Do you recall the "back to the future" movies where doc puts food scraps into the time machine? Seems far fetched but when we look to si-fi of the past most of it has become reality.
We produce a lot of waste and it costs heaps to process and dispose, imagine that one day our sewer system could be delivering the ingrediant to be turned into hydrogen. Remember that there is no polution in burning hydrogen all that is emmitted is H2O
