Chapter 21 New Renewables' Central Case: Iceland Moves Toward a Hydrogen Economy

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Chapter 21 New Renewables. Central Case
Iceland Moves Toward a Hydrogen Economy

• Iceland pioneered geothermal power years ago, but
  relies on imported fossil fuels and emits many
  greenhouse gases.
• An activist professor convinced politicians and
  businesses that Iceland should now pioneer a
  hydrogen economy.
• In 2003 Icelands buses began converting to
  hydrogen a filling station openedinitial steps
  in a historic transition.

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New renewables

• Solar
• Wind
• Geothermal
• Hydrogen fuel and fuel cells
• Ocean sources from the tides and from waves

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Renewable sources for electricity

• Renewable sources presently generate 9 of
  electricity in the U.S.

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Growth of renewable sources
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Solar energy Active solar

• 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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Passive solar
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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.

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Solar power
Harnessing solar energy is more profitable in
some areas than in others.
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Pros and cons of solar power

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

• PROS
• Renewable as long as sun keeps on shining
• Suns energy abundant, if technology can capture
  it
• Allows for local control over power
• Solar cookers in developing nations lessen
  workloads.
• No direct greenhouse gas emissions

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Wind power Wind turbines

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

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Wind power

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

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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

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

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Wind power

• Wind speeds vary tremendously from place to
  place.
• Windiest in the U.S. are mountainous areas and
  parts of the Great Plains.

Annual average wind power
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Wind power

• So its not surprising that wind power has been
  most developed so far in those states with the
  best wind resources.

Wind generating capacity in 2004
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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.
• Some people object to aesthetics.
• Blades kill birds, bats.
• High start-up costs

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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.

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Geothermal energy

• Iceland uses geothermal energy to heat water for
  86 of its homes.
• Geothermal energy is growing 9 annually.

Geothermal plant in Iceland
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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.
• Thermal power Exploits differences in warm and
  cold water. Not yet commercially developed.

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Tidal energy
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Wave energy
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Pros and cons of ocean power sources

• 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
• OTEC not yet commercially feasible

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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

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Fuel cells
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Algae as a hydrogen fuel source
Algae could generate large amounts of hydrogen.
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Pros and cons of hydrogen

• PROS
• We will never run out of hydrogen.
• Can be clean and nontoxic, 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
• Emission of hydrogen to atmosphere might have
  unforeseen impacts

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Conclusion

• Renewable energy sources with sustainability
  promise include solar, wind, geothermal, and
  ocean.
• By using electricity from renewable sources to
  produce hydrogen fuel, we may be able to use fuel
  cells to produce electricity when and where it is
  needed.
• Most renewable energy sources have been held back
  due to lack of funding and artificially cheap
  market prices for nonrenewable resources.
• Despite this, renewable technologies have
  progressed far enough to offer hope for a shift
  away from fossil fuels.

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QUESTION Review

• Which of the following is NOT a disadvantage of
  wind power?
• a. Not everywhere is windy enough.
• b. Spinning blades kill birds.
• c. Some people hate the way turbines look.
• d. Operation emits large amounts of greenhouse
  gases.

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QUESTION Review

• Which is NOT true of geothermal energy?
• a. Radioactive decay of elements deep in Earths
  core creates heat that rises toward the surface.
• b. Water spurts through to the surface in
  geysers.
• c. Geothermal power plants use the energy of
  naturally heated water to generate electricity.
• d. The heated water must be used at an extremely
  high rate to make the process efficient.

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QUESTION Review

• In a hydrogen fuel cell?
• a. Electrolysis is performed
• b. Hydrogen and oxygen are combined to form
  water, and electricity is produced
• c. Fossil fuels are split to make hydrogen
• d. Hydrogen ions are joined to make hydrogen gas,
  and electricity is produced

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QUESTION Interpreting Graphs and Data

• Why are there two pipes leading underground?

• a. To pull up twice as much heat
• b. To maintain pressure in the aquifer
• c. To prevent greenhouse gas emissions
• d. To cool water