Can black body retain it`s absorbed heat energy?

[CHANDRABHAN]

Can black body retain it`s absorbed heat energy? If yes, then why we can not convert this energy into a usefull form such as into electric energy as solar do?

 

[DrClaude]

Blackbodies are ideal objects, none exist in reality. In any case, anything that absorbs sunlight could be used as a source of energy, see for instance

https://en.wikipedia.org/wiki/Thermal_energy_storage
https://en.wikipedia.org/wiki/Concentrated_solar_power
https://en.wikipedia.org/wiki/Solar_cooker
https://en.wikipedia.org/wiki/Solar_pond

 

[sophiecentaur]

Can black body retain it`s absorbed heat energy? If yes, then why we can not convert this energy into a usefull form such as into electric energy as solar do?

Hi and welcome to PF.
If your black body retained its heat then, by definition of the word 'retained', the energy couldn't be retained.
On the other hand. a black body (say a dark painted brick) can be placed in a solar furnace (just to improve the process`) and the retained heat could be used to boil some water and work a steam engine / generator.
There's a sort of general principle that, to make anything 'happen', Energy has to be transformed from one form to another.

 

[anorlunda]

Can black body retain it`s absorbed heat energy? If yes, then why we can not convert this energy into a usefull form such as into electric energy as solar do?

Yes. But the ability to extract energy depends on the temperature difference. See https://en.wikipedia.org/wiki/Carnot_cycle

So you can store any amount of energy, but if the temperature difference to the environment is too small, you can't extract it usefully.