440 likes | 603 Views
Part 3. Energy. Objectives. 1. Distinguish between developed and developing world energy consumption issues and potential problems. 2. Analyze appropriate energy policies for achieving a balance between economic growth and sustainable environment.
E N D
Part 3 Energy
Objectives • 1. Distinguish between developed and developing world energy consumption issues and potential problems. • 2. Analyze appropriate energy policies for achieving a balance between economic growth and sustainable environment. • 3. Understand the impact of renewable and non renewable energy sources for a sustainable environment. • 4. Examine the ethical consideration of increased fossil fuel usage.
Energy • Energy is the most basic infrastructure needed to enable economic growth. • Since the Industrial Revolution, the world has become increasingly dependent on fossil fuels. • Modern civilization is based on nonrenewable sources, which puts a finite limit on the length of time our civilization can exist.
Energy • The United States is responsible for almost 25% of the world’s total energy consumption. • The United States is responsible for 24% of the carbon emissions of this climate changing gas. • Oil production has reached a plateau or declined for 33 of the 48 largest oil producers.
Energy • Americans can cut the energy consumption in half by 2030 by using energy more efficiently and by using more renewable sources. • A human being at survival level needs about 2,000 kilocalories of energy per day. Americans consume 230,000 kilocalories of energy a day, 115 times the level needed for survival. • One fifth of the world’s population accounts for 70% of the global energy use.
Fossil Fuel Fundamentals • Despite tremendous advances in technology, fossil fuels remain the number one source of energy. • Coal, crude oil, and natural gas are fossil fuels. • These fossil fuels are non renewable. • Fossil fuels were formed millions of years ago by the decomposition of plants and animal matter.
Fossil Fuel Fundamentals • Crude oil accounts for 38% of energy production, coal for 26% and natural gas for 23%, with hydroelectric power, nuclear power, and renewables accounting for the remainder (www.eia.doe.gov). • According to some estimates, oil is supposed to last for 44 years, natural gas for 60 years and coal for 300 years. • The Middle East holds most of the world’s oil supply, the former Soviet Union and the United States possess most of the coal, and the former Soviet Union, United States, and Middle East possesses most of the gas. • Coal is the worst polluter, followed by oil and then gas (acidification of rain, and carbon di oxide (CO2) pollution).
Fossil Fuel Fundamentals • The world adds about 6 billion tons of CO2 to the atmosphere a year whereas a sustainable amount would be 1 billion tons a year. • The concern is that this will lead to global warming resulting in climate change, ice melts, and other drastic ecosystems patterns.
Fossil Fuel Fundamentals • In the last 20 years engineers and scientists have produced cars that get 70 or more miles per gallon, appliances that use half the energy that they used 10 years ago, lighting fixtures that last for years and use a fraction of the energy, and more efficient heating and cooling of homes. • Adoption of these new technologies could reduce growth in demand by 47% (http://www.oilcrisis.com/Cleveland/openletter.htm).
Fossil Fuel Fundamentals • Energy consumption in the USA (2003): • Wood (waste, ethanol) 2.93% • Hydroelectric 2.83% • Nuclear 8.1% • Coal 23.13% • Natural Gas 22.93% • Petroleum 39.8% • Source: www.eia.doe.gov
Fossil Fuel Fundamentals • Coal: • Coal is an organic rock present in the earth’s crust. • Coal has a complex molecular structure consisting of carbon, hydrogen, sulfur , and nitrogen. Sulfur is converted to sulfur oxide and contributes to acid rain. • Two types of coal: • Low rank coal (lignite and subbituminous): 50-100 million years old. Lower heating value. • High rank coal (bituminous and anthracite): 350 million years old. Higher heating value.
Fossil Fuel Fundamentals • Advantages of coal: • Abundant energy resource. • Versatile: burned directly, liquefied, or turned into gas (coal gasification). • Inexpensive. • Drawbacks: • Source of pollution (sulfur dioxide, nitrogen dioxide) • Strip mining can mar the landscape • Coal liquefaction and gasification require large amounts of water. • Coal is bulky (more difficult to transport).
