A solar energy system that doesn’t require sunlight is almost as bizarre as a tidal power system that doesn’t use water – however that’s exactly what researchers at MIT have cooked up. The team just unveiled a new photovoltaic energy conversion system that can be powered by heat, the sun’s rays, a hydrocarbon fuel, or a decaying radioisotope. The button-sized power generator that can also run three times longer than a lithium-ion battery of the same weight.
The science behind the device is not necessarily groundbreaking, as engineers have long used the surface of a material to convert heat into precisely tuned wavelengths of light. However MIT’s method to convert light and heat into electricity is much more efficient than previous versions.
Described in the journal Physical Review A, MIT’s breakthrough was enabled by a material with billions of nanoscale pits etched on its surface. When this pitted material absorbs heat, it radiates energy at precisely chosen wavelengths depending on the size of the pits. It is hoped that the technology may one day be used to generate power for spacecraft on long term missions where sunlight may not be available.
“Being able to convert heat from various sources into electricity without moving parts would bring huge benefits,” says Ivan Celanovic, research engineer in MIT’s Institute for Soldier Nanotechnologies (ISN), “especially if we could do it efficiently, relatively inexpensively and on a small scale.” Celanovic went on to say that he believes his team could triple the efficiency of their prototype, adding that “It’s a neat example of how fundamental research in materials can result in new performance that enables a whole spectrum of applications for efficient energy conversion.”
Considering that space firms are looking for new ways to power spacecraft efficiently now that the shuttle fleet has been retired, we imagine NASA will be among the many companies interested in this technology.