Transcript Energy through Hydrogen THE FUEL CELL

Energy Futures: Hydrogen
and THE FUEL CELL
Sources of information:
– Heliocentris “Energy through Hydrogen” Research notes
– Thames and Kosmos “Fuel Cell Car and Experimtent
Kit” Lab manual
– World Fuel Cell Council: World Fuel Cell Council Welcome
OUTLINE: Energy Futures: Hydrogen
and FUEL CELLS
• From the sun to consumable energy (year 2000).
• From the sun to consumable energy (possible
future).
• From the sun to energy: an overview.
• Where will the hydrogen come from?
• How will the hydrogen be used?
• How does a fuel cell work?
Summary Slide (cont.)
• What is a fuel cell system?
• What is the history of the fuel cell?
• What are some of the challenges facing fuel cell
development?
• What about the infrastructure job market?
• Where are we now?
• Reality and vision…
• What are some of the issues that government
agencies may need to address?
Introduction: From the sun to
consumable energy (year 2000).
• The source of
almost all
energy on earth
is the sun.
• Present energy
consumption is
dependent on
fossil fuels.
• Fossil fuels
create
environmental
problems.
Introduction: From the sun to
consumable energy (possible future).
In the future:
solar, wind, and
hydropower
may be utilized
to electrolyze
water to
produce
hydrogen.
From the
sun to
energy: an
overview.
Where will the hydrogen come from?
• Fossil fuels:
– Examples: Coal / Oil /
Methane (CH4)
– Hydrogen is obtained
from fossil fuels by a
process called reforming.
– This is currently the
cheapest method to
obtain hydrogen.
Where will the hydrogen come from?
• Plants like corn…
– Used to produce
alcohols which have a
significant amount of
hydrogen: ethanol
(C2H5OH).
– Hydrogen is again
obtained by the
reforming process.
Ethanol plant, Monroe WI
Where will the hydrogen come from?
• Water
– Electrolysis (breaking up by electricity) of H2O
• Conventional – An electrical current is induced in a water
and electrolyte (a substance that produces electrical current
carrying ions) solution. Water is ionized (broken up into
positive (H2+) and negative (OH-) ions) and the ions collect
at opposite electrodes. (Aswan dam, Egypt: largest H2
production by electrolysis.)
– The hydrogen gas is collected and may be used later as a fuel.
– Demonstration: Electrolysis using a solar cell as an electrical source.
• Solid electrolyte membranes – When electrical current is
applied to the water in a fuel cell, H2+ protons move through
a Proton Exchange Membrane (PEM) and unite with
electrons (e- on the other side of the membrane to form
hydrogen gas (H2).
– Demonstration: Electrolysis using a reversible PEM fuel cell.
How the Solar Cell works – pn Junction
Silicon Atomic Structure
The Entire
Process
How will the hydrogen be used?
• Use it as any other flammable gas would be:
– Gas grills have been converted to use hydrogen.
– Internal combustion engines can be retrofitted for H2.
–
– This may be the quickest way to implement a hydrogen
economy but may not be the best long term solution.
– Environmental pollutants are few but not zero.
How will the hydrogen be used?
• FUEL CELLS that use hydrogen are currently under
development to replace internal combustion engines
and for cogeneration of electricity and heat.
– Fuel cells are 50%-60% efficient compared to internal
combustion engines that are 15-20% efficient.
– There are no moving parts and run silently.
– There is little maintenance.
– The fuel used is proportionate to the load.
– There are no environmental pollutants.
– The only byproducts are water and heat (which is why they
are perfect for use in spacecraft!).
• Demonstration: Car with PEM running on hydrogen gas.
How does a fuel cell work?
• A model of
a reversible
PEM fuel
cell.
• It changes
water to H2
and O2 if
electrical
energy is
supplied and
H2 and O2 to
water (H2O)
if hydrogen
is supplied.
Fuel Cell Animation
What is a fuel cell system?
What is the history of the fuel cell?
• Sir William Grove (a British lawyer) discovered the
process by which fuel cells operate in 1839!
• Grove’s discovery was called a “gas battery” but had a
very low energy capacity.
• Future development was slow mostly due to the rapid
corrosion of the electrodes.
• In the 1950”s, Francis “Tom” Bacon succeeded in
producing the first practical fuel cell.
• In the 1960’s the first PEM fuel cells were developed
by General Electric and chosen by NASA for the
space program. The fuel cell used a membrane that
had a working lifetime of about 500 hours.
What is the history of the fuel cell?
• A few months later Dupont finished development
on an improved membrane that had a lifetime of
thousands of hours.
• NASA had already made its choice of the GE fuel
cell membrane and this decision is thought to have
held back the development of proton exchange
membrane (PEM) fuel cells by at least 15 years!
• Modern emphasis on fuel cell
development began in the 1980”s.
What are some of the challenges facing
fuel cell development?
• How to increase the efficiency of the cells:
– Currently 50% at full power and 60% at half
power consumption.
– Cogeneration (making use of the heat and
electricity) reaches 90%.
– Development of better materials that will
produce more power from the cells.
– Decreasing internal resistance when a stack of
fuel cells is used.
What are some of the challenges
facing fuel cell development?
• How to reduce the capital costs $$$$$$:
– In the stationary power market, fuel cells would be
competitive at a cost of $1500/Kilowatt… present cost is
$4000!
– In automobiles the competitive cost is $60$100/Kilowatt!!!!
