Clear Solar Cells Could Help Windows Generate Power

ckwu writes "The vast real estate of windows in office buildings and skyscrapers could be a fruitful field for harvesting solar energy—if lightweight solar cells could be made with a high enough conversion efficiency and appealing aesthetics. Now researchers at Oxford University report semitransparent solar cells that might do the trick. The team made solar cells using a perovskite, a class of mineral-like materials that have properties similar to inorganic semiconductors and show sunlight-to-electricity conversion efficiencies of more than 15%. The team deposited a thin film of perovskite onto glass so that the material formed tiny crystalline islands. The islands absorb photons and convert them to electrons, while light striking the empty areas passes through. The result was a semitransparent solar cell with a grayish tint."

Comments

But ..

[savuporo]

Will they be available as a service pack for XP ?

Re:But ..

[jfdavis668]

And how about a Linux version? Why must we always wait for someone to finally port it to Linux?

Re:It's not about places to put them.

[Anonymous Coward]

When those problems are REALLY solved, we won't need to have dark windows to generate our energy needs

I think the point of this was that windows are already darkened in office buildings. The solar cells are just a different darkening process that has a nice side-effect of actually generating energy.

Re:It's not about places to put them.

[dwywit]

What's the issue/s with durability? Mine are warranted for 80% of claimed output up to 20 years (BPSolar), the rooftop mounts are cyclone-rated, and the panels themselves are rated for hail up to (can't remember right now) size.

I've had people ask me about this great offer they've had from some local start-up that offers them cheap chinese panels with a five-year warranty, and I tell them to say "no" until they are offered well-known brands with better warranties. At least those people were smart enough to ask around for advice and opinions - I suppose others who don't ask for advice and opinions might get stuck with poor durability.

Re:It's not about places to put them.

[timeOday]

You are missing a big point. Windows already cost money. The added cost of making them produce power is all that needs to be justified here.

Second, windows need not be "darkened" to provide solar power. Most of the energy in sunlight is not in the visible spectrum.

Re:It's not about places to put them.

[Ken_g6]

The challenges for solar cell adoption are:
Cost-effective manufacturing methods
The market price of silicon
Efficiency of conversion
Storing the energy for when it's required (or moving it to where it is helpful)
and Durability

The price of silicon isn't the biggest problem now. Solar cells are already at parity with coal in India, and keep getting cheaper every year.

Efficiency is generally sufficient. A house's whole roof can generally power it.

Durability also isn't generally an issue. Solar cells usually last for upwards of 20 years.

The primary challenges now are:
Installation costs
Electrical connection costs (i.e. an inverter)
and Storage (or grid hookup costs)

Re:Pseudo Science...

[bziman]

Speaking of pesky laws of physics, o hater of all things right and good...

According to Wikipedia, only about 44% of the sun's electromagnetic radiation that reaches the ground is in the visible light range.. Photovoltaics are typically responsive to limited wavelength ranges. It would make perfect sense to tune semi-transparent photovoltaics to absorb radiation that falls outside the visible spectrum, while transmitting most of the visible light.

You get all the benefits of Low-E glass, plus electricity.

Re:It's not about places to put them.

[timeOday]

If you think the cost of glass at $0.25/sf has anything to do with the cost of the windows installed in an office building (or even a home) then you have never bought any.

Re:Pseudo Science...

[anubi]

Car tints were exactly what popped in my mind when I saw this article.

We are beginning to design stuff into cars which continuously draws power, much like the numerous things in our homes that never turn completely off.

Solar cells built into car windshields can be used to mitigate the effects of a car not having its engine running. An owner of a solar-cell windshield equipped car will be able to return to his car, parked at an airport after it has sat unused for possibly several weeks, and have the battery fully charged upon his return. I have traveled and it has always been a concern to me whether the car will start after I have ignored it for a week.

Just a few hundred milliamperes going into the battery would have mitigated this concern.

I do agree with the posters who have already pointed out that using this for office building windows is a lot of wasted expensive effort for a negligible ( and likely negative sans tax credits ) return on investment, considering the cost of line power. A car in a parking lot usually has no line power available.

Paying to distribute the surplus electricity

[MillionthMonkey]

Another challenge is the fines and penalties for installing solar cells on your roof.

An alliance of corporations and conservative activists is mobilising to penalise homeowners who install their own solar panels- casting them as "freeriders" - a sweeping new offensive against renewable energy, the Guardian has learned.

These people are actually freeloaders but of course he can't say what they really are because of political correctness that forces him to use softer words like "freeriders".

Further details of ALEC's strategy were provided by John Eick, the legislative analyst for ALEC's energy, environment and agriculture program.

Eick told the Guardian the group would be looking closely in the coming year at how individual homeowners with solar panels are compensated for feeding surplus electricity back into the grid.

"This is an issue we are going to be exploring," Eick said. He said ALEC wanted to lower the rate electricity companies pay homeowners for direct power generation - and maybe even charge homeowners for feeding power into the grid.

"As it stands now, those direct generation customers are essentially freeriders on the system. They are not paying for the infrastructure they are using. In effect, all the other non direct generation customers are being penalised," he said.

Eick dismissed the suggestion that individuals who buy and install home-based solar panels had made such investments. "How are they going to get that electricity from their solar panel to somebody else's house?" he said. "They should be paying to distribute the surplus electricity."

I don't want sewage electricity being forced down my throat after it's been on some other guy's filthy roof already! I'm an American; I have a right to choose clean electricity!

In November, Arizona became the first state to charge customers for installing solar panels. The fee, which works out to about $5 a month for the average homeowner, was far lower than that sought by the main electricity company, which was seeking to add up to $100 a month to customers' bills.

IN THE BEGINNING God created heavens and the earth. The earth was formless and void, and darkness was over the surface of the deep, and the Spirit of God was floating on the surface of the waters. God said "let there be light" and there was light. God saw that the light was good; and God separated the light from the darkness with a thin film of perovskite on glass so that the material formed tiny crystalline islands. The islands absorbed photons and converted them unto electrons, whilst light striking the empty areas passed through. And God saw that it was good. Then God said "let the rooftops sprout with panels: panels bearing light from the heavens"; the ceilings brought forth electricity, freeriders yielding current with voltage in it, unto the grid. And God saw that it was good. Then to be fair he charged the freeriders $100 per month, which Arizona reduced to $5, for those who drilled the formless void of the earth for the Spirit of God, and have to distribute the unwanted surplus electricity. And God saw that it was good.

Re:How do they do that?

[Muros]

Wrong. The photoelectric effect explains how electrons energized by photons can escape their atomic bonds. It does not involve photons being converted into electrons.