Water Power Hydro dams offer a clean energy source, but the trend in recent years has been to dismantle rather than build them. That's because the construction has been shown to interfere with wildlife and water supplies downstream. In their place, researchers have begun developing less intrusive devices that can harness the energy of water flow. These units are often anchored underwater and use revolving propeller-like devices to capture the motion of waves, currents and tides. Dunn also foresees the day when water can be tapped to provide hydrogen to power fuel cells.
Fuel cells generate electricity by splitting hydrogen atoms into electrons and protons.
Fuel cells now mainly rely on other hydrogen-rich materials, including natural gas and liquid hydrogen. But both the process of extracting hydrogen from water, and of creating fuel cells themselves, remains expensive. Until more cars and buses are designed to run on the units, their production is likely to remain costly. Nuclear power has largely been dismissed in recent years due to its history of dangerous meltdowns and the ongoing dilemma of how to store nuclear waste. But recent polls suggest as traditional power resources become more rare and more expensive, Americans are warming up to the idea of nuclear waste as a cost-efficient power source.