realmystik t1_iu6iwsc wrote
Reply to comment by aecarol1 in Low-cost 'transparent' solar cells reach new efficiency record, electricity-generating windows incoming? by VeterinarianProper42
its funny cause you dont know how it works and you are arguing with people based on your sense
aecarol1 t1_iu6l1nr wrote
I'm not sure what you mean.
First off, they are excited to announce the things last 500 hours.
They also talk about test surfaces 2.8 cm2. That's a bit bigger than one square inch. They are announcing a breakthrough that lasts 500 hours for one square inch. They have presented no evidence that this will scale to window size coatings and that it will be uniform enough to look like clear glass. Eyes are sensitive to windows that are "splotchy" or not uniform clarity.
This isn't ready for prime time and belongs in same bucket as the "amazing battery breakthrough" stories we see Every. Single. Week. That come to nothing.
But getting back to what they claim might be possible.... they don't produce much power (every bit of light you see, is light that's not converted to electricity. If 1/2 the light is passed in so you can actually see outside, that means its base production is only 1/2 of a normal panel.
No matter the technology, it's low voltage, which means it must be connected to an inverter to create AC power. You can combine multiple windows to a shared inverter, but if one window is shaded (even a bit), then all the windows must turn off. The alternative is to have micro inverters one-per-window (or at least sections that are shaded together).
All of that requires extra wiring. If the inverters are near the windows, you must have lots of inverters scattered around the building, wired together. If they are in a single location then you must have low voltage lines connecting each window to their inverter. Low voltage lines that are long must be very thick to avoid losses.
Low buildings tend to have trees or shrubs that shadow. Tall buildings tend to be built next to other tall buildings. Of course there are places where things line up and there is a lot of windows that face the sun, in that case you might get some measure of power from it.
If a company has thousands of extra dollars and they want to do more than make showy press releases, that money is better spent on roof-top solar, and if that's full, then they will save more aggregate energy with LED lights, better thermal insulation, and more efficient heating/cooling.
dubiousadvocate t1_iu9lkom wrote
That’s why they’re called Proofs of Concept. The Wright brothers first functional aircraft was widely ridiculed too but ten years later they were essential in WW1.
aecarol1 t1_iua37ps wrote
Absolutely! "Proofs of Concept" are valuable and this should be explored.
There is a plausible way forward. I think this is worth pursuing and experimenting with, but we should not be overselling this or its potential based on very, very, very early experiments with none of the obvious downsides being talked about in these press releases.
They advertise the costs of the panel to be lower, but they still need the same controllers, inverters, and wiring as regular solar panels and those cost the same. The required electronics typically cost 40% of what the panels cost. The price of panels has gone down, but per-watt generated, you will need to spend about 40% on inverters etc.
In small business level installations, the cost of the panels is typically 25% of the total cost. Even if they drop significantly in price, the other 75% isn't going down. The total price is lower, but not nearly as much as naively looking only at panel prices would imply.
For example, if the price of solar panels dropped 50% overnight, the total cost for an installation would drop by about 12.5%. Nice savings, but not the 50% we might have hoped for.
Bottom line, I like exploring this, there may be real benefits that are worth looking for. That said, I would not be counting eggs or presuming anything will come of it.
"They laughed at the Wright brothers, but they also laughed at Bozo the clown."
dubiousadvocate t1_iuaadt4 wrote
>"They laughed at the Wright brothers, but they also laughed at Bozo the clown."
Yeah. That was kind of, no actually was, Bozo's business model. And they made millions. That's a strange take.
That said I appreciate the knowledge you brought to this thread even as it is a peculiar mix of optimism and pessimism.
aecarol1 t1_iuabsze wrote
My comment was simply to show that one technology being derided and then becoming a spectacular success (aviation), isn't applicable to another unrelated technology being derided. The critics being wrong on one, doesn't mean they are wrong on an another.