– Possible reductions may be made in the areas of:
• Lower cost materials (platinum = $5000/pound and rhodium in
the range of $9000/pound).
• Reducing the complexity of an entire system.
• Minimize temperature restraints.
• Scaling up and streamlining production.
What are some of the challenges
facing fuel cell development?
• How to increase the rate of the chemical reactions
associated with the hydrogen formation and the fuel
cell:
• Reaction rates are increased by:
–
–
–
–
–
Higher temperatures.
Greater concentrations of reactants.
More surface area of any solid reactants.
Monitoring the frequency of light striking the reaction.
Catalysts (most research is being done in this area).
Platinum is the chief catalyst and still is the best so
research is directed at using the minimum amount
possible.
What are some of the challenges
facing fuel cell development?
• Developing safe and convenient hydrogen storage:
– Hydrogen in not commonly thought of as a safe fuel… in
part because of the belief that the Hindenburg disaster of
1937 was caused by a hydrogen explosion. Recent
research however supports the theory that the rapid burn
was caused by the flammable nature of the fabric
covering!
– In fact hydrogen is considered to be safer than gasoline:
• It quickly escapes upward into the atmosphere vs. flowing
under a vehicle.
• It burns quickly and must have the right ratio of oxygen.
• Gasoline vapors are a known carcinogen…Hydrogen nontoxic.
• Vehicles with hydrogen storage have been tested and are safe.
But the challenge is…….
• Hydrogen is a very small molecule so storage and
transport systems must be capable of keeping this small
molecule contained…think about how a helium balloon
quickly loses its gas…hydrogen would be even faster.
• Hydrogen is a gas and and as such requires a very large
volume of storage capacity. To travel 300 miles using a
PEM fuel cell would require 3600 liters (36 cubic meters)
of hydrogen at normal temperature and pressure.
– Liquifying hydrogen like we do propane (LP) is costly and the
pressure in the tanks would be dangerously high.
– Recent developments have concentrated on absorbing hydrogen
into metal hydrides. It may be possible that the fuel for a 300
mile trip could be stored in a volume of 50 liters.
Storage challenges….
Hydrogen tanks
fill the trunk of
this sports car.
And some possible solutions???
What are some of the challenges
facing fuel cell development?
• Development of a hydrogen production and
distribution infrastructure.
– Options for production are:
• large central solar stations electrolyzing water to hydrogen
• smaller on site production facilities.
– There will be massive costs to convert refueling stations.
Some estimate in the range of $300 billion in the USA
alone!
• One must remember however that this cost will be spread over
many years…the time frame for our last infrastructure change
from horses to automobiles took 20 years.
And just think about the infrastructure
job market…
• Hydrogen fuel production and distribution
personnel will be in demand.
• Qualified service and maintenance personnel will
be needed.
• Continued research and development will be
imperative.
Where are we now?
• There are several types of fuel cells in various stages of
development:
Where are we now?
• International cooperation to develop a hydrogen
economy is strong:
– November 2003: the world’s leading fuel cell
organizations announced that they have entered into a
cooperative agreement to advance commercialization of
fuel cells worldwide…represented are more than 300
businesses and research institutions!
– Governments are negotiating multilateral programs to
promote fuel cells and hydrogen.
– Automakers from around the world…Asia, Europe,
America are forming coalitions to develop fuel cell cars.
Where are we now?
• Two broad categories of fuel cell technology are
developing: Stationary or on site for homes and
businesses and mobile, especially in the area of
transportation.
• STATIONARY:
– Dow Chemical Company and General Motors have agreed to
develop the largest fuel cell installation (June 2003). This should
ultimately produce enough electricity to power 25000 homes.
The benefit of this plan is that GM will move from building lab
specimens to production fuel cells and DOW will acquire clean
energy.
– A few homes have smaller solar/hydrogen fuel cell systems for
cogeneration of electricity and heat.
Where are we now?
• MOBILE:
– Almost forgotten is that there is a real possibility that fuel
cells will replace batteries in consumer electronics…just
add a few milliliters of alcohol when needed!
– PEM fuel cells are the area of most research and
development for automobiles. At the November 2003
Tokyo Motor show Toyota, Nissan, and Suzuki concept
cars drew the most attention, but…
– Japan carmakers like Mazda were also showing hydrogen
internal combustion engines at the show.
– January 2004, California unveils a plan to provide an
Interstate hydrogen fueling network of 200 stations
within the next decade.
Reality and vision…
• A methanol fuel cell could provide power to small
electronic devices up to 20 times longer than a battery. The
last problem for this technology is to prove that the cells can
be mass produced cheaper than batteries.
• Some banks and organizations that cannot afford to lose
power are using fuel cells to provide complete security of
supply. More to come?
• Provided there is a fuel supply, the fuel cell can be put in
any size needed at a point of use and provide 10’s of
thousands of uninterrupted hours of electricity.
• Our high-voltage national electrical grid is not very
efficient. A combination of fuel cell, photovoltaic, and solar
energy technology could eventually replace the grid with an
efficient, low polluting source of energy.
What are some of the issues that
government agencies may need to
address?
• Of course ….funding!
• Codes and standards for permits will need to be
determined and enforced!
• Will unmanned operation be generally permitted?
• Will there be any emissions regulations?
• Will the fuel be taxed like gasoline?
• Can insurance for these installations be obtained?
• What depreciation schedules will be allowed?