Got solar? It’s in the bag

New MIT project could result in cheap solar for developing countries That’s the hope of MIT researcher Andreas Mershin, Ph.D., who’s developing a material that could be delivered in a bag and then mixed with local plant materials like grass clippings to create photovoltaics. Actually, Mershin wants to simplify it even more.

“Ideally, there is no bag at all, just a one page cartoon flyer with universally understandable instructions on how to assemble universally available materials into solar-power generating devices,” Mershin said.

You know, like an Ikea instruction manual.

The result could be photovoltaics mixed together in a bucket, painted on a surface area, connected to wires and used. It could be huge in helping developing countries and remote areas get access to energy for lighting, cooking and keeping food safe.

The idea is based on work by Shuguang Zhang, a principal research scientist and associate director at MIT’s Center for Biomedical Engineering. Zhang derived photosystem-I (PS-I), the structures in plant cells that carry out photosynthesis and harnessed them to produce an electric current when exposed to light.

However, the effect worked only under laser. Mershin’s work is in boosting the performance to usable levels, and he wants help.

At this point he and his team have boosted performance to 0.1 percent conversion efficiency. But given the cheapness of materials, when the technology reaches 1 percent to 2 percent efficiency, it will be good enough for commercial use.

Mershin published his research in the open-access journal Scientific Reports on Feb. 2.

“We hope to have our record beaten early and often by many labs around the world. The real experiment here is to see the impact of the paper. The hope is to crowd-source enough iteration to achieve the optimization necessary to make the next order of magnitude improvements in efficiency and time life,” Mershin said. “For this part we still need labs; once it reaches about 1 percent to 2 percent and a decent lifetime and at the expected-to-be, ultra-low cost, I think we may have a disruptive moment to celebrate.”

But more research needs to be done.

“When we get to the first ‘Betty Crocker Solar-Power Cake Mix’—which can only happen after more labs around the world join the currently very niche and "clique" efficiency/lifetime biophotovoltaic race—I think this bag will still have to contain four things,” Mershin said.

The four things needed will be: stabilizing peptides to keep the PS-I from decomposing, electrolytic chemicals, a conducting treatment for the sun and some chemicals that will increase the substrate surface structure—like nanowires—so it can absorb more sunlight.

That last bit sounds tricky, but isn’t really.

“A good example is zinc oxide nanowires that grow automatically when a zinc metal sheet is simply immersed in water containing a handful of non-hazardous, non-perishable, inexpensive chemical compounds,” Mershin said.

Thus far the lab has made the devices from a number of materials, including bacteria, pine, cypress and coffee trees, according to Mershin. The lab’s also tried using seaweed, but they released too much sugar when ground up. Basically, it’s really a whatever’s-in-your-backyard approach to making your own solar.