The highest temperature reachable using the solar light as an energy source

[wdlang]

now in many houses, there are solar water heaters

the problem is that, what is the highest possible temperature reachable using the sunlight?

another problem is, what if the sunlight is replaced with a laser light?

 

[DaveC426913]

now in many houses, there are solar water heaters

the problem is that, what is the highest possible temperature reachable using the sunlight?

There is no theoretical upper limit* on the size of a solar collector, though there are myriad practical ones.

*OK, there is. The absolute upper limit would be an elliptical reflector that completely encloses the sun with the sun at one focus and the Earth at the other. It would collect 100% of the output of the sun.

 

[wdlang]

There is no theoretical upper limit* on the size of a solar collector, though there are myriad practical ones.

*OK, there is. The absolute upper limit would be an elliptical reflector that completely encloses the sun with the sun at one focus and the Earth at the other. It would collect 100% of the output of the sun.

i mean the highest temperature achievable

i do not mean the highest power achievable

 

[DaveC426913]

My point is that the question is far too vague. You set no parameters.

 

[phinds]

i mean the highest temperature achievable

i do not mean the highest power achievable

But the two go together directly and you have set no parameters. It would not take a great deal of power to raise a couple of molecules to a VERY high temperature, but that would be utterly useless for anything practical.

I'm just saying what Dave already said. You're question is too vague to have any meaning.

 

[wdlang]

But the two go together directly and you have set no parameters. It would not take a great deal of power to raise a couple of molecules to a VERY high temperature, but that would be utterly useless for anything practical.

I'm just saying what Dave already said. You're question is too vague to have any meaning.

no, i believe there is some thermodynamics

i cannot let heat go from a cooler object to a hotter object

 

[Ken G]

A passive system, which does nothing but absorb heat, could never reach a temperature above that of the Sun, some 5780 K. But if you take the absorbed energy and extract work from it, you could channel that free energy into as small a system as you like, and get an arbitrarily high T, as has been said.

 

[wdlang]

A passive system, which does nothing but absorb heat, could never reach a temperature above that of the Sun, some 5780 K. But if you take the absorbed energy and extract work from it, you could channel that free energy into as small a system as you like, and get an arbitrarily high T, as has been said.

you are right!

 

[DaveC426913]

you are right!