Building-integrated solar glass generates electricity, often qualifies for financial incentives, and has the uniqueness of custom glazing that generates electricity. (Solar Design Associates photo)

Why it matters
The long-term implication of integrated solar glass is two-fold: It's a renewable energy source that is aesthetically pleasing and therefore hardly objectionable to neighbors; and it occupies building surfaces that would otherwise require reflective glass and window shades to avoid energy (heat) gain from the sun.

A walkway canopy protects visitors as they enter the MITRE Center, and generates solar power. The feature served as a catalyst for the design team's excitement about sustainable design overall. (Stubbins Associates photo)

Who makes it
Solar Design Associates specified and supplied the solar components for the MITRE Center's solar canopy, built in 2005. They recommended modules from the Dutch company Scheuten (pronounced like a cross between "shoyten" and "sweeten") Solar. Other companies, including Saint Gobain and Spheral, also manufacture building-integrated solar glass.

What it costs
"Any time an architect is considering unique glass for their buildings, we like to present them with the option of using productive glass, glass that produces electricity," says Craig Munger, electrical engineer for Solar Design Associates.

Does it cost more to use energy-producing glass? Before financial incentives, yes. After incentives… generally, yes. Unless you compare it to another truly unique form of custom glazing.

"Using ordinary glass in the MITRE canopy would have been around US$20 per square foot, where the custom electricity-producing glass was between $80 and $100," says Munger. There's also the cost of wiring, concealed conduits, and balance-of-system components like inverters.

Why consider it
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.

Says Munger, "When people find out about financial incentives, and they see solar glass as a way to set their building apart, they get excited about it."