1. Two sources, side by side, emit water into the uniform flow in a water channel. 2. Fuel-cell-powered vehicles, ideally, emit only water. 3. Promoters say fuel cells create no polluting particles or gases, and emit only water as exhaust. 4. Fuel cells produce electricity through a reaction between hydrogen and oxygen, and emit only water. 5. The fuel cell emits only water as a byproduct of the electro-chemical reaction. 6. They emit only water and heat as exhaust and have become the focal point of research in an industry seeking cleaner alternatives to the internal-combustion engine. |