NONRENEWABLE ENERGY SOURCES

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1 ENERGY Chapter 13 NONRENEWABLE ENERGY SOURCES Two primary categories of nonrenewable energy resources are fossil fuels and nuclear fuels. Fossil fuels are derived from biological material; gain heat energy from their combustion Coal, oil, and natural gas are the three major fossil fuels. Fossil carbon; carbon found in plants of this era= modern carbon Biggest users: USA, China, & European Union Nuclear fuels are derived from radioactive materials that give off energy. UNITS OF ENERGY Basic unit of energy is the joule ( J ) A gigajoule ( GJ ) is 1 billion ( 1 x 10 9 ) joules. That is about as much energy as is contained in 30 L (8 gallons) of gasoline. An exajoule ( EJ ) is 1 billion (1 x 10 9 ) gigajoules. Only in the US is the unit quadrillion used = 1 x Btu One quad is equal to EJ ENERGY USE IN THE US In 2008, total world energy consumption was approximately 495 EJ per year. Roughly 75 GJ per person per year Although only 20 percent of the world s population lives in developed countries, those people use 70 percent of the world s energy each year. The United States was 355 GJ per person per year almost 5 times greater than the world average. v ANIMATION: ENERGY USE 1

2 COMMERCIAL ENERGY FOR THE WORLD AND UNITED STATES MORE ENERGY CATEGORIES Commercial energy sources are those that are bought and sold Coal, oil, and natural gas Subsistence energy sources are those gathered by individuals for their own immediate needs. Wood, charcoal, animal waste, human and animal energy Especially used in developing countries; particularly rural areas. Changes in energy demand generally reflect the level of industrialization that is occurring in a country or region. ENERGY TYPES & QUALITY If you tried to run your car on coal, if would take a larger volume of it than you would need of gasoline. With gasoline you get farther on a smaller volume. Liquid energy resources that are relatively compact have a high energy-to-mass ratio. Another consideration is the speed with which they can provide or cut off the energy supply. Gasoline is ideal for speed. Coal and wood are great for building heat. SCIENCE FOCUS: NET ENERGY It takes energy to get energy. High-quality energy & Laws of thermodynamics Wasted energy is the low quality energy released in each step. Net energy- the usable amount of high-quality energy available from a given quantity of an energy resource taking into account the energy needed to find, extract, process, etc. Ratio of energy produced to energy used to produce it ENERGY RETURN 2

3 Energy Return On Energy Investment (EROEI) is how much energy we get out of an energy source for every unit of energy expended on its production. EROEI = Energy obtained from the fuel Energy invested to obtain the fuel A larger number suggests a more efficient and more desirable energy source. Suppose it takes 8 units to produce 10 units of energy 10/8 means 1.25 benefit, less than 1 would mean a loss ENERGY LOSS Energy loss on energy return can come from: Extraction process Transport Processing Energy conversion / combustion (2 nd law of thermodynamics) Disposal of waste Electricity generation and transmission Fuels are primary sources of energy. Electricity is a secondary source of energy obtained by conversion of a primary source. It is an energy carrier. 14 MAKING ELECTRICITY Fuel is delivered to a boiler, where it is burned. The burning fuel transfers energy to water, which becomes steam. Many air pollutants are given off at this step. The kinetic energy contained within the steam is transferred to the blades of a turbine. As steam turns the turbine, the shaft in the center of the turbine turns the generator, which generates electricity. Cogeneration is when the use of fuel has more than one purpose; to generate electricity and produce heat. 3

4 purpose; to generate electricity and produce heat. 15 ELECTRICAL ENERGY Approximately 40 percent of the energy used in the United States is used to generate electricity. However of that 40% only 13 percent is available for end uses. A typical power plant in the United States might have a capacity maximum electrical output of 500 megawatts. Most power plants, however, do not operate every day of the year. The capacity factor is the fraction of the time a plant is operating. Therefore, you multiply this along with hours and days of operation OIL CORE CASE STUDY: OIL Oil supplies 1/3 of world s energy Projected 80% depletion between 2050 and 2100 Options Look for more oil Use or waste less oil Use something else 19 DEPENDENCE ON OIL Fossil fuels are made from the decaying remains of organisms. Petroleum (crude oil)- oil as it comes out of the ground; made from remains of ocean dwelling phytoplankton found in sedimentary rock. a.k.a Conventional (light) oil The oil is contained in the sandstone naturally capped by rock like shale. Contains hydrocarbons along with sulfur, nitrogen & oxygen impurities 4