I am hopeful for this, but I think this technology has more in common with battery advancements than aviation. On so many technology subjects, we see press releases masquerading as news talking about incredible breakthroughs which reporters extrapolate to societal changing implications. Sometimes they are right (cell phones), mostly they are wrong (Segway)
I enjoyed debating the merits with you also! I hope this pans out, we certainly need as much power as we can obtain and the sun is a great source.
RedditorsArGrb t1_iu6wtv8 wrote
>You can combine multiple windows to a shared inverter, but if one window is shaded (even a bit), then all the windows must turn off.
what is your basis for this (ridiculous) statement?
aecarol1 t1_iu6xm1e wrote
Because that's how solar panels work. There are technologies to mitigate this, but they require more complex wiring and more sophisticated electronics.
If all the panels share one inverter (least expensive option), and if one panel has shade (even partial shade) then the entire array shuts down. If it doesn't the shaded sections actually consume power and will become very hot. Bypass diodes will help, but not always.
If you have micro inverters (each panel gets its own inverter) then one shaded window only reduces the power by that specific window, all is good. But now you need an expensive inverter box for each window. This is not cheap,
There are lots of schemes and systems to work around this and they work to varying degrees, but the thing in common is that they require more electronics to make that work and the entire point of this is to be "cheap".
https://www.solaredge.com/sites/default/files//se_technical_bypass_diode_effect_in_shading.pdf
If that's not enough, I can provide endless cites for the solar panel shading problem and the current solutions.
RedditorsArGrb t1_iu6yv95 wrote
yeah, I know what bypass diodes are. since you know what they are too it's kind of strange that you wrote a comment pretending they don't exist.
aecarol1 t1_iu6zf7v wrote
My point is that this can be fixed, but requires a lot more than the dead-simple shared inverter. That goes against the central point that this is supposed to be "cheap" and easy to deploy.
Low windows are often shaded by parked vehicles, trees, and shrubs. Tall buildings are often in dense places with other tall buildings that cast shadows.
This can work, but not for most places.
Either way, they have only shown this lasts 500 hours and they've only tested something slightly bigger than one-square inch. This is no better than the endless updates we get on "breakthrough batteries" every week that almost never end up working as well as hoped and almost never ship.
When they actually get this to last years, and they get it to work on full sized windows, and they get it uniform to not look splotchy and they keep their efficiency, and they solve the shading problem. Then we'll have something exciting. Right now it's a press release and nothing more.
RedditorsArGrb t1_iu72aup wrote
are bypass diodes "a lot more"? or are they a cheap and common element of most existing PV systems?
and yes, those major technical challenges mean this is very far from the market, if it ever makes it there, and all the articles deliberately do a poor job of explaining that.
but you can do better than being one of the many "helpfully" chiming in to let us know windows need to let some sunlight through as if that dooms the economic prospects out of the gate. It doesn't - these technologies are cheap to fabricate and new buildings are going to need glass somethings in the window frame. "It will always be better to build a normal building but then also pay a crew to go mount and install conventional solar panels in a field" is very much not a certainty, and private building developers probably don't care very much even if it's true.
aecarol1 t1_iu77mzp wrote
I'm "one of those guys" because the crowd that loves this idea heavily overlaps the "put solar panels on the roads" people. There is so much wrong with that idea it boggles the mind people don't think about it and rush to support a really crappy idea.
People like simple solutions to complex problems, especially those that show we "are doing something" especially with "out of the box thinking" technology.
This idea is certainly better than solar roads, but even with their "breakthrough" this isn't really ready for prime time. Even if this was "built into the windows" it still has to be wired into the building and all the support electronics such as inverters, controllers, etc, has to be wired and installed.
It's a lot easier to have a crew on a single flat roof, free to run conduit without cosmetic concerns, than it is to have electricians run extra wiring through walls and install extra electronics in every windowed room on every floor.
If all the ducks line up just right, this idea might well have a net positive, but it's far from clear and the history of this kind of announcement indicates it's not likely to.
We need to look at this holistically. After the easy fix of solar on the roof, is the money better spent on solar windows or on more efficient lighting or air conditioning?
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