What is a good science fair project for environmental engineering?

Science fair projects are meant to solve problems, not to show how something works. I'd like to do a science fair project in the category of engineering using my LEGO Mindstorms robotics kit. The judges at the science fair especially like environmental projects, so I want to do an environmental engineering project. An example would be "What alternative energy source is the most efficient: water, wind, or geothermal?" Something like that would be good. If you have any ideas, I would greatly appreciate to see them.What is a good science fair project for environmental engineering?Put a solar panel on the robot. Use the controller for the robot to make it move around using the suns energy. Say this should be the use of energy for cars, making them run by electricity. If they ask about nighttime, give the example of a glow-in-the-dark magnet. It gathers the energy it needs during the day. uses it at night. Also use the example about the terrible oil spill in the gulf of mexico thats going on right now. Say that would be abolished if we were to use an alternative energy source for our cars and machines, aka the suns energy.Don't know much about enviormental engineering, but I think this falls into that catagory. Not very original but good examples for it are here.What is a good science fair project for environmental engineering?Check out Thames and Kosmos kits. They have several environmental engineering ones: Power House, Hydro Power, Wind Power, Solar Physics, etc. You can find most of them at xump.com (http://www.xump.com/Science/ThamesKosmos.cfm) The great thing about their kits is that they come with amazing full color booklets that guide you through experiments.

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