MIT Designing Solar Panels Out of Plant Cells
MIT researcher Andreas Mershin is digging in to a new way to create cheap, effective solar panels. Building off work started by Shuguang Zhang of MIT’s Center for Biomedical Engineering, Mershin is working on how to take the molecules responsible for photosynthesis in plants (PS-I) and put them to work on solar panels, and to do so in such a way that any lab anywhere in the world could replicate the process.
MIT reports, "The new system’s efficiency is 10,000 times greater than in the previous version — although in converting just 0.1 percent of sunlight’s energy to electricity, it still needs to improve another tenfold or so to become useful, he says."
Mershin states that improving efficiency means getting more of the PS-I substrate exposed to the sun, and he thinks the key to this is to mimic pine trees in a forest, the needles of which are the ideal shape for getting the most out of what sunlight is available, and the trees have branches all the way down the trunk to capture any sunlight that makes it through the top of the canopy.
Turning that insight into a practical device took years of work, but in the end Mershin was able to create a tiny forest of zinc oxide (ZnO) nanowires as well as a sponge-like titanium dioxide (TiO2) nanostructure coated with the light-collecting material derived from bacteria. The nanowires not only served as a supporting structure for the material, but also as wires to carry the flow of electrons generated by the molecules down to the supporting layer of material, from which it could be connected to a circuit. "It’s like an electric nanoforest," he says.
In the video below, Mershin explains the concept:
Eventually, as efficiency is gained, this concept can be used all over the world without the cost or materials being prohibitive -- any green plant material is fair game to create the substrate. That means solar technology could be cheap and simple enough to provide new solar panels to the most rural areas.
There are two aspects to be considered for this interesting design -- one is that it uses nanomaterials, and we don't yet fully know the environmental impact of nanomaterials. Also, how does this affect how, or if, the solar device can be recycled? We are just starting to move into rules and regulations about recycling solar panels, and technology like this could need its own recycling process. Both of these are important to consider as the design is perfected.