ENERGY

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ENERGY
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Topics to be addressed

• Energy sources that fuel our civilization
• History of energy use
• Patterns of energy production and consumption
• Crude oil, coal, natural gas, and nuclear energy
• Environmental, political, and social impacts of
  fossil fuel use

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Energy sources used today
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• Growth in coal has slowed, but oil and gas are
  still rising.

Figure 17.5
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Canadians are the highest per-capita energy
users on planet Earth !
CLIMATE
DISTANCES
INDUSTRY
LIFESTYLE/WEALTH
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Figure 17.3
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OIL

• Hydrocarbons
• Found in sedimentary rock
• Remains of prehistoric animals, forests
• and sea floor life (FOSSIL FUELS)
• Toxic to wildlife (spills)
• Climate change
• Air pollution and acid rain

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Canadian production about 3 million
barrels/day (ie., now red on map!)
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Fossil fuels

• These are fossils in the sense that they are made
  of remnant decayed material from ancient
  organisms.
• Compressed tissues of plants (and some animals)
  from 100500 million years ago store chemical
  energy from photosynthesis.
• This greatly concentrated energy is released when
  we burn coal, oil, or gas.

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Fossil Fuels

• Anaerobic (without oxygen) decomposition is
  required for fossil fuel formation.
• (Aerobic decay in presence of oxygen)
• Anaerobic environments exist at the bottom of
  the ocean, in deep lakes, and in swamp sediments.

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FOSSIL FUEL FORMATION

• Plants and animals die
• Organic material settles in anaerobic site and is
  partly decomposed
• Organic material is buried
• Heat and pressure alter chemical bonds
• Coal, gas, oil formed

Figure 17.6
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• Coal Compressed under high pressure to form
  dense carbon structures.
• Natural gas Primarily methane, CH4, is produced
• By bacteria near surface
• By heat and pressure deep below ground
• Crude oil Sludgelike mix of hundreds of types of
  hydrocarbon molecules. Forms at temperatures and
  pressures found 1.53 kilometers below ground.

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Alaskas North Slope
The ANWR National Wildlife Reserve Contentious
US Issue
Figure 17.1
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Distribution of Conventional Fossil Fuel Reserves
Figure 17.8
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Distribution of Conventional Fossil Fuel Reserves

• Saudi Arabia has the most oil.
• Russia has the most natural gas.
• The U.S. has the most coal.

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Oil Drilling

• Liquid oil exists in pores in rock deep
  underground.
• We must drill into rock and extract oil by using
  a pressure differential.
• The more oil is extracted, the harder it is to
  extract

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Refining Crude Oil

• Crude oil from the ground is a messy mix of
  hundreds of hydrocarbons.
• It is put through a refining process to segregate
  different components.
• Small-chain hydrocarbons boil at cooler
  temperatures in a distillation column, isolating
  lighter weight oils (e.g., butane).
• Long-chain hydrocarbons boil at hot temperatures,
  isolating heavier oils (e.g., lubricating oils).

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Refining crude oil
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Petroleum Products

• Refined components of crude oil are used to
  manufacture many of the material goods we use
  every day.
• Petroleum products include
• Helmet, water bottle, sunglasses, clothing,
• sunscreen, gear and chain grease

Figure 17.11
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Oil Conservation

• Although oil is a limited resource, prices have
  remained low enough that few people feel the need
  to conserve
• Conservation measures taken in the 1970s
  resulting from fears of oil shortages were mostly
  abandoned, but recent price increases may cause
  history to repeat itself
• As oil supplies dwindle, conservation will again
  become popular.

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• Geologist M. King Hubbert predicted U.S. oil
  production would peak around 1970 and then
  decline.
• He was only a few years off.

Figure 17.15a
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Depletion of Oil Reserves

• World oil reserves are a finite resource as well.
• Some observers predict they have peaked.

Figure 17.15b
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Vehicle Fuel Efficiency

• Automobile fuel efficiency rose after the oil
  shocks of the 1970s, but has stagnated since then.

Figure 17.13
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OIL SANDS

• Clay, sand, water and bitumen
• Black oil rich in sulphur
• Oil sands must be heated and treated
• with steam to separate bitumen
• Energy intensive
• Sulphur dioxide emissions
• Huge waste disposal ponds
• Habitat fragmentation
• Greenhouse gas emissions

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Tar sand
Bitumen
Photos Syncrude
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COAL
New technology may present cleaner coal burning
options (eg. improved boiler efficiency)

• Most CO2 and
• air pollution per
• unit energy
• Sydney tar ponds
• - the most
• contaminated site
• in Canada

Illustration Brooks Johnson, Ontario Clean Air
Alliance
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• Several types of coal exist, depending on the
  amount of heat and pressure that overlying
  sediments have exerted.

