Energy Now and in the Future Part 1 Energy Now: Nonrenewable Energy

Core Case Study: How Long Will the Oil Party Last?  The world may have years of oil left.  Peak oil will most likely occur within 20 years  We need to replace oil for transportation energy within 50 years. Figure 16-1

Fig. 16-3b, p. 357 Hydropower geothermal, solar, wind 3% Nuclear power 8% RENEWABLE 8% Coal 23% Natural gas 23% Oil 39% Biomass 4% NONRENEWABLE 93% United States

CRUDE OIL  Crude oil (a.k.a. petroleum) is a thick liquid containing hydrocarbons that we extract from underground deposits and separate into products such as gasoline, heating oil and asphalt.

OIL  Refining crude oil: Based on boiling points, components are removed at various layers in a giant distillation column. Based on boiling points, components are removed at various layers in a giant distillation column. The most volatile components with the lowest boiling points are removed at the top. The most volatile components with the lowest boiling points are removed at the top. Figure 16-5

Fig. 16-5, p. 359 Gases Gasoline Aviation fuel Heating oil Diesel oil Naptha Grease and wax Asphalt Heated crude oil Furnace

NATURAL GAS  Natural gas, consisting mostly of methane, is often found above reservoirs of crude oil. When a natural gas-field is tapped, gasses can be liquefied and removed as liquefied petroleum gas (LPG). When a natural gas-field is tapped, gasses can be liquefied and removed as liquefied petroleum gas (LPG).  Some analysts see natural gas as the best fuel to help us make the transition to improved energy efficiency and greater use of renewable energy.

COAL  Coal is a solid fossil fuel that is formed in several stages as the buried remains of land plants that lived million years ago. Figure 16-12

Fig , p. 369 Waste heat Coal bunker Turbine Cooling tower transfers waste heat to atmosphere Generator Cooling loop Stack Pulverizing mill Condenser Filter Boiler Toxic ash disposal Coal-Fired Power Plant

COAL  Coal reserves in the United States, Russia, and China could last 225 to 900 years. The U.S. has 27% of the world’s proven coal reserves, followed by Russia (17%), and China (13%). The U.S. has 27% of the world’s proven coal reserves, followed by Russia (17%), and China (13%). In 2005, China and the U.S. accounted for 53% of the global coal consumption. In 2005, China and the U.S. accounted for 53% of the global coal consumption.

NUCLEAR ENERGY  When isotopes of uranium and plutonium undergo controlled nuclear fission, the resulting heat produces steam that spins turbines to generate electricity. The uranium oxide (ore) consists of about 97% nonfissionable uranium-238 and 3% fissionable uranium-235. The uranium oxide (ore) consists of about 97% nonfissionable uranium-238 and 3% fissionable uranium-235. The concentration of uranium-235 is increased through an enrichment process. The concentration of uranium-235 is increased through an enrichment process.

NUCLEAR ENERGY  After three or four years in a reactor, spent fuel rods are removed and stored in a deep pool of water contained in a steel-lined concrete container.  Plutonium is one of the most harmful substances on Earth Figure 16-17

NUCLEAR ENERGY  After spent fuel rods are cooled considerably, they are sometimes moved to dry-storage containers made of steel or concrete. Figure 16-17

Yucca Mountain, Nevada National Nuclear Waste Disposal Site Yucca Mountani is “ready” to store US nuclear waste, but Nevada and states through which the waste must pass have blocked it’s use.

Part 2 The Future of Energy Energy Efficiency and Renewable Energy

The Coming Energy-Efficiency and Renewable-Energy Revolution  It is possible to get electricity from solar cells that convert sunlight into electricity. Can be attached like shingles on a roof. Can be attached like shingles on a roof. Can be applied to window glass as a coating. Can be applied to window glass as a coating. Can be mounted on racks almost anywhere. Can be mounted on racks almost anywhere.

Fig. 17-3, p. 386 Solutions Reducing Energy Waste Prolongs fossil fuel supplies Reduces oil imports Very high net energy Low cost Reduces pollution and environmental degradation Buys time to phase in renewable energy Less need for military protection of Middle East oil resources Creates local jobs Reducing energy waste (a.k.a. increasing energy efficiency) is the easiest and most powerful step humans can take toward a sustainable energy future.

REDUCING ENERGY WASTE AND IMPROVING ENERGY EFFICIENCY  Four widely used devices waste large amounts of energy: Incandescent light bulb: 95% is lost as heat. Incandescent light bulb: 95% is lost as heat. Internal combustion engine: cars and trucks lose 75-80% of their energy as heat. Internal combustion engine: cars and trucks lose 75-80% of their energy as heat. Nuclear power plant: 92% of energy is wasted as heat through nuclear fuel enrichment and the energy needed for waste management. Nuclear power plant: 92% of energy is wasted as heat through nuclear fuel enrichment and the energy needed for waste management. Coal-burning power plant: 66% of the energy released by burning coal is lost as heat. Coal-burning power plant: 66% of the energy released by burning coal is lost as heat.

WAYS TO IMPROVE ENERGY EFFICIENCY- Hybrid Engines (Prius)  Has a small internal combustion engine AND an electric motor.  Battery is recharged by braking.  These “gas sipping” cars account for less than 1% of all new car sales in the U.S. Figure 17-7

Fuel-Cell Vehicles  Electric vehicles powered by a fuel cell that runs on hydrogen gas are being developed.  Combines hydrogen gas (H 2 ) and oxygen gas (O 2 ) fuel to produce electricity and water vapor (2H 2 +O 2  2H 2 O).  Emits no air pollution or CO 2 if the hydrogen is produced from renewable-energy sources.

