Published on January 22, 2008
Earth Science Ch. 21:Energy Resources: Earth Science Ch. 21: Energy Resources Ch. 21-1: What Are Fossil Fuels: Ch. 21-1: What Are Fossil Fuels Key Terms Fossil Fuel Hydrocarbon Combustion California Content Standards for Earth Science Addressed:: California Content Standards for Earth Science Addressed: Earth Science 8(b) Students know the global carbon cycle: the different physical and chemical forms of carbon in the atmosphere, oceans, biomass, fossil fuels, and the movement of carbon among these reservoirs. Ch. 21-1:Why Do I Need To Know This?: Ch. 21-1: Why Do I Need To Know This? Because we use fossil fuels for many different things such as making plastic, fertilizers, electricity, heating our homes, cooking our food and powering our cars. Because fossil fuels come in many different forms which have many different uses. Because we are using up fossil fuels at an alarming rate and may run out of some forms of fossil fuels in your lifetime! Key Sections Ch. 21-1: Key Sections Ch. 21-1 What Are Fossil Fuels Coal Oil and Natural Gas Uses of Fossil Fuels Fossil Fuel Shortages What Are Fossil Fuels?: What Are Fossil Fuels? Fossil fuels are energy sources that formed from the remains of dead plants and animals. They contain many hydrocarbons, which are molecules made up of Hydrogen and Carbon. When hydrocarbons react with Oxygen, they give off lots of heat and energy. We call this reaction combustion! The 3 main fossil fuels are: Coal Oil Natural Gas Coal: Coal Coal is a solid fossil fuel that has been used for over 4000 years! Coal is a metamorphic rock that forms in 4 stages. As heat and pressure is added it changes from: Peat Lignite Bituminous Coal Anthracite Anthracite is the most rare and most useful coal since it emits the least amount of pollution. Oil and Natural Gas: Oil and Natural Gas Liquid fossil fuels are called oil or petroleum. Petroleum forms from the remains of plants and animals that were buried in areas that used to be covered by oceans. Petroleum usually builds up in deposits in pores and cracks in limestone and sandstone (like groundwater). Oil that is removed from these deposits is called crude oil. Oil and Natural Gas: Oil and Natural Gas Most crude oil comes from drilling down into the deposits. Some crude oil comes from tar (like the La Brea Tar Pits) and oil shale. Oil shale can be converted into crude oil, but it is very expensive. Natural Gas is a less dense form of a fossil fuel that is often found with crude oil. Since it is less dense, it usually floats on top of the crude oil. Uses For Fossil Fuels: Uses For Fossil Fuels Fossil fuels are the main sources of energy for industry, transportation and homes. Industry is the main use for fossil fuels followed by transportation. Crude oil is used to make gasoline for cars, plastics, asphalt, wax, fabrics, medicines and fertilizers. Coal is primarily used to produce electricity. Natural Gas is primarily used to heat homes and for cooking. Fossil Fuel Shortages: Fossil Fuel Shortages Every day, humans are using an amount of fossil fuels that took more than 1000 years to form! It is estimated that the United States has only about 400 years of coal left (at present levels of use). As for oil and natural gas, the United States will most likely run out of those by the year 2060 and the whole world will run out around the year 2080! We will run out of fossil fuels in your lifetime! Ch. 21-2: Energy From The Sun: Ch. 21-2: Energy From The Sun Key Terms Solar Energy Photovoltaic Cell California Content Standards for Earth Science Addressed:: California Content Standards for Earth Science Addressed: Earth Science 4(a) Students know the relative amount of incoming solar energy compared with Earth's internal energy and the energy used by society. 9 The geology of California underlies the state's wealth of natural resources as well as its natural hazards. As a basis for understanding this concept: 9(a) Students know the resources of major economic importance in California and their relation to California's geology. Ch. 21-2:Why Do I Need To Know This?: Ch. 21-2: Why Do I Need To Know This? Because solar energy is a renewable energy source that does not give off pollution. Because we can solve a large portion of our energy needs through solar energy—especially here in Southern California. Key Sections Ch. 21-2: Key Sections Ch. 21-2 Energy From The Sun Passive Solar Heating Active Solar Heating Solar Cells Power Towers Energy From The Sun: Energy From The Sun Without light from the sun, life would not be possible on the planet. Solar energy is the energy source for the winds and ocean currents and is a renewable energy source. The amount of solar energy received on the Earth