Well, that brings us back to earlier in the thread. It's not only about money-expensive. If it gets more energy-expensive to produce/store/route/... energy tha

Well, that brings us back to earlier in the thread. It's not only about money-expensive. If it gets more energy-expensive to produce/store/route/... energy than the amount of energy we end up with in the end, the game is over. So, in practice, there are limits to reserves. There is, of course, the possibility that these limits can change with new technologies, which in turn depends on money-cost as you mention.