So fuel cars,by 2020?

A fuel cell is the electrochemical cell that converts chemical energy from a fuel into electricity through an electrochemical reaction  The most plentiful and simplest of the chemical element is Hydrogen,so it was only a matter of time before we began exploring it as a potential fuel source. A hydrogen fuel cell is similar in principle to a battery, except it doesn't need recharging; it recharges itself while operating. In a hydrogen fuel cell, hydrogen is combined with oxygen from the air to produce water and in turn electricity.

The only by-products of a hydrogen fuel cell are heat and water. The fuel cells can produce electricity continuously as long as fuel and oxygen are supplied. In addition to electricity,fuel cells produce water,heat and depending on the fuel source ,small amount of nitrogen dioxide and other emissions. Because hydrogen doesn't need to be extracted from fossil fuels, it can be extracted from water using sunlight, the most obvious application for these fuel cells is in cars.