in 1 day is enough to meet our energy needs for 30 years! Because solar energy is spread out across the entire planet, it must be collected and turned into electricity to be useful and must be stored for night-use or rainy weather. Passive Solar Heating: Passive Solar Heating Passive solar heating is one method for using energy from the sun. Passive solar heating means that we are just using natural sunlight to heat something. For example, we might build a building with the windows facing South to let more light in and to heat the building. We can also use passive solar heaters to heat water for showers, washing dishes, and washing clothes. Since about 50% of all energy used in a home goes towards heating water, we could save a lot of energy by using passive solar heating! We already use a form of passive solar heating when we adjust our clocks for daylight savings time. Active Solar Heating: Active Solar Heating Active solar heating requires building special collection boxes to trap in the heat from the sun. Often these are built out of black or dark materials and covered with plastic. Water is then run through the collection device and heated up and stored for later use. Many homes have active solar heating systems built onto their roofs. Solar Cells: Solar Cells Devices that change energy from the sun into electricity are called photovoltaic cells (solar cells). Solar cells use the element silicon to convert energy from the sun into electricity. Many small appliances such as calculators rely on photovoltaic cells for their electricity. It is possible to produce enough electricity to power a car or even a house with photovoltaic cells. As the prices for fossil fuels go up and technology gets better, more people will use photovoltaic cells. Power Towers: Power Towers Power Towers collect the solar energy from a wide area and condense into a very intense beam (like using a magnifying glass to burn a leaf). Already, a Power-Tower is in use in Australia and produces a large amount of energy with no pollution. The only problems with Power Towers are the lack of use during bad weather and at night. Ch. 21-3: Wind and Water: Ch. 21-3: Wind and Water Key Terms Hydroelectric Power California Content Standards for Earth Science Addressed:: California Content Standards for Earth Science Addressed: Earth Science 4(a) Students know the relative amount of incoming solar energy compared with Earth's internal energy and the energy used by society. 9 The geology of California underlies the state's wealth of natural resources as well as its natural hazards. As a basis for understanding this concept: 9(a) Students know the resources of major economic importance in California and their relation to California's geology. 9(c) Students know the importance of water to society, the origins of California 's fresh water, and the relationship between supply and need. Ch. 21-3:Why Do I Need To Know This?: Ch. 21-3: Why Do I Need To Know This? Because most of the major rivers in the United States have been dammed up to produce hydroelectric power. Because there are many risks associated with hydroelectric dams. Because we can solve a large portion of our energy needs through wind power, especially when combined with solar power. So you can finally say “they dammed the damn dam” and only use 1 dirty word! Key Sections Ch. 21-3: Key Sections Ch. 21-3 Wind and Water Wind Energy Water Energy Wind and Water: Wind and Water Both wind and water energy are indirect forms of solar energy. That’s because the energy to move the wind and water comes from the sun. Wind and water energy have both been used for thousands of years. The oldest known sailboat comes from 3,000 BCE. Some other uses for wind and water energy include windmills and water wheels—both of which were very important in the industrial revolution. Wind Energy: Wind Energy Wind energy forms from the unequal heating and cooling of our atmosphere. As our atmosphere heats up, it rises up and expands, causing winds. As it cools, it comes back together and sinks down, causing more wind. Windmills were first used around 1860 to pump water for farms. By 1900, windmills were producing electricity. Wind Energy: Wind Energy Today, wind energy can be used to make large amounts of electricity. Scientists seek out places where the wind blows reliably (such as in the valley on the way to Palm Springs) and blows at least 13 kph. We can then “farm” the wind by placing large amounts of electricity producing windmills on the land. Although wind energy is not always reliable, most scientists believe that we can produce at least half of all the electricity needed in the U.S. from windfarms! Water Energy: Water Energy Water energy results from flow of