Total available solar energy is the same per square centimeter, whether you make a bigger PV panel or use a Fresnel lens to concentrate on a smaller panel: your total maximum insolation is going to be based on that area.
At most. But all arrangements will have inefficiencies, and some will be more inefficient than others.
I was fortunate enough to see the molten salt solar power plant in Gansu province, China. Really beautiful; not just the bright core but you can also see the beams of light converging.
ok, its a concentrator.,
the solar panels become less efficient when they get hotter, and so concentrating the sunlight just reduces their inefficiency, and longevity due to high temperature is already an issue, basically they are just surviving the natural sunlight…
And then, the concentrator has to pay off , but if it only works for part of the day, it has limitted ability to pay off, and then when its not working well, is it creating a shadow, so its actually able to cost more than it makes ???
There are other issues, such as maintenance requirement… the grooves and bowls and dishes and moving parts and stuff, all create maintenance.. the very flat glass of the flat solar panel has been found to be very low maintenance and easy to clean… groves in fresnel lenses sound like they would hold dirt and lichen, and be a real pain to clean. parabolas and other bowls will collect leaves and other debris…
I would argue that this “less than ideal” distance is actually the ideal distance. OP didn’t say “focal length”.
Any of the above, depending on circumstances. For example, outside temperature and solar irradiation. A panel that would work fine when operating in a hot plain close to the equator would benefit from a solar concentrator (which OP is describing) if operating somewhere in the far north or south.
However, if you just put the panel down and place the lens in front of it, you will lose. With concentration, you are much more sensitive to the suns position, meaning tracking is almost a must.
As a side note, heavy solar concentration is actually used for solar cells made from gallium arsenide, due to them being extremely expensive.
That video sadly contains a common error made by those unfamiliar with the topic. The open circuit voltage and short circuit current alone are useless for determining the efficiency of a solar panel. For that, you need to find the maximum power point, or the fill factor, and that requires more than just a standard multimeter.
However, the angle at which that light reaches the panel has a huge impact.
It seems to me the ideal shape would be a parabolic concentrator trough with a row of solar cells inside. This relies less on having to track the sun, if the trough is east-to-west direction. It still has the annual movement of the sun north to south to worry about. I do too wonder what benefit this is on cloudy days.
I would imagine there is an ideal limit, somethng like 3 or 4 times normal insolation. You’re trying to collect energy, not set the cell on fire. All this discussion is centered around mirror setup (or lenses) being substantially cheaper than solar cells themselves. Othewise, why bother? Plus the need to clean the mirrors. (and solar cells)
Compound Parabolic Concentrator (as noted above) is more efficient than a simple parabolic concentrator.
This isn’t a direct answer to your question, but here is my understanding.
Years ago there were experiments with doing this, to magnify the sunlight into a small solar panel. So maybe the magnifier would be a square foot in size, while the panel was only a few square inches.
However as time has passed, solar panels have gotten extremely cheap. At this point, solar panels are only about $0.20 to $0.50 per watt, depending on the scale of how many you are buying.
So I think its just not economical anymore. 20 years ago, the panels were the expensive part of a solar setup. Now they aren’t. Years ago it may have cost $5-10 per watt of solar panels, and all other costs of installing solar panels (other hardware, permits, installation, etc) may have cost $3 per watt. So the panels were like 75% of the cost of a solar setup.
However now the panels are maybe $0.30 per watt, and all the other costs are an additional $3 a watt. The panels themselves are not the price bottleneck.
I’m wondering if a defocusing lens might be useful. A setup with something like a one-square-meter lens spreading light over two square-meters of solar cells. The idea is that the cells stay cooler and operate at a higher efficiency.
Likely the efficiency gains aren’t enough to justify the added expense of lens, but I wouldn’t know until I see numbers.