By Peter Weiss
Here’s a recipe for a cleaner, healthier planet: Take some water, add solar energy, extract hydrogen, and use it to power fuel cells for running cars and other machines. Then, collect their water emissions and start the procedure again.
One look at the list of ingredients in today’s fuel cells, however, shows that this ideal isn’t yet being followed. Because processes that use sunlight to extract hydrogen remain costly and inefficient, fossil fuels still supply the hydrogen in most fuel cells.