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