The concept of a liquid, paint-on solar cell is old news these days, but a research team from the University at Buffalo in New York has come up with an interesting new angle. The team is working on a paintable solar material enhanced with nanoparticles of metal, in order to achieve a cost competitve level of efficiency. Does that mean solar paint could be as cheap as ordinary paint some day?
Lowering The Cost Of Solar Paint
The UB team is working on a class of organic photovoltaic material that can be loosely described as plastic. In contrast to conventional solar cells made of silicon and other inorganic substances, organic solar cells are based on long chains of hydrocarbon molecules called polymers.
Organic solar cells are far less efficient at converting sunlight to electricity than conventional solar cells. However, organic materials have several major offsetting advantages.
Namely, organic materials are far less expensive than conventional solar cell materials, and organic solar cells can be manufactured using standard, inexpensive processes. Organic solar material could also piggyback on other building surfaces as paint, or it could replace ordinary window glass in the form of transparent solar windows.
Enhanced Solar Paint
Offsetting can only get you so far, though, and that’s where the nanoparticle enhancement comes in.
According to the research team, organic solar cells need to reach a conversion efficiency of about 10 percent to be competitive in the mainstream market. To get closer to that goal, the researchers deployed an emerging player in solar technology, the field of plasmonics.
Plasmonics refers to the ability of light and metal to produce an electrical charge, as electromagnetic waves and free electrons oscillate between metals and semiconductors. The plasmonic effect can be induced with nanoparticles of metal or with nanostructures (the research team has tried both), with the result that more light is trapped within the solar material.
A team based at Stanford University is also working on plasmonic-enhanced solar material, and a team at UC-Santa Barbara is working on a free-floating plasmonic devicethat could harness solar energy to convert water into hydrogen fuel.
Solar Paint As Cheap As Ordinary Paint!
Now, let’s pick apart this idea that solar paint could simply sub in for conventional paint in terms of price. “Solar panels as inexpensive as paint?” is the headline of the University at Buffalo’s recent press release for the research team, but a straightup cost comparison between solar paint and ordinary paint is not exactly what the researchers had in mind.
The comparison refers to the idea that conventional solar cells are far too expensive for many property owners and will probably remain that way for the foreseeable future, but solar paint could become relatively inexpensive.
The researchers are aiming to develop a solar paint that could fall into the category of affordable property upgrades. Maybe not quite as cheap as a fresh coat of ordinary paint, but not too much more than that, either.
That may seem a bit optimistic at this point in the research, but considering how fast the price of photovoltaic modules has been falling (an 80 percent drop since 2008), there’s at least a good possibility of success.
Do-It-Yourself Solar Power For The Masses
Let’s take that a step farther and consider the overall installed cost of solar power instead of just the price of the solar cell.
Bringing down the installed cost of solar power is a top priority of the Obama Administration, because shipping, permitting, installation and other “soft” costs typically account for fully half the cost of a solar array.
In terms of paintable solar cells, that means the cost of a gallon of solar paint could be partly offset by other factors, such as lower shipping costs.
Solar paint also opens up the affordable solar power field to property owners who can put their own sweat equity into a solar array, which would also lower the installed cost of solar paint compared to conventional solar modules.
The difference is that very few property owners have the capability to install their own solar panels, but practically anyone can slap on a fresh coat of paint (leaving the electrical hookup to professionals, of course).
May 15th, 2013 by Tina Casey