Fossil Fuel Fundamentals • Petroleum: • Crude oil is a complex liquid mixture that consists of 83-87 % carbon, 11 – 16 % hydrogen, 0- 7 % nitrogen, and 0 – 4 % sulfur. • The typical output of an oil well in Saudi Arabia is 10,000 barrels per day, whereas an oil well in the US produces an average of 15 barrels per day. • The crude oil is refined by fractional distillation into various fuel products: gasoline, diesel, kerosene, and fuel oils. A small fraction is used to produce petrochemicals (used in pharmaceuticals, cosmetics, plastics, detergents, and textiles).
Fossil Fuel Fundamentals • Advantages of petroleum: • Oil is one of the most abundant energy resources. • Its liquid form makes it easy to transport and use. • Oil has a high heating value. • Drawbacks: • Oil burning leads to carbon emissions. • Oil has finite sources. • Oil recovery needs to be developed to provide better yields. • Oil transportation (by ship) can lead to spills, causing environmental damage.
Fossil Fuel Fundamentals • Natural Gas: • Natural gas also known as methane, is a colorless, odorless fuel that is one of the most commonly used sources of energy today. • Burning of natural gas emits up to 45% less carbon dioxide than other fuels. • According to Natural Gas Vehicle Coalition (www.ngvc.org), the natural gas vehicles reduced CO emissions by 70%, and NOx by 87%.
Fossil Fuel Fundamentals • Natural Gas Advantages: • Natural gas is inexpensive compared with oil. • Natural gas is less polluting than oil and other fossil fuels. • Natural gas burning does not produce any ash particles. • Natural; gas has a high heating value. • Drawbacks: • Natural gas is not a renewable source. • Natural gas is a finite resource.
Fossil Fuel Fundamentals • Future Strategies for a Sustainable Environment: • 1. Conservation: Energy conservation should be our central strategy to meet future energy needs. • 2. Alternate Fuels: Improve efficiency of solar and wind power. • 3. New Technologies: High temperature superconductors can reduce the loss of energy in transmission lines. • 4. Education: Teach the importance of responsible use of energy. • 5. Environmentally Friendly Policies: Public policy promoting conservation and use of alternative fuels.
Fossil Fuel Fundamentals • A 42 gallon barrel of oil produces: • 19 gallons of gasoline • 4 gallons of distillate fuels • 4 gallons of jet fuel • 3 gallons of diesel and heating fuels. • 2 gallons of other byproducts including oil, grease, wax, and asphalt.
Nuclear Technology • Today in 32 nations, more than 440 nuclear power reactors generate 366,913 MW, 1/6th of the world’s electricity production. • In the US 104 nuclear plants provide 19 % of the electricity. • 26 power reactors are under construction. • A typical 1000 MW nuclear reactor generates a large amount of nuclear waste. • Depending on the type of element, it can take hundreds , thousands, or even millions of years for nuclear material decay to occur.
Nuclear Technology • Each nuclear plant yields about 30 tons of high level waste. The world’s high level nuclear waste approaches 15,000 tons annually. • Accidentally released radiation can spread through air or water to contaminate the environment. • The radiation released from Chernobyl (April 26, 1986) will be responsible for an estimated 14,000 to 475,000 cancer deaths.
Fuel Cells and the Hydrogen Economy • A fuel cell is an electromechanical device that converts chemical energy into electrical form. • A fuel cell is like an active battery because it does not require recharging as long as fuel (hydrogen) is supplied. • Hydrogen can be obtained from 2 sources: methane and the electrolysis of water.
Fuel Cells and the Hydrogen Economy • Advantages of fuel cells: • Fuel cells have high efficiency(45%). • Fuel cells produce energy for longer periods. • Fuel cells generate power with little pollution. • Fuel cells operate with low noise level. • Fuel cells can be quickly recharged by refueling compared to batteries that require time consuming recharge. • Disadvantages: • The cost is higher than conventional systems. • The durability of fuel cells is not yet established. • Platinum group metals used as catalysts are expensive. • Production of hydrogen for fuel cells causes emissions of CO2 in the atmosphere. • Power density is low compared to combustion engines and batteries.
