An Israeli company called Emefcy has developed a process that promises to decrease the energy drain of wastewater treatment. This week, Energy Technology Ventures—a joint venture between GE, NRG Energy, and ConocoPhillips—invested in the company, marking the venture's first-ever investment in a non-U.S. company.

Conventional wastewater treatment consumes 2 percent of global power capacity, some 80,000 megawatts, at a cost of $40 billion per year.

Using conventional microbial fuel-cell technology and its own proprietary engineering, Emefcy harvests energy from wastewater, generating enough to power the entire treatment process. In the treatment of particularly carbon-rich industrial wastewater, the company says, the process produces excess electricity that can be fed back into the grid at a profit.

In microbial fuel cells, naturally occurring microorganisms oxidize wastewater. An anode and cathode, placed a critical distance apart in the water, create an electrical circuit from the electrons gained from this oxidation.