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1. Economics of Biofuels
- Biofuels are made from agricultural sources and are added to transportation fuels
- Petroleum is refined into gasoline and diesel fuel
- Completely different source
- Biofuels cost more than their respective fossil fuel source
- If they were cheaper, we would be using them
- Usually subsidized by governments of developed countries
- Analysis is similar to recycled materials
- Similar to recycled materials, the demand has to be high for market to supply biofuels
- Government uses mandates to force petroleum refiners to blend a percentage of biofuels into the petroleum fuel
- Transportation fuels market
- Supply - petroleum and biofuels refineries
- Demand - car drivers
- Market Price is P T
- Market Quantity is Q T
- In theory, petroleum refineries can lower their production level
- They decrease their demand for petroleum
- Both market price and quantity decreases
- Biorefineries increase their demand for agricultural feedstocks
- Feedstocks can also be made into food for the people or animal feeds
- A strong biofuel industry will increase vegetable prices and increase production
- Some claim biofuels are a backstop technology
2. Ethanol - substitutes for gasoline
- Sources for the United States
- Sugar crops - sugar beets, sugarcane, and sweet sorghum
- Sugar is fermented into ethanol using yeast
- Opportunity costs
- Diverts commodities from the human food and animal feed markets
- Some crops and commodities are exported, like sugar
- Could worsen a trade deficit
- Starch crops - corn, rice, wheat, potatoes, barley, etc.
- Starch is long chains of sugar
- Use acids or enzymes to break starch down into sugars
- Yeast ferments sugars into ethanol
- Opportunity costs
- Diverts commodities from the human food and animal feed markets
- Some crops are exported
- Could worsen a trade deficit
- Energy crops - fast growing perennials that can be converted to ethanol
- Switchgrass, willow, and hybrid poplar
- Called lignocellulosic fermentation
- Experimental
- Break down into five types of sugar
- Requires multiple processing stages
- Requires different types of organisms
- Has higher capital costs
- Opportunity costs
- Land could be used to grow food and vegetables for people and animals
- Energy crops could be burned with coal to generate electricity
- Agricultural residues
- All crops leave behind residues
- Uses lignocellulosic fermentation
- Same process as energy crops
- Opportunity costs
- Crop residues provide surface cover
- Adds organic material and nutrient to the soil
- Prevent soil erosion
- Companies would be limited in how much could be removed
- Could be burned with coal to generate electricity
- Wood residues
- Saw mills generate many residues like sawdust and wood chips
- Use lignocellulosic fermentation to convert to ethanol
- Opportunity costs
- Could be burned with coal to generate electricity
- Wood chips and residues are used in particle boards, paper, cardboard, etc.
- Benefits
- Contains 36% oxygen - burns cleaner than gasoline
- Gasoline contains almost no oxygen
- Tail pipe emissions are cleaner
- EPA requires petroleum distributors to add oxygenates to fuel for cities with ozone or carbon monoxide problems
- Recycles carbon dioxide from the atmosphere
- Plants and trees remove carbon dioxide from atmosphere
- Carbon is store in plants
- Plants are processed into fuels
- Fuels are burned and carbon is released back into atmosphere
- Carbon recycling is not 100% efficient
- Fossil fuels are used to grow and process fuels
- Thus, wide-scale use of ethanol could greatly slow down greenhouse gas emissions into atmosphere
- Increases incomes for farmers
- Causes higher prices for agricultural commodities
- Reduced imports of petroleum
- Could reduce trade deficits if country imports a significant amount of petroleum
- A carbon permit system could increase the production of ethanol fuel
- Problems
- Vehicles can only use up to 15% ethanol by volume
- Flexible fuel vehicles can use up to 85% by volume
- So gasoline is still needed
- Contains lower energy than gasoline
- Ethanol contain 66% less energy by volume
- Dissolves some rubber seals and gaskets in the fuel system and engine
- Ethanol-gasoline blends separate in the presence of water
- Cannot be re-blended until all the water is gone
- Fuel tanks tend to accumulate moisture from humidity, especially during system
- Ethanol-gasoline blends dissolves the nasty stuff in gasoline, like benzene, toluene, etc.
