SIEMENS

Light emitting diodes (LEDs) have a reputation for running cool. Touch one and all you’ll feel is a serene glow. But just try and pack dozens of them together in a tight space and they’ll get so hot that they can burn out within seconds. Now, however, Progressive Cooling, a startup company funded by Sie - mens’ Berkeley, California-based Technologyto- Business Center (TTB), has developed a solution that makes it possible to pack over 80 of the brightest white LEDs onto a one-squareinch circuit board. The result: A light source significantly brighter yet far more energy efficient than the metal halide or sodium lamps now used to light factories, warehouses, a height of 18 to 30 feet, resulting in an ideal 30 foot candles on the work surface. “To put that in perspective,” says Progressive Cooling Senior Scientist Dr. Praveen Medis, “a 100-Watt incandescent bulb typically produces 1,200 lumens. So what we are saying is that we have packed the equivalent of twelve100-watt bulbs into a flat one-square-inch device, making it the brightest LED source in the world.”

In addition, the device cuts energy demand by 60 percent compared to conventional metal halide lamps, and, thanks to the fact that it can be addressed wirelessly and dimmed from zero to 100 percent, its power demand can be reduced by an additional 20 to 25 percent in response to changing lighting requirements. Reduced maintenance costs are another major advantage. While metal halide lights typically last 12 to 18 months, Progressive Cooling’s device is rated to last five years and has been designed to screw into an existing mount. “That’s a key feature,” says Shuja, “because changing high-bay lights at a height of 18 feet requires a scissor jack and two experienced workers.” Plans call for Progressive Cooling to begin seeding the market with its mercury- free LED product this year.

Banyan: Focus on the Sun. Probably the biggest barrier facing widespread implementation of photovoltaic energy is the high cost of streets and airport runways. “In the U.S. alone there are about 100 million so-called ‘high-bay’ fixtures in commercial buildings and about 60 million bulb changes per year,” explains Progressive Cooling CTO and founder Dr. Ahmed Shuja.

The technology that allows tightly-packed LEDs to keep their cool is a patented micro thermal management engine that contains some 60 million vertically-etched uniform pores per square centimeter on a flat silicon substrate.

The technology allows capillary force to efficiently channel heat away from diodes and into a halo of fins that surround Progressive Cooling’s light source.

Originally developed at the University of Cincinnati to reduce the cooling requirements for microchips on miniature satellites and subsequently adapted to server farms (see article “Saving Our Planet for Tomorrow”, Pictures of the Future 1/2008), Progressive Cooling’s concept has been “re-vec tored to the LED market to take advantage of the fact that a totally integrated LED fixture will have significant competitive advantage in the commercial illumination market over traditional metal halide bulbs,” says Shuja.

Based on Osram’s newest Oslon LED, which can be driven to produce up to 200 lumens, Progressive Cooling’s new device delivers some 15,000 lumens over an 80-degree angle from a height of 18 to 30 feet, resulting in an ideal 30 foot candles on the work surface. “To put that in perspective,” says Progressive Cooling Senior Scientist Dr. Praveen Medis, “a 100-Watt incandescent bulb typically produces 1,200 lumens. So what we are saying is that we have packed the equivalent of twelve100-watt bulbs into a flat one-square-inch device, making it the brightest LED source in the world.” In addition, the device cuts energy demand by 60 percent compared to conventional metal halide lamps, and, thanks to the fact that it can be addressed wirelessly and dimmed from zero to 100 percent, its power demand can be reduced by an additional 20 to 25 percent in response to changing lighting requirements. Reduced maintenance costs are another major advantage. While metal halide lights typically last 12 to 18 months, Progressive Cooling’s device is rated to last five years and has been designed to screw into an existing mount. “That’s a key feature,” says Shuja, “because changing high-bay lights at a height of 18 feet requires a scissor jack and two experienced workers.” Plans call for Progressive Cooling to begin seeding the market with its mercury- free LED product this year.

Banyan: Focus on the Sun. Probably the biggest barrier facing widespread implementation of photovoltaic energy is the high cost of silicon panels. With this in mind, five former graduate students of the University of California at Berkeley and Stanford University have for - med Banyan Energy, a company whose patented technology and proprietary intellectual property promise to reduce the area of silicon photovoltaic material in a standard module by 90 percent while producing the same amount of power as a conventional module. What’s more, the inventors calculate that the cost of production facilities for such modules will be 75 percent lower than for today’s facilities.

Funded by an investor group led by Sie - mens, the company has been selected by the U.S. Department of Energy for a technology development subcontract and is already working with the U.S. National Renewable Energy Laboratory. “Siemens TTB not only invested in us from the start,” says Banyan CEO Shondip Ghosh, “they really drove the process and did the due diligence.” Adds Ayman Fawaz, PhD, Director of Venture Technology at TTB Berkeley, “We are helping Banyan demonstrate that their technology is viable. The next step will be to see if Siemens’ solar organization will adopt the technology.” Simply put, Banyan’s concept is to replace expensive silicon cell material with economical optics. Ghosh explains that while many other companies have attempted to adapt clumsy magnification systems to PV panels, Banyan’s “aggregated total internal reflection” concept uses a sheet of optical elements that is only 1 cm thick.

“The energy falling on the optics is aggregated and delivered to a focal area, which is where the photovoltaic material is located. The key is that the collection process is performed by the optical layer rather than by the silicon cells,” says Ghosh. Since the technology can be integrated into the standard dimensions of current PV panels, it offers numerous downstream advantages, including identical shipping, handling, installation, and cleaning requirements. But perhaps its greatest advantage is that it reduces the capital expenditure of manufacturing the panels themselves. Today, such panels are covered with silicon wafers. The wafers are sliced from ingots and then processed and mounted. “To build a conventional fabrication facility with a gigawatt worth of annual production capacity, you would have to spend about $1.2 billion,” says Ghosh.

“But with our system you can shrink your plant size for the ingot, wafer and cell steps by a factor of ten. As a result, a gigawatt facility would now cost only about $300 million. So we can significantly reduce the capex for manufacturing, which means that for every dollar such a company invests, they can build four times the production capacity as they otherwise would.”

Banyan is particularly interested in entering the market for large field installations that are designed for tracking the sun – an application that maximizes the yield from its unique optics. “Installations that track the sun produce about 25 percent more energy than static installations,” says Ghosh. “This more than offsets the added cost of tracking systems. What’s more,” he adds, “the growth rate in large field installations is twice the rate of the rest of industry.” The world market for solar panels is now at five gigawatts per year and rising rapidly.