’s good news: More than a year after securing a power purchase agreement with the Southern California Public Power Authority, EnviroMission says it “has received a formal commitment to provide the entire development and construction capital” for the project.
Mind you, the Solar Tower still isn’t a sure thing. The support from the unnamed source “is subject to the due diligence and the acceptance of related banking instruments by EnviroMission’s legal advisors and bankers,” EnviroMission says. But if the money comes through – and EnviroMission said it expects to know early this year – the Australia-based company says it will “form the basis of the ongoing financing for the development of Australian Solar Tower power stations in the U.S., and other global markets, including Australia.”
Now, you might have seen towers associated with solar-power development before. But this utility-scale tower-based technology is nothing like the power tower projects that have popped up in Europe and are coming to the United States. Those systems, known as concentrating solar power, use vast arrays of heliostats to direct light to the top of a tower several hundred feet high, where water or other liquids can be heated to help produce electricity.
The EnviroMission tower concept uses the greenhouse effect and thermal dynamics to produce power. Air is heated under the vast canopy (the greenhouse, if you will). The warm air expands and becomes less dense. It needs to rise – and what do you know, there’s an immense tower at the center of the canopy, where the ambient air is cooler every step of the way upward. That creates a convective effect. Swoosh! The air under the canopy is sucked up into the tower, passing by and turning turbines on its journey.
EnviroMission says this technology was actually used in real life – on a much smaller scale – in Spain.
“Solar Tower technology has been tested and proven with a successful small-scale pilot plant constructed in Manzanares, Spain,” the company says on its website. “The pilot project was the result of collaboration between the Spanish government and the German designers, Schlaich Bergermann and Partner. The plant operated for seven years between 1982 and 1989, and consistently generated 50 kilowatt output of green energy. The pilot plant conclusively proved the concept works and provided data for design modifications to achieve greater commercial and economic benefits associated with an increased scale of economy.”
The company has said the project can be built for $750 million.