DARPA has a number of tough-to-believe projects going on at any moment of time, that leads to the agency often being called the Pentagon’s mad science division. This time around, they are looking for an environmentally friendly energy source, or basically, using poop to power portable nuclear reactors.
The reactors will most likely be used at overseas bases, where the Pentagon has to spend a lot of money to get rid of human waste that gets accumulated around outposts. And that is probably why the agency has recently issued a Request for Information asking for methods the waste could be used to generate electricity and fuel for land and water based operations.
Any such proposal should have the capability to generate at least 15,000 gallons of fuel everyday, and of course, be portable and easy to deploy. Another requirement from DARPA is that the method should not generate any by products that can be harmful for the environment.