Harvesting the power off the windows may not be such a bad idea. Look at any large city and see a skyline skyscrapers with windows. Even with sub-metering all large buildings have common areas that the building owner is responsible for the electricity. Harvest some of that sunshine and you could reduce the electric bill for the building owner.

The questions are:

How low can they get the cost? $0.10/Kw for the window? It can not add a lot of cost a dime a Kw may be the required price point (not counting the inverters, marketing, installation, etc..) Add too much to the window pane and the price pain will kill the idea.

What does it do to the color (CRI)? How much light does it filter out? Too much and you will offset the energy produced with electric lights.

Shadows from other buldings and sunlight easements - the next fertile ground for the legal professionals.

How well does it hold up to the weather -- and that all corrosive bird splat?? Any problems with window washers?

How do you connect to the windows? Inside pane, outside pane?

Broken windows - who is responsible? On smaller buildings - it is often the tenant.

If you can get the cost down enough - why not consider east and west building windows. Pickup some of the early morning sunlight, top off with the late afternoon.

Even at 4% a tall skyscraper with PV windows on three sides may be able to provide enough power for the common areas for greater than 50% of the year. Remember those cells produce power even on the weekends when building use is down!

Low cost high volume always sounds great - but we've yet to see the low cost and high volume electronically dimmable windows. Sometimes great ideas do not pencil out. And unfortunately in the solar world there have been perhaps thirty solar manufacturers that have gone out of business in the last eighteen months.

Windows could be a niche - but they would need to get the price down significantly.