Iceland • Iceland began heating homes with geothermal energy in the 1940’s. • Today 90% of the country’s buildings are heated with geothermal water. • Several towns in the countryside use geothermal heat to run greenhouses for horticulture. • Geothermal is also used for power generation. • It is estimated that only 1 % of its geothermal energy potential has been utilized.
Iceland • Iceland declared independence from Denmark in the 1940s. • It is one of the world’s most wealthy nation’s today. • Hydroelectricity provides 19% of Iceland’s energy. • Iceland is unique among nations in that 99.9 % of its electricity is from renewable sources – geothermal and hydroelectric. • The overall energy system, including transportation, is roughly 58% dependent on renewable sources.
Iceland • In Iceland imported oil (850,000 tons per year) accounts for 38% of the nation’s energy use, of which 57% is used for motor vehicles and boats. • Iceland has a large fishing industry, the nation’s leading source of exports. • The other third of Iceland’s greenhouse emissions is found primarily in the smelting industry, in the production of metals like aluminum. • The world’s cheapest electricity ($.02 per kw) has attracted energy intensive industries.
Iceland • Iceland is committed to becoming the world’s first hydrogen economy over the next 30 years (www.worldwatch.org). • Iceland has been producing hydrogen since 1958. • The production process uses hydro generated electricity to split water into hydrogen and oxygen molecules, by a process called electrolysis. • About 13 megawatts of power is used to produce 2,000 tons of liquid hydrogen which is then used to produce ammonia for the fertilizer industry.
Iceland • By the late 1990’s the fuel cell, an electrochemical device, that combines hydrogen and oxygen to produce electricity and water had achieved dramatic cost reductions. • Iceland has a 5 phase scenario for the hydrogen transformation. • In phase 1 hydrogen fuel cells will be used on 100 public transit buses (enough for 250 km, the average daily distance traveled by a Reykjavik bus). • In phase 2 the entire city bus fleet, and possibly those in other parts of the island will be replaced by fuel cell buses. • The price tag is $ 50 million.
Iceland • Phase 3 involves the introduction of private fuel cell passenger cars. They will be run on liquid methanol, which will be converted to hydrogen on the vehicle to power the fuel cell. • In the final two phases , methanol will be used to power the entire boating fleet. The trawlers use electric motors that are 1 to 2 megawatts.
Biomass Energy • Biomass refers to any organic material – except coal, oil, natural gas, etc – that is used for energy generation. • It includes terrestrial and aquatic vegetation, agricultural and forest residues, and animal wastes. • Biomass is a renewable energy source. • Typical applications for biomass energy include heat generation, electrical generation, and production of liquid fuels for vehicles.
Biomass Energy • Advantages of biomass energy: • There is an abundance of biomass sources (crops, plants, trees, wood residues, crop waste, animal waste). • Biomass sources are inexpensive and widely available. • Biomass sources are easy to store and transport. • Biomass is a renewable source of energy. • Disadvantages: • Air emissions from biomass sources are not always less than the emissions from fossil fuels. • Growth of trees requires considerable time (months for crops and years for trees).
Solar Energy • The sun is expected to radiate energy for billions of years. • The average solar radiation reaching the earth is 630 watts per meter. • In 2003, the cumulative solar photo voltaic generating capacity was 3,146 megawatts. • The largest markets were Japan, Germany, and California. • Only 5 countries (Denmark, Germany, India, Japan, and Spain) and half a dozen U.S. States account for approximately 80% of world market for wind and solar energy technologies.
Solar Energy • Advantages of solar energy: • Solar energy is a continuous source of energy. • Solar energy is a clean source of energy. • Solar energy is a safe source of energy. • Disadvantages: • Solar power is not steady and depends on cloud cover, season, latitude, and time of day. • Solar energy is not available at night. • Solar energy needs to be converted to other forms (electrical) for useful applications.
Wind Power • The use of wind power dates back to thousands of years. • It was employed for grinding grain and pumping water. • Wind power can be used to turn blades attached to a shaft. The revolving shaft spins the rotor of a generator, which produces electricity. • During the past two decades, wind energy technology has evolved to a point where it can compete with most conventional forms of power generation. • The average turbine size has increased from 100-200 kW in the early 1990s to more than 900 kW in 2004.
