Solar Window: Cool!

[3113]

Or hot, depending on how you look at it:

A lot of sunlight hits tall office buildings, only to go to waste. Their relatively small roofs don't offer much space for solar panels. A solar array crammed onto the top of a typical office tower could produce, at best, a tiny fraction of the electricity the building and its tenants need.

But what if the building's windows could serve as solar panels?

Pythagoras Solar in San Mateo has developed a window laced with solar cells, a window that generates and saves electricity at the same time. Thin horizontal rows of silicon cells embedded between dual panes of glass catch light from above. And through a trick of optics, the window blocks direct sunlight from entering the building, cutting the amount of power needed for air conditioning.

"Instead of heating the room, the light generates clean solar power," said Gonen Fink, chief executive officer of Pythagoras. "It's relatively simple and straightforward optics. The challenge is making everything work together."

From here.

 

[voluptuary_manque]

Can I replace the south facing windows on the cave?

 

[Weird Harold]

Can I replace the south facing windows on the cave?

Unless the price has come Waaaaaaaaaaaaay down since I first read about the idea several years ago, you'd have to sell the cave and the cubs to replace windows with solar windows. The Return on Investment in retrofit applications was estimated at about 50 years back then.

They aren't quite so cost-prohibitive for new construction, but it does take an entire skyscraper to make them cost effective even then.

 

[3113]

Unless the price has come Waaaaaaaaaaaaay down

I don't know about waaaay down, and as you say they seem to be focusing on skyscrapers but....

the company estimates that for a typical customer, the windows will pay for themselves within three to five years. Pythagoras already installed some of the windows at Chicago's Willis Tower, formerly known as the Sears Tower.

 

[Weird Harold]

I don't know about waaaay down, and as you say they seem to be focusing on skyscrapers but....

They have modified the system since I first read about it --

The solar cells Pythagoras uses aren't transparent. Instead, they look like open venetian blinds. They capture about 14 percent of the sunlight's energy.

Fink won't reveal the system's cost per watt. But the company estimates that for a typical customer, the windows will pay for themselves within three to five years. Pythagoras already installed some of the windows at Chicago's Willis Tower, formerly known as the Sears Tower.

-- the previous version just used the edges of the glass for the actual collectors; the 14% figure is about the same though. If their claim is correct then the cost/watt dropped nearly 90% over early projections -- or maybe it is the increased cost of energy that reduced the payback time.


The problem is that most buildings don't have enough windows for a decent ROI -- for most buildings photovoltaic paint would be a better, cheaper option; even if it is much less efficient per CM^2. (5-7% range last I saw, but incredibly cheap as photovotaic installations go)

 

[Handley_Page]

It strikes me that PV power would be worth it provided:-

1 Salesmen shut up
2 Government officers ditto
3 The makers were more honest about how efficient they are
4 they were made in such sizes/quantities as to be a lot cheaper (fat chance!).

Efficiency ? You'd be hard pushed to get 5% according to some technical blurb I read recently.

And in the UK, our energy bills have risen to pay for more "green power" (growl !!)

 

[Weird Harold]

It strikes me that PV power would be worth it provided:-

1 Salesmen shut up
...

It occured to me last night that things like "Solar Windows," "Solar Paint," "Oil from Algae" and a host of other green "breakthroughs" seem to get publicity on roughly the same schedule as PBS pledge drives.