Global Gardening

MIT researcher Andreas Mershin wants people in developing countries to have cheap solar cells to charge lamps or cell phones, using natural photosynthesis based on plant protein.

The research is published in the open journal Scientific Reports and builds upon earlier MIT research by Shuguang Zhang. The earlier plant molecule solar cells required expensive lab equipment but the new system can use simpler technology. The efficiency is still only 0.1% (much less than conventional solar cells) but if other researchers can help improve the method then perhaps 1 or 2% efficiency could be the result.

The system uses molecules that plants use for photosynthesis (called photosystem-I or PS-l). Mershin used a simpler way to obtain PS-I molecules and coat an array of tiny zinc oxide nanowires that carry the current and provide a large surface area. He had the idea from looking at how pine trees use their layered branch and leaf structures to absorb as much light as possible.

“You can use anything green, even grass clippings” as the raw material, Mershin says. The research team has proposed using inexpensive membranes to filter and extract the plant protein. “It can be very dirty and it still works, because of the way nature has designed it. Nature works in dirty environments — it’s the result of billions of experiments over billions of years.”

If the PS-I molecule stabilizing chemicals can be given to villagers in remote locations, with some simple instruction, they could extract the protein, roughen up a tin roof and paint it on, generating power during the day for use at night in LED lighting, eliminating dangerous, expensive and unhealthy kerosene lanterns, Mershin adding that “Nighttime illumination is the number one way to get out of poverty,” as it allows people who work all day to read at night and get an education.

Via MIT News & Scientific Reports