In a marketplace with viciously plunging solar module costs, what strategy best serves a startup solar cell manufacturer?
Well, if you’re Alta Devices, you stay away from rooftops and solar fields, at least for now, and go after military and portable markets — where efficiency is crucial and price-per-watt is much less important.
Alta has made technical strides in flexible gallium arsenide (GaAs) photovoltaics, setting records for the materials system and able to boast NREL-verified 28.8 percent cell efficiencies for a single junction solar cell. (The theoretical maximum solar cell efficiency limit for a single junction device, the Shockley-Queisser Limit, is 33.5 percent. SunPower’s crystalline silicon Gen 3 cells have efficiencies in excess of 23 percent.)
Alta Devices uses an epitaxial lift-off (ELO) technique pioneered by Eli Yablonovitch that produces flexible layers of GaAs one micron thick. Substrate re-use and cost is an issue in this type of technology, as it is with Crystal Solar and Solexel. Alta still has to scale and scrub away cost in the face of technical and economic challenges with ELO and the firm’s novel MOCVD processes.
Late last year Chris Norris, the firm’s CEO, spoke of a 10-watt iPad cover in MIT Technology Review which reported that Alta had “started selling solar panels to the military to power small unmanned aerial vehicles, and by the end of next year it plans to start selling an iPad cover powerful enough to make plugging in unnecessary.”
This week Alta announced “reference designs” for solar chargers using the company’s cells in portable power, military, automotive, and unmanned systems. Reference designs are presumably provided to ease integrating Alta’s cells into an OEM’s end product. So — Alta is now in the high-efficiency solar cell business. And maybe in the charger business.
These applications suit the high-efficiency and light-weight of Alta’s thin-film solar cells. Recall that these are also applications pursued by CIGS vendor Global Solar, amorphous silicon vendor ECD, and organic solar cell vendor Konarka — may they rest-in-peace. What Alta does have, that GSE or ECD or Konarka didn’t, is the potential to bring really high-efficiencies to these applications.