The windows of the future will not only be used to illuminate rooms, but also as a power source, MIT specialists believe. A new report, which appeared in the July 11 issue of the online journal Science, allows us to dream that the energy self-sufficient house will one day be part of the normal architectonical landscape.
The basic idea is actually simpler than it sounds: solar cells need to be placed around the edges of the window, which would allow the system to work like a “solar concentrator,” as Marc A. Baldo, co-author of the study and MIT professor said.
The technology involves planar waveguides with a thin-film organic coating on the face and inorganic solar cells attached to the edges which absorb the light that solar cells will later collect. Such solar concentrators have been reported to have quantum efficiencies of over 50% for existing solar-panel systems, and projected power conversion efficiencies as high as 6.8 percent.
As professor Baldo explained to BBC, “the light comes in and hits the dye which absorbs it and re-emits the light, but now it’s inside the glass so it bounces along there until it gets to the edge. So you only need to mount the solar cells around the edge.”
According to the study, organic solar concentrators would reduce the cost of photovoltaic power. The idea is not new, as it dates back decades ago, but it has been abandoned as scientists didn’t manage to make the light go far enough to the edges of the concentrator.
However this time, with the help of a mixture of dyes in certain ratios, the light is capable of traveling much farther with less energy loses on the way, increasing tenfold the amount of power that solar cells on the edge convert.
Solar concentrators are not likely to replace traditional rooftop solar panels that soon, as the experiments have shown they produce less energy, but according to Baldo, it seems to be a less expensive alternative.