- Ethanol seeps out of pipelines at a gas station, contaminating the soil.
- Contamination areas are wider than gasoline leaks that contain no ethanol
- Note
- Industry could use butanol
- A larger chain alcohol molecule
- Has better fuel properties
- Engines can burn any percentage of gasoline-butanol blends
- Water and moisture is not a problem
- Has 85% the energy as gasoline by volume
- Uses a different microorganism, so all the capital for ethanol could be used
- Problem - has a much lower yield
3. Biodiesel - substitute for diesel fuel
- United States - take oil, lard, tallow, and yellow grease and convert them into a substance that resembles diesel fuel
- Oil crops - main sources are corn and soybeans
- Oil is extracted from the seeds
- The residues contain high levels of protein that can be used in animal feeds
- Residues are devoid of oil
- Opportunity costs
- Biodiesel industry competes with food for humans and animal feed
- These commodities are exported
- Lower exports worsen a trade deficit
- Lard and tallow - products from the meat industry
- As cattle, pigs, etc are processed into meat, tallow is produced as a byproduct
- Opportunity cost - usually this oil is mixed in with animal feeds to increase fat content
- Problem - a limited source, because tallow is a byproduct of the meat market
- A derived demand - people eating meat indirectly produce tallow as a byproduct
- Yellow grease - used cooking oil from restaurants and fast food places
- Limited source for biodiesel
- Derived demand - people eat out and yellow grease is created as a byproduct
- Yellow grease is a byproduct of the restaurant industry
- Benefits
- Can be blended in any ratio with diesel fuel
- Lubricates engine parts, possibly extending engine life
- Recycles carbon dioxide from the atmosphere
- Could slow down the buildup of greenhouse gases
- Could boost farmers' incomes
- Biodiesel is not as flammable as diesel fuel
- Problems
- Biodiesel from vegetable oils freeze solid around 0 degrees Celsius
- Biodiesel from tallow and lard have much higher freezing points
- Biodiesel cannot be used in winters where temperatures dip below freezing
- Vegetable oils are expensive
4. Electric cars - uses alternatives other than gasoline and diesel fuels
- Cars use electric motors and batteries
- Or use hybrid engines
- Gasoline engine for driving at high speeds or acceleration
- Use electric motor to maintain speed
- Gasoline engine recharges batteries as car idles
- It doubles the distance that once can drive on a tank of gas
- Benefits
- Reduces pollution in a city
- However, requires more electricity
- Most electricity is generated by coal power plants
- Problems
- Have to upgrade the electricity transmission grid
- Very expensive capital improvement
- Batteries wear out after five years
- Batteries use strong acids or akalines
- Presents disposal problems
- Has short driving distances as batteries charge are used up
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1. Hydroelectric power - use moving water like rivers to turn generators
- Most common renewable energy source in the world
- Used by ancient man
- Grind grains into flour, cut lumber, textile machines, dock cranes, irrigation, etc.
- Used for 20% of world electricity production
- Three Gorges Dam in China is the largest hydroelectric station in the world
- Pay for itself within 3 to 8 years
- Benefits
- Produces very little greenhouse gases
- Remember - greenhouse gases are released when producing and pouring concrete
- Produces the lowest greenhouse gases
- Mitigate greenhouse gases - if a hydroelectric plant replaces a coal plant, then it lowers greenhouse gases
- Has long capital life
- Uses no input fuel
- Automated - little labor costs
- Not too expensive to build
- Can vary output
- Easy to reduce power when people are using little electricity
- Creates lakes
- People can enjoy the lake, like swim, fish, water ski, etc.
- Support industries
- Creates a cheap source of electricity
- Aluminum industry needs electricity to produce aluminum
- Problems
- Limited geographical areas for dam construction
- Dam failure - dam breaks
- Quickly floods a city further down stream
- Banqiao Dam failure in Southern China
- Vajont Dam in Italy in 1963
- Legal problems for the United States
- Impacts wildlife like fish, turtles, etc.