5 Contains hydrocarbons along with sulfur, nitrogen & oxygen impurities Petrochemicals are byproducts of oil distillation Natural gas is often found at the top of the oil containing rock MAJOR OIL-SUPPLYING NATIONS Control of oil reserves index.cfm?view=reserves Saudi Arabia has the largest proven oil reserves. Whereas Russia is the largest oil producing country. Now US is producing more due to oil shale. OPEC- Organization of the Petroleum Exporting Countries It pursues ways and means of ensuring the stabilization of prices eliminating harmful and unnecessary fluctuations; giving due regard at all times to the interests of the producing nations. Distribution of proven reserves TRADE-OFFS: CONVENTIONAL OIL USE OIL SAND & SHALE OIL SHALE AND SHALE OIL NATURAL GAS NATURAL GAS IS A USEFUL AND CLEAN-BURNING FOSSIL FUEL Natural gas- majority methane; often near oil deposits Liquefied petroleum gas (LPG)- propane & butane Liquefied natural gas (LNG) World supply of conventional natural gas years 5

6 World supply of conventional natural gas years TRADE-OFFS: NATURAL GAS COAL COAL IS A PLENTIFUL BUT DIRTY FUEL World s most abundant fossil fuel U.S. reserves should last about 300 years Sulfur, mercury, radioactive pollutants Pollution control and environmental costs CONVERTING COAL INTO GASEOUS AND LIQUID FUELS Synfuels Coal gasification Synthetic natural gas (SNG) Coal liquefaction Methanol or synthetic gasoline Extracting and burning coal more cleanly TRADE-OFFS: COAL NUCLEAR ENERGY 13-3 WHAT ARE THE ADVANTAGES AND DISADVANTAGES OF NUCLEAR ENERGY? Nuclear energy is derived from the fission of radioactive nuclei like uranium. low environmental impact 6

7 low environmental impact low accident risk high costs of reactor build, & training radioactive wastes vulnerability to sabotage, and the potential for spreading nuclear weapons technology have limited its use NUCLEAR WASTE STORAGE ANIMATION: CHERNOBYL FALLOUT CASE STUDY: HOW DO WE HANDLE RADIOACTIVE WASTES IN THE U.S.? Yucca Mountain, Nevada- site officially approved by Nuclear Regulatory Commission in 2014 Permanent disposal site with deep burial Concerns over groundwater contamination High level radioactive wastes Possible seismic activity Transportation accidents and terrorism WHAT IS THE FUTURE FOR NUCLEAR POWER? Dependence on foreign oil Reducing global warming Advanced light-water reactors Breeder nuclear fission reactors Research & development of nuclear fusion SUSTAINABLE ENERGY RENEWABLES Potentially renewable resources are those sources that can be regenerated rapidly. 7

8 be regenerated rapidly. Biomass energy As long as we do not consume them more quickly than they can be replenished. Nondepletable energy resources that cannot be depleted no matter how much we use them. The amount available tomorrow does not depend on how much we use today. Solar, wind, geothermal, hydroelectric, and tidal energy Renewable energy resources include potentially renewable and nondepletable energy resources ENERGY EFFICIENCY AS A POWER SOURCE A truly sustainable approach to energy use must incorporate both energy conservation and energy efficiency. Energy conservation means finding ways to use less energy. Although renewable energy is a more sustainable energy choice than nonrenewable energy, using any form of energy has an impact on the environment. Conservation could involve individualized approaches or larger efforts on the part on government through incentives or penalties. CONSERVATION AN ENERGY SOURCE Conservation and efficiency are like sustainable energy sources in that they save energy that could be used later when it is really needed. We could save more than 40% of all the energy we use by improving energy efficiency. When electricity-generating plants are unable to handle the demand during high-use periods, brownouts or blackouts may occur. Brownout= a period of reduced voltage due to shortage; example reduced illumination. Blackout= total loss of power in an area Peak demand is the greatest quantity of energy used at any one time. May be larger than the overall average demand 8

