According to Asahi Shimbun, Japanese Defense Minister Taro Kono wants to get the Defense Ministry and the Self Defense Forces to 100 percent renewable energy.
I think that is a great idea.
If you think that the climate emergency is the biggest threat to security right now and there is an urgent need to do something about this problem, there is no need to leave the military out from the fighting.
And actually, this kind of thing could go way farther than a goal of just powering the ministry building and the military operations.
I recall the idea of putting a massive amount of renewable energy right into the Mongolian Gobi desert. I recall that Masayoshi Son started out with such a project under his Asia Super Grid initiative.
Why not give that project some military help? Get some solar capacity built right in that desert as an exercise in fighting the biggest threat of the century.
Better yet, do that as a sort of competition held in regular intervals. Give participating military forces a time frame and a square of desert land to fill and compete for the gold medal. The winner would be the team installing the most capacity in that time frame.
The original modern Olympic idea had keeping peace as one of its motivations. Having soldiers compete to build renewable capacity instead of killing each other would be a good match to that basic idea.