Can you see the solar glass incorporated into this building at the Hong Kong Science Park? It's the darker blue glass. The electricity is generates is fed back into the grid. Solar glass is a kind of solar installation called BIPV or Building Integrated PhotoVoltaics. It basically a kind of solar cell that can be incorporated into a house or building in a virtually seamless way. Solar glass generates electricity, while still being aesthetically pleasing, and it occupies building surfaces that would otherwise require reflective glass and window shades to avoid the sun's heat. The only drawback to solar glass is that doesn't produce much electricity, and it's fairly expensive (about fives times as much as regular glass, not counting components such as wiring and inverters).
On a strict analysis of energy cost savings, integrated solar glass rarely pays for itself. But that doesn't deter architects and owners around the world from installing it. Solar glass generates electricity at a predictable cost, qualifies for financial incentives and often has publicity value. Not to mention the uniqueness of a building with custom glazing that generates electricity.