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Printing on Aluminum Boosts Solar Efficiencies May 13, 2010

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Nanosolar, a San Jose (CA) energy company, has opened an automated facility for manufacturing an innovative new process for cheaper solar panels.  The solar panels are made by printing a semiconductor material called CIGS on aluminum foil.

Nanosolar located the factory in Luckenwalde near Berlin, Germany, in part because German government incentives for the purchase of solar cells has created a large market for solar panels.  The panel factory is automated to sustain a production rate of one panel every ten seconds, or an annual capacity of 640MW when operated 24×7.

It’s not that the cells are that much more efficient than others.  On average, the company’s solar panels convert just 11 percent of that energy into electricity, about the same as most good quality cells, and a little less than high-end cells, which have demonstrated up to 16% efficiency.

What makes Nanosolar’s technology unique is the producability improvements of the panels, and the transmission increases in the panels.  By using large aluminum-foil sheets to collect electrons from each panel, Nanosolar decreases the amount of wiring per panel and has increases the current its panels can generate, up to 160 watts each, compared to 70 watts for standard panels.

But what matters most to consumers is that making panels this way eases installation and lowers production and operations cost.  Based on DoE’s life cycle amortized cost methods,  using these in sunny locations could produce electricity at less than six cents per kilowatt hour (compared to 12 cents for conventional panels), almost as low as coal-fired generation plants.

Nanosolar started in a small laboratory in 2002.  It strives to be a “green” company both in its products and its practices.  It also strives to maintain a  small company feel.  For example, “almost everyone eats lunch in the office café, sitting at whatever table has an opening and enjoying conversations with Nanosolar people from all different departments, executives and operators alike.”

sources: Technology Review, NanoSolar website

Concentrated Solar Shines Bright May 7, 2010

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Concentrating the sun’s rays on a smaller spot is a great approach to boosting efficiency of solar power.  It’s a half-step toward making solar economically viable.

Traditional solar thermal systems use highly concentrated sunlight to create steam that drives electric turbines.  Trouble is, that way takes massive amounts of water to create steam, but abundant clean water is coming to be one of the scarcest commodities in the world.  And taking water from fish and wildlife habitats puts you sideways from environmental regulators.

What Amonix (a California-based startup) has done is to combine Fresnel lenses, a tracking system, and solar cells for large, highly efficient solar-power installations.

Step one is the lens. I know about Fresnel lenses from theater. It takes a small light source (a bulb) and spreads it out to provide wide coverage of an area on stage. Amonix turned it around, to take a wide coverage of sunlight and concentrate it on a small solar collector. These thin, plastic Fresnel lenses, measuring about 350 square centimeters, focus sunlight down to a 0.7 square centimeters spot. That concentrates the sunlight to 500 times its normal intensity.

That concentrated sunlight hits an ultra-efficient multi-junction solar cell made by Spectrolab, the most efficient in the world. They’ve shown 41% efficiency in the lab, and Amonix is able to get 39% in field tests.

These cells are set in an array that’s 23.5 meters by 15 meters, 165 co-joined panels worth. Then Amonix uses a tracking system that keeps the lenses pointed to within .8 degrees of the angle of the sun all day long.

That’s a lot of miracles happening all at once. And we’re worried about the long-term viability of plastic lenses exposed to that much UV radiation. But at least it holds promise for the future.

source: http://www.technologyreview.com/business/25209/?a=f

July 8, 2009

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Bill Gross is CEO of eSolar, and thinks he’s finally found a way to use the power of the sun to generate massive amounts of energy.  He calls it a “disruptive revolution” in carbon-free energy.

Rather than using direct solar to electric conversion, which remains a technical challenge to do efficiently, Gross wants to use a “field of tabletop-sized glass panels” to reflect solar rays on liquid-filled towers.  The heat creates steam to drive a traditional turbine.

The system incorporates video cameras, a bank of Dell servers and complex software to monitor and move the mirrors to track the sun’s position.

Gross claims his power will cost around 10 cents per kilowatt-hour. That would make it less than wind power.    But then, Gross has been called a”serial entrepreneur” –  he’s launched more than 30 tech companies.  He’s also founder of startup incubator Idealab, based in Pasadena, CA.

I hope it works.

Sources:  Technology Review/Solar Thermal Heats Up, by Evan I. Schwartz and eSolar website.

