In the end you're still powering something by letting something cold grow warm, so I'm not seeing how you could avoid the second law of thermodynamics. I suppo

In the end you're still powering something by letting something cold grow warm, so I'm not seeing how you could avoid the second law of thermodynamics. I suppose that in theory the cooling step would be where you could recoup your losses a bit by using an efficient heat pump, but getting the coefficient of performance greater than 1 could be pretty difficult for such extreme temperature differences.