CHAPTER 20: Hydrogen and Future Energy Sources
We learned in Chapter 8 that fossil fuels were formed
before and during the time of the dinosaurs - when plants
and animals died. Their decomposed remains gradually changed
over the years to form coal, oil and natural gas. Fossil
fuels took millions of years to make. We are using up the
fuels formed more than 65 million years ago. They can't be
renewed; they can't be made again. We can save fossil fuels
by conserving and finding ways to harness energy from
seemingly "endless sources," like the sun and the wind.
We can't use fossil fuels forever as they are a non-renewable
and finite resource. Some people suggest that we should
start using hydrogen.
Hydrogen is a colorless, odorless gas that accounts for
75 percent of the entire universe's mass. Hydrogen is found on
Earth only in combination with other elements such as
oxygen, carbon and nitrogen. To use hydrogen, it must be
separated from these other elements.
Today, hydrogen is used primarily in ammonia
manufacturing, petroleum refining and synthesis of methanol.
It's also used in NASA's space program as fuel for the space
shuttles, and in fuel cells that provide heat, electricity
and drinking water for astronauts. Fuel cells are devices
that directly convert hydrogen into electricity. In the
future, hydrogen could be used to fuel vehicles (such as the
DaimlerChrysler NeCar 4 shown in the picture to the right) and
aircraft, and provide power for our homes and offices.
Hydrogen can be made from molecules called hydrocarbons by applying
heat, a process known as "reforming" hydrogen. This process
makes hydrogen from natural gas. An electrical current can
also be used to separate water into its components of oxygen
and hydrogen in a process called electrolysis. Some algae
and bacteria, using sunlight as their energy source, give
off hydrogen under certain conditions.
Hydrogen as a fuel is high in energy, yet a machine that
burns pure hydrogen produces almost zero pollution. NASA has
used liquid hydrogen since the 1970s to propel rockets and
now the space shuttle into orbit. Hydrogen fuel cells power
the shuttle's electrical systems, producing a clean
by-product - pure water, which the crew drinks.
You can think of a fuel cell as a battery that is
constantly replenished by adding fuel to it - it never loses
its charge.
To view a FLASH video of how a fuel cell works, go to the
Ballard Power Systems website.
Fuel Cell Uses
Fuel cells are a promising technology for use as a
source of heat and electricity in buildings, and as an
electrical power source for vehicles.
Auto companies are working on building cars and trucks
that use fuel cells. In a fuel cell vehicle, an
electrochemical device converts hydrogen (stored on board)
and oxygen from the air into electricity, to drive an
electric motor and power the vehicle.
Although these applications would ideally run off pure
hydrogen, in the near term they are likely to be fueled with
natural gas, methanol or even gasoline. Reforming these
fuels to create hydrogen will allow the use of much of our
current energy infrastructure - gas stations, natural gas
pipelines, etc. - while fuel cells are phased in.
In the future, hydrogen could also join electricity as
an important energy carrier. An energy carrier stores, moves
and delivers energy in a usable form to consumers.
Renewable energy sources, like the sun, can't produce
energy all the time. The sun doesn't always shine. But
hydrogen can store this energy until it is needed and can be
transported to where it is needed.
Some experts think that hydrogen will form the basic
energy infrastructure that will power future societies,
replacing today's natural gas, oil, coal, and electricity
infrastructures. They see a new "hydrogen economy" to
replace our current "fossil fuel-based economy," although
that vision probably won't happen until far in the future.
Solar Power Satellites
One suggestion for energy in the future is to put huge solar
power satellites into orbit around the earth. They would
collect solar energy from the sun, convert it to electricity
and beam it to Earth as microwaves or some other form of
transmission. The power would have no greenhouse gas
emissions, but microwave beams might affect health
adversely. And frequent rocket launches may harm the upper
atmosphere. This idea may not be practical for another
century; if at all.
The picture on the right is an
early and simple drawing of how a space solar power satellite
would beam energy to electrical power grid on Earth.
Other Ideas
Some people have claimed they've invented a machine that
will "save the planet." Others are convinced that there's a
vast conspiracy by fossil fuel and / or nuclear power
companies to stop such devices from getting to the public.
Some of these contraptions use theories called "Free
Energy," "Over Unity" or "Zero-Point Energy." As a matter of
fact, you can find all sorts of information about such
devices on the Internet. Just plug in any of those words.
But none of these devices have ever been proven, either
theoretically or physically. The "free energy" area is
filled with con artists selling unintelligible information,
often clouded with technical sounding jargon, and seeking
people with money to develop their inventions or ideas.
As the old saying goes, "a fool and his money are soon
parted."
Most of these devices are perpetual motion machines,
which violate known laws of science. Even the U.S. Patent
Office will not issue a patent for such devices. With energy
and the universe (at least as we know it today), there's no
such thing as a free lunch; or free energy. You can't get
energy from nothing because of the fundamental laws of
physics that energy cannot be created or destroyed.
What about matter and anti-matter? What about energy
that they use on Star Trek and in other science fiction
stories? The ideas are interesting, but they are still
fiction. Though science fiction has a basis in some fact.
Jules Verne wrote about traveling under the water more than
a hundred years ago, and today we have submarines. He also
wrote about going to the moon, and in 1969 humans first set
foot on our closest neighbor in space.
So, while some ideas being used by writers are
fiction... there could be some basis in fact. Who knows,
someone might create a mater-antimatter energy system that
could revolutionize the way we think about energy and our
universe.
Here are some additional websites to check out.