A combination of biology and electronics has led to progress in the efforts to make low-cost solar cells from plants. A recently published paper in Scientific Reports described an improved method for making biophotovoltaics that produce electricity without complicated laboratory equipment that was previously needed. The researchers announced that custom-designed chemicals can mix with green plants, including grass clippings, to create a photovoltaic material by harnessing photosynthesis.
Massachusetts Institute of Technology researcher and one of the study’s co-authors, Andreas Mershin, said that those interested in lowering the cost of their energy bill and switching to solar water heating might be able to take the bag of chemicals, mix it with plant material and simply paint it on the roof of a residence. Mershin is hopeful that the affordable solar cells can be used by those who are in developing countries and don’t have the benefit of professional solar installers to connect to the power grid to charge lamps or cellphones.
Mershin said that by extracting the light-absorbing proteins in raw agricultural waste, mixing it with a stabilizer and spreading the resulting paste onto a flat substrate, such as glass or metal, people could make their own solar panels.
“After many ears of research, we’ve managed to make the process of extracting this protein and stabilizing it and putting on a surface that is made in a way to allow for the photovoltaic effect to happen to be very easy,” Mershin said in a video provided by MIT.
Former projects have attempted to make solar cells from the set of molecules within plant cells that do the work of photosynthesis, but the equipment was too expensive and the current produced was too low. The
MIT researchers are expanding on a previous project that was started by Shuguang Zhang and Michael Graetzel eight years ago, which found isolating and stabilizing a complex of molecules known as photosystem-I and layering it on a glass plate could produce electricity through exposure to sunlight.
Despite the groundwork that was laid by the other two MIT researchers eight years ago, Mershin said his system is 10,000 times more efficient than previous efforts. He has spent seven years working on the project, which included creating a small collection of zinc oxide nanowires and sponge-like titanium dioxide nanostructures that were covered with light-collecting materials from bacteria to increase the surface area of a small solar cell.
The researchers at MIT noted a number of challenges still to be addressed with regard to the green solar cells, including durability and efficiency, but the initial performance tests for the new technique gives a promising route for the future.
“Commandeering this intricately organized photosynthetic nanocircuitry and re-wiring it to produce electricity carries the promise of inexpensive and environmentally friendly solar power,” according to the paper.
This breakthrough in biophotovoltaics is only one of many recent innovations in solar technology; thanks to others, startup companies are beginning to set new power records. One startup recently set the record for the most efficient solar cell, which is able to convert 23.5 percent of sunlight into electricity.
“Our goal is to optimize the production economics of solar so that it is competitive with fossil fuels without subsidies, leading to broad adoption of solar generated electricity,” solar energy expert Christopher Norris said in a statement about the new super-efficient cell technology.