A generator able to harvest electricity from cold air offers a novel way to produce renewable energy at night.
Developed by a team from UCLA, the prototype device features a polystyrene disk painted black and elevated on a small table, along with an off-the-shelf thermoelectric generator. The dark disc will absorb heat during the day that it slowly releases at night, causing the exposed side to become colder than the side touching the table’s surface. That difference in temperature is enough to generate a small flow of electricity of up to 25 milliwatts per square meter.
Although the power generated is quite small, the team sees the prototype as a promising complement to solar, operating during the time solar cells can not.