Schuco Designs a Cooler Module

Energy Technical Advances

April 30, 2009

Schuco Designs a Cooler Module

Schuco has redesigned its photovoltaic modules to help them stay cool. As they heat up in the sun, today's silicon PV cells lose about one half percent of their power for every degree Celsius. Schuco engineers used the FloVENT computational fluid dynamics (CFD) software from Mentor Graphics Corporation Mechanical Analysis Division (formerly Flomerics) to model energy absorption and reflection, and to simulate heat flow out to the aluminum frame and surrounding air. By optimizing heat flow, Schuco gets a cooler, more powerful module. "As the first in our industry to perform CFD simulation, we believe that we are now able to provide our customers with substantially higher power output than an equivalent competitive design," said Hamid Batoul, technical director of Schuco's solar department in Paris.

Suntech Pluto Cells Achieve 18 Percent Efficiency
Suntech announced in March that it's routinely achieving conversion efficiencies up to 19 percent with monocrystalline photovoltaic cells and 17 percent with multicrystalline cells, in large-scale production, by using the Pluto anti-reflective technology developed at the University of New South Wales.

Independent testing at the Fraunhofer Institute for Solar Energy Systems in Germany confirmed 18.8 percent conversion efficiency for a monocrystalline Pluto PV cell, and 17.2 percent for a multi-crystalline cell. Both cells came from Suntech's 34MW Pluto production line.

Dr. Stuart Wenham, Suntech's chief technology officer, noted that this performance compares to 16.5 percent and 15.5 percent, respectively, using conventional screen-printed surface technology.

The patent-pending Pluto technology is based on the PERL texturing technology, dramatically reducing reflectivity to achieve a world record efficiency of 25 percent in the laboratory. Pluto texturing should improve power output by approximately 12 percent above conventional screen-printed cells, and it can be applied to a variety silicon grades. Within two years the company expects to achieve 20 percent conversion efficiency on production monocrystalline cells and 18 percent on multicrystalline cells. A total of 100MW of installed Pluto capacity was operating in May, and the company planned to ship more than 50MW of Pluto modules in 2009.

California Solar Farm Tests Thin-Film
Against Crystalline Modules
In late March, Conergy completed installation of what they believe is the world's first single-axis tracking system using thin-film photovoltaic panels, for the South San Joaquin Irrigation District (SSJID) in Manteca, Calif. The 419-kilowatt array is Phase 2 of a 1.6 MW solar farm designed to handle nearly all the power needs of the DeGroot Water Treatment Plant, which process 40 million gallons daily for 155,000 customers in Manteca, Tracy, Escalon and Lathrop. Energy savings of nearly $400,000 a year will stabilize customer costs during a state-wide water crisis. Construction is supported by $6 million in cash incentives from the California Solar Initiative program, which pays up to 30 percent of system costs for businesses, public agencies and home owners who go solar.

The project tests crystalline against thin-film technologies. Phase 1 uses 6,720 Conergy 175-watt crystalline modules mounted on a single axis solar tracking system. According to Conergy's Western U.S. Project Director David Vincent, First Solar thin-film modules were selected for Phase 2 because they perform at a lower cost-per-watt than traditional crystalline. "Early indications show the output per DC kW of First Solar thin-film is about 10 percent higher than that of crystalline," he added. Installation time was three months.

Using a Fat Spaniel monitor system, SSJID can also compare output with a 1 MW Conergy fixed-axis roof-mount system on a fruit-packing house in nearby Hanford, Calif. Thus far the single-axis systems have run 15 to 18 percent ahead of the fixed array.

World's Largest PV Plant to Power America's First All-Solar City
In March, Florida Power & Light (FPL) announced plans to build a $400-million, 75-megawatt photovoltaic array near Fort Myers, Fla. It would be the biggest PV installation in the world.
In April, real estate developer Syd Kitson unveiled plans to feed FPL's PV output into smart grid for the nation's first solar-powered city. His $2 billion Babcock Ranch project would build 19,500 new homes, all certified by the Florida Green Building Coalition. 6 million square feet of residential, industrial and retail space would provide about 20,000 permanent jobs.
The townsite sits in the middle of a 73,000-acre tract contracted for sale to the State of Florida for preservation and recreational use. The state chapters of the Audubon Society, the Sierra Club and local conservation groups sent representatives to a press conference April 9 to endorse the plan.
FPL hopes to break ground on the PV plant before the close of 2009, and Kitson expects to sell houses in 2011.

Waste Heat Drives Heat Pump Cooler
Engineers at Oregon State University have designed a heat-pump cooling system that runs off the waste heat from an internal combustion engine. The U.S. Army hopes to add the unit to stationary diesel generator sets, where exhaust heat could drive air conditioning for electronic equipment or living quarters. The strategy could improve cooling efficiency by 20 to 30 percent.
The system, based on microchannel heat transfer technology developed jointly by OSU and the Pacific Northwest National Laboratory, should be demonstrated this summer, according to Richard Peterson, a professor of mechanical engineering at OSU.
The first prototype will be a 5 kilowatt cooling system, a little larger than an automobile air conditioner, Peterson said. Eventually the new heat-driven cooler might replace most automotive air conditioning, making good use of heat energy that's now being blown out the tailpipe. The integration of a generator into this technology might allow it to also produce electricity instead of air conditioning, depending on what was needed.
A chiller could also be driven by moderately concentrated solar energy to provide a building's air conditioning on hot, sunny days.

MIT Team Uses Virus to Grow Lithium Battery
A team led by Angela Belcher at MIT in March announced successful tests of a light, flexible lithium battery based on carbon nanotubes. The battery is "grown" by engineered viruses.

By manipulating a couple of genes, the bacteriophage virus M13 was induced to fix ions to carbon nanotubes, forming electrodes. In 2006, the team announced creation of nanowire anodes in which the virus attached negatively-charged cobalt oxide and gold particles. The rest of the battery came together with the demonstration of a cathode, fixing iron phosphate.

In both processes, the virus attaches at one end to the nanotube and at the other end to the oxide or phosphate material.

With more robust chemistry, possibly using manganese or nickel phosphates, Belcher says the process could be used to grow light, flexible, powerful batteries in the shape of any container. Because it's a room-temperature process using only water as a solvent, biobattery manufacturing might have a low energy footprint and benign environmental impact. The virus itself, in nature, attacks certain bacteria and is harmless to humans.

Posted by Seth Masia, SOLAR TODAY | pv technology,April 2009