Transcript Unit Five “Environmental Solutions”

Unit Four
“Renewable Energy Alternatives –
Conventional & New Methods”
Review
 CO2 is a greenhouse gas that exist naturally in the
atmosphere
 CO2 is also a chemical released as a byproduct of
electricity generation (coal) and the use of internal
combustion engines (gas in cars)
 Too much CO2 may be causing global warming
 Coal and oil reserves are still present, and will be
available for at least 20 or more years – Will
society keep using them at the same rate until
they are totally depleted?
Current Energy Usage
 Fossil Fuels account for 80% of the world’s
supply of primary energy
 http://www.eia.gov/totalenergy/data/annual/p
ecss_diagram.cfm
U.S.A. Energy Breakdown
Conventional Alternatives to Fossil
Fuels
 There are three alternatives that are not
considered new technology, and as a result,
are called “conventional”:
– Nuclear
– Biomass
– Hydroelectric
Nuclear Power Benefits
 A fraction of the amount of nuclear fuel is
needed compared to coal to generate the
same amount of electricity – it is a more
efficient fuel source
 If there are good safety measures in place,
a meltdown is highly unlikely – look to
France for examples
 There is no pollution emitted from nuclear
power facilities
Nuclear Power Drawbacks
 It is nonrenewable as there is only a finite amount
of “fuel” available within the earth
 There has been only one major incident involving
nuclear power – Chernobyl in 1986
 The spent fuel rods must be stored somewhere
safe (no moisture, secure from terrorists) for
hundreds of years
 Public perception is the biggest problem in
reference to establishing more nuclear power
facilities
Types of Nuclear Power
 Fission – the splitting of atomic nuclei thereby
releasing energy (heat and radiation)
– Breeder Nuclear Fission is the most efficient form of
nuclear power by using less fuel, producing more
power, and also much less waste
 Fusion – combining two small atoms into a larger
one thereby releasing large amounts of energy
(heat and radiation)
– The Sun: Hydrogen atoms fuse to form Helium atoms,
and by doing so, release massive amounts of energy
– This process requires very high temperatures, and
therefore is not used currently to generate electricity
Nuclear Fission
Nuclear Fusion
Biomass Energy
 Any organic material that can be burned to
generate heat or fuel an internal combustion
engine
– Biopower – heat used in power plants
 Wood
 Manure
– Biofuels – fuels that power automobiles
 Crops
 Crop Residues (corn stalks – ethanol)
Biofuel Benefits
 It is a renewable source of fuel and does not
require extraction from the earth
 It reduces car emissions
 The “Big Three” car makers in the U.S.A.
manufacture cars that run on a mix of 85% ethanol
and 15% gasoline: E-85 fuel
 In Brazil, most new cars are flex-fuel vehicles
 Many other nations now have cars that can use
ethanol as fuel
Biofuel Drawbacks
 Growing crops specifically for fuel leads to
monocultures, which leads to loss of
nutrients from the soil and eventual
desertification
 Biofuels lead to higher costs for other
consumer products because corn is a feed
for cows and other farm animals
Biomass Benefits
 It is a renewable source of energy
 It is fairly cheap and does not require extraction
from the earth
 It releases no net carbon into the atmosphere; net
carbon flux to the atmosphere is reduced
 Biomass is fairly equally distributed across the
globe
 More energy efficient than fossil fuels
 Reduces pollution emissions (sulfur and nitrogen)
that are released in coal fired power plants
Biomass Drawbacks
 Harvesting wood at a rapid rate leads to
deforestation, soil erosion, desertification,
and lastly, loss of biodiversity
 Burning manure can cause noxious odors
that can negatively affect the quality of life
and possible health of citizens nearby
Hydroelectric Power
 Two main types of Hydroelectric Power
Plants
– Reservoir/Storage – Lake Meade and the
Hoover Dam
– “Run of River” – Niagara Falls
Reservoir/Storage
“Run of River”
Hydroelectric Power Benefits
 It is a renewable energy source
 It does not generate any pollution
 “Run of River” has minimal impact on the
surrounding ecosystems
Hydroelectric Power Drawbacks
 Can only build these power plants where
water is plentiful (near large lakes or rivers)
 Reservoir/Storage technique has a
substantial negative impact on surrounding
ecosystems
New Renewable Energy
 Reason for “New” moniker
– 1) They are not yet used on a wide scale as that
of fossil fuels and conventional energy
alternatives
– 2) They are harnessed using technology that is
still being developed and refined
– 3) They will most likely come to play a larger
role in our global energy production in the future
New Renewable Energy
 Reason for “New” moniker
– 1) They are not yet used on a wide scale as that
of fossil fuels and conventional energy
alternatives
– 2) They may be harnessed using technology
that is still being developed and refined
– 3) They will most likely come to play a larger
role in our global energy production in the future
New Renewable Energy
 The benefits of all new renewable energy forms
are as follows:
– 1) emits no pollution
– 2) requires no mineral extraction/ altering of the
landscape
– 3) infinite supply
– 4) reduces the U.S.A. dependence on foreign sources of
energy
– 5) energy source is free of charge (do not pay to use the
energy from the sun or wind etc.)
New Renewable Energy Examples




