Fossil fuels are in limited supply and are flooding the atmosphere with harmful greenhouse gasses, so the hunt for effective, bountiful and clean energy sources is in overdrive. NASA already uses primarily clean-burning hydrogen fuel in the space shuttle. The organization also directs research into fuel for Earth-bound technologies.
One NASA study is focusing on using principles of life in space to make clean fuel for life on Earth.
When astronauts travel to space, they're living in a closed system. They have to bring everything they need with them, and space is limited. So whatever they have on hand should do as many jobs as possible. An extreme example of this is cleaning astronauts' urine so it can then be used as drinking water.
The latest NASA idea for renewable energy actually comes from the organization's research into new ways to recycle wastewater on missions.
NASA scientists have developed a method of deriving clean fuel from algae. Many species of algae produce oil.
The idea is to place semipermeable membranes filled with wastewater out in the ocean. Algae will grow in the membranes, feeding on the nutrients in the waste. The byproduct is biofuels, which will then be harvested from the bags. The added bonuses are that the only other byproducts of the process are oxygen and water (algae perform photosynthesis), and the algae "treat" the waste by consuming it, so it doesn't pollute the oceans.
Up next on the list is a more far-reaching approach to environmental health -- and one that NASA does particularly well.