Presentation on theme: "Energy Resources Electricity makes downtown Los Angeles sparkle at dusk. Prepared by Pat Davis, Science Teacher, Durham Middle School, Lewisville ISD."— Presentation transcript:
1 Energy ResourcesElectricity makes downtown Los Angeles sparkle at dusk.Prepared byPat Davis, Science Teacher,Durham Middle School, Lewisville ISD
2 Energy and Fossil Fuels Energy exists in several different forms:MechanicalThermalChemicalElectricalElectromagneticNuclear.
3 Energy Transformation Energy can be changed from one form to anotherA change from one form of energy to another is called an energy transformationSometimes called energy conversion
4 Energy Transformations in the Home Water Heatersheating element that transforms electrical energy into thermal energywater to become hotterCooling Systemstransfer thermal energy from a cool area to a warm area This diagram shows the basic parts of a refrigerator.
5 Fuels and Energy A fuel is a substance that provides a form of energy ExamplesHeatLightElectricityMotionElectric power plants generate electricity by converting energy from one form to another. In the furnace, fuel is burned, releasing thermal energy. This energy is used to boil water and make steam. The mechanical energy of the moving steam turns the blades of a turbine. The turbine turns the shaft of the generator, producing an electric current.
6 Fuels and Energy The process of burning a fuel is called combustion. Fossil fuels are the energy-rich substances formed from the remains of once-living organisms.made of hydrocarbons = energy-rich chemical compounds that contain carbon and hydrogen atomsCoalOilNatural Gas
7 Fossil FuelsBecause fossil fuels take hundreds of millions of years to form, they are considered nonrenewable resources.natural resources that are not replaced as they are usedOne fourth of all the oil earth has already been used
8 Oil A thick, black, liquid fossil fuel. Sometimes called Petroleum More than one third of the energy produced in the worldFuel for: cars, airplanes, trains, ships any many homesrelatively cheap and plentiful energy sourceproducing and using petroleum does affect the environmentburning it contributes to air pollution.The United States consumes about one third of all the oil produced in the world. But only three percent of the world’s supply is located in this country. The difference must be purchased from countries with large oil supplies.
9 Oil Finding oil is difficult Use sound waves to test an area for oil Measure echoesMeasure time sound waves travel through solid rock or liquid oils.about one out of every six wells drilled produces a usable amount of oil.
10 Refining OilA factory where crude oil is separated into fuels and other products by heating is called a refinery.Products produced from oil.Gasoline, heating oilPetrochemicalsPlasticsPaintsMedicinesCosmetics.Oil refineries can affect the environment. Chemicals produced in the refining process may escape into the air or water, causing pollution.
11 Natural Gas Fossil fuel Mixture of methane and other gases. Natural gas actually has no odor.Gas companies add a chemical with a distinct smell to the gas before it is piped to homes and businesses so that any leaks will be noticed.Fossil fuelMixture of methane and other gases.Less dense than oilAdvantagesproduces large amounts of energylower levels of air pollutantseasy to transportDisadvantagegas leak can cause a violent explosion and fire.
12 Coal Solid fossil fuel Formed from plant remains Coal mining can be a dangerous job.New safety procedures and better equipment, including robots and drills that produce less coal dust, have made coal mining safer.CoalSolid fossil fuelFormed from plant remainsProvides 23 percent of the energy used in the United StatesMajor use is to fuel electric power plantsminedDifficult to obtainDeposits of coal know as reservesMost plentiful fossil fuel in the United StatesEasy to transportProduces a lot of air pollution
13 Renewable Sources of Energy Renewable resources are naturally replaced in a short period of time.SunlightWindTreesThese resources help meet people’s energy needs.
14 Energy From the Sun Solar Energy The sun constantly gives off energy in the form of light and heat.Solar energy is the source, directly or indirectly, of most renewable energy resources.Can be thought of as a inexhaustible resourceSolar TechnologiesSolar Plants - rows of mirrors focus the sun’s rays to heat a tank of waterSolar Cells - a “sandwich” of very thin layers of the element silicon & other materials. The upper and lower parts of the sandwich have a negative and a positive terminal, like a battery. When light hits the cell, electrons move across the layers, producing an electric current.powers calculators, lights, telephones, and other small devices
15 Solar Heating Systems Passive solar system Active solar system converts sunlight into thermal energy without using pumps or fans.Active solar systemcaptures the sun’s energy, then uses fans and pumps to distribute the heat
16 Solar HouseThis solar house uses passive and active heating systems and solar cells to convert solar energy into heat and electricity
17 Sources of Renewable Energy WaterHydroelectric power is electricity produced by flowing waterBiomass materialsWoodCrop wastesFood wastesManure.
18 Hydroelectric Power Plant Hydroelectric power is generated by changing energy from one form to another.
19 Sources of Renewable Energy Geothermal EnergyIn Iceland and New ZealandMagma heats underground water to the boiling point. The hot water and steam are valuable sources of geothermal energy.In Reykjavik, Iceland, 90 percent of homes are heated by water warmed underground in this way. Geothermal energy can also be used to generate electricity.A geothermal power plant uses heat from Earth’s interior as an energy source. Cold water is piped deep into the ground, where it is heated by magma. The resulting steam can be used for heat or to generate electricity.
