It just seems like there wasn't much critical thinking in this article. It doesn't give us an idea of the real magnitude of the potential energy that could be

It just seems like there wasn't much critical thinking in this article. It doesn't give us an idea of the real magnitude of the potential energy that could be produced this way. For example, "6.4 trillion liters" is just a headline grabber (and an effective one), but if it only produces a trivial amount of energy, who cares? It also doesn't mention that there are useful alternatives that may be more economically worthwhile for waste (see the other comments here).