Figure 17.16
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• Coal is mined either underground, in subsurface
  mining, or from the surface, in strip mining.

Figure 17.17
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Natural Gas

• Gaseous hydrocarbon mixture
• Primarily methane CH4
• Also C3H8 and C4H10
• Now 45 of Canadas energy production
• Much cleaner and more efficient
• Problems potent greenhouse gas,
• wildlife disruption, flaring H2S

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Natural Gas History

• Seeps known for 2,000 years
• Used for street lighting in the 1800s
• Became commonly used after WWII once pipeline
  technology became safer

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Natural Gas Formation

• Forms in two ways
• Biogenic gas formed at shallow depths by
  anaerobic decomposition of organic matter by
  bacteria
• Thermogenic gas formed at deep depths as
  geothermal heating separates hydrocarbons from
  organic material
• (Formed directly OR from crude oil altered by
  heating. Thus gas deposits often occur with oil
  deposits.)

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Gas Extraction

• Initially, gas comes out on its own from natural
  pressure.
• Later, it must be pumped out.

Horsehead pump to extract natural gas
Figure 17.18
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NUCLEAR ENERGY
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15 of Canadas electricity gt50 of Ontarios
electricity
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Nuclear Power

• 6.8 of worlds primary energy supply
• 16.9 of worlds electricity production
• Grew 15-fold since 1970
• Has stagnated due to safety concerns and economics

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Nuclear energy

• Two ways to produce nuclear energy
• Fission used for power
• Fusion not yet used commercially

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Nuclear Energy

• Comes from the radioactive element uranium
• The nuclear fuel cycle enriches forms of uranium
  to make it into usable fuel.
• Waste fuel is radioactive and must be specially
  disposed of.

Figure 17.24
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Nuclear Energy Fission

• Fission energy is released by splitting apart
  uranium nuclei by bombarding them with neutrons.
• This is the process used in nuclear reactors and
  weapons.

Figure 17.25a
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Nuclear Energy Fission

• Note that several neutrons
• are produced from each
• reaction with one neutron.
• This means the reaction
• could be a runaway reaction, or explosion.
• In a commercial reactor, the reaction must be
  controlled.
• Metal rods are used to absorb the extra neutrons.
  Engineers move these control rods to regulate the
  reaction.

Figure 17.25a
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Nuclear Reactor

• In a reactor, fission boils steam to turn a
  turbine and generate electricity

Figure 17.26
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Nuclear Troubles

• Although nuclear power is clean, lacking the
  pollutants of fossil fuels, it has faltered, due
  to
• Cost overruns
• Public fears of catastrophic accidents
• Three Mile Island, 1979
• Chernobyl, 1986
• 450 nuclear plants remain operating today in the
  world 100 have closed.

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• No greenhouse gas emissions/air
• pollution (except mining)
• Minimal land disturbance
• High energy output with minimal
• environmental impact
• Problems
• Storage of nuclear waste
• (DGD in Canadian shield proposed)
• Expensive
• Public trust / meltdown risk
• (older systems)

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Renewable Energy Sources

• Biomass Biogas from combustion of organic
  material
• Hydropower from water flowing through dams
• Solar from the suns rays
• Wind from the wind
• Geothermal from heat and heated water beneath
  the ground
• Ocean sources from the tides and from waves
• Hydrogen fuel and fuel cells that store
  renewable energy in usable form

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GLOBAL ENERGY SUPPLY
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SOURCES OF ELECTRICITY
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Renewable Sources Outlook

• The outlook for renewable sources is good.
• Growth should continue.
• But will governments raise subsidies to the
  level offered to fossil fuels?
• Will research and development proceed fast
  enough?
• Will consumers choose alternative energy sources

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HYDROELECTRIC POWER
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Turbine generator inside dam
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• Hydro Power
• 12 of Canadas energy
• No air pollution
• Downstream irrigation regulation

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Pros and cons of hydroelectric power

• PROS
• Renewable as long as water is not overdrawn from
  river system
• Clean no greenhouse gas emissions

• CONS
• Dams cause numerous disruptive ecological effects
  to riparian environments
• Dams bring a mix of impacts for people

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WIND ENERGY
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Wind Power

• Takes kinetic energy of wind and converts it to
  electrical energy
• Fastest growing power source today
• Technology wind turbines, machines with turning
  blades that convert energy of motion into
  electrical energy by spinning a generator
• Windmills have been used for centuries.
• First wind turbine for electricity late 1800s

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Mean 50m Wind Speed in Canada (m/s)
Source Canadian Wind Energy Atlas
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Wind power
Annual average wind power
Figure 18.12a
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Wind Power Wind Turbines

• Wind spins the blades, which turn the gearbox,
  which turns the generator to produce electricity.

