The apple gives you a good picture of where we stand...

A brief history of consumption
http://www.ecotality.com/

And then I read about the ecobus (right here in the USof A)...

Arizona Showcases Hydrogen Fuel Cell Bus

Arizona's first hydrogen powered bus is on the move in Arizona. The
ECObus is powered by a fuel cell that runs on pure hydrogen. ECOtality
has teamed up with Arizona Public Service (APS) company to bring the
ECObus to the state of Arizona with the objective of educating the
public on the use of renewable energies.

Beginning its excursion in Phoenix, Arizona, this zero-emissions bus
showcases the capabilities of hydrogen fuel cell technology.

Fuel Cell Technology is Good for the Environment

When hydrogen is used in a fuel cell, it produces electricity without
any harmful emissions. In fact, all that comes out of the tailpipe is
a small amount of water vapor. This is in sharp contrast to the
conventional vehicles we drive and ride-in today. Current conventional
vehicles are fueled by petroleum and powered by internal combustion
engines, contributing significantly to greenhouse gases and other
noxious substances that are emitted into our atmosphere daily.

As such, hydrogen is an ideal renewable energy source, answering
today's complex energy problems with its ability to power cars,
trucks, homes and businesses with no pollution or greenhouse gases.

Transportation of the Future

The bus uses three HyPM® 65 Fuel Cell Power Modules capable of
providing a total of 180 kilowatts (kW) of power. A 720-volt bank of
ultra-capacitors provides the remaining power needed to reach the peak
power requirements of 350 kW.

While the dominant power source comes from fuel cells, the bus'
efficient, hybrid-power construction represents an attractive solution
for future fuel cell powered buses. This is mainly because a hybrid
configuration enables the system to readily provide instantaneous full
power, with reduced capital cost and increased fuel efficiency. The
anticipated cost reduction is seen as a pathway that could speed up
the commercialization of fuel cell technology.

http://www.ecotality.com/ecobus/