For the past eight years, Andreas Mershin has worked on isolating photosystem-I (PS-I) molecules from plants to use in solar panels. The PS-I is a protein complex which carries out photosynthesis. They’ve been isolating PS-I, stabilizing it with expensive chemicals and complex lab equipment, and putting a layer of the resultant goo on glass, which is even cooler to do to your windows than lining them with aluminum foil. The biggest drawback to their earlier methods, besides the high expense, was that the panels were so weak they would only produce a current when hit with a high-powered laser. Oh man, I need more panels to produce enough electricity to run this high-powered laser.
Now Mershin and his team at MIT (along with Barry Bruce from the University of Tennessee) have accomplished the hardest part: greatly reducing the expense and complexity of isolating the PS-I while raising the efficiency enough to produce a small current in regular light. The downside is that the newest design has an efficiency of only 0.1% while most modern solar panels have 15% to 18% efficiency. The upside is that the materials involved are not rare, not toxic, and not expensive, unlike some conventional solar panel components. They’ve replaced the expensive chemicals and lab equipment with an easy-to-use readymade “stabilizing powder”.
The stabilizing powder is made from inexpensive, common chemicals which can be added to agricultural waste (like grass clippings) to create a green goo with the PS-1 structures still performing photosynthesis even after the plant’s death. The ingredients include zinc oxide and titanium dioxide, both to increase the surface area (to increase efficiency) and to protect the PS-I from damage caused by UV rays. Wait, slathering common sunscreen ingredients on plants keeps their photosystems safer? I will use this information in a completely rational way that doesn’t frighten my neighbors at all.
The stabilizing powder — much like your mom — is cheap and easy enough to be used by hobbyists and classroom labs. The team hopes this ease of experimenting with panels will lead to improvements in the design. Mershin says the efficiency of the panels would have to increase at least tenfold (to 1% efficiency or more) for the panels to be good enough for use on roofs in the third world.
You can watch Mershin discussing these solar cells in the video below, although he never explains whether or not I should slather the trees in my yard with sunscreen. I’m just going to assume the answer is an emphatic yes.