Spinach May Offer Big Boost for Solar Cells
Just like Popeye’s muscles, solar panels can get a boost of power from spinach. Researchers at Vanderbilt University have discovered a method for combining the leafy green with silicon, the material used in most photovoltaic cells.
A protein in spinach can convert sunlight into electricity even after it’s extracted from the plant. The photosynthesis is almost 100 percent efficient (meaning nearly all the sunlight that hits it can be converted into energy). In comparison, average solar panels on the market today are usually only around 15 percent efficient, with the best available solar panels offering about 20 percent efficiency.
Researchers have known about the protein for more than 40 years, but haven’t known until now how to effectively integrate it into solar cells. At Vanderbilt, scientists were able to create “biohybrid” cells with the spinach protein that generated more than 2.5 times more electricity than previous designs. They’ve patented the new technology.
However, it’s not a perfect technology yet. Early prototypes deteriorated quickly, and the cells don’t yet create as much electricity as current silicon solar cells. But the researchers believe the technique has potential. Their next step is to create another functioning solar cell with their design, and to continue to improve longevity and efficiency. If the technology continues to progress as expected, they believe that it could rival current solar cells within three years, though it would take longer to become commercially available.
In addition to the efficiency potential, spinach has the huge advantage of being easy to grow, renewable, nontoxic and cheap. Current solar panel designs rely on certain rare materials like gallium arsenide, tellurium and indium — all of which there are limited global supplies. Tellurium, for example, has only two known high concentration deposits in the world. By moving toward plant-based components, solar can become more truly renewable.
Main image credit: Nick Saltmarsh/Flickr; secondary image credit: Amrutur Anilkumar/Vanderbilt University