Philippe Cousteau looks at renewable sources of energy that can replace our reliance on fossil fuels and consequently, help clean up our atmosphere.  Solar panels, wind turbines and hydro-power are clean forms of energy that are being developed and deployed throughout the world.  There's also an environment-friendly replacement for gasoline in the form of algae biofuel.  Philippe shares all the exciting new developments in this area and gives hope for a healthier future of our planet.