What are you implying? That looks efficient to me! (/s)
What are you implying? That looks efficient to me! (/s)
Should you at the very least not have the energy difference between something like 20°C and whatever the max is (100°C for water, as you put). All the energy down to 0K will not be possible to extract. This should favour sand even more.
Hey, he must be the guy from the comic