precipitation downhill as it returns to the ocean. Since the source of energy for the water cycle is the sun, water energy is an indirect form of solar energy. By the 1700s water wheels were used to make cloth and to grind wheat and corn. By the 1880s, dams were used to produce electricity from falling water. This type of electricity is called hydroelectric power. Water Energy: Water Energy Dams work by holding back the flow of water. As gravity pulls the water down, it flows through pipes and moves turbines. The moving turbines create mechanical energy to produce electricity. Hoover dam is an example of a major dam in the U.S. There are many problems with dams, such as major environmental damage, risks of floods, etc. And, most of the rivers in the U.S. that can be dammed up have already been dammed up—so we cannot produce more hydroelectric power. Ch. 21-4: Nuclear Energy: Ch. 21-4: Nuclear Energy Key Term Nucleus Chain Reaction Nuclear Fission Nuclear Fusion California Content Standards for Earth Science Addressed:: California Content Standards for Earth Science Addressed: Earth Science 9 The geology of California underlies the state's wealth of natural resources as well as its natural hazards. As a basis for understanding this concept: 9(a) Students know the resources of major economic importance in California and their relation to California's geology. 9(b) Students know the principal natural hazards in different California regions and the geologic basis of those hazards. Ch. 21-4:Why Do I Need To Know This?: Ch. 21-4: Why Do I Need To Know This? Because about 20% of our electric energy in the United States comes from nuclear power. Because we live about 25 miles from a nuclear power plant. Because there are many risks and many benefits to nuclear power. Because many of our political leaders want to build more nuclear power plants in order to solve the energy needs for the United States. Key Sections Ch. 21-4: Key Sections Ch. 21-4 Nuclear Energy Nuclear Fission Nuclear Power Plants Problems With Nuclear Power Nuclear Fusion Nuclear Energy: Nuclear Energy All atoms are composed of 3 primary particles: Protons Neutrons Electrons Protons and Neutrons are found at the center of an atom called the nucleus. Each element has a specific number of protons in it (adding 1 proton changes the element so the element’s number on the periodic table of elements is the number of protons in it). An atom can have different numbers of neutrons in the nucleus and still be the same element. These atoms with different numbers of neutrons are called isotopes. The larger the nucleus gets, the less stable it becomes. Nuclear Fission : Nuclear Fission Albert Einstein predicted that large amounts of energy could be made by splitting a very small amount of atoms. He developed the equation E=MC2 to predict how much energy could be produced. In 1939, a team of scientists split an atom of U-235 (an isotope of Uranium) and produced a large amount of energy, as predicted. This type of energy is called nuclear fission because it involves splitting 1 large atom into 2 new atoms. Nuclear Fission : Nuclear Fission Nuclear fission creates a process known as a chain reaction. A chain reaction occurs when neutrons from one atom undergoing fission break apart other atoms and continue the process of fission. A chain reaction will last as long as there are atoms large enough to be split apart. A chain reaction can be controlled to produce electricity or uncontrolled to make an atomic bomb. Nuclear Power Plants : Nuclear Power Plants Nuclear power plants use controlled chain reactions to produce electricity. The nuclear power plant uses the heat to turn water into steam and then moves the steam through pipes to push a turbine (much like water in a dam). As long as the reaction stays controlled, a nuclear power plant is safe (all American nuclear power plants have many safety systems to slow down the chain reaction). One major advantage to nuclear power is that it does not produce air pollution. Problems With Nuclear Power : Problems With Nuclear Power There are 4 main risks associated with nuclear power. They are: Leaking Radiation What To Do With the Radioactive Wastes Meltdowns Security. The biggest risk with a nuclear power plant is a meltdown, which is when the reaction happens too fast and it overheats, resulting in the area completely melting. This is what happened in Chernobyl, Russia in 1986 and released a large cloud of radioactive gas. Security is also a major concern because terrorists could use the waste material to produce an atomic bomb. Nuclear Fusion : Nuclear Fusion Nuclear fusion is the opposite of fission and produces more energy In fusion, 2 small atoms (hydrogen, which has only 1 proton, 