New World: New light on solar energy

By JUDY SIEGEL-ITZKOVICH, Jpost.com

A new type of glass cell that absorbs solar energy and concentrates it so it converts into electricity more efficiently than conventional solar panels by taking only the radiation without the heat has been developed by Prof. Renata Reisfeld, longtime expert in sol-gel glasses at the Hebrew University’s inorganic chemistry department. It can absorb solar energy even on a cloudy day without direct sunlight – albeit less efficiently than on a sunny day.

Reisfeld, who is chief technology officer of the GreenSun company that is working to commercialize the product, developed it in her Jerusalem laboratory. The glass cell panels, made in bright colors, concentrate the light in the center of the glass plate and thus is cheaper than conventional ones because it needs silicone only there rather than on the whole panel. The plates absorb specific parts of the light spectrum of the sun, Reisfeld says, adding that they can lie on a roof and absorb dispersed light without facing the sun most of the day.

The heat from solar radiation in fact damages the cells, says the inorganic chemist, so the new technique intentionally causes the heat to be dispersed. Walls and windows could be made out of the glass to turn a building into a power generator on the outside. However, some experts say that using the technology will hike construction expenses, as it is more expensive than conventional building materials. In addition, the panels’ efficiency is not yet high enough to be used routinely.