The Coming Hydrogen Economy?
This will only be scalable if we are
clever enough to use dedicated renewable energy to produce hydrogen
in situ, rather than grid connected power at those dedicated locations |
The Hydrogen Future Ultimate Green Power?
- US no longer dependent on external fuel sources
- All Hydrogen is domestically produced from a variety of sources including renewables, such as biomass and water; fossil fuels, using advanced technologies to ensure that any carbon released in the process does not escape into the atmosphere; and nuclear energy.
- Hydrogen is delivered and stored routinely and safely.
Hydrogen-powered fuel cells and engines are as common as the gasoline and diesel engines of the late 20th century; they power our cars, trucks, buses, and other vehicles, as well as our homes, offices, and factories.
To achieve this future requires the same kind of national committment that allowed manned
lunar landings? Do we still have the leadership ability to do this?
The benefits of a hydrogen economy, relative to the current situation are large!
- Improved National Energy Security:
The US currently uses 20 million barrels of oil per day at a total cost of
$2billion per week. The barrells come from other countries and the money goes to them.
In the year 2030, do we now wish to buy all our oil from Russia or should we be off of
fossil fuel based energy sources?
- Reduced Greenhouse Gas emissions duh ... But, we just might
be sufficiently stupid to use Fossil Fuels to produce hydrogen in keeping with our style
over substance traditions ...
- Reduced air pollution No shit Sherlock ...
- Improved Energy efficiency: A conventional combustion-based power plant typically generates electricity at efficiencies of 33 to 35 percent, while fuel cell plants can generate electricity at efficiencies of up to 60 percent. When fuel cells are used to generate electricity and heat (co-generation), they can reach efficiencies of up to 85 percent.
Internal-combustion engines in today's automobiles convert less than 30 percent of the energy in gasoline into power that moves the vehicle. Vehicles using electric motors powered by hydrogen fuel cells are much more energy efficient, utilizing 40-60 percent of the fuel's energy.
all of the above is true, however, each percentage for hydrogen quoted above
has to be multiplied by .67 which is the efficiency of manufacturing hydrogen via electrolysis (
more on this later)
Barriers to achieving this Future:
- Hydrogen production and delivery Cost is the biggest impediment to using hydrogen more widely as a fuel. Hydrogen is currently more expensive to produce than conventional fuels, such as gasoline, and many of the more cost-effective production methods generate greenhouse gases.
In addition, the current system for delivering conventional fuels to consumers cannot be used for hydrogen. Many expensive changes must be made in our nation's energy infrastructure to accommodate hydrogen.
so Tax gasoline and use the revenue to make these investments!
- Hydrogen Storage Hydrogen has low volumetric energy density. This
makes it difficult to store enough energy in a reasonably sized space. This is a particular problem for hydrogen-powered fuel cell vehicles, which must store hydrogen in compact tanks.
Energy Density Comparison (KHW/kg)
- Hydrogen ------------------------- 38
- Gasoline ------------------------ 14
- Lead Acid Batteries -------------- 0.04
The problem here is that the volume that is required to store 1 kg of gaseous hydrogen is
very large. At atompsheric temperature, liquid hydrogen has a density of about 7% that
of water. Compared to gasoline (about 75% the density of water) hydrogen has 2.7 times the energy
density per unit mass, but the smaller density means that effectively, hydrogen requires about 4
times the volume storage for a given amount of energy.
So, a 15 gallon gas tank that contains 90 pounds of gasonline would need to be 60 gallons
containing 34 pounds of hydrogen this means that for the near future,
hydrogen powered cars are not practical, but trucks and busses are very practical.
High-pressure storage tanks are currently being developed, and research is being conducted into the use of other storage technologies such as metal hydrides and carbon nanostructures (materials that can absorb and retain high concentrations of hydrogen).
This is an engineering and materials development problem which can be
solved
- Fuel Cell Cost and Durability High-temperature fuel cells, in particular, are prone to material breakdown and shortened operating lifetimes. PEM fuel cells must have effective water management systems to operate dependably and efficiently.
Hydrogen Fuel Cells
|
This animation shows the process that goes on inside an individual fuel cell. The red Hs represent
hydrogen molecules (H2) from a hydrogen storage tank. The orange H+ represents a hydrogen ion
after it's electron is removed. The yellow e- represents an electron moving through a circut to do
work (like lighting a light bulb or powering a car). The green Os represent an oxygen molecule (O2)
from the air, and the blue drops at the end are for pure water--the only byproduct of hydrogen
power. |
In addition, all fuel cells are prone, in varying degrees, to catalyst poisoning, which decreases fuel cell performance and longevity.
- Safety, Codes and Standards needed to ensure safety, as well as to commercialize hydrogen as a fuel.
- Distribution network is needed can extant gas stations be retrofitted
with hydrogen "pumping" facilities?
- Public Acceptance: Consumers will have concerns about the dependability and safety of fuel-cell-powered equipment, just as they have about other modern devices when they were introduced.
An Erroneous Perception of the Dangers of Hydrogen.
Production of Hydrogen.
About 95% of the hydrogen we use today comes from reforming natural gas. The remainder, high-purity hydrogen from water electrolysis, is produced using electricity mainly generated by burning fossil fuels.
We can do much better than this by more fully utilizing the following techniques:
Some important equivalencies to consider in your regional energy portfolios if you want
to seriously consider hydrogen production.
- 2.38 KWHs of energy is equivlant to the production of 1 liter of liquid Hydrogen
- 3 kwh hours will get you 1 cubic meter of hydrogen gas; 33 KWH will get you 1 KG of
Hyrogen gas.
- One liter of gasoline is equivalent to .35 Cubic Meters of Hydrogen Gas or .28 liters of
liquid Hydrogen
In principle, you could use a wind farm to make X number of liters of liquified Hydrogen or
X number of KG of hydrogen on site. You could then transport that hydrogen, someway, to
individual houses, and recover 90% of the KWHs that went in to producing it.
This is cheaper than trying to build a 1000 km transmission line from a wind farm to
an urban area.
Once standards are developed for handling and distributing hydrogen, the industry is going to
wake up to this financial reality.
Some infastructre already exists:
Bottom Line: All of this is possible, but it will take 20 years of steady investment in
compression technology, hydrogen distribution facilities and dedicated hydrogen production
sites. It can be done. Will it be done?