We need to burn the sewage for power.
Seriously, guys. Solar & wind power are great energy sources other than the fact that they're intermittent. Current battery tech is inadequate to smooth out the production distribution, so we need a clean power supply that we can turn on & off rapidly to suit our needs. Shit is an abundant, fully renewable, and environmentally sustainable biofuel that's so cheap that most of us PAY to get rid of the stuff. What the hell are we doing?