Solar
Wind
Geothermal
Ocean Water




0.2%
2.3%
5.6%
0%
** U.S. total primary
energy from new
renewable sources
Solar Energy
 Passive Solar – buildings are designed and
constructed to maximize direct absorption of
sunlight in winter, and to keep the interior
cool in summer
– Example: Student Union at UCF
Solar Energy
 Active Solar – utilization of components and
devices that focus, move, or store solar
energy
– Example: Solar Array
https://solarems.net/kiosks/157
Passive Solar Specifics
 Focuses on designing the most energy efficient
edifice in reference to building materials used and
placement of windows and overhangs
 If constructed properly, a passive solar building
will save money on energy bills by keeping it cool
in the summer and warm in the winter
 It does so by using the energy from the sun and
the building materials in the most effective manner
Passive Solar Specifics
 Electricity providers can assist with energy
audits to enable citizens to become more
passively solar efficient
 UCF Green Roof is an example of passive
solar techniques in action (with a twist)
– http://www.progressenergy.com/shared/stw/main.html
– http://www.fpl.com/residential/electric/highbill.sh
tml
Active Solar Specifics
 Energy to Electricity Steps
– 1) Photovoltaic cells collect and convert the
sun’s radiant energy to electricity (moving
electrons)
– 2) electricity is stored in batteries for use when
the sun is not available (night)
*** An Array is made of a Panel, which is made of
many PV Cells
Current Solar Use
 Used on a very limited basis mainly due to a lack
of investment
 Federal funding for Solar Power has been erratic
as a response to the availability and cost of oil
 As the cost of PV Cells and batteries decline, the
amount of electricity generated as a result of the
sun’s radiant energy will increase
The future of Solar
 There are only two major
disadvantages to solar
power:
– 1) some regions are not
conducive
– 2) initial set up cost
*** The future looks “bright” for
solar power
Wind Energy
 Wind energy is available due to the action of
the sun’s differential heating of air masses
causing the movement of those air masses
(wind)
 Wind Turbines are used to generate
electricity – they convert the kinetic energy
of wind into electrical energy
The Process of Wind Energy
 1) Winds turn a blade
 2) The blade causes
the shaft to spin
 3) the shaft enables
the magnets and
copper wire to move
passed each other
thereby generating
electricity
Current Wind Use
 The U.S.A. (16%) ranks
second to Germany in it’s
total wind capacity
 California and Texas
account for 2/3 of the wind
power generated in the
U.S.A.
 Globally, only a very small
portion of this resource is
being used
The Future of Wind
 Meteorological evidence suggest that wind power
could supply the entire electrical needs of the
U.S.A.
 Off shore sites may be an excellent place to build
wind farms as the wind speed is fairly high and
constant – need to address initial cost of set up,
ongoing maintenance, and protection from strong
wave action
The Future of Wind
 Only three disadvantages:
– 1) intermittence of wind
– 2) transmission of electricity from wind farm to urban
areas
– 3) NIMBY phenomenon
http://www.pickensplan.com/index.php?bcpi
d1842760405?bclid=1842745810&bctid=
1653634930&page=white
Geothermal Energy
 This form of quasi-renewable energy (aquifer levels and
geothermal activity) does not come from the sun
 Magma is expelled through fissures in the tectonic plates
within the earth’s crust and heats water in aquifers
throughout the world
 Magma is very hot and this energy can be used to heat
water into steam that turns a turbine thereby generating
electricity
 Can harness this energy at the surface via Geysers, but
usually electricity is generated from water heated within
aquifers located in the Earth’s crust
The Process of Geothermal Energy
 1) Hot water from the Aquifer
(close to the fissure) is pumped
to the surface
 2) heat is transferred to water in
the closed turbine section
 3) the heated water in the
closed turbine section turns into
steam
 4) the force of the steam turns
the turbine which generates
electricity in the generator
through the interaction of copper
wire and magnets
Current Geothermal Use
 Currently Japan, China, and the U.S.A. lead
the world in use of geothermal power
 Northern California has several geothermal
facilities which operate due to the presence
of geysers
 Iceland has high geothermal activity and the
country is taking advantage of this resource
to generate electricity
The Future of Geothermal
 Very little electricity is generated worldwide from
geothermal activity
 There is much room for growth of this form of
energy for use in electrical generation
http://geothermal.marin.org/geomap_1.html
Ocean Water Energy
 Similar to the Hydroelectric process in that the
motion of water (kinetic energy) is used to turn a
turbine to generate electricity
 Main disadvantage is the remoteness of wave/tidal
farms to urban centers
 Two types of ocean water energy:
– 1) Wave Motion (air turns turbine)
– 2) Tidal Motion (water turns turbine)
Tidal Energy
Wave Energy
Future of Ocean Water Energy
 Highly underutilized resource currently
 Waters off the coast of Scotland have great
potential for tidal energy use
 The “Aqua Buoy” may be the future of wave
energy
http://www.youtube.com/watch?v=A5AY71sFe
Uw
Hydrogen as a Renewable Energy
Source
 This technology is being developed mainly to
address the transportation needs of the planet
 The energy source, water, is renewable
 The exhaust from this type of engine is water
vapor
 This is a very promising technology in reference to
sustainable automotive travel
http://www.youtube.com/watch?v=oy8dzOB-Ykg
Hybrid Automobiles
 Internal combustion engine: gasoline
 Battery: recharged by kinetic energy of the
vehicle
 At slower speed the battery powers the
vehicle; at speeds exceeding 30 MPH the
internal combustion engine powers the
vehicle
Hybrid Automobiles
 Toyota manufactures the Prius; Honda
manufactures the Insight
Electric Automobiles
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There is no internal combustion engine
The engine is the battery
GM introduced the EV1 in the late 90’s
Electric automobiles were removed from the
market in the USA in the early 2000’s.
 Electric automobiles are now back on the
market ~ 2013: Tesla and Nissan Leaf
Electric Automobiles
 Can either charge vehicle at home or at
charging stations (free to use currently)
 Tesla has a range of 300 miles and provides
charging stations nationally to Tesla owners
 Nissan Leaf has a range of 70 miles but
there is no Nissan charging station
infrastructure
 There are some free charging stations at
various locations in urban areas
Electric Automobiles
 Tesla Model S and the Nissan Leaf