Our technology, which is the basis for our power plants, is "reshaping solar energy" in a very literal way: Most of today's solar energy systems take the form of flat panels or boxes-with-lenses and require large amounts of heavy, expensive materials. Our inflated solar concentrators, on the other hand, are shaped like balloons and are primarily made of inexpensive and free materials. This design approach radically reduces material requirements as well as our plant deployment costs and time.
Our inflated, balloon-shaped concentrators are key to Cool Earth's innovative design. Each 8-foot-diameter concentrator is made of plastic film—the same kind of plastic film used to bag potato chips, pretzels, and so on—with a transparent upper hemisphere and a reflective lower hemisphere. When inflated with air, the concentrator naturally forms a shape that focuses or concentrates sunlight onto a PV cell placed at the focal point. This means we need fewer cells to produce a lot more electricity. In fact, a single cell in our concentrator generates about 300 to 400 times the electricity of a cell without a concentrator.
The inflated structure is naturally strong—strong enough to support a person's weight—and aerodynamically stable, able to withstand winds of 125 miles per hour. Finally, the transparent upper surface protects the PV cell and mirrored surface from the environment, including rain and snow, as well as insects and dirt.
Each concentrator has additional structural components: a small steel strut and a harness. The steel strut, tethered in place, holds the cell at the focal point inside the concentrator and provides a conduit for a small water loop that cools the cell. A lightweight, flexible steel band forms a harness around the circumference of the concentrator and is used to hold and point the concentrator.
The concentrators are suspended with our patented support system, which is based on the architectural principles of tensegrity. (Tensegrity structures stabilize their shapes by continuous tension or "tensional integrity" rather than by continuous compression.) The resulting system of wood posts and steel cables uses a minimum amount of material, has a small footprint, and causes the least disruption to the natural environment of any solar power plant.
All in all, a simple, elegant solution.
Just how much electricity does the world use?
Electric power plants produced 17,320 terawatt-hours (TWh) in 2005. In 2030, the world is projected to need about 33,264 TWh—nearly double the amount of 2005.
Source: 2008 EIA International Energy Outlook Report.
How much energy does the Sun provide?
The amount of sunlight that hits the Earth's surface in one hour is enough to power the entire world for a year.
How many solar power plants would the U.S. need to meet its electric needs?
One solar power plant, using Cool Earth's technology, covering 150 miles by 150 miles, would generate enough power to meet all the electrical needs of the United States through 2030.
What exactly is tensegrity?
Tensegrity is an architectural concept first defined by R. Buckminster Fuller. For more information, see this page from the Buckminster Fuller site or view this YouTube video on building step-by-step tensegrities.