Cool Earth has developed breakthrough solar technology that can ultimately produce enough clean energy to address the global energy crisis. This patented concentrated photovoltaic (CPV) technology dramatically reduces the cost and time to develop solar power plants capable of generating massive amounts of clean energy at prices competitive with fossil fuels.
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.
Solar Concentrators Focus the Sun…
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.
A Support System Holds It All in Place…
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.
…And, That's It!
All in all, a simple, elegant solution.
For More Information— Please download a copy of our Solar Power 2006 Presentation in PDF format.