Wind Power • Advantages of wind power: • Wind power is a clean source of energy. • Wind power is a renewable source. • Disadvantages: • For most locations wind power density is low. • In most cases wind velocity must be greater than 7 mph to be useable. • Problem exists with the variation in power density and duration of wind. • Wind power may have some environmental effects (bird migration patterns).
Hydroelectric Power • Hydroelectric power is the conversion of the controlled release of water reservoirs through turbine generators. • It supplied 21% of electricity worldwide (692 GW) in 1986, less than coal and oil, but more than nuclear power. • The United States is second only to Canada in production of hydro power.
Hydroelectric Power • Advantages of hydroelectric power: • No air, thermal, or chemical pollution. • Low production costs. • High efficiency (90%). • Water reservoir can provide flood protection downstream. • Groundwater reserves are increased. • Can store large volumes of water for long periods of time. • Disadvantages: • High construction costs. • Limited feasible sites. • Severe drought can hamper production. • Causes loss of agricultural land. • Silt accumulation. • Prevents upstream migration of fish.
Electric Car • The biggest roadblock for electric cars has been the storing of electricity to run them. • Lead acid batteries have a range of 70 to 90 miles. • Nickel metal hydride cells can increase the range between 150 and 200 miles. • Nickel cadmium and lithium batteries could increase the range or decrease the weight of the car. • The cost falls between $480 and $640 per month – like a Cadillac DeVille. • As production picks up the price will fall considerably.
Case Study 1: Chernobyl • At 1:24 am on April 26, 1986, two massive explosions destroyed unit four of the Chernobyl nuclear power plant. • The plant located 80 miles north of Kiev, the capital of Ukraine (a republic of the former Soviet Union), had four reactors. • The plant’s roof was blown off, and radioactive gases and materials were released into the atmosphere. • An estimated 50 to 250 million curies of radiation were released. Hiroshima and Nagasaki released an estimated 1 million curies.
Case Study 1: Chernobyl • The Chernobyl disaster rendered an area the size of New York State unsafe for human habitation. • Some 200,000 residents were evacuated. • The accident killed 31 people immediately and 224 deaths within the next few days. • Since Chernobyl cancer rates have increased 300 %, respiratory diseases by 2,000 % . The estimate is from 14,000 to 475,000 cancer deaths. • 6.7 million people were exposed to the radiation. 800,000 fire fighters and soldiers were involved in the cleanup.
Case Study 2: Tasman Spirit Oil Spill • A Greek oil tanker, Tasman Spirit, which was carrying 67,500 tons of crude oil ran aground near Karachi, Pakistan, and broke into two halves. • A 14 km beach was covered with thick oil, killing thousands of fish, turtles, and birds. • The disaster might have been avoided by adequate contingency planning and acquisition of pollution control materials (booms, skimmers and absorbents).
Case Study 3: Exxon Valdez Oil Spill • On March 24, 1989, the single hulled oil tanker, Exxon Valdez hit a rock off the coast near Alaska. • More than 11 million gallons of oil spilled out within 5 hours. • The resulting oil slick was 1,000 feet wide and 4 miles long. • Estimates indicate that the oil spill killed more than 250,000 sea birds, 2,800 sea otters, 300 harbor seals, 250 bald eagles, 22 killer whales, and billions of salmon and herring eggs (Sierra club press release, 2004).
Conclusion • During the past 50 years the global economy has increased five fold, world population has doubled, and world energy use has tripled. • It is predicted that if energy consumption styles do not change, world energy consumption will increase by 50 to 60 %. • Carbon dioxide emissions will also increase by 50 to 60 %.
Home Work Questions (page 1) • 1. Why is there a finite limit on the length of time our civilization can exist? • 2. How and by how much can Americans cut their energy consumption? • 3. What are 3 sources of fossil fuels? • 4. Why is excessive CO2 emissions harmful? • 5. What new technologies could reduce growth in energy demand by 47%?
Home Work Questions (page 2) • 6. What products do we get from fractional distillation of crude oil? • 7. How many nuclear reactors are there in the world and how much energy do they produce? • 8. What is a fuel cell? • 9. Which country generates 99.9% of its electricity from renewable sources? What are these renewable sources? • 10. What is biomass?