To me a solar cell is kind of like a Lamborghini: difficult to acquire, difficult to maintain, and unless you’re extremely lucky, only semi-functional. Today’s solar cells only convert a small percentage of the energy from the sun into electricity, and that’s before they get dirty.  “It’s challenging to get high efficiencies of conversion. For example, the basic single junction solar cell is fundamentally limited to an efficiency of 30 percent. So, if you made a perfect solar cell, the highest efficiency would be 30 percent. Currently, manufacturing cells with anything near that level of efficiency requires high heat, a vacuum, and is very expensive.” (O’Brien and Walton).  For the solar energy industry to take off what we really need is the sun-powered equivalent of a Honda Civic – something easy to find, cheap to service, and crazy reliable.

Image courtesy physorg.com

Energy start-up NextGen thinks their solar paint has the potential to go 100,000 miles without batting an eye (so to speak).  Their “new breed of cheap solar paint is closer than ever now that the company has raised half of the $1 million it needs to move out of the lab and into the real world. The company’s solar paint is expected to provide up to 40% efficiency at a third of the cost of traditional photovoltaic panels. That’s partially because the paint captures more wavelengths of light than traditional cells. The material, which forms small connected solar cells as it dries, can be applied to nearly any surface–windows, walls, roofs, and more” (Schwartz). It would be easy to repair damaged paint too – you’d just apply another coat.

Image courtesy gliving.com

NextGen isn’t the only organization working on solar paint and spray-on solar cells; others include the National Institute of Standards and Technology, the University of Texas, and the National Renewable Energy Laboratory (Schwartz).  At UT, a research group is making nanocrystals out of copper, indium, gallium, and selenide, dispersing small particles of the inorganic material in a solvent to create an ink or paint that can be sprayed on plastic, glass, and even fabric to create a solar cell. Nanocrystals and nanotubes 10,000 times thinner than a strand of human hair absorb a larger number of light wavelengths onto the photovoltaic cell. The paint can be applied to almost any surface and once dry hooks into the light-sensitive grid to start pumping out electricity (Stefano).

Image courtesy homepage.mac.com

Solar paint technology would be a good fit for something like a government buildings where solar paint could offset energy consumption while giving taxpayers a break, but it should be noted that solar paint is still bleeding edge and “has yet to prove itself in a commercial setting. But if it is successful, NextGen’s paint could help reach the elusive goal of bringing solar power down to price parity with coal power” (Schwartz).  Another issue researchers face is finding raw materials can be used if this technology can be mass produced; copper, indium, gallium, and selenide are not particularly cheap nor are they readily available. Challenges acknowledged, I have a feeling that if this works out we’ll all be slathering our homes and businesses with solar paint and selling energy back to the grid. Then we’ll all go out and buy Lamborghinis.

WU XING:

While it seems somewhat paradoxical, I have filed solar paint under FIRE because it generates electricity, and under WATER because it is a coating.

Cited:

O’Brien, Miles and Marsha Walton. “Getting a Charge out of Solar Paint.” Physorg.com 02/14/11. Accessed 02/16/11. URL.

Stefano, Greg. “Nano Solar Paint: Liquid cells potentially reinvigorate solar power industry.” Coolhunter.com 09/30/10. Accessed 02/16/11. URL.

Schwartz, Ariel. “NextGen Announces Cheap Solar Paint on the Horizon.” Inhabitat.com 04/12/10. accessed 02/16/11. URL.