3 Objectives Name several energy resources. Explain how the sun is the source of most energy on Earth.Evaluate the advantages and disadvantages of using various energy resources.
4 Question What is a renewable resource? What is a nonrenewable resource?
5 Nonrenewable Resources Nonrenewable resources- resources that cannot be replaced, or are replaced slower than they are used.Fossil fuels- nonrenewable energy resources formed from the remains of organisms that lived long ago.Fossil fuels are concentrated forms of the sun’s energy.
7 Uses of Fossil FuelsCoal- used to produce steam, to run electric generatorsPetroleum- gas, kerosene, wax, and petrochemicals come from petroleum.Natural gas- used in heating systems very low emission levels when burned
9 Nuclear EnergyNuclear Energy Another way to generate electrical energy is to use nuclear energy.In a process called nuclear fission, the nucleus of a radioactive atom is split into two smaller nuclei, which releases nuclear energy.Because the supply of radioactive elements is limited, nuclear energy is a nonrenewable resource.
10 Question What are disadvantages of Nonrenewable resources? What are advantages?
11 Renewable ResourcesRenewable resources- naturally replaced quicker than they are used.
12 Solar Energy Solar energy can heat a home. Houses use solar energy by allowing sunlight to come through large windowsSolar panels can be used to run electrical devices.
13 Solar EnergySunlight can be changed into electrical energy through solar cells.Solar cells can be used in devices such as calculators. They can also be placed on the roof of a house to provide electrical energy.
14 Energy From WaterSun causes water to evaporate and fall again as rain that flows through rivers.In a hydroelectric dam, falling water turns turbines. The turbines are connected to a generator that changes kinetic energy into electrical energy.
15 Wind Energy Wind is caused by the sun’s heating of Earth’s surface. The kinetic energy of wind can turn a windmill’s blade.A wind turbine changes the kinetic energy of the air into electrical energy by turning a generator.
16 Objectives Name several energy resources. Explain how the sun is the source of most energy on Earth.Evaluate the advantages and disadvantages of using various energy resources.
17 Geothermal EnergyThermal energy caused by the heating of Earth’s crust is called geothermal energy.Water returns to the surface as steam.
18 BiomassPlants, wood, and waste that can be burned to release energy is biomass.Some countries depend on biomass for energy.
19 The Two Sides to Energy Resources All energy resources have advantages and disadvantages. Many factors determine when one energy source is a better choice than another.Choosing the Right Energy Source Energy planning in all parts of the world requires careful consideration of energy needs and the availability and responsible use of resources.
20 Question What are disadvantages of renewable resources? What are advantages?
21 Table 1 Advantages and Disadvantages of Energy Resources Fossil fuels • provide a large amount of thermal energy per unit of mass• are easy to get and transport• can be used to generate electricity and to make products such as plastic• are nonrenewable• produce smog• release substances that can cause acid precipitation• create a risk of oil spillsNuclear • is a very concentrated form of energy• does not produce air pollution• produces radioactive waste• is nonrenewableSolar • is an almost limitless source of energy• does not produce pollution• is expensive to use for large-scale energy production• is practical only in sunny areasWater • is renewable• requires dams, which disrupt a river's ecosystem• is available only where there are riversWind • is relatively inexpensive to generate• is practical only in windy areasGeothermal • power plants require little land• is practical only in areas near hot spots• produces wastewater, which can damage soilBiomass • is inexpensive• requires large areas of farmland• produces smoke
22 Question What energy resource would be good for Chicago? Seattle? Tennessee?
23 Objectives Name several energy resources. Explain how the sun is the source of most energy on Earth.Evaluate the advantages and disadvantages of using various energy resources.