A paper published in Scientific Reports last week describes an improved method for making electricity-producing ‘biophotovoltaics’ in such a way that any lab anywhere in the world can replicate the process. Researchers said custom-designed chemicals could be mixed with green plants, even grass clippings, to create a photovoltaic material by harnessing photosynthesis.
MIT researcher Andreas Mershin explains his vision: “Leaves and plants are natures’ solar panels. The first step into photosynthesis is to change sun rays into a little bit of electricity but then get converted into the processes of life. If we manage to somehow hijack the molecules that are responsible for photosynthesis in plants and other photosynthetic organisms, and then use them to generate electricity for our own needs this would mean a fantastic new step in the way in which we can generate solar power electricity in general. Imagine if the raw material for a solar panel would be something that you normally think of as trash and you actually pay people to take away. Imagine that your grass clippings can become an active ingredient in a solar panel that you can create at your own home”.
Mershin’s work is an extension of a project which began eight years ago by Shuguang Zhang, a principal research scientist and associate director at MIT’s Center for Biomedical Engineering. Zang’s work had some drawbacks, it required expensive chemicals and sophisticated lab equipment. Mershin’s system pulls out the molecules responsible for photosynthesis and used chlorophyll – the ‘star’ protein – to transform photons into electrons. After stabilization, the molecules get widely distributed on a glassy surface swarming with titanium dioxide ‘sponges’ and zinc oxide nano wires. The first are busy converting the light into electricity, whilst the latter transfer it. This type of solar technology could make cheap energy available in rural places and developing countries where people don’t have access to affordable energy. The simplified process could be replicated by any lab – including even college and high-school labs – allowing researchers around the world to start exploring the process and make further improvements.
But now the downside: Mershin’s solar panel only has an efficiency of 0.1%. To be of any use — to power more than a single LED light from an entire house covered in these cheap solar panels — an efficiency of 1 or 2% is required. With such a low barrier to entry, though, Mershin hopes that scientists the world over can now work on boosting the efficiency.