Traditional silicon-wafer cells and thin-film solar cells have an upcoming rival—solar cells of the spray-on kind.
Spray-on solar cells for glass windows (Image from newenergytechnologies.com)
Since 2010, New Energy Technologies based in Columbia, Maryland has been busy developing their breakthrough dubbed as SolarWindow in partnership with the University of Florida. In lieu of the traditional clunky silicon-wafer cells or the flexible thin-film solar cells that have to be strategically installed, SolarWindow is simply sprayed onto glass surfaces, turning that previously transparent pane of glass into an efficient harvester of the sun’s energy.
This process of spraying “ultra-small” plastic solar cells using nanotechnology no doubt allows for easier application not just onto glass but onto other substrate materials such as plastics and even paper. SolarWindow has a much cleaner carbon footprint as well, compared to traditional silicon-wafer cells which rely on high temperatures and high-vacuum for their production. Thin-film cells are considerably easier to manufacture, but spray-on solar cells are about to make that ease one step further.
In its own website New Energy Technologies recently announced good news about its spray-on solar cells. Fabrication time is faster now, which takes only a few hours now compared to several days in the past. Transparency has also generally improved. The group has come up with a uniform coating for the glass which is aesthetically attractive for consumers. Perhaps more importantly, power conversion has also increased efficiency by two-fold although the researchers are mum as to the specific power output per square meter.
Of course, spray-on solar cells have their own share of cons, as traditional photovoltaic cells are still more durable than their plastic counterpart. Also, health concerns regarding the airborne particles of the spray medium have yet to be addressed.
Silicon Then and Now
In 2012, photovoltaic solar cell installation experienced a mere 1.6{e3829ec1db02d54faaf9fa2de0d48db26af01d7a7944a63c3b26976124791cab} growth compared to the 172{e3829ec1db02d54faaf9fa2de0d48db26af01d7a7944a63c3b26976124791cab} boom from 2009 to 2010. The 2012 slump is partly due to the reduced solar incentives of many European countries at that time. Production of polysilicon for the solar cells exceeded market demand at that time, resulting in a plummet in prices.
This 2013, PV solar cell installations is estimated to range from 15{e3829ec1db02d54faaf9fa2de0d48db26af01d7a7944a63c3b26976124791cab} to 25{e3829ec1db02d54faaf9fa2de0d48db26af01d7a7944a63c3b26976124791cab} according to SolarCellCentral.com, with China taking the third spot for gigawatt output after Germany and Italy.
Spray-On Solar Cell Still in the Offing
Right now, the SolarWindow mini-modules are being considered for large-scale devices. Previously, the target for SolarWindow’s commercialization was in 2011, but that hasn’t panned out yet. With this new announcement, the green building industry is certainly curious what improvements this new product can have for solar energy capture.
The quest for streamlining production processes and costs of solar cells does not end here. Newer technologies can still harness the sun’s energy in the cleanest way possible, but for now spray-on solar cells are set to change the game.