- Turbine blades cut up the fish
- Harms salmon - salmon return to the stream to create new offspring
- Dams construct fish ladders
| Country |
Energy Production |
Installed Capacity |
Percent Total Electricity |
| |
TWH |
Giga-Watts |
100% |
| China |
585.2 |
171.52 |
17.18 |
| Canada |
369.5 |
88.974 |
61.12 |
| Brazil |
363.8 |
69.08 |
85.56 |
| United States |
250.6 |
79.511 |
5.74 |
| Russia |
167 |
45 |
17.64 |
2. Geothermal - uses heat from the earth to turn water into steam that turns the turbines for the generators.
- Used by ancient man
- For heat and steam baths.
- Used for 0.3% of world electricity production
- A total of 10 gigawatts of capacity is installed
- Used also for heat
- Water can be pumped directly into radiators
- Reykjavík, Iceland
- Located near hot springs
- Use geothermal heat to heat buildings
- Then water leaving buildings heat sidewalks and roads, melting the ice
- Benefits
- Emits very little greenhouse gases
- Carbon dioxide and methane gases are emitted from the ground
- So are sulfur oxide emissions
- Mitigates greenhouse gases - if geothermal plant replaces a coal plant, then greenhouse gases emissions are lower
- Occupies very little space
- Pipes are put directly into the ground
- Sustainable - could produce electricity for a long time
- Some hot springs, etc. have shown cooling
- Extracting too much heat
- Heat is generated from gravitational forces and radioactive decay deep in the earth
- Water source is cut off
- Problems
- Very few areas can support geothermal plants
- Located near places where tectonic plates meet
- Places with earthquakes
- A plant was in Switzerland was shut down after it triggered earthquakes
- Very expensive to drill into the earth to lay the pipes
- Nevada - $10 million to drill, with a 20% failure rate.
- Note - heat pumps have greater application
- Only requires slightly warm temperatures
- Pipes are buried around a house or building
- Water is pumped through the pipes collecting heat energy and then taken to a heat exchanger
- Heat exchanger connects to a building’s heating system
- Helps lower heating bills
3. Wind Power - use wind to turn large blades that in turn rotate a generator
- Ancient form of energy
- Man has used wind to push sailboats
- Used windmills since 7 AD to grind grains into flour or pump water
- Wind supplies about 1.5% of the electricity energy in the world
- 121 gigawatts of capacity are installed
- Feed-in tariffs - a country guarantees a price for each watt of electricity a wind farm generates
- Most costs are capital, thus producers know what price they are getting.
- Canada and Germany
- Germany guarantees a price of 8.4¢/kWh for wind
- Benefits
- Relatively cheap - approximately 5-8 cents/kWh
- Has low capital costs for turbines, generators, and towers.
- Could have higher costs if located too far away from the grid
- Produces no greenhouse gases when operating
- Does produce greenhouse gases when equipment is manufactured
- Could mitigate the buildup of greenhouse gases
- If wind power replaces a coal electric plant, then greenhouse gas emissions are lower.
- Wind generators can be small
- A farmer can put a couple on his property to provide electricity for his farm
- Rural communities can also use wind generators
- Connecting or upgrading the grid may cost too much
- Problems
- Limitations where windmills can be placed
- Are located in areas with lots of wind
- If a wind stops blowing, then the wind farm stops generating electricity
- Coal generators have to be operating at low capacity
- Then turn them on all the way up to make up for the loss of power
- Otherwise, if the supply of electricity is not enough for demand, then the system shuts down.