Figure 18.9
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Wind Power Wind Turbines

• Turbines are often located in groups (wind
  farms) at sites with exceptionally good wind
  conditions.

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Wind Power

• Most wind power so far is concentrated in a few
  nations.

Figure 18.11
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Wind Power

• By surveying with anemometers that measure wind
  speed, people can determine sites that will be
  best for wind power production.

From The Science behind the Stories
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• Near zero environmental impact
• Potential exists to reverse current
• level of impact from other sources
• Each turbine powers at least 250
• Alberta homes!
• Its windy here!

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Pros and Cons of Wind Power

• PROS
• Renewable, as long as wind blows
• No emissions after equipment made, installed
• Can allow local decentralized control over power,
  and local profit from electricity sales
• Costs low after initial investment costs
  dropping

• CONS
• Not everywhere is windy enough
• Windy sites can be far from population centers
• Blades kill birds, bats
• High start-up costs

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Biomass

• Organic substances produced by recent
  photosynthesis
• (unlike fossil fuels, products of ancient
  photosynthesis)
• More than 1 billion people
• burn fuelwood as their
• principal power
• source for cooking,
• heating, etc.

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• Biomass
• Wood, agricultural wastes, garbage
• 15 of worlds energy
• 6 of Canadas energy
• Mainly in developing nations
• Less emission of greenhouse gases if
• forest replacement exceeds removal (wood)
• Biofuels for cars (ethanol - Brazil)
• Problems land clearing and associated
• problems (wood)

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Pros and Cons of Biomass

• PROS
• Renewable, as long as forests arent depleted
• Usually inexpensive
• Some waste can be used for energy
• Capturing methane reduces that greenhouse gas

• CONS
• Does not always reduce CO2 emission as much as
  other renewables
• Cutting trees for fuelwood can lead to
  deforestation
• Growing crops for fuel (e.g., corn for ethanol)
  is highly inefficient

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• Biogas Production from Manure
• Electricity Generation
• Gas for cooking
• Heat
• Utilized in Southern Alberta
• (eg. Iron Creek Hutterite Colony)

Photos Rokai Pig Farm, Kaunas,
Lithuania http//www.folkecenter.dk/en/rokai/rokai
.html
INLET
OUTLET
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• Difficulties
• Temperature optima maintenance
• Acidity pH sensitive anaerobic bacteria
• (lime required)
• NH3 toxicity (control input rate)
• CH4 wont liquefy difficult to store
• (must use or burn)

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Geothermal Energy
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Geothermal Energy

• Radioactive decay of elements deep in Earths
  core creates heat that rises toward the surface.
• This heats magma of volcanoes, and also
  underground water.
• Sometimes water spurts through to the surface in
  geysers.
• Geothermal power plants use the energy of
  naturally heated water to generate electricity.

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Geothermal Energy

• Underground heat warms water, and steam turns
  turbines and generators.
• Condensed steam is reinjected into the aquifer to
  keep up pressure.

Figure 18.13a
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Geothermal Energy

• Iceland uses geothermal energy to heat water for
  86 of its homes.
• Heat pumps using surface heat can also be very
  efficient.

Geothermal plant in Iceland
Figure 18.13b
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Pros and Cons of Geothermal Power

• PROS
• Renewable, as long as water is heated naturally
• Much lower greenhouse gas emissions than fossil
  fuels
• Can be inexpensive in areas where geothermal
  heating naturally occurs

• CONS
• Heated water may give out after a whilehotspot
  moves or aquifer pressure drops
• Salts in water can corrode equipment, shorten
  lifespan
• Limited to geographic areas where geothermal
  heating naturally occurs

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Ocean Energy Sources

• Three sources from oceans
• Tidal power The twice-daily flow of tides
  (rising and falling of seas due to the moons
  gravitational pull) creates energy of motion that
  can be converted to electricity.
• Wave power Motion of waves at ocean shores
  creates energy of motion that can be converted to
  electricity.

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Tidal Energy

• The LaRance power station in France is the
  worlds largest tidal generating station. Its
  turbines spin with both incoming and outgoing
  tides.

Figure 18.14b
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Tidal Power
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Wave Energy

• There are several designs for wave energy
  stations.
• In this one, air is compressed in a chamber with
  each incoming wave, driving a turbine to spin a
  generator.

