Pythagoras Photovoltaic Glass Units - Combining Windows and Solar PVs

This is a really interesting product that a friend alerted me about, and which has been featured on several green building websites - combining a transparent window and solar cells in such a way that light is let into the building while electricity is generated with an energy payback time of five years suggests some very exciting possibilities. I would think that the product would make a lot of sense in countries that have to build upwards because they lack land - India comes to mind, as do the various small Gulf Arab nations - and these are all nations with severe power shortages already. These are also nations that receive abundant sunlight. I would hope that someone in these countries (and in India in particular) checks these windows out.