PORTLAND, Ore. — In cooperation with Airlight Energy Manufacturing SA of Biasca, Switzerland, IBM Research of Zurich has repurposed its micro-channel water cooling system for high-performance computing that is 10X more efficient than air cooling. The dish-based photovoltaic system that concentrates the sun's rays up to 2,000X and converts up to 80% of them to produce 12KW of electricity and 20KW of heat -- enough for several houses -- from multi-junction InGaAs solar cells. In addition, it can reuse the heated water for cooling air or desalinating and making drinkable 30 to 40 liters of water in arid climates near the sea.
"The water cooling system is modeled after the biological hierarchical branch network of blood vessels in the human body to minimize the pressure drop in cooling to only 1%," Bruno Michel, a research scientist at IBM, tells EE Times.
Airlight Energy already produces trough-based solar concentrators that produce megawatts for industrial applications, but it is collaborating with IBM to bring the price of solar power down enough that individual businesses and homes can afford these products. Airlight Energy recently spun off Dsolar (dish solar) to market, license, and sell standardized dish-based solar concentrators worldwide. Dsolar pays royalties for cooling technologies it has licensed from IBM.
This solar dish produced up to 20 KW thanks to a collaboration between Airlight Energy, which has perfected low-cost solar concentration to 2,000X, and IBM, which has perfected water-cooling chips down to 105 degrees that would otherwise be driven up to 1,500 degrees.
(Source: IBM/Airlight Energy)
"Airlight Energy has proved the concept, and by the end of 2014 will have a full-scale prototype, ready for pre-commercial early adopters by the end of 2015," Ilaria Besozzi, business development manager at Airlight Energy tells EE Times. IBM is also announcing today a Smart City Challenge to cities and communities worldwide where two winners will have Dsolar dishes installed on their sites in 2016. Airlight Energy is also offering an Early Adopters in businesses challenge, the five to seven winners of which will have Dsolar dishes installed in 2016, too. Then in 2017 Dsolar will offer fully commercial dishes for sale to anyone.
Most solar concentrators achieve about a 500X increase, but because of IBM's chip cooling system, they can increase the solar concentration to 2,000X, allowing the system to reduce the number of expensive multi-junction solar cells required.
A small prototype of the IBM cooling manifold extracting the heat from the nine multi-junction solar cells in the center.
Thus the "Sunflower" as its inventors call it, reduces the cost of the solar cells by a factor of four -- since four times more sunlight is concentrated on them. Replacing a steel dish with reinforced concrete cuts the dish's cost by a factor of three. Besozzi points out that combining electricity generation with desalinization and air cooling (based on a thermal-driven sorption chiller cooler) makes the Sunflower a unique value for areas of the world where all three types of systems are needed and otherwise would have to be purchased separately.
Airlight has been experimenting with concrete substrates and plastic foil mirrors for several years, the first two were trough-based, but the sunflower is its third-generation solar concentrator. The Sunflower is 10 meters (32 feet) in height. The dish measures 40 meters (132 feet) in diameter. It can be molded into any shape in less than four hours, with a mechanical strength similar to aluminum at one-fifth the cost.
The concrete dish houses 36 elliptic mirrors made of 200-micron-thick aluminum foil with a silver coating that concentrates the sun's energy on an array of multi-junction photovoltaic cells, each one centimeter (0.4 inches) square, each of which produces 57 watts on a sunny day. A tracking system rotates the Sunflower to keep it directly aimed at the sun for maximum electricity generation. The whole assembly is enclosed in an inflated greenhouse-like plastic dome to keep it clean.
The Sunflower has an expected lifetime of 60 years with proper maintenance, including replacing the mirrors every 10 to 15 years and the photovoltaic cells every 25 years.
For more information view the TED@IBM presentation, which will be available soon.
— R. Colin Johnson, Advanced Technology Editor, EE Times