These Glass Pyramids basically are solar cells wearing better clothes. Developed by The Center for Architecture Science and Ecology (CASE), each of these little pyramids is a concentrating solar power system. At the center of each pyramid is a small photovoltaic cell.
Tracking mechanisms ensure that the pyramids face the sun throughout the day. When solar energy falls on these glass pyramids, they magnify the incoming light and incident it on the solar cell.
They can be used as an energy-generating glazing that would generate power, without hindering natural light for the interiors of a building. They might actually serve to increase the natural lighting, thereby reducing need for artificial lights.
CASE also intends to put to use the thermal energy trapped in these cells and not converted to electricity. This energy would be used for heating and cooling systems. As of now, these Glass Pyramids are not commercially available, but they would soon be with support from interested manufacturers.