Advent Solar Shuts Manfacturing Plant August 1, 2008

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Solar is hot, right?  Then why aren’t solar companies selling products hand over fist?  That brings us to the story of Advent Solar.

In February, Advent Solar won a marketing award.  Advent is a leading manufacturer of innovative solar cells and modules. Its unique, exclusive EWT cell technology was originally developed at Sandia National Laboratories and is in a class of solar cells referred to as back-contact cells. This technology is the basis for Advent’s high performance products with the potential for dramatically lower cost than conventional solar photovoltaic technology.

So, fresh off such prestigious press, with notice to the world that this company produces some of the best solar cells available, Advent Solar decided it wasn’t enough.  Less than 3 weeks after the award was announced, Advent has closed up manufacturing.   Rather than produce solar cells for sale, they laid off all 68 manufacturing staff (but not the marketing staff).

They say they want to retool for new technology.  The CEO, on the job less than a single fiscal quarter, announced he wanted to retool the whole plant for a new kind of solar cell.  Rather than continue manufacturing, providing collaboration between R&D and those who actually produce the results, he sent his workforce packing.

“Once the technology solution is perfected and put into place, this company has excellent long-term prospects,” said CEO Peter Green. “We will be looking to hire back any of our employees who are interested in returning. There’s not a one I wouldn’t hire back.”

They freely admit that “The industry is growing at 30% to 40% per year, and with the cost of oil going through the roof, demand will remain strong.”

All I have to say is, it better be a huge improvement, at an appropriate price point, or Green will have just closed the company.  And unless he can offer significant incentives to the employees who trust he has just destroyed, it’s gonna take more than a year to get them back.

Look for solar to take off in the market place.  Just be careful putting too many bets on Advent.

Windows as Solar Electricity Collectors April 10, 2008

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One of the most energy inefficient parts of commercial buildings- those massive walls of glass – could soon become the means of powering that same building.

Researchers at the Institute of Sustainable Resources (ISR)  at Queensland (Australia) University of Technology (QUT) have been working with Dyesol (an Australian company) to develop transparent solar cells that act as both windows and energy generators in houses or commercial buildings.

Officials at Dyesol explain that “the solar the panels are constructed in a laminated structure, with the tiles connected and sandwiched between two panes of glass and fully encapsulated in the UV resistant transparent laminating polymer (Solar Wall Panels). … Electrical interface can be typically via a short DC bus to a local area network for distribution or inversion to AC.”

Professor John Bell explained that the solar cells contain titanium dioxide coated in a dye that increases light absorption.

“The transparent solar cells have a faint reddish hue but are completely see-through,” Professor Bell said.  “The glass captures solar energy which can be used to power the house but can also reduce overheating of the house, reducing the need for cooling.”

“As long as a house is designed throughout for energy efficiency, with low-energy appliances it is conceivable it could be self-sustaining in its power requirements using the solar-cell glass,” he said.

sources:  expertguide.com.au and Dyesol web site

“The Persian Gulf of Solar” February 24, 2008

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Abengoa Solar will soon begin construction of the world largest solar generation plant, a 280-megawatt plant 50 miles southeast of Phoenix. The plant is expected to be in operation by 2011, and will be producing enough energy for 70,000 homes, in partnership with Arizona Public Service.

Abenga says the solar plant has been named Solana, meaning “a sunny place” in Spanish. The company’s fact sheet says that “the plant will employ a proprietary Concentrating Solar Power (CSP) trough technology developed by Abengoa Solar, and will cover a surface of around 1,900 acres.”

The Solana Generating Station’s technology uses “trackers with high precision parabolic mirrors that follow the sun’s path and concentrate its energy, heating a fluid to over 700 degrees Fahrenheit.” Unlike most solar energy, Solana will use the sun’s heat, not its light, to produce power, and that region of Arizona can reach 120 degrees in the summer.

Abengoa CEO Santiago Seage said the plant will use thousands of giant mirrors to harness the sun’s heat. The plant uses the stored heat to create steam to turn generation turbines. This unique approach will let them store the heat to be able regulate when and how much electricity they will produced, even after the sun has set.

In a CNN story on the new plant, Arizona governor Janet Napolitano said she envisioned the state as a solar powerhouse. She said “There is no reason that Arizona should not be the Persian Gulf of solar energy.”