What do you get when you cross a solar panel with an energy-efficient window? You may find an answer from Pythagoras Solar, a solar photovoltaic (PV) technology design company.

Pythagoras recently revealed its newest product, the solar window, which the company is calling the “first energy efficient, transparent and high power-density photovoltaic glass unit (PVGU).” Pythagoras has already inked deals with several solar energy system manufacturers, and the new product could hit the market as soon as late 2010.

Gonen Fink, Co-Founder and CEO of Pythagoras Solar, had the following to say about his company’s new product:

“Our new PVGU technology finally bridges the gap between energy efficiency and energy generation — enabling the architecture, engineering and construction sectors to accelerate the deployment of cost-effective distributed power generation and to advance aesthetically-pleasing Net Zero Energy Buildings. Our partners across the value chain are responding very positively to the combination of economic, environmental and aesthetic benefits.”

According to Pythagoras, which has offices in California, Israel and China, the new product will reduce heating and cooling costs by virtue of its energy-efficient design. Because it blocks heat radiation while allowing light through, the window also promises to reduce the need for artificial day lighting. Finally — and this is the best part, in our eyes — Pythagoras’ product produces clean energy. Company reports indicate the window converts about 14 percent of the sun’s rays into electricity. If this figure is shown to holds up in real-world conditions, it’ll be a respectable rate, indeed.

As for the cost? Pythagorus has not made that public. But the company says the system should pay for itself in around five years, considering its ability to reduce the amount of energy that goes into artificial lighting, and heating and cooling.

The promise of these kinds of products — sometimes called building-integrated photovoltaics, or BIPV, is hard to deny. At present, not many BIPV technologies have been widely commercialized for use in the residential solar market. As these products continue to evolve, however, they’re likely to play an increasing role in cutting energy costs while adding to the aesthetic appeal of new-construction buildings.

Related, check out this three-minute plug from Pythagoras: