Chapter 5: Energy Resources

1. Chapter 5: Energy Resources

2. Section 1: Natural Resources Natural Resource: any natural material that is used by humans such as water, petroleum, minerals, forests and animals

3. The energy we get from many natural resources, such as gasoline and wind ultimately comes from the sun’s energy.

4. Renewable Resource: a natural resource that can be replaced at the same rate at which the resource is consumed

5. Non-Renewable Resource: a resource that forms at a rate that is much slower than the rate at which it is consumed

6. Conserving Natural Resources • Use only when necessary • Take care of resources even when not using them

7. Energy Conservation • need to limit use of energy or resources won’t be available in the future • Conserve energy by being careful to use resources only when needed

8. Recycling: the process of recovering valuable or useful materials from waste or scrap; the process of reusing some items

11. Section 2: Fossil Fuels Fossil fuel: a nonrenewable energy resource formed from the remains of organisms that lived long ago Examples: oil, coal and natural gas

12. Types of fossil fuels • All living things are made of the element Carbon. • Fossil fuels are formed from the remains of plants and animals. • Most of the carbon in fossil fuels exist as hydrogen-carbon compounds (hydrocarbons). • May exist as solids, liquids or gases.

13. Petroleum • A liquid mixture of complex hydrocarbon compounds; used widely as a fuel source • AKA – crude oil • Examples of fossil fuels separated from petroleum = gasoline, jet fuel, kerosene, diesel fuel, fuel oil

14. Natural Gas • A mixture of gaseous hydrocarbons located under the surface of the Earth, often near petroleum deposits; used as fuel • Most used for heating but also used to generate electrical energy • Very flammable • Methane a main component; also butane and propane

15. Coal • A fossil fuel that forms underground from partially decomposed plant material • Was once a major source of energy in US until cleaner energy resources became available

16. Formation • All fossil fuels form from the buried remains of ancient organisms

17. Petroleum & Natural Gas Formation • mainly form from remains of microscopic sea organisms that settled to bottom of ocean and over millions of years and are transformed through physical and chemical changes

18. Coal Formation • Forms underground from decayed swamp plants over millions of years • 4 stages of coal formation • Peat = bacteria & fungi change sunken swamp plants into peat. 60% carbon • Lignite = sediment buries peat, which increases pressure & temperature. Peat slowly turns into lignite. 70% carbon • Bituminous coal = as lignite becomes more buried temperature & pressure continue to increase. 80% carbon • Anthracite = as bituminous coal becomes more buried temperature & pressure continue to increase. 90% carbon

20. Some fossil fuels found on land and others beneath the ocean. The US has large reserves of petroleum, natural gas and coal, but still imports petroleum from the Middle East, South America, Africa, Canada & Mexico.

21. How do we obtain fossil fuels? Oil & natural gas = drilling wells - on land and in ocean (off-shore rigs on platforms) Coal = surface or strip mining

22. Problems with Fossil Fuels • Burning coal without pollution controls releases sulfur dioxide = acid precipitation: precipitation such as rain, sleet, or snow that contain a high concentration of acids

23. Problems with Fossil Fuels • Coal surface mining removes soil, can destroy wildlife habitats, can lower water tables and pollute water supplies as well as endanger lives of miners

24. Problems with Fossil Fuels • Producing, transporting and using petroleum can cause environmental problems and endanger wildlife (especially when spilled)

25. Problems with Fossil Fuels • Burning petroleum can cause smog: photochemical haze that forms when sunlight acts on industrial pollutants and burning fuels (Los Angeles)

26. Section 3: Alternative Resources Nuclear Energy: the energy released by a fission or fusion reaction; the binding energy of the atomic nucleus Fission: a process in which the nuclei of radioactive atoms are split into 2 or more smaller nuclei = a large amount of energy released Fusion: the joining of 2 or more nuclei to form a larger nucleus releasing a large amount of energy (example = sun)

27. FISSION We use this process in nuclear power plants which produce dangerous radioactive wastes that must be removed and stored until the radioactivity decreases to a harmless level (thousands of years). There is also always a possibility that the plant’s cooling system could overheat releasing radiation into the environment.

28. The main advantage is it produces few dangerous wastes. FUSION The main disadvantage is very high temperatures are required for the reaction to take place. No known material can withstand such high temperatures so the reaction must happen within a special environment (magnetic field). Controlled fusion reactions have been limited to lab experiments.

29. CHEMICAL ENERGY Chemical energy: the energy released when a chemical compound reacts to produce new compounds Example: a vehicle powered by fuel cells – converting chemical energy into electrical energy by reacting hydrogen and oxygen into water (creating no pollution) US has used in space travel

30. SOLAR ENERGY • Solar Energy: the energy received by the Earth from the sun in the form of radiation • A renewable resource • Can be used directly to heat buildings and to generate electrical energy – however we do not have the t4echnology to generate the amount of electrical energy we need from solar energy

31. Solar Heating • Solar energy is used through direct heating through solar collectors. • These are dark colored boxes that have glass or plastic tops. Used especially with water heaters in Florida and California.

32. Pros and Cons of Solar Energy • Pro: doesn’t produce pollution • Pro: renewable • Con: some climates don’t have enough sunny days to benefit from solar energy • Con: although solar energy is free the solar cells and collectors are very expensive

33. WIND POWER Wind power: the use of a windmill to drive an electric generator Wind turbines can generate a significant amount of electrical energy, is renewable and doesn’t cause pollution. However, in many areas wind isn’t strong enough or frequent enough to create energy on a large scale.

34. HYDROELECTRIC ENERGY • Hydroelectric energy: electrical energy produced by falling water • Pro: Causes little pollution • Pro: renewable • Con: need large volumes of falling water – not available everywhere and building the dams often destroys forests & wildlife

35. BIOMASS: organic matter that can be a source of energy • Burning biomass – 70% of people in developing countries (1/2 world’s population) burn wood, charcoal and animal dung to heat their homes & cook (only 5% of US)

36. GASOHOL: a mixture of gasoline and alcohol that is used as fuel • 1 acre of corn can produce 1000 L of alcohol that can be burned as fuel. • In the US people use a large amount of fuel for cars and corn harvest could only provide about 10% of fuel needed – rest of land is being used for crops/food and livestock

37. GEOTHERMAL ENERGY • Geothermal energy: the energy produced by heat within the Earth • Geysers (natural vents) discharge the steam and hot water and they escape through wells drilled in rock – can be used by some power plants to produce electricity