אפשר לספק את כל צרכי האנרגיה של העולם עם רוח, שמש ומים

The general struggle for existence of animate beings is not a struggle for raw materials – these, for organisms, are air, water and soil, all abundantly available – nor for energy, which exists in plenty in any body in the form of heat Q, but of a struggle for entropy S, which becomes available through the transition of energy from the hot sun to the cold earth.
Ludwig Boltzmann. (1886). The Second Law of Thermodynamics
In B. McGinness (ed.), Ludwig Boltzmann: Theoretical physics and philosophical problems: Select Writings