Roofs Covered With Plastic Grass Could Harness Wind Energy

One group of scientists is trying to harness wind energy by mimicking the motions of a field of grass rippling in the breeze—except their grass is made of plastic and their field is on a roof.

According to the findings publishing in the journal Advanced Materials, a joint team of Chinese and American researchers created an experimental turboelectric nanogenerator (TENG). Here's how it works: The team adhered plastic strips to a board in a way that makes them stand upright in rows. One side of each strip is coated with nanowires and the other side with indium tin oxide (ITO). When the “grass” is pushed by the wind, the nanowires brush against the ITO sides of the surrounding strips, allowing electrons to pass from one piece to the next. This generates a current via the triboelectric effect.

This method of generating wind power could be practical in many situations. In addition to harnessing power from steady gusts, the technology would be able to effectively work with choppy winds blowing in any direction and would be ideal for spots where windmills would be impractical.

The experimental TENG—which so far has only been tested in a lab by using an electric fan and 60 strips of plastic on a model rooftop—generated enough energy to light 60 LEDs. The system was also functional in wind speeds as low as 13 mph and was most effective in close to 62-mph winds—a speed too high to be practical, as one researcher noted to New Scientist.

While the project is still far from ready to be used out in the real world, a 985-square-foot rooftop carpeted with the strips would generate 7.11 kilowatts, enough energy to mostly power a home, according to the researchers. For now, the team is focused on figuring out a way to efficiently store the energy that’s generated. They will also need to find a substitute for indium tin oxide because it's both toxic and expensive.