Concentrating solar tech has been getting the stinkeye from some industry observers, with the main beefs being high complexity and high costs compared to conventional solar panels. Nevertheless, the US Energy Department has made a national showpiece out of five gigantic utility-scale thermal solar power plants, and last year the agency threw some grant dollars at Xerox’ cutting edge PARC company to work on the micro-scale, photovoltaic end of the concentrating solar field.
#thanksobama For Micro-Solar Tech
The PARC micro-scale concentrating solar project aims at whittling down both the cost and complexity of concentrating solar power, by integrating tiny hexagonal solar elements directly into a flat panel.
The solar elements, measuring 150 x 150 micrometers, were developed by Sandia National Laboratories and can be mass produced using conventional MEMS (microelectronic and microelectromechanical systems) fabrication technology.
Sandia is partnering with PARC on the current project, so group hug for US taxpayers.
CleanTechnica took a look at Sandia’s micro-solar work back in 2009, when it was still under development. The lab was excited about the potential for using the glitter-sized elements to solarize irregular surfaces such as fabrics and roof shingles:
The tiny cells could turn a person into a walking solar battery charger if they were fastened to flexible substrates molded around unusual shapes, such as clothing.
The solar particles, fabricated of crystalline silicon, hold the potential for a variety of new applications. They are expected eventually to be less expensive and have greater efficiencies than current photovoltaic collectors that are pieced together with 6-inch- square solar wafers.
Cheaper Concentrating Solar, Micro-Scale Style
The Sandia micro-solar elements solve one part of the cost problem by using a fraction of silicon to accomplish what a larger chunk would provide in terms of conversion efficiency.
PARC is aiming to reduce the cost of the manufacturing part, and our friends over at MIT Technology Review recently took a look and had this to say:
The new process will build on a larger effort by PARC researchers to invent a new kind of printer that can precisely deposit “inks” made of tiny semiconductor chips, called “chiplets,” by using assembly principles similar to those behind Xerox photocopiers.
Last summer, the PARC research team presented their work at the 42nd IEEE Photovoltaic Specialists Conference.
Here’s how they described the manufacturing problem at hand:
Unfortunately, one of the essential and unfavorable scaling factors is the assembly cost due to the many micro-scale components that must be deposited, positioned, oriented, and connected over large areas.
The solution is something that PARC calls a “general, massively parallel, high throughput micro-assembly tool.” The process translates Xerox’ printing expertise into solar manufacturing:
In this digital manufacturing process, the “inks” are micron-scaled PV components that Sandia has developed and the “image” is the micro-CPV module itself.
The team demonstrated enough milestones to win a grant last September from the Energy Department’s cutting edge ARPA-E funding agency, to develop the micro-scale solar printer for commercial application under the agency’s MOSAIC (Micro-scale Optimized Solar-cell Arrays with Integrated Concentration) initiative.
What Is MOSAIC?
MOSAIC aims to tackle one of the main obstacles for deploying concentrating photovoltaic solar technology throughout more areas of the US. Currently the technology is effective only in the southwest, where direct sunlight is optimal. If the technology could be improved to handle diffuse sunlight (scattered by clouds and other atmospheric conditions), then concentrating rooftop solar panels could become common in a much broader geographic area of the country.
MOSAIC also takes aim at the rooftop solar market from the size angle. Smaller, more efficient panels would make it possible to reach down to smaller roofs, or roofs that are only partially exposed to enough sunlight.
As for the concentrating solar thermal technology projects referenced at the top of this article, the Energy Department seems to be satisfied with its stable of five utility-scale solar power plants for now, but last year it launched a new round of $32 million in funding aimed at bringing down the cost of concentrating solar power to compete with conventional energy, so stay tuned.
Image: Hexagonal solar elements via Sandia National Laboratories.