alternative fuels presentation
Post on 14-Apr-2017
61 Views
Preview:
TRANSCRIPT
Alternative Fuels
Kimberly MurphyGEO 4333Dr. Hugli
Alternatives to Coal
Solar Power Hydroelectric Energy Wind Energy Geothermal Energy Nuclear Energy
Solar Power
Solar power is energy from the sun that is converted into thermal or electrical energy
Sunlight falls on a layer of semiconductor (silicon) panels and the jostles electrons, creating an electrical current
Advantages of Solar Power
Solar power is a free, abundant, and nonpolluting source of energy
Produces energy without any environmental hazards
Reduces dependence on fossil fuels
Disadvantages of Solar Power
Would take about 10,000 square miles of solar panels to satisfy all of the United States electricity needs
High construction and consumer costs Only a small percent of daily sunlight can be
captured– Only certain wavelengths of the UV spectrum
Sensitive to environmental changes– Won’t work on cloudy or rainy day
Leading Producers of Solar Power
Germany Japan United States Europe China India
Hydroelectric Power
What is hydroelectric power?
– The generation of electricity by using the motive power of water
Typical Hydrodam
Dam is built on a large river that has a large drop in elevation
Near the bottom of the dam there is a water intake
Gravity forces the water through the penstock and then turns a turbine connected to a metal shaft
Typical Hydrodam
The shaft of the turbines goes up into an electric generator and carries the electricity out via power lines
Wave Power
The wave rises into chamber and forces air out
The moving air spins a turbine, generating electricity
When the water falls it allows air back into the chamber, forcing turbine to spin and generating more electricity
(Other methods use the up and down motion of the wave to power a piston that moves up and down inside a cylinder)
Tidal Power
When tides come to shore they can be trapped in reservoirs behind dams
When the tide recedes, the water behind the dam can be let out just like in a regular hydroelectric power plant
– Note size of turbine
Ocean Thermal Energy
Uses temperature differences in warm surface water and cold deep water to produce electricity
Warm water is drawn from the surface layer into a heat exchanger (boiler) to vaporize a liquid
Ocean Thermal Energy
Vapor drives turbine attached to an electric generator
Vapor from turbine is condensed in a second heat exchanger, which is cooled by water pumped from the cold water source below
Benefits of Hydroelectric Energy
Reduces dependence on coal No carbon emissions Relatively low construction costs Low operating and consumer costs
Downfalls of Hydroelectric Energy
Requires 50 years to collect hydrological data Disruptive to surrounding aquatic life (fish
populations)– Dams block upwardly migrating fish such as Salmon – Fish are sucked into turbines and killed
Changes downstream river environment (sediment carried in currents)
Sensitive to environmental changes (weather patterns)
Ocean Thermal: Not very effective– Pumping water is a huge engineering problem
Leading Hydroelectric Producers
Canada 341,312 GWh
United States 319,484 GWh
Brazil 285,604 GWh
China 204,300 GWh
Russia 160,500 GWh
Norway 121,824 GWh
Japan 84,500 GWh
India 82,237 GWh
France 77,500 GWh
Sweden 70,823 GWh
Venezuela 60,600 GWh
Paraguay 51,910 GWh
Italy 47,054 GWh
Austria 41,727 GWh
Wind Energy
Power derived by wind– Wind strikes the blade of
the windmill causing it to turn
– This turns a shaft to rotate a generator and produce electricity
Depends on two factors:
– Area swept by the windmill blade
– Wind Speed
Wind Energy
Pros– Reduces dependence on
fossil fuels– No carbon emissions– No waste products– Low operating costs
Cons– Can only be used in
locations that have enough wind over an extended part of the day.
