Image via WikipediaBrown energy (n.) - Energy derived from non-renewable resources, usually through highly poluting methods. The opposite of green energy. A snarky term for any energy source, technology, or industry that the environmentalist movement doesn't approve of. Brown energy, in concept if not in name, is typically depicted as a root cause of environmental collapse in ecopocalypse and greenpunk fiction.
I bring it up because: The Bloom Box is making the rounds as the savior energy technology du jour, offering highly efficient refrigerator-sized industrial fuel cells. At sufficient scale, the Bloom Box can supposedly convert natural gas and oxygen into electricity with no toxic byproducts and for less cost per kilowatt-hour than conventional commercial electricity. Nonetheless, the Bloom Box runs on non-renewable natural gas and a single Starbucks-powering Bloom Box Energy Server will run your $800,000. So is this green energy, because it's non-polluting, or is it brown energy, because it's non-renewable? It's probably a little bit of both, but even money says a Bloom Box-esque eco-energy source gets namechecked in a quasi sci-fi TV show within the next six months. It's too trendy to ignore.