Figure 18.15
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Pros and Cons of Ocean Power

• PROS
• Renewable, as long as oceans behave as they
  always have
• No greenhouse gas emissions

• CONS
• Development could take up large portions of
  coastline valuable for other uses
• Could interfere with ecology of estuaries and
  intertidal shorelines

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SOLAR ENERGY
Source DOE, USA
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Solar Energy

• Use of energy
• from the Sun
• Huge potential Each day Earth receives enough
  sunlight to power human consumption for 27 years,
  if we could somehow capture it all.

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Solar energy

• Passive solar designs buildings to maximize
  capture of sunlight in winter, but keep buildings
  cool in summer through window placement,
  absorbent materials
• Active solar uses technological devices to
  focus, move, or store solar energy
• Solar panels dark heat-absorbing metal plates in
  glass-covered boxes, often mounted on roofs

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Solar energy Active solar

• Portable solar cookers focus suns rays onto a
  small areahere, boiling water in Nepal. These
  are becoming popular throughout the developing
  world.

Figure 18.6
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• Numerous mirrors focus sunlight on a receiver
  atop a power tower in the California desert.
  This facility was the first to generate much
  solar power commercially.

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Solar Furnace, Ordellio, France
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Application Steel Production Facility
Source www.technologystudent.com/energy1/solar4.h
tm
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Solar Energy Active Solar

• Gaviotas, Colombia, uses solar panels in homes
  and businesses for heating, cooling, and water
  purification
• (This photo is from Bogotá)

Figure 18.5
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Solar Energy PV Cells

• Photovoltaic cells (PV cells) convert solar
  energy directly into electrical energy by making
  use of the photoelectric effect
• Sunlight strikes one of a pair of
  negatively-charged metal plates
• Electrons migrate to opposing plates, and
  electric current is produced.
• In PV cells, light strikes negatively charged
  phosphorus-
• enriched silicon, and electrons migrate downward
  through silicon to positively charged
  boron-enriched silicon.

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Solar Energy PV Cells

• Electrons move from the phosphorus side of the
  silicon plate to the boron side, creating
  electric current. PV cells are arranged in
  modules, panels, and arrays.

Figure 18.8
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Solar Power

• Is little used, but fast growing
• Currently only 0.04 of primary energy supply
  in the U.S.
• Growing at 33 per year Cheaper technologies
  are taking off in developing countries.
• More expensive technologies are growing more
  slowly in developed countries.

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Pros and Cons of Solar Power

• PROS
• Renewable, as long as sun keeps on shining
• Suns energy abundant, if technology can capture
  it
• Allows for local decentralized control over power
• No greenhouse gas emissions (although some are
  created in manufacture of technology)

• CONS
• Not everywhere is sunny enough
• Up-front investment cost is high takes years to
  pay for itself

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HYDROGEN POWER
Photo WIRED
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Hydrogen

• Hydrogen simplest and most abundant element in
  universe
• Could potentially serve as basis for clean, safe,
  efficient energy system
• How it would work
• Electricity generated from intermittent renewable
  sources like wind or solar can be used to produce
  hydrogen.
• Fuel cells can then use hydrogen to produce
  electrical energy for power.

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Production of Hydrogen Fuel

• Hydrogen gas (H2) does not exist freely on Earth.
• We need to make it.
• Electrolysis is the cleanest way
• Split water into hydrogen and oxygen
• 2 H2O ? 2 H2 O2
• This can potentially be very clean, releasing no
  greenhouse gas emissions.

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Production of Hydrogen Fuel

• However, cleanliness of hydrogen production
  depends on source of electricity for
  electrolysis!
• If the source of electricity needed for
  electrolysis is not clean (e.g., from coal), then
  greenhouse emissions will still occur.
• Besides electrolysis, hydrogen can also be
  produced from organic molecules like fossil
  fuels. This entails greenhouse emissions.
• H 75 of the universes mass !
• Combustion engines can be fuelled by hydrogen
  (Ballard Power Canadian company and leader in
  this field)

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Fuel Cells

• In a fuel cell, hydrogen gas is used to produce
  electricity.
• The reaction is simply the opposite of
  electrolysis
• 2 H2 O2 ? 2 H2O
• How it works
• Hydrogen molecules are stripped of electrons.
• H ions move through a membrane.
• Electrons complete a circuit, creating
  electricity.

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Fuel cells
Figure 18.16
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O2 4H 4e- gt 2H2O
2H2 gt 4H 4e
NET REACTION 2H2 O2 gt 2H2O
You can drink the exhaust !
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Pros and Cons of Hydrogen Power

• PROS
• We will never run out of hydrogen
• Can be clean and non toxic, with no greenhouse
  gas emissions
• Fuel cells potentially convenient, safe, and
  efficient

• CONS
• Depending on way hydrogen is produced, it may not
  be environmentally clean