No joke – a tiny New Zealand startup called Aquaflow Bionomics has figured out out to harvest the algae that grows naturally in, ahem, “effluent ponds”. After a person poops, all the waste gets piped to a sewage treatment plant (let’s assume dry weather. Storm water overflow is too gross to be thought about to deeply). It then sits in a settling pond to separate solids from liquids. When the liquid is piped off for further treatment, the solid remains, and it becomes a tasty feeding ground for algae. Once you’ve got algae, it’s no great trick to convert it into biofuel, and in fact, there’s far more energy in algae fuel than in ethanol from corn or sugar. You can get 10,000 gallons of ethanol from an acre of algae, compared to 60 gallons from an acre of corn. And growing the algae on human waste – that’s just genius. The company’s website says that Boeing is looking into Aquaflow’s process for possible distillation into jet fuel.
In fact, converting our waste into energy has become a bit of a trend lately. Using a process called Plasma incineration, a few companies propose to convert solid trash waste into fuel for natural gas electricity generation. The process uses something similar to an arc welder to heat the trash very rapidly so that it melts into a big piece of slag. The trash ingots are then washed, to reduce the heavy metal content, and then sent to a natural gas electricity plant.
Of course, neither of these are as good idea as just building some solar and wind plants and driving electric vehicles. A 100-mile square of solar panels in Nevada would generate enough electricity to power the United States. Or, alternatively, there’s enough harnessable wind in North Dakota, Texas, and Kansas to power the nation. Somehow these technologies make more sense to me than building giant plasma incinerators or trying to extract car fuel from poop. Of course, then we still need to figure out what to do with the poop.