Presentation on theme: "Ch. 26 – Energy Resources Where does energy come from? Sun Video - EnergyVideo Humans have the ability to alter the environment to meet their needs. Examples:"— Presentation transcript:
Ch. 26 – Energy Resources Where does energy come from? Sun Video - EnergyVideo Humans have the ability to alter the environment to meet their needs. Examples: AC & Heat To produce heat, AC, or power fuels are needed. The earliest uses of fuels were natural fires (lightening). Traditional fuels include wood, dried field crops, dried fecal material. The total amount of living things in an ecosystem is its biomass. Biomass fuels are derived from living things. Video – Earth & EnergyVideo
Wood is the primary source of energy for more than half the world’s population. Only 4% of the U.S. population uses wood as a primary source of energy. However, 1.5 billion people throughout the world use wood as a primary source of energy. Deforestation is a problem because of this. Field crops for heat is becoming more common. Corn burning stoves. Villagers from India, Pakistan, Afghanistan collect animal feces for fuel and dry it on the outside walls of their stables. Pg. 685.
Peat – a spongy mass of dead and partially decayed plant material that builds up in bogs. Peat is burned with more efficiency than wood. Fossil fuels – energy sources that formed over geologic time as a result of the compression and partial decomposition of plants and other organic matter. These are nonrenewable because they take thousands of years to form. Examples: Peat, coal, natural gas, petroleum. Most countries rely on these fossil fuels for electricity from power plants and fuel for vehicles.
Coal changes forms: Peat Lignite Bituminous coal Anthracite These changes are due to an increase in heat and pressure. Most of the coal burnt is bituminous coal. Petroleum is Greek for “rock oil”. Crude oil is pumped out of the ground and refined into a wide variety of petroleum products (gasoline and kerosene). Crude oil and natural gas migrate sideways and upward from their place of formation through pores of sedimentary rock. They continue to rise until they reach an impermeable layer of sedimentary rock. Geologist now use remote sensors, magnetometers, and seismographic equipment that create subsurface maps.
Alternative Energy Resources It is estimated that petroleum resources may be used up in the next 60 years. Alternative energy resources are being studied for uses, these include solar energy, wind, water, geothermal energy, and biomass. –Video – Alternative EnergiesVideo Wind energy converts wind energy into mechanical energy with the use of wind turbines. It is estimated that wind power could supply more than 10% of the world’s energy by Most of the wind farms are in California. –http://www.awea.org/resources/awealinks.htmlhttp://www.awea.org/resources/awealinks.html –FHSU SITE –Wind ProblemsWind Problems
Hydroelectric Power – use of a flow of water to produce electricity. Fig (Niagara Falls). Large turbines spin as water falls over them to create electricity. Dams can also be used is a similar fashion to produce electricity. This provides 20% of the world’s electricity and is continuing to grow. Geothermal energy – energy produced by natural occurring steam and hot water. Old Faithful produces tall fountains of steam and hot water. Water is trapped underground in fractures or in porous rock that is heated by the Earth’s internal heat. This escapes through cracks in the Earth’s crust.
Nuclear Fission is to process in which a heavy nucleus divides to form smaller nuclei and1 or 2 neutrons. After 50 years of development nuclear energy is only producing 17% of the world’s energy. No new nuclear plants have been built in the U.S. since This is due to poor management, poor designs, high operating costs, and concerns about disposal of waste. Chernobyl and Three Mile Island are examples of accidents with nuclear power plants, which can leave major problems.
Biomass fuels includes wood, dried field crops, and dried fecal materials. Cottonwood trees can be burned and converted into gas or fermented into alcohol fuel. The disadvantage is the release of carbon dioxide when burnt. Biogas is a mixture of gases that includes 50 to 70% methane gas and 30-48% carbon dioxide gas. Plant and animal wastes can be converted into methane gas in simple containers called digesters. China uses individual digesters in households for cooking.
Liquid ethanol grain alcohol comes from corn, sorghum, sugar cane, and sugar beets. Gasohol is the mixture of ethanol with gasoline. This reduce the dependency on foreign petroleum. Video – fuel cellsVideo Gz8 – electric carshttp://www.youtube.com/watch?v=nsJAlrYj Gz8
Passive Solar Heating – the use of windows or solar absorbent material to capture solar energy. Example – south facing windows. Active Solar Heating – use collectors such as solar panels that absorb solar energy and fans or pumps that distribute energy throughout the house. Solar collectors on the roof of a house can heat water up to 149° F (wash dishes an clothes). Solar cookers are being used to cook food by directing light on a given area. Fig pg Photovoltaic cells – is used to covert solar energy into electrical energy. They use thin, transparent wafers of boron and phosphorous rich silicon. As sun hits the cell electrons are released as a flow of electricity and stored in batteries.
Conservation of Energy Resources Fig (pg. 698) – Industrialized vs. Developing Countries –Use of Renewable vs. Nonrenewable Energy efficiency is the use of energy resources in ways that are most productive. Methods: 1. recycle old appliances and vehicles and purchase newer energy-efficient models. 2. add more insulation, solar panels, windows to homes. 3. power companies can use more alternative resources. 4. the government can provide tax savings to people who buy energy- efficient products. Video – conservationVideo – story of stuffhttp://www.youtube.com/watch?v=gLBE5QAYXp8
A high demand for energy causes the price of electricity (energy) to rise. Electricity used in homes is wasteful. 43% of the energy used to run a vehicle and to heat a home is wasted. Replacing an incandescent light bulb with a compact fluorescent light bulb will save the consumer $35 to $50 in 10 years. Replacing 25 incandescent light bulbs with fluorescent would save the consumer $87 to $125 a year in electricity. This would save businesses billions of dollars per year in electricity. This would also decrease the use of fossil fuels and greenhouse gases.
Cogeneration is the production of 2 usable forms of energy at the same time from the same process. The use of hybrid cars and the development of hydrogen cars will lower the production of petroleum. Metropolitan areas are using more public transportations systems and car pooling. Industries can cut down on packaging to reduce solid wastes. Biodegradable products. Better insulation, weather-stripping, and caulking older windows can help with energy-efficiency. Sustainable energy – the global management of Earth’s natural resources to meet current and future energy needs without causing environmental damage. Video - conservationVideo