– Wind is weakest in summer and winter when the demand for power is greatest
– Unsightly and noisy– Blades kill migrating birds– High construction and
consumer costs– Sensitive to environmental
changes (weather patterns)
Leading Wind Energy Producers
Germany 12,247 MW
United States 16,818 MW
Spain 15,145 MW
India ~8,000 MW
China 6,050 MW
Geothermal Energy
Energy derived from the heat in the interior of the earth
Volcanoes, geysers, hot springs, steam vents and tectonic plate boundaries
3 methods for producing geothermal energy
– Vapor-dominated– Water-dominated– Binary cycle
3 Methods of Geothermal Energy
Vapor-Dominated– Steam from underground wells is carried by a pipes to a turbine
generator– The steam turns the turbine, generating electricity
Water-Dominated– Uses hot water flowing from wells– A fraction of the water is allowed to vaporize into steam at a
certain pressure – The steam then travels to a turbine, generating electricity
Binary Cycle– Brings geothermal water under high pressure from wells but does
not allow it to vaporize– Instead, hot water is used to heat a second fluid that has a lower
boiling point– The steam produced by the fluid powers the turbine and
afterwards cools and returns to its liquid state to be used again
3 Methods of Geothermal Energy
Geothermal Energy
In all three methods, used geothermal fluid is pumped back into the ground, both to preserve the environment and to maintain pressure in the reservoir
Advantages of Geothermal Energy
Reduces dependence on fossil fuels Renewable resource Little effect on the land used Unaffected by changing weather conditions
Disadvantages of Geothermal Energy
Can only be achieved in limited parts of the world
Releases gases such as hydrogen, sulfur, sulfur dioxide, and ammonia
Pollution of water by runoff of geothermal well
High construction and consumer costs Locations may cool down or lose pressure
– Debates on whether geothermal energy is renewable
Leading Producers of Geothermal Energy
United States 2,228 MWe
Philippines 1,909 MWe
Italy 785 MWe
Mexico 755 MWe
Indonesia 590 MWe
Japan 547 MWe
New Zealand 437 MWe
Iceland 170 MWe
El Salvador 161 MWe
Costa Rica 142 MWe
Nicaragua 70 MWe
Kenya 45 MWe
Nuclear Energy
Nuclear power is alternative energy source that can be obtained from either the splitting the nucleus of an atom (nuclear fission) or the combining of the nuclei of atoms (nuclear fusion)
Nuclear Energy
There are 15 different types of nuclear reactors Most common type is the boiling-water reactor
– A single cooling loop contains water at high pressures– Water is pumped into the reactor and as it flows through the core it
is heated by fission causing it to boil– Steam generated in the core region drives the turbine directly and
creates electricity
Nuclear Energy
Pros:– Relatively Safe (safety
record unparalleled by any other industry)
– Abundant– Reduces dependence on
fossil fuels– No carbon emissions– Low consumer costs
Cons:– High construction costs– Not a renewable resource– Nuclear waste management
Unsatisfactory methods of storing high-level wastes
– Risk of loss of coolant Melt down would release
radioactive particles to the rest of the plant and even possibly the outside environment
– Transportation Accidents Has never happened
– Nuclear Proliferation Terrorism
Leading Nuclear Power Producers
European Union 370,721 MW
United States 99,209 MW
France 63,363 MW
Japan 47,593 MW
Russia 21,743 MW
United Kingdom 11,852 MW
South Korea 16,810 MW
Canada 12,599 MW
Germany 20,339 MW
India 3,557 MW
Energy Cost Comparisons
Resource Type Average Cost (per kWh)Hydroelectric 2-5
Nuclear 3-4Coal 4-5
Natural Gas 4-5Wind 4-10
Geothermal 5-8Biomass 8-12Solar PV 15-32
Worldwide Energy Supply
Alternatives to Natural Gas
Alternatives to Natural Gas
Biomass– Ethanol– Biodiesel
Vehicles– Electric – Hybrid– Hydrogen
Ethanol
Ethanol holds the promise of reducing carbon emissions by recycling carbon in the atmosphere into presently growing plants (carbon neutral)
– Burning ethanol releases carbon from plants– Photosynthesis captures carbon in plants
By contrast, burning fossil fuels increases carbon emissions by releasing ancient carbon that was once locked within the earth
Ethanol
Ethanol is fuel derived from biomass
Ethanol can be made from:– Corn – Sugar Cane– Switchgrass– Wheat– Barley– CELLULOSE
(We will be discussing corn, sugar cane and cellulosic ethanol)
Corn Ethanol
Corn is ground into a fine powder, mixed with water, and heated Enzymes are added to convert the starch into sugars Yeast is added to ferment the sugars into alcohol Alcohol is then separated by distillation A small amount of gas is added to render the liquid undrinkable
ONLY 1% OF THE PLANT IS ACTUALLY USED– Byproducts are put back on the fields
Corn Ethanol
Would require more than 20 million acres of corn, or about one-quarter of the U.S. total corn acreage
Requires large doses of herbicide and nitrogen fertilizer
Causes more soil erosion and requires more water than any other crop
1:1.3 energy ratio 22% less emissions than gasoline
Sugarcane Ethanol
Unlike corn, in which the starch has to be broken into sugars, the entire sugarcane stalk is already 20% sugar and starts to ferment almost as soon as it is cut
Cane yields 600-800 gallons of ethanol an acre– Twice as much as corn
Sugarcane Ethanol
Fields are burned before harvest to kill snakes and make the cane easier to cut by hand
Harvest burns release methane and nitrous oxide into the atmosphere
Sugar cane is harvest by hand– Increase in labor costs– Cutters die of exhaustion every year
Does not require fossil fuels for distillation – Burn cane waste, known as bagasse, for heat and power
1:8 energy ratio 56% less emissions than gasoline
Pros of Ethanol
Ethanol is renewable Ethanol can be domestically produced Reduces dependence on foreign oil Ethanol burns cleaner than gas Eases pressure to drill in controversial and
environmentally sensitive areas at home
Cons of Ethanol
May be contributing to deforestation Sensitive to environmental changes Does not reduce carbon emissions
– Major controversy of ethanol Takes food from third world countries
– Prices of crops and crop based products would increase significantly
– Amount of crops need to sustain energy needs is equal to amount exported
Cons of Ethanol
Cannot be transported through a pipeline– Transported by trucks, trains, or barges– Increases emissions and cost
Is not cost competitive with natural gas Has two-thirds the energy value of gasoline
Major Controversy of Ethanol
Does the amount of the fossil fuel energy needed to make ethanol equal the energy it produces?