20 Sources of Renewable Energy Wind“wind farms” consist of many windmills1 percent of the world’s electricityPortions of Texas have a high potential for utilizing wind energy.The Panhandle contains the state's greatest expanse with high quality winds. Well-exposed locations atop the caprock and hilltops experience particularly attractive wind speeds.
21 Sources of Renewable Energy Hydrogen Powerburns cleanlywater is the byproductcreates no smoke, smog, or acid raintransported through pipelineshydrogen can be obtained by passing an electric current through watertakes more energy to obtain the hydrogen than is produced by burning it againThe object fascinating these three astronauts is a bubble of water—the harmless byproduct of the hydrogen fuel cells used on the space shuttle.
22 Nuclear Energy Fission Reactions and Energy The central core of an atom that contains the protons and neutrons is called the nucleus.The reactions that involve nuclei, called nuclear reactions, involve tremendous amounts of energy. Two types of nuclear reactions are:fissionfusion.Fission Reactions and EnergyAlbert Einstein developed a formula that described the relationship between energy and matter.E = energym = massC = speed of lightThis equation states that when matter is changed into energy, an enormous amount of energy is released.
23 Nuclear fissionNuclear fission is the splitting of an atom’s nucleus into two smaller nuclei.When the neutron hits the U-235 nucleus, the nucleus splits apart into two smaller nuclei and two or more neutrons.In a nuclear fission reaction, a neutron “bullet” strikes a U-235 nucleus. As a result, the nucleus splits into two smaller nuclei. More neutrons are released, along with a great deal of energy.
24 Nuclear Power PlantsControlled nuclear fission reactions take place inside nuclear power plants.reactor vessel is the section of a nuclear reactor where nuclear fission occursreactor contains rods of U-235, called fuel rodsThe reactions are controlled by placing control rods made of the metal cadmium between the fuel rodsHeat is removed from the reactorfluid passes through a heat exchangerfluid boils water to produce steamwhich runs the electrical generatorIn a nuclear power plant, the heat released from the reactions is used to change water into steam. As in other types of power plants, the steam then turns the blades of a turbine to generate electricity
25 The Risks of Nuclear Fission Nuclear power plants generate about 17 percent of the world’s electricityThe fuel rods generated so much heat that they started to melt, a condition called a meltdown.In 1986, in Chernobyl, Ukraine, the reactor vessel in a nuclear power plant overheated. A series of explosions blew parts of the roof off and injured or killed dozens of plant workers and firefighters. Radioactive materials escaped into the environment. Today, the soil in an area the size of Florida remains contaminated with radioactive waste.
26 The Quest to Control Fusion Second type of nuclear reaction is fusionCombining of two atomic nuclei to produce a single larger nucleusIn a nuclear fusion reaction, two nuclei combine to form a single larger nucleus.Two kinds of hydrogen nuclei are forced together in a fusion reaction.
27 Energy ConservationAlthough fossil fuels may never be completely used up, they will eventually become scarcer and more expensive.What can be done?find new sources of energymake the fuels that are available now last as long as possibleNonrenewable fossil fuels generate over two thirds of the nation’s electricity.
28 Conservation and Efficiency Reducing energy use is called energy conservation.Efficiency is the percentage of energy that is actually used to perform work.Lighting10 percent of the electricity in your homeMost of lights is lost on heatImprove efficiency by changing to fluorescent bulbsHeating and CoolingLoss of energy through roof and wallsIncrease efficiency by adding insulationTransportationDevelopment of Hybrid cars.Improve tiresChange the fuel to ethanol
29 What You Can DoYou can reduce your personal energy use by changing your behavior in some simple ways.Keep your home cooler in winter and warmer in summer. Instead of turning up the heat, put on a sweater. Use fans instead of air conditioners.Use natural light instead of electric lights when possible.Turn off the lights or television when you leave a room.Walk or ride a bike for short trips. Ride buses and trains.Recycle, especially metal products. Recycling an aluminum can uses only 5 percent of the energy making a new can uses!The items in this list are small things, but multiplied by millions of people they add up to a lot of energy saved for the future.
30 Key IdeasA fuel is a substance that provides a form of energy as a result of a chemical change.Energy can be converted from one form to another.The three major fossil fuels are coal, oil, and natural gas. These fuels release more energy when they are burned than most other substances do.Because fossil fuels take hundreds of millions of years to form, they are considered nonrenewable resources.
31 Key IdeasThe sun constantly gives off energy in the form of heat and light. Solar energy can serve directly or indirectly as a renewable energy source.Because the sun causes winds and drives the water cycle, wind power and water power are considered indirect forms of solar energy.Biomass fuels, geothermal energy, and hydrogen power are other renewable energy sources that are currently in limited use.
32 Key IdeasNuclear reactions include fission reactions and fusion reactions.In a fission reaction, the impact of a neutron splits an atom’s nucleus into two smaller nuclei and two or more neutrons. In a fusion reaction, two kinds of hydrogen nuclei are forced together. A large amount of energy is released in both processes.In a nuclear power plant, the thermal energy released from controlled fission reactions is used to generate electricity.Disadvantages of nuclear power include the risk of a meltdown and radioactive waste.
33 Key IdeasTo avoid an energy shortage in the future, people must find new sources of energy and conserve the fuels that are available now.Insulation keeps a building from losing heat to, or gaining heat from, the outside.Ways to conserve energy use in transportation include making more efficient vehicles, carpooling, and using public transit.