Fig. 17-8, p. 390 Body attachments Mechanical locks that secure the body to the chassis Air system management Universal docking connection Connects the chassis with the drive-by-wire system in the body Fuel-cell stack Converts hydrogen fuel into electricity Rear crush zone Absorbs crash energy Drive-by-wire system controls Cabin heating unit Side-mounted radiators Release heat generated by the fuel cell, vehicle electronics, and wheel motors Hydrogen fuel tanks Front crush zone Absorbs crash energy Electric wheel motors Provide four-wheel drive; have built-in brakes

WAYS TO IMPROVE ENERGY EFFICIENCY  We can save energy in buildings by getting heat from the sun, superinsulating them, and using plant covered green roofs.  We can save energy in existing buildings by insulating them, plugging leaks, and using energy-efficient heating and cooling systems, appliances, and lighting.

Saving Energy in Existing Buildings  About one-third of the heated air in typical U.S. homes and buildings escapes through closed windows and holes and cracks. Figure 17-11

Producing Electricity with Solar Cells  Photovoltaic solar cells convert sunlight to electricity.  Their costs are high, but dropping quickly. Figure 17-16

Fig , p. 399 Trade-Offs Solar Cells AdvantagesDisadvantages Fairly high net energyNeed access to sun Work on cloudy days Low efficiency Quick installation Need electricity storage system or backup Easily expanded or moved No CO 2 emissions High land use (solar-cell power plants) could disrupt desert areas Low environmental impact Last 20–40 years Low land use (if on roof or built into walls or windows) High costs, but dropping rapidly Reduces dependence on fossil fuels DC current must be converted to AC

PRODUCING ELECTRICITY FROM WIND  Wind turbines can be used individually to produce electricity. They are also used interconnected in arrays on wind farms. Figure 17-21

PRODUCING ELECTRICITY FROM WIND  Wind power is a very promising energy resource because it is abundant, inexhaustible, widely distributed, cheap, clean, and emits no greenhouse gases.  Much of the world’s potential for wind power remains untapped.

PRODUCING ELECTRICITY FROM WIND  Capturing only 20% of the wind energy at the world’s best energy sites could meet all the world’s energy demands.  Full development of all US wind sites could produce 3 times the total current US electricity demand.

Fig , p. 403 Trade-Offs Wind Power AdvantagesDisadvantages Moderate to high net energySteady winds needed Backup systems needed when winds are low High efficiency Moderate capital cost Low electricity cost (and falling) High land use for wind farm Very low environmental impact No CO 2 emissions Visual pollution Quick construction Noise when located near populated areas Easily expanded Can be located at sea Land below turbines can be used to grow crops or graze livestock May interfere in flights of migratory birds and kill birds of prey

PRODUCING ENERGY FROM BIOMASS  Plant materials (like tree bark) and animal wastes can be burned to provide heat or electricity or converted into gaseous or liquid biofuels. Figure 17-23

Converting Plants and Plant Wastes to Liquid Biofuels: An Overview  Motor vehicles can run on ethanol, biodiesel, and methanol produced from plants and plant wastes.  The major advantages of biofuels are: Crops used for production can be grown almost anywhere. Crops used for production can be grown almost anywhere. There is no net increase in CO 2 emissions. There is no net increase in CO 2 emissions. Widely available and easy to store and transport. Widely available and easy to store and transport.

Case Study: Producing Ethanol  Crops such as sugarcane, corn, and switchgrass and agricultural, forestry and municipal wastes can be converted to ethanol.  Switchgrass can remove CO 2 from the troposphere and store it in the soil. Figure  Georgia may become a leader in the production of switchgrass.

HYDROGEN  Some energy experts view hydrogen gas as the best fuel to replace oil during the last half of the century, but there are several hurdles to overcome: Hydrogen is chemically locked up in water an organic compounds. Hydrogen is chemically locked up in water an organic compounds. It takes energy and money to produce it (net energy is low). It takes energy and money to produce it (net energy is low). Fuel cells are expensive. Fuel cells are expensive. Hydrogen may be produced by using fossil fuels. Hydrogen may be produced by using fossil fuels.

Fig , p. 413 Wood Coal Natural gas Oil Hydrogen Solar Nuclear Contribution to total energy consumption (percent) Year

Fig , p. 414 Small solar-cell power plants Bioenergy power plants Wind farm Rooftop solar cell arrays Fuel cells Solar-cell rooftop systems Transmission and distribution system Commercial Small wind turbine Residential Industrial Microturbines

Fig , p. 416 What Can You Do? Energy Use and Waste Get an energy audit at your house or office. Drive a car that gets at least 15 kilometers per liter (35 miles per gallon) and join a carpool. Use mass transit, walking, and bicycling. Superinsulate your house and plug all air leaks. Turn off lights, TV sets, computers, and other electronic equipment when they are not in use. Wash laundry in warm or cold water. Use passive solar heating. For cooling, open windows and use ceiling fans or whole-house attic or window fans. Turn thermostats down in winter, up in summer. Buy the most energy-efficient homes, lights, cars, and appliances available. Turn down the thermostat on water heaters to 43–49°C (110–120°F) and insulate hot water heaters and pipes.