Controversy of Ethanol
Producing corn ethanol consumes as much fossil fuel as the ethanol itself replaces
Heavy use of diesel machinery required to harvest crops– increases emissions
Most ethanol plants burn natural gas or coal to create the steam that drives the distillation
– increases emissions Cannot be transported through pipeline
– Transported by trucks, trains, or barges which require fossil fuels– Increases emissions and price
Ethanol delivers 30% fewer miles to a gallon– Requires 1.4 times as much
Lower fuel economy= increased emissions
Cellulosic Ethanol
Cellulose is the tough chains of sugar molecules that make up plant cell walls
Finding a way to break down the cellulose chains would significantly increase our ethanol sources
Cellulosic Ethanol
Sources of cellulosic ethanol– Agricultural Residues
Leftover material from crops– Forestry wastes
Wood chips, sawdust, tree bark– Municipal solid wastes
Household garbage, paper products– Paper pulp– Fast growing plants that require less energy and
that can be grown on marginal land
Pros of Cellulosic Ethanol
Reduce dependence on foreign oil Cellulose is highly abundant Energy can be derived from organic waste
material– Saves the environmental and economic cost of
their disposal Does not compete with food crops 1:36 energy ratio (HUGE AMOUNT) 91% less emissions than gasoline
Con of Cellulosic Ethanol
More research is needed– Trying to develop a way to reproduce digestive
enzymes in the stomach of termites Only organism that can digest cellulose
We are years away from developing an effective economic process of producing cellulosic ethanol– Some of us may not even see it our lifetime
Biodiesel
Renewable fuel made from vegetable or animal fat
Sometimes mixed with conventional, petroleum-based diesel
Biodiesel
Pros– Reduces carbon
emissions 68% less than gasoline
– More energy than gasoline
Increases mileage– Can be used with any
diesel engine– 1:2.5 energy ratio
Cons– Fuel system problems at
low temperatures– Is not cost competitive
with gasoline
Electric Vehicles
Has an electric motor rather than gasoline engine
Consumes no energy at idle or coasting Regenerative braking Car itself produces zero emissions
Electric Vehicles
Electricity still has to come from coal-fired power plants
Electric vehicles only transfer the emissions source from the vehicle to the power plant
Energy is lost in process (20%) Ultimately there is an increase in carbon emissions
Hybrid Vehicles
At idle, hybrids’ computer automatically turns off the gasoline engine and restarts it once the driver starts accelerating.
Every time the driver brakes, the car recovers that momentum as electricity and stores it in a battery (Regenerative Braking)
Hybrid Vehicles
Pros– Delivers high fuel efficiency– Low emissions of tail pipe pollutants
Because of fuel efficiency and electric motor One tenth the pollution of conventional gasoline cars
Cons– Still dependent on natural gas and create carbon
emissions– Only good for stop and go traffic
Hybrid Vehicles
Only good for stop and go traffic, however:– 80% of driving is on interstate– Battery weighs approximately 600 lbs
– Scenario: You’ve been driving on the interstate and your still three hundred miles from home when your 600 lbs battery dies. What happens?
Decrease in fuel economy Ultimately increases emissions
Hydrogen Vehicles
Two Methods:– In combustion, the
hydrogen is burned in engines in fundamentally the same method as traditional gasoline cars.
– In fuel-cell conversion, the hydrogen is reacted with oxygen to produce water and electricity, the latter of which is used to power an electric traction motor.
Hydrogen Vehicles
The only emission from the vehicle itself is water However, refining hydrogen requires energy from fossil fuels Emissions source is merely transferred from the vehicles to the
smoke stack
Energy Content
References
“Alternative Energy Sources.” U*X*L Encyclopedia of Science. Ed. Online. Detroit: U*X*L, 2007. Science Resource Center. Thomson Gale. 17-February-08. <http://galenet.com/servlet/SciRC?ste=1&docNum=CV2644300053>
"Biodiesel." U.S. News & World Report, Jan 11, 2008 pNA. Science Resource Center. Gale. 23 February 2008 <http://galenet.galegroup.com/servlet/SciRC?ste=1&docNum=A173388760>
Bourne, Joel K. “Green Dreams.” National Geographic October 2007:38-59. Clifford, John. "Wind energy." World of Physics. Ed. Kimberley A. McGrath. Online.
