Predendum, for lag of a better term, many if not most of the questions I pose here, are answered in part or in full along the way, but I leave them as is just the same. The process itself can sometimes be illuminating also.
--- The actual reply ---
First of all, wow, just wow.
Your question focusses on, essentially, three aspects:
- Wavelength conversion efficiency
- Angle of the majority of the rays
- Brightness
Wavelength
All cheap solar cells are made with silicon as the primary material, and as a result all will have a efficiency curve that is most efficient at infrared, and tapers in efficiency toward ultraviolet. If your sky appears blue, then you'll likely understand that scattered sunlight hitting the ground tends to be shorter wavelengths (blue & ultraviolet) rather than longer wavelengths (red and infrared). In the absence of atmosphere, clouds, etc you'd find that the only time the solar panel gets power is when the sun's light falls on the panel, and you would have zero power otherwise. With atmosphere you find that your panels will provide power when in shadow due to light scattering. Unfortunately for us, Rayleigh scattering means that much of the incidental light tends toward blue, where the solar panels have a lower efficiency. Further, ultraviolet photons are more energetic than infrared photons, so can produce more energy per photon.
I knew, or at least should've known and recalled much of this, but to simplify matters, am I to understand that the main focus in the hunt for the perfect technology should be not only effective use of UV, but just as, if not more importantly the blue part of the spectrum, or is the potential gain insignificant in comparison?
However, "Sunlight energy that reaches the ground is around 4% ultraviolet, 43% visible light, and 53% infrared. Solar panels mostly convert visible light into electrical energy, and they also can make use of almost half the infrared energy." (
source )
So the reality is that scientists and manufacturers have already developed the correct panels for our use on the surface of the Earth. Newer panels tweak the recipe and increase the efficiency of conversion of the solar energy that hits the ground to improve it, but at this point there's no magic new technology or significant change we can make that will result in a significant improvement. Perhaps in the future, but it's not a questions of what type of energy we see at the surface, we know exactly what is available in direct and indirect solar radiation. It's now just a question of what technology will have the best conversion ratio.
I see your point, however I do believe that the difference between the parts of the world where development has likely been focussed to be suitable for, as the potential gains are that much greater, and where I live in the Nordics, where large scale solar farming is perhaps not all that great of an investment, is somewhat significant.
53% infrared, which presumably is in terms og actual energy and not something else, like the number of photons, is a lot, but if this does not penetrate the clouds, haze and/or the additional atmosphere given the tilt of the earth and so on, the efficiency becomes irrelevant, be it 0 or 100%. As I understand it, this is exactly the main difference, whereas Ultra Violet plays a far greater role under such circumstances, in reality promoting those 4% to perhaps twice that and potentially a lot more.
You pretty much seem to confirm my interpretation, and yet conclude that it is not worth to technologies that are perhaps not as well development or have other drawback, even though they promise an absorption curve (?) more fitting the circumstances.
I'm not really sure that I'm misunderstanding here. Presumably I've missed or misinterpreted something important.
Brightness
...
The reality is that we really can't improve the brightness of the light that hits the ground by changing the solar technology or the world in any way that is reasonable given the tradeoffs involved.
This much is obvious. Well, perhaps not to everyone, but least to me, however flawed and inept I am otherwise, but then again, many speak out against wind, because it is unpredictable and thus unreliable (this of course is not true, not entirely), but still there is much focus on the area, only now there's an increased focus in regards to location, even areas with almost prohibitive costs, because that gain is that much greater in the long run, not least due to them becoming more reliable in terms of continuos wind and thus power. Might it not in the same way make sense to focus your energy on reliability when it come to solar, only instead of location on earth, location on the spectrum, where the the energy production is more reliable? In any case, this is exactly what I am trying to do, though of course I do not actually expect to succeed. If it was that easy, it wouldn't be that difficult for me to figure out if it's even worth attempting.
Angle of the majority of the rays
...
Solar trackers are generally not cost effective, but there are coatings on higher efficiency panels that take light received at an angle tot he panel surface and direct it down into the panel. This is done by changing the reflectivity of the glass so more light is refracted into the glass and panel than reflected away from the glass and panel. Some even have micro lenses to improve the capture of light. The more light a panel absorbs and doesn't reflect, the more black a panel will appear to our eyes.
I have read about the micro lenses at least, but only now comprehension has dawned on me, as I was somewhat mystified as to how this could improve anything, but naturally it is all about the angle. Check.
... but if you could improve your solar efficiency by 1% at a cost increase of 5,000%, would you consider it?
Being European I rather enjoyed the prospect of simply answering yes, but of course the three zeroes confused me, until it dawned on me (no, it didn't take that long).
So yes to a factor of 5.000, not so much 5,000.
So, the answer to your question is this: The panels that are most efficient for any surface solar use are going to be the panels that are most efficient for you, if you're going to use them on the surface of the earth.
This answers, and by the way also all the others, vastly surpass any expectations I might have had, when first venturing into this forum. I really mean it when In say that my appreciation ends only due to the need for breathing, and other mundane necessities of life.
Still, I'm not quite certain what to conclude from your answer. Certainly my venture is not, nor will it ever be cost effective, but I knew that even before I started doing research. Truth be told, solar really is far from optimal, given other available options, under the circumstances, but it also has its advantages, like modularity, expandability and even cost, I think.
But at the end of the day the question really is a simple one. Am I really to understand that it doesn't matter, at all, if I go for crystalline, mono or poly, silicon or or some obscure isotope of bismuth, Amorphous, thin film or whatever the various technologies are called, just as long as their efficiency rating is the same?
In reply to your later answer, as I cannot handle more right now, you are most certainly right that I need to reevaluate, but this is exactly the point of this exercise, and the way I work in general. In order to evaluate or indeed reevaluate, you need accurate and reliable knowledge and in order to gain this, you need a source, which in some ways have been exceedingly difficult to find, but you have most certainly been a valuable, and I do believe reliable source, so again, I thank you.