- i.e. a blackout
- Variability of wind means wind could never be a dominant energy source
- Windmills are not attractive
- Be located outside in the country and rural areas
- Blades used to chop birds in half
- Some generators run at lower speeds so birds avoid them
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2005 |
2008 |
| Rank |
Country |
Wind Power |
% of Total |
Wind Power |
% of Total |
| 1 |
United States |
17.8 |
0.40% |
52 |
1.30% |
| 2 |
Germany |
27.2 |
5.10% |
38.5 |
6.6% |
| 3 |
Spain |
20.7 |
7.90% |
31.4 |
11.10% |
| 4 |
People's Republic of China |
1.9 |
0.10% |
12.8 |
0.40% |
| 5 |
India |
6.3 |
0.90% |
14.7 |
1.9% |
| 6 |
Italy |
2.3 |
0.70% |
4.9 |
1.40% |
| 7 |
France |
0.9 |
0.20% |
5.6 |
1.10% |
| 8 |
United Kingdom |
2.8 |
0.70% |
5.9 |
1.5% |
| 9 |
Denmark |
6.6 |
18.50% |
6.9 |
19.10% |
| 10 |
Portugal |
1.7 |
3.60% |
5.7 |
11.30% |
Note - The 2008 numbers for Germany, India, and United Kingdom are actually 2007.
4. Solar Energy - use energy from the sun to generate electricity
- Ancient Greek legend - Archimedes used polished shields to concentrate sunlight on the invading Roman fleet and repel them from Syracuse.
- Solar photovoltaic - silicon wafers that convert sun radiation into electricity
- Can use mirrors and lenses to focus a sun's rays
- Sun's energy heats water and then steam drives a turbine for a generator
- Useful for modular locations (e.g. remote lighting, signs, etc.), but not for mainstream use.
- Germany and Spain are the biggest investors in solar energy
- Both use feed-in tariffs to guarantee prices to producers
- Germany guarantees a price of 55¢/kWh for solar
- France, Italy, South Korea, and United States are catching up
- Benefits
- Reduces greenhouse gas emissions
- No emissions after solar panels are installed
- Releases a lot of emissions during manufacturing
- Silicon is heated up to form a crystal
- Homeowners can place solar panels on roof
- Supplement's a household's electricity
- Install reversible power meters
- If more energy is generated from the solar panels than what is used by the household, the power is supplied back through the line
- The meter runs backward
- Solar cells and wind power are complementary
- Sunny days tend to have little wind
- Cloudy days tend to be windy
- Can power electric signs and meters in sunny locations
- A battery supplies power at night or on cloudy days
- When the sun is shining, the batteries are re-charged
- Power sources for satellites and space crafts sent into outer space
- United States and Soviet Union
- Problems
- Are very expensive
- Solar photovoltaics have lower energy efficiency
- Only 6% of sunlight is converted to electricity
- Greatly increasing this inefficiency could make them more attractive
- Sunlight is intermittent
- Power is greatly reduced on cloudy days
- No power is supplied at night time
5. Nuclear energy
- Use a radioactive reaction as a heat source
- Heat water, sodium, etc and send it to an energy exchanger
- Minimize the transfer of radioactive substances
- Usually water is heated at the exchange into steam
- Steam turns the turbines
- The turbines turn the generators
- Nuclear power plants are usually located near a water source like a lake
- Lake cools the water
- Temperature differences allow the nuclear power plant to create electricity
- Nuclear energy supplied 15% of the world's electricity in 2005
- 439 nuclear reactors in the world
- 31 countries use nuclear power
- 150 navel vessels are powered by nuclear power
- U.S. Navy - submarines and aircraft carriers
- Soviet-Russian Navy
- Three largest producers of nuclear power
- United States - nuclear power supplies 19% of the electricity
- France - nuclear power supplies 78% of the electricity
- France has no petroleum resources
- Japan - nuclear power supplies 30% of electricity
- Japan has few natural resources
- Construction costs
- United States
- Construction costs have skyrocketed
- New regulations and lawsuits delay projects
- New nuclear plant could cost from $6 to $10 billion in the United States.