1 neutron and 1 electron) are combined using tremendous heat and pressure to create 1 new atom of helium. This is what happens inside our sun each and every second of every day. This is how all atoms other than hydrogen have been formed—they were formed inside the center of stars through fusion. As the stars ran out of hydrogen to fuse, they would fuse 2 helium atoms, etc. to produce all the elements in the universe! Ch. 21-5: Alternative Energy Sources: Ch. 21-5: Alternative Energy Sources Key Term Geothermal Energy Tidal Energy Biomass Gasohol California Content Standards for Earth Science Addressed:: California Content Standards for Earth Science Addressed: Earth Science 9 The geology of California underlies the state's wealth of natural resources as well as its natural hazards. As a basis for understanding this concept: 9(a) Students know the resources of major economic importance in California and their relation to California's geology. 9(b) Students know the principal natural hazards in different California regions and the geologic basis of those hazards. Ch. 21-5:Why Do I Need To Know This?: Ch. 21-5: Why Do I Need To Know This? Because we will need to find an alternative to fossil fuels if we want to maintain our standard of living. Because our tax dollars are being spent researching and subsidizing these alternative fuels. Because each type of alternative energy has advantages and disadvantages. Key Sections Ch. 21-5: Key Sections Ch. 21-5 Alternative Energy Sources Geothermal Energy Tidal Energy Biomass Direct Burning Alcohol Production Hydrogen Power Alternative Energy Sources : Alternative Energy Sources 90% of the world’s energy comes from fossil fuels. At present rates of use, we will begin to run out of fossil fuels in the year 2060. In order to meet our energy needs for the future, we will need to find alternative fuel sources. And to fix many of problems from pollution, we will have to find sources of energy that do not cause as much pollution. Geothermal Energy : Geothermal Energy Geothermal energy is one type of alternative energy that does not emit pollution. A geyser is an example of something moved by geothermal heat. Geothermal energy uses heat from inside the Earth (usually magma near the surface of the Earth) to produce steam. The steam then makes electricity like a nuclear power plant. Geothermal energy is used in New Zealand, Iceland, Mexico and California. The problem with geothermal energy is that there are not many places on the Earth where this can be done. Tidal Energy : Tidal Energy Energy can be produced by the rising and falling of the tides. Twice a day, the tides rise and fall due to the moon’s gravitational pull. As a result, a low dam can be built across a bay to produce electricity as water flows through the dam. Unfortunately, there are very few places where tidal energy is practical. Biomass : Biomass Any materials that can burn is combustible. Any living thing contains carbon, and therefore can be burned. Around the world, wood is still the main source for heating and cooking. In the future, biomass can be used to produce energy either by burning it directly or by using it to produce liquid fuels. Direct Burning : Direct Burning Wood and plants have been used to produce heat and energy for hundreds of thousands of years. Electricity can be produced from biomass as well by turning water into steam (like a nuclear or fossil fuel plant). Some future sources for biomass direct burning include corn husks, sugar canes, sunflowers, seaweed, and animal wastes. Some cities are also burning their trash in incinerators to produce electricity as well! Alcohol Production : Alcohol Production Another use for biomass is to produce alcohols to use as liquid fuels. Liquid biomass fuels can be produced from sugar canes, corn stalks, and potatoes. The two main liquid fossil fuels produced are ethanol and gasohol. Current research is being done on developing fuel from left over grease from restaurants. These liquid fossil fuels are renewable, but highly controversial as many scientists do not believe that their benefits outweigh their costs. Hydrogen Power : Hydrogen Power Most scientists believe that our fuel needs for the future will be met from fusion using hydrogen. This is because our planet is covered with water which contains hydrogen. The goal for many scientists is to create “cold fusion” which is fusion at a temperature much lower than that of our sun so that we can control the process. If we can control fusion, we will solve our future energy needs. Other scientists are working to develop cars that run on hydrogen gas. These types of cars are called hydrogen fuel cell cars. The only pollution from a hydrogen car would be water.