Detroit: Thomson Gale, 2007. Science Resource Center. Gale. 22 February 2008 <http://galenet.galegroup.com/servlet/SciRC?ste=1&docNum=CV2434500580>
Clifford, John. “Hydroelectric energy.” World of Physics. Ed. Kimberly A. McGrath. Online. Detroit: Thomson Gale, 2007. Science resource Center. Thomson Gale. 21-January-08. <http://galenet.galegroup.com/servlet/SciRC?ste=1&docNum=CV2434500238>
"Emission-free Europe: hydrogen projects, from Iceland to Italy.(hydrogen fuels)." E, Jan-Feb 2007 v18 i1 p16(2). Science Resource Center. Gale. 24 February 2008 <http://galenet.galegroup.com/servlet/SciRC?ste=1&docNum=A159390911>
“Free power.(Energy)(Brief article)." R & D, Sept 2007 v49 i9 p29(1). Science Resource Center. Gale. 22 February 2008 <http://galenet.galegroup.com/servlet/SciRC?ste=1&docNum=A169595152>
References
“Geothermal Energy”. Earth Sciences for Students. Ed. E. Julius Dasch . New York: Macmillan Reference USA, 1999. Science Resource Center. Thomson, Gale. 21-January-08. <http://galenet.galegroup.com/servlet/SciRC?ste=1docNum=CV2640550095>
“Geothermal Energy”. Encyclopedia Americana International Edition. Copyright 2004. Scholastic Library Publishing Company.
“How Tidal Power Plants Work”. Mary Bellis. Copyright 2008. About Inc, The New York Times Company. 27-January-08. <http://inventors.about.com/od/tstartinventions/a/tidal_power.htm>
“Hydroelectric Power”. Encyclopedia Americana International Edition. Copyright 2004. Scholastic Library Publishing Company.
“Hydroelectric Power”. Webster New MillenniumTM Dictionary of English, Preview Edition (v 0.9.7) Copyright 2003-2008. Lexico Publishing Group, LLC
“Hydroelectric Power: How it works”. Howard Perlmen. September 11, 2006 U.S. Department of the Interior. U.S. Geological Survey. 27-January-08. <http: //ga.water.usgs.gov/edu/hyhowworks.html>
Johnson, Jeff. “Ethanol- Is It Worth It?” C&EN Washington January 1, 2007:19-31 Marsden, Ann T. "Harnessing Solar Power and Earth's Renewable Energy Sources.”
Science and Its Times. Ed. Neil Schlager and Josh Lauer. Vol. 7. Detroit: Gale Group, 2001. Science Resource Center. Thomson Gale. 21 January 2008 <http://galenet.galegroup.com/servlet.SciRC?ste=1&docNum=CV2643450807>
References
Newton, David E. "Geothermal energy." Environmental Encyclopedia. Ed. Marci Bortman and Peter Brimblecombe. 3rd ed. Detroit: Gale, 2003. Science Resource Center. Gale. 24 February 2008 <http://galenet.galegroup.com/servlet/SciRC?ste=1&docNum=CV2644150617>
Newton, David E. “Tidal Power.” Environmental Encyclopedia. Ed. Marci Bortman and Peter Brimblecombe. 3rd ed. Detroit: Gale, 2003. Science Resource Center. Thomson, Gale. 21-January-08. <http://galenet.galegroup.com/servlet/SciRC?ste=1&docNum=CV2644151381>
Nuclear Energy. Encyclopedia Americana International Edition. Copyright 2004. Scholastic Library Publishing Company.
“Nuclear Power.” U*X*L Encyclopedia of Science. Ed. Rob Nagel. 2nd ed. Detroit:U*X*L, 2007. Science Resource Center. Thomson, Gale. 21-January-08. <http://galenet.galegroup.com/servlet/SciRC?ste=1&docNum=CV2644300701>
Toupin, Laurie. "Electric vehicles." Gale Encyclopedia of Science. Ed. K. Lee Lerner and Brenda Wilmoth Lerner. 4th ed. Detroit: Gale Group, 2008. Science Resource Center. Gale. 24 February 2008 <http://galenet.galegroup.com/servlet/SciRC?ste=1&docNum=CV2644030770>
Parfit, Micheal. “Freeedom!” National Geographic August 2005: 4-31 "Wind, Energy from." Earth Sciences for Students. Ed. E. Julius Dasch. New York:
Macmillan Reference USA, 1999. Science Resource Center. Gale. 22 February 2008 <http://galenet.galegroup.com/servlet/SciRC?ste=1&docNum=CV2640550245>
top related