User blog comment:Yuy168/Merging some works from MW into here./@comment-3155949-20131229093513/@comment-4364108-20131230054012

The yeilds provided are only sustainable for up to 10 seconds or so. They typically operate at about half that rate. We did the math. But the yeilds will be drastically decreased so that they don't take over the universe like they would if they had the tech they did before.