9 May be larger than the overall average demand So electric companies keep back up sources like natural gas fired generators. 46 HOW CAN WE MAKE A TRANSITION TO A MORE SUSTAINABLE ENERGY FUTURE? Current: centralized and geographically concentrated system of large power plants Sustainable Energy Future lies in dispersed micropower instead of centralized macropower. Combination of improved energy efficiency Use of sustainably produced biofuels to aid in the transition to renewable energy Find ways to reduce the harmful environmental impacts of fossil fuel use SMART GRID An energy economy based on nondepletable energy sources requires reliable electricity storage and affordable (more efficient) distribution networks. One solution may be the smart grid, an efficient, selfregulating electricity distribution network that accepts any source of electricity and distributes it automatically to end users. A smart grid uses computer programs and the Internet to tell electricity users when there is excess capacity on the grid. Coordinating energy use with energy availability. Ex: With smart appliances a computer on the appliance would be programmed to run it anytime between midnight and 5 AM, depending on when there is a surplus of electricity. ENERGY PARKS Our current infrastructure relies on a system of large enrgy producers regional electricity generation plants. When one plant goes off-line, the reduction in available generating capacity puts greater demands on the rest of the system. 9

10 generating capacity puts greater demands on the rest of the system. A better system would be a large number of small-scale electricity generation parks that rely on a mix of fossil fuel and renewable energy sources. More reliable Save money Save energy by transporting electricity a shorter distance. Safer Widespread outages less likely FUEL CELLS CAN HYDROGEN REPLACE OIL? A fuel cell combines hydrogen and oxygen to produce electricity, heat, and water. Hydrogen is environmentally friendly Problem Most hydrogen is in water Hydrogen takes energy to produce Fuel is expensive Air pollution depends on production method Storage HYBRID AND FUEL-CELL CARS Super-efficient and ultralight cars Gasoline-electric hybrid car Hydrogen fuel cells BUILDING & BUILDING MATERIALS SAVING ENERGY IN NEW BUILDINGS Green architecture 10

11 Green architecture Solar cells, fuel cells, eco-roofs, recycled materials Super insulation Straw bale houses 55 SAVING ENERGY IN EXISTING BUILDINGS Use energy-efficient windows Stop other heating and cooling losses Heat houses more efficiently Heat water more efficiently Use energy-efficient appliances and lighting THERMOGRAM OF BUILDINGS SHOWING HEAT LOSS RENEWABLE ENERGY Shift towards renewables would Result in a decentralized energy system making us less vulnerable in the event of supply cutoffs Reduce need to import oil and trade deficits Reduce air pollution and greenhouse gas emissions Create jobs and save consumers money Sustainability mostly depends on solar energy Direct forms Indirect forms SOLAR ENERGY PASSIVE AND ACTIVE SOLAR HEATING 11

12 60 61 PASSIVE: SOLAR COOKER SOLAR ENERGY FOR HIGH-TEMPERATURE HEAT AND ELECTRICITY Solar thermal systems- use mirrors or lenses to focus sunlight to make steam for generating electricity Solar thermal plants are better suited to desert areas (space requirements) Solar cookers Photovoltaic (solar) cells TRADE-OFFS: PASSIVE OR ACTIVE SOLAR HEATING SOLAR CELLS SOLAR CELLS PROVIDE ELECTRICITY FOR A VILLAGE TRADE-OFFS: SOLAR CELLS HYDROPOWER HYDROPOWER Energy generated from (1) falling water or (2) rate of flownatural or manipulated Dams and reservoirs: use rate of flow to produce electricity Micro-hydro generators Tidal and wave energy: movement of water dependent on gravitational pull of the moon WIND POWER PRODUCING ELECTRICITY FROM WIND 12

13 Indirect form of solar energy World s second-fastest source of energy Vast potential Land and offshore Great Plains states TRADE-OFFS: WIND POWER BIOMASS ENERGY FROM BURNING BIOMASS No net CO 2 increase if harvested and burned sustainably (Carbon neutral?? depends on net removal of forest) Can make use of urban waste Planting could restore degraded land BUT: soil erosion, loss of habitat, compete with crop land BURNING COW DUNG GROWING SWITCHGRASS FOR CONVERSION TO BIOFUEL BIOFUELS Ethanol is an alcohol based plant fuel mixed gasoline Biodiesel is derived from plant and animal fats Problems: land use shifted from food production to fuel production or more land simply acquired for fuel production; 13

14 land use shifted from food production to fuel production or more land simply acquired for fuel production; lower CO 2 emissions, but higher NO x emissions; low net energy yield GEOTHERMAL ENERGY ENERGY BY TAPPING THE EARTH S INTERNAL HEAT Geothermal energy Geothermal heat pumps Hydrothermal reservoirs Dry and wet steam Hot water TRADE-OFFS: GEOTHERMAL POWER CASE STUDY: ICELAND Future economy on renewable energy Hydropower, geothermal, wind Use to produce electricity, hydrogen Problems Building fueling stations for cars High cost of fuel cells 14