Unlike ancient wars when men fought in battles face-to-face, body-to-body with simple armory wars of modern days are about the use of equipment over the capabilities of individuals. The one that has more tanks, rockets, or drones, the threat of nuclear weapons is mostly the winner. The war of materials depends on a sophisticated supply chain. Arab nations like Saudi Arabia became wealthy not only by processing crude oil but by the need of western powers to have oil for their armies. It was a lesson learned from the past.
During WWII supply of oil to move tanks and trucks became a problem to the extent that Adolph Hitler eventually had to retract from the East flank in Russia. He was unable to reach the oil fields around the Caspian Sea in time, the filling station out of reach. Rockets and aircraft, fighter jets, submarines, and tanks depending on the supply chain of oil.
When armies no longer depend on the power of oil but on renewable energy like the wind for aircraft carriers, submarines, trucks, and aircraft on an independent basis with no need for a charging facility (aircraft with solar panels as outside structure, etc.)...will this change the face of war with traditional weaponry and drones? Humans no longer needed face-to-face? More or fewer wars are possible as casualties and blood is no longer part of the sad story of war? What seems to be science fiction is a possibility worth discussing.
This scenario potentially makes more wars possible as the obstacles not to doing it will be lowered. Blood is not directly flowing only in destroyed structures and the fall of the war complexity can encourage nations to go for a war that would not have been able to do so.
It furthermore changes potentially the power structure of the world. Oil-blessed countries like the Arab nations, Venezuela, Nigeria, and former Soviet countries might lose their position even earlier than anticipated in the course of fighting for clean air, water, and land.
This development can potentially open the door for the underdogs, the place where humans and humanity were born and educated once the nations decide wisely for the leader's visionary minds that like Moses lead them to the promised land.