Renewable SourcesRenewable Sourcesof Energyof Energy
Resources
Non-Renewable: can not be replenished in a reasonable amount of time Coal Oil (petroleum) Natural Gas Radioactive
Elements
Renewable: can be replenished in a reasonable amount of time Solar Wind Water (hydroelectric) Biomass Geothermal Hydrogen
Renewables:
Biomass Hydroelectric Solar Wind Geothermal Hydrogen
Biomass Energy
Biomass: Consists of the organic material that makes up living organisms
Biomass Energy: From plant and animal matter, such as charcoal, wood, manure, crops. These can be burned to generate heat or electricity
Biomass Fuels: some biomass can be converted into fuels: Ethanol: from fermentation (corn) -can be added to
gasoline and used in “Flex-Fuel” cars Biodiesel: from vegetable oil, grease, animal fat-
mixed with ethanol, used in diesel engines
Biomass…
Methane (as a landfill gas from the anaerobic decomposition of organic matter)
Biomass can also be vaporized at high temps (anaerobically) to create a mixture of gases: H2, CH4 , CO
These gases can be used together in a gas turbine to create electricity, or separately, for ex: H2
Biomass….
Benefits
Carbon-neutral (carbon produced from burning it is the same carbon used during its production (recent photosynthesis)
Geographically balanced Inexpensive No N2 or S emissions
Drawbacks
Indoor burning creates pollutants
Competes with crops for food
Crops require energy to grow
Hydropower: The kinetic energy of moving water can turn turbines and generate electricity
Benefits
Clean Renewable
Drawbacks
If overused, can become non-sustainable
Dams create problems for ecosystems, etc
SolarSolar Technologies are still being developedTechnologies are still being developed
– Passive solar energy collectionPassive solar energy collection: construction that : construction that optimizes the sun’s heat and lightoptimizes the sun’s heat and light
– Active solar energy collectionActive solar energy collection: utilizes technology to : utilizes technology to collect and convert solar energycollect and convert solar energy
– Photovoltaic cellPhotovoltaic cell: collects sunlight and converts it into : collects sunlight and converts it into electricity. Can be used directly or stored in a battery. electricity. Can be used directly or stored in a battery. Used in chips, panels, roofing tilesUsed in chips, panels, roofing tiles
Solar…Solar…
BenefitsBenefits
Needs no other fuelsNeeds no other fuels Individuals (not power Individuals (not power
companies) can control itcompanies) can control it No pollutionNo pollution Can sell it back to the gridCan sell it back to the grid
DrawbacksDrawbacks
Still expensiveStill expensive Not all locations have Not all locations have
enough sunenough sun
Sales of PV cells up 63% in Japan, up 25% in the US
Storage is still difficult
Solar Panels Solar Roof TilesSolar Panels Solar Roof Tiles
Wind
Wind turbines convert kinetic energy of wind into electricity
Wind is an indirect form of solar energy Turbines can be small enough to mount on
the roof of a house or have a span of a football field
Wind speeds offshore are 20% greaterhttp://www.bergey.com/
http://www.talcoelectronics.com/c-24-wind-power.aspx?gclid=CPHE99b8opcCFRKAxgodawt1dAhttp://www.skystreamenergy.com/
Wind…
Benefits: Very efficient No fossil fuels needed No emissions (except
for construction)
Drawbacks: Variable winds “not in my backyard” Threat to birds, bats
Wind Farm
Geothermal
From the decay of radioactive elements, under extreme pressure, deep within the earth, that generates heat
Underground water can be heated…will rise through natural fissures (cracks) in earth (geysers and natural spas)
Can drill down to the heated water and pump it up to the surface
Geothermal…
Drawbacks: Can release gases
trapped in the water-- Dependent on location May not be totally
renewable if water is pumped out too quickly
HydrogenHydrogenthe simplest and most abundant elementthe simplest and most abundant element
Fuel CellsFuel Cells use H use H22 to produce electricity to produce electricity Fuel cells were used by NASA in the 1960’sFuel cells were used by NASA in the 1960’s
HH22 gas does not exist freely on Earth. gas does not exist freely on Earth.
The atoms must be released from their The atoms must be released from their compoundscompounds
Hydrogen from water…Hydrogen from water…
ElectrolysisElectrolysis: produces : produces pure hydrogen pure hydrogen
Requires *energy Requires *energy inputinput
22HH22O O 2 2HH22 + O + O22
HydrolysisHydrolysis: the : the reverse process after reverse process after electricity is produced electricity is produced in the fuel cellin the fuel cell
22HH22 + O + O2 2 2 2HH22OO
*Hydrogen production is only as “clean” as the energy used to obtain it.
How a fuel cell works:
C:\Documents and Settings\mrecchia\Desktop\fuel cell video.htm
Hydrogen from other sources…Hydrogen from other sources…
From From algaealgae: When certain algae are : When certain algae are deprived of light, they produce Hdeprived of light, they produce H22 at at the end of photosynthesisthe end of photosynthesis
From From biomass biomass or or fossil fuelsfossil fuels::– Can be separated from methane (a Can be separated from methane (a
form of natural gas):form of natural gas):
CHCH44 + 2H + 2H22O O 4H 4H22 + CO + CO22
Hydrogen Economy?Hydrogen Economy?
Benefits:Benefits:– RenewableRenewable– Most abundantMost abundant– CleanClean– Zero-emissionZero-emission– As safe as gasolineAs safe as gasoline
DrawbacksDrawbacks– Leakage could Leakage could
deplete deplete atmospheric ozoneatmospheric ozone
– Public fearPublic fear
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