One of the most efficient alternative fuels nowadays is hydrogen. Pure H2. It has emissions of pure water. It is a eco-friendly alternative that produces drinkable exhausts. (See Pac-car, one of the previous blogs, for more info.) But, there are problems that have to be solved before we can go around driving our water-producing cars. One of the biggest problems is where do we fuel up? There are less than 100 hydrogen fueling stations worldwide. Do people in Colorado buy a hydrogen powered car, and when they need to fill up, they go to California, or fly to France? How would that be possible, especially with people with busy schedules. (see diagram for where filling stations are.)
Another problem. Money. Yes, it's the root of all evil, and causes people to become not environmental. I mean, do you want to buy a $58,000 or a $160,000 hydrogen car. Yes, a hydrogen fuel cell powerful enough to power a car can add $100,000 to the price of a car.
Yet another problem. The hydrogen has to liquid. And to be liquid, hydrogen has to be kept very, very, cold. Below -421 degrees Fahrenheit. How would we keep it that cold? In the filling station, that's not a very big problem. They can just chill it using electronic cooling. In the cars, the cryogenic system takes care of this. But, if you don't turn the car on for a few days, the hydrogen will turn to vapor and leave through the vents.
Hydrogen is a genius alternative fuel, but in the end there are just too many problems to use hydrogen powered cars around the world.
(red- operable, green-planned, white-not functional)