Philip Kreveld
The earth is surrounded by a working fluid, air, and the wind is a result of alternate heating and cooling of the globe (elementary heat engine).
Same principle in steam turbines running generators (abstract heat from a high temperature source and reject heat to a cool temperature sink)
Wind turbines make use of the earth’s heat engine
Photo-electric power is provided by solar panels- They produce direct current power (the same power for computers) . May be in the future we can cut out the conversion from alternating current to direct current which is what is happening today .
High voltage transmission line are likely to largely disappear within 50 years, and we will see more microgrids servicing smaller population centres rather than having to maintain some 600.000 kilometres of distribution lines.