Pointless solar panel question

[itchy]

Both panels will have the same reflectivity/absorption properties. Therefore the one being used will have a slightly lower temperature than the one not being used, because some of its input energy is converted into electricity.

The one not being used will reach an equilibrium at a slightly hotter temperature. As solar panels don't generate much energy per unit area, the difference will be quite small.

IMO.

But does not the movement of electrons produce heat?

It could be 50/50 its one of them things that hurts the noggin.

 

[Minstadave]

But does not the movement of electrons produce heat?

It could be 50/50 its one of them things that hurts the noggin.

Yes it does produce heat, just not enough to change anything, the used panel still has to be cooler.

It's not a 50/50 thing. It's one of the few 100/0 things.

 

[Glaucus]

But does not the movement of electrons produce heat?

It could be 50/50 its one of them things that hurts the noggin.

just remember that you cant get energy from nothing, therefore if you are pulling energy out of one system and not the other, the other system must be dissipating the energy in another way, most likely as heat.

 

[adolf hamster]

But does not the movement of electrons produce heat?

It could be 50/50 its one of them things that hurts the noggin.

Depends, the movement of electrons up and down the shells of an atom produces light, and to some extent a solar panel works on the reverse of this principle.

But the simple thermodynamic solution is any closed system has energy coming in and energy going out, if some of that energy is electricity then heat output is reduced.

The same theory that a fan in a closed room heats the room up (even ignoring heat from any motor/power source)

 

[Chris Wilson]

The loaded panel will be warmer as the energy transfer from light to electricity is not, of course, 100% efficient. The working panel will self generate heat as well as current. The unloaded panel will show voltage at its terminals, but until current is drawn it's not producing electrical energy.

 

[Tefal]

point a bloody ir thermometer at them and find out

 

[Tefal]

The loaded panel will be warmer as the energy transfer from light to electricity is not, of course, 100% efficient. The working panel will self generate heat as well as current. The unloaded panel will show voltage at its terminals, but until current is drawn it's not producing electrical energy.

nope, because the heat produced from the current comes from the initial solar energy which is converted directly to heat in the unconnected panel.



lets use numbers


numbers are wildly inaccurate and not representative of real life they have been chosen purely to keep things round.



each panel receives 200 Watts of solar energy, panel's reflect 50% of the solar energy

the panel's are 50% efficient at converting light to electricity, and 80% efficient at conducting that electricity internally.


200W falls on unconnected panel 100W reflected 100W absorbed and converted to heat


200W falls on the connected panel, 100W reflected. Of the remaining 100W, 50W are converted to electricity, of that 20% is lost as heat through inefficiency in conductors (10W), the other 50w is turned to heat



which leaves us with unconnected panel receives 100W of heating energy

connected panel only receives 60W of heating energy.

 

[Snookums]

Its far to late to go into the complexities of this but, a solar panel is not a heat sink.

Its Photovoltaic and uses light not heat to generate electricity.

A un used solar panel will get the same amount of infrared radiation as a used one. But the used one will be generating heat as its energy is expelled.

You're correct the one generating electricity will produce heat, but that will be as a waste product. Conservation of energy simple makes it impossible for the connected one to generate more heat. A solar panel absorbs all electromagnetic waves in the visible spectrum which is your bass input of energy

Connected panel - 100% turns into 90% electrical energy and the other 10% would be waste/product loss in this case mainly heat energy therefore around 10% of incoming energy is lost as heat energy.

Unconnected panel - 100% turns into ~100% heat energy this is a much high energy to dissipate as heat therefore the greater the energy the greater the heat.

My numbers will be off as I'm not aware of solar panel yields etc and I'm sure some energy goes else where as well but it was just to get the idea. The unconnected HAS to be hotter due heat being one of the only ways to dissipate it's energy incoming.

EDIT: or as Tefalhas said. Whichever you find easier to grasp.

 

[Minstadave]

The loaded panel will be warmer as the energy transfer from light to electricity is not, of course, 100% efficient. The working panel will self generate heat as well as current. The unloaded panel will show voltage at its terminals, but until current is drawn it's not producing electrical energy.

Someone needs to read the thread before posting.