Fluff? Where are the 'current per square meter' stats? They claim 'half your electricity from windows' but where's the data?

My windows are not in direct sunlight most of the day and all of the night. Most are never - on the north side, east side, west side.

All of them are never optimally directed at the sun even when fully illuminated.

The opportunity to generate power from accidental/incidental sources is very limited. Its always better to plan a real power installation with all the factors considered. 10x to 100x better.

The only way this might make sense is if the added cost of quantum dots in a window is tiny.

Not sure what this means dollar-wise, but accord o e article,

“Both – quantum dots ad perovskites can be easily placed on the surfaces and have comparable costs of production”

Not sure what perovskites cost, but that should give you your answer (or a way to figure it out).

Are windows in some part of the world optimally oriented towards solar radiation? Most residential windows in the US are shaded by awnings or face completely away from the path of the sun. It seems like only multi-story glass-clad buildings would be moderately relevant for this technology, and refacing, say, the Salesforce tower seems like it would be prohibitively expensive to make sense from an roi perspective.

Greenhouses maybe. Those are usually constructed in a way to get the most out of the incoming sunlight, right?

So many near sighted comments.

Many buildings have little space for solar panels. Most building need to reglaze every thirty years. Many building have no optimally oriented glass.

This does not mean that PV Glass is worthless. If efficiency and cost work out then there may we’ll be a place for PV glass.

What about stability and longevity, since the first breakthrough 10 years ago various teams were struggling to make them work in solar cells as quantum dots are chemically unstable under oxidizing conditions and undergo photo corrosion reactions?

It all boils down to: what is the energy return on energy invested .

Not my field of natural science but I saw a very bright future for this a decade ago.

Quite promising equations.

Non-rechargable batteries costs more electricity than they'll ever produce in their lifespan, and producing them makes sense.

That's different. Those are used in places where having a cord to a power source is impossible or impractical, so we accept the trade-off.

But if my assumption is true, you might burn a bunch of coal to make these windows, and then never offset that energy use (because the windows break/stop working after X years).

Local generation is worth paying a premium for if it allows transmission infrastructure to be avoided.

half of green tech can be thrown out under this kind of scrutiny. there are so many shell games to gobble tax money that ultimately originates in the great wealth fountain that is fossil fuels

the blinders people put on talking about this stuff are incredible

True, but it doesn't necessarily mean that the incentives are a bad thing. The incentives do promote activity in the "green tech" space, much of which is waste, or even fraud, but maybe some of it will turn out to be useful.

It would be great if the structure of the incentives could be adjusted to reduce waste and fraud, but accepting that there will be some level of abuse may be the price of encouraging progress.

> What if it costs more electricity to produce this glass than it will ever produce in its entire lifespan?

Fair question. This was precisely the problem with early solar cells. I think one has to take a multi-decade view on some of these things. If the science tells us we can improve the technology within a reasonable time horizon and achieve positive ROI, then it makes sense. Otherwise it is a bad idea.

Side note: We don't want UV light inside buildings. If this kind of glass makes economic sense and it can filter out UV light while producing some electricity, it is a win-win. I believe nearly all glass used in large buildings has UV cut coatings/treatment. If the cost is comparable this could be a viable substitute. The problem, of course, is that this might not be viable as a retrofit but rather something you would include in new designs (you need a new electrical design for the building in order to connect all glass to the grid).

It depends if the glass was produced with low carbon emissions (Nuclear, renewables) and avoid final users to use less coal power plants.

Yes, though solar furnaces are possible. If we are talking about windows that would be manufactured with or without quantum dots, then likely the added energy needed for the quantum dots will still be recouped in their operating lifetime.

There are probably better ways of exporting energy than making glass.

I agree, but like the Tesla roof tiles, you should buy those windows when you need to replace existing ones.

Glass is very rarely replaced and is exposed to 100% of the sunlight that will be around during its installation life time - shaded or not. That’s going to add up to considerable energy regardless of input cost.

Glass, sure, but what about these quantum dots? LED light bulbs were supposed to last 25 years, but everyone I know that has these replaces them well under that time frame.

> everyone I know that has these replaces them well under that time frame.

Survival bias. Nobody is thinking about the bulb they haven't had to change in 20 years.

The LED bulbs often fail due to the driver electronics, not the LED parts themselves. At least with large PV installations the inverters are separate from the panels and can be replaced.

They're probably not getting superheated like a light bulb.

That depends. If the cost of production can be reduced with mass production, or the efficiency increased, so that it becomes energy positive, if the energy source required to make these windows is variable, for example by using any thermal energy source, or if it displaces the energy required to make normal windows, it's worth continuing to research in that direction.

Unlikely. Quantum dots are currently manufactured at scale and solar panels based on them reach decent efficiencies.

That being said they can't beat regular crystalline silicon solar cells on cost. Their major advantage is that they can be made transparent and lend themselves for usage in multi-junction solar cells.