- Costs 30% more over the life of fossil fuel plant
- Fear of nuclear accidents
- 1986 Chernobyl disaster in Ukraine
- 1979 accident at Three Mile Island , Pennsylvania
- Pakistan, Japan, China and India are active in developing more nuclear reactors
- Their economies may grow fast, fueling the need for more energy
- Benefits
- Nuclear power plants emit very little greenhouse gases
- Problems
- Nuclear accidents
- Radioactive waste
- United States has an estimated 50 thousand metric tons of wastes
- After 10,000 years, this waste would no longer pose a health risk to humans
- Recycling
- France and Britain many other countries recycle the spent uranium rods
- However, they extract plutonium which could also be used in nuclear weapons
- Thought it required a breeder reactor???
- Requires a breeder reactor
- Russia is the only country with one
- Japan, India, and China plan to build breeder reactors
- Backstop Technology
- May not be a backstop technology
- Legal and regulatory barriers that prevent construction of nuclear power plants
- Environmental hazard of storing nuclear waste for thousands of years
- Costs 30% more over the life of fossil fuel plant
- If developed countries developed a carbon permit system for greenhouse gas emissions
- Coal electric power plants become expensive
- Nuclear power becomes more attractive
6. Biomass - burn crop and wood residues with coal to generate electricity
- The feedstocks are the same ones as for ethanol
- Energy crops - burn the fast growing perennials with coal
- Switchgrass, willow, and hybrid poplar
- Crops residues and manure
- Wood residues from saw mills - places where trees are cut into products
- Benefits
- Has cleaner emissions
- Recycles carbon from atmosphere - reduces greenhouse emissions
- Problems
- Crops residues, energy crops, and wood residues are bulky and light weight
- Costs could rise exponentially the further the distance to haul the feedstocks to the electric power plant
- Power plants would have to be located near their sources
- Requires upgrades in equipment for the power plant
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1. Carbon sequestration - a process to remove carbon out of the air and store it
- Process can be biological, chemical, or physical process
- Large variety of technologies - only the most common are discussed
- Mitigates the accumulation of greenhouse gases in atmosphere
- On a large scale, it could lower greenhouse gases
- Also called sinks
2. Change tillage technology
- Standard farming practice is to till the soil by breaking it up and turning the soil over
- Carbon in the soil is exposed to oxygen and reacts to it
- Reaction is small, but over millions of acres, it adds up
- No till - machine bores a small hole into soil and places seed
- Problem - soil has a limit to how much carbon can be stored
- Change fertilizer applications can reduce greenhouse gas emission
- Nitrogen increases emissions from Nitrogen dioxide (N2O)
3. Re-Forestation - plant more trees
- Have to ensure trees thrive and grow
- If a tree rots or is burned, then the carbon is released back into the atmosphere
- If trees are harvested, then carbon is still stored in roots and lumber
4. Fertilization of the oceans
- Controversial method - unsure of the impact on ocean life
- Dump iron and fertilizers into the ocean
- Encourages plankton growth
- Plankton - simple plant life that float in the water
- Can see plankton blooms from outer space
- Could potentially remove large amounts of carbon dioxide out of the ocean
5. Pyrolysis of wastes - Burn wastes slowly without oxygen
- Could use special ovens to breaks down wastes into carbon which can be mixed into soils
- Could be done on a large scale with wastes that are heading to a landfill
- Could increase greenhouse gas emissions, because the heat source creates carbon dioxide
- Terra Preta - created by humans between 450 BC and AD 950 in the Amazon
- Terra Preta - means black earth
- Contains high amounts of carbon
- Carbon encourages microbial activity
- Microbes increase carbon activity
- carbon content could increase over time
- Soil attracts earth worms
- Carbon helps retain the nutrients in the soil
- Soils are very healthy
6. Capture the carbon dioxide
- Emissions from a coal power plant is pumped into an old mine shaft, salt dome, deep water in a bay, etc.
- Deep water formations - contain calcium and magnesium deposits
- Carbon dioxide reacts with salt and minerals in the water to form carbonates
- Carbonates are stable
- Limestone is calcium carbonate
- Carbon dioxide is also injected into petroleum wells to increase output
- Note
- Burial wastes in landfills or dumping it into the seas is another way to capture the carbon
- As long as methane and carbon dioxide does not reach the atmosphere
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