Solar panel with peak some distance from sun?

[seanth]

I was reading http://forum.kerbalspaceprogram.com/showthread.php/38408-Rotating-solar-panels-(Unity-configuration) and I think I understand how the solar panel's powercurve section works.

What's not clear to me is whether one can make a panel that works best at a certain distance from the sun. For example, a panel the works best in Laythe's distance from the sun, but as you get closer to the sun, it is less effecient. Ditto if you move further away out, beyond Laythe's orbit.

Would that be something like:

#key=<distance from sun> <multiplier> <optional#1> <optional#2>

powerCurve

{

key = 206000000000 0 0 0 #distance from sun it stops working

key = 13599840256 0.5 0 0 #Kerbin distance

key = 68773560320 1.0 0 0 #Jool

key = 0 0 0 0 #Sun

}

}

[Faark]

Sure, it should work... just try it. But it also does not really make any sense. Why should your solar panel produce more energy when less sun hits it?

[PringleMan]

Remember the photoelectric effect and the role it would have on a solar panel. Whether or not electrons are liberated by an incident photon is completely dependent on the frequency of the light, but the volume of electrons liberated is dependent on the magnitude of photon flux on the surface. That is to say, if the light source is going to generate current at all, then it will generate significantly more current closer to the source than away. We don's really see the effects of that in a lab here on Earth because the distances we can manage in a lab are practically 0 for all intensive purposes. But in space, it is an inverse square law. That is to say if you are at 2 AU, you have 1/4 the intensity of light, so your power generation from the same sized solar cell will be accordingly really small.

[seanth]

I know I said "solar panel", but the underlying idea is how to model photosynthetic life that evolved around the orbit of Jool. Anything that evolved to photosynthesize that far away from the sun would have peak efficiency where it evolved. Closer to the sun or further away would see decreases in activity.

[jfull]

Well, maybe. But that would only be because they might be intolerant to brighter light for other biological reasons. I'm fairly certain that any photosynthetic or photoelectric effect will only get more effective as the light level increases.

[seanth]

Well, maybe. But that would only be because they might be intolerant to brighter light for other biological reasons. I'm fairly certain that any photosynthetic or photoelectric effect will only get more effective as the light level increases.

See http://en.wikipedia.org/wiki/Photoinhibition for more info.

[Greys]

Photosynthesis gets less efficient outside a range because the cells can't provide enough basic materials, don't want to provide, or get damaged

Photovoltaics will perform better until they start to be damaged by heat and radiation, exceed the circuit capacity, or the bulk of the light it is receiving is unsuited

Your link agrees with this: Photosystem II (PSII) is more sensitive to light than the rest of the photosynthetic machinery, and most researchers define the term as light-induced damage to PSII. Above a certain magnetude of irradiation PSII begins to break down too much and the plant can only keep up with it for a while, then another limit is reached and the plant can't keep up with it, limiting the entire process.

This simply doesn't apply to photovoltaics

http://en.wikipedia.org/wiki/Solar_cell_efficiency#Factors_affecting_energy_conversion_efficiency

Heat, energy level of the photons, radiation damage, and the circuit's resistance are the primary factors reducing efficiency of a solar panel so yes, the heat inefficiency factor will increase as you approach the sun, and radiation damage to the cells will shorten their lifespan drastically when you get real close, but the fill factor should be dynamically adjusted to maintain peak efficiency and the energy level of the individual photons will remain stable, there will just be more of them. Assuming you have an active cooling system on the back of your panels you can largely eliminate the heat factor and maintain peak conditions, all while the intensity is growing

KSP doesn't simulate panel lifespan or heat factor, or fill factor. As well the later two can be compensated for with proper design goals, so reasonably you would not have Solar Panels that get less efficient the closer to Kerbol.

My question, are you making solar panels or a garden?

[seanth]

My question, are you making solar panels or a garden?

Excellent question. I'm considering a garden, but using the photovoltaic mechanic.