[kjuhygtfrde]

Another way of stating it is that heat flows from hot->cold. You can't concentrate the light/heat from a blackbody source to more than the temperature of the source.

So you can't focus sunlight to more than 6000k however many mirrors you use.

[btilly]

The laws of thermodynamics do not prevent energy from flowing from cold to hot. They just say that for that to happen, entropy elsewhere must increase more.

As a trivial example disproving your claim, energy from the Sun can be collected in solar panels that can be used to run devices that can hit any temperature you want. For an extreme example, for fusion experiments they produce temperatures of over 11,000,000 degrees C.

For another trivial example, most of us have refrigerators that can transport heat energy from a colder place (the inside of the fridge) to a warmer place (your kitchen).