A single windmill can power several servers… so the savings goes pretty far. Also, even if you use a “heavy” platform, if it’s not under load the difference in CPU heat/watts used is a minimal difference, if you really want to go there. The fact is that the time it takes you has a finite cost, and that cost is time. Time you can’t get back. Energy may be renewable, time in your life that you can do other things is not.