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Renewable Energy Chapters16 Living in the Environment , 11 th Edition, Miller. Advanced Placement Environmental Science La Canada High School Dr. E. Energy Efficiency Solar Energy Hydropower Wind Power Biomass Geothermal Sustainability. www.bio.miami.edu/beck/esc101/Chapter14&15.ppt.
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Renewable EnergyChapters16Living in the Environment, 11th Edition, Miller Advanced Placement Environmental Science La Canada High School Dr. E
Energy Efficiency Solar Energy Hydropower Wind Power Biomass Geothermal Sustainability www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Energy Efficiency • Increasing energy efficiency of common devices has economic and environmental advantages • Reducing oil imports • Prolonging fossil fuel supplies • Reducing pollution and environmental degradation • Saving money • Buys time to develop new technology • Creating jobs
Efficiency of Some Common Devices Device Efficiency (%) • Dry-cell flashlight battery 90 • Home gas furnace 85 • Storage battery 70 • Home oil furnace 65 • Small electric motor 62 • Steam power plant 38 • Diesel engine 38 • High-intensity lamp 32 • Automobile engine 25 • Fluorescent lamp 22 • Incandescent lamp 4
Energy Efficiency percentage of energy input that does useful work in an energy conversion system www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Ways to Improve Energy Efficiency • Between 1985 and 2001, the average fuel efficiency for new motor vehicles sold in the United States leveled off or declined • Fuel-efficient models account for only a tiny fraction of car sales • Hybrid-electric cars are now available and sales are expected to increase • Fuel-cell cars that burn hydrogen fuel will be available within a few years • Electric scooters and electric bicycles are short-range transportation alternatives
Energy use of various types of transportation www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Ways to Improve Energy Efficiency • Superinsulated house is more expensive than a conventional house, but energy savings pay back the extra cost • Strawbale houses have the additional advantage of using an annually renewable agricultural residue, thus slowing deforestation
Ways to Improve Energy Efficiency • Existing homes can be made more energy efficient • adding insulation • plugging leaks • installing energy-saving windows • wrapping water heaters • installing tankless models • buying energy-efficient appliances and lights
Natural Gas or Electricity • Water heater • Electricity is produced at power plant via gas or coal and transferred via wire to your home • Some energy is lost over the wire, …
Water Heater • Tank • Water is heated 365/24/7 • Because heat is lost through the flue and the walls of the storage tank (this is called standby heat loss), energy is consumed even when no hot water is being used.
Water Heater • Tankless • The energy consumption of these units is generally lower since standby losses from the storage tank are eliminated. • Demand water heaters with enough capacity to meet household needs are gas- or propane-fired. • http://www.aceee.org/consumerguide/topwater.htm
Energy Efficiency Solar Energy Hydropower Wind Power Biomass Geothermal Sustainability
Solar Energy • Buildings can be heated • passive solar heating system • active solar heating system • Solar thermal systems are new technologies that collect and transform solar energy into heat that can be used directly or converted to electricity • Photovoltaic cells convert solar energy directly into electricity
Suitability of Solar Usage best when more than 60% of daylight hours sunny www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Solar Heating Passive system: Absorbs & stores heat from the sun directly within a structure Active system: Collectors absorb solar energy, a pump supplies part of abuildings heating or water heating needs. www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Solar Energy Passive solar • Large south-facing windows, heavy drapes to trap heat at night, interior bricks to trap heat • Shade windows in summer • Even though back up systems are required, and solar heating may only lessen the need for heating oil a few %, it will help us adapt to diminishing oil supplies. Active solar • Photovoltaic (PV) panels can be used to convert the energy from the sun into electricity. • Electrons from the silicon in the PV panel are “pushed” through a wire by photons from the sun creating an electric current.
Solar - Advantages • No greenhouse gas emissions • Unlimited resource in certain areas • Land disturbance is minimal (in passive solar heating) • Solar cells are reliable and quiet with no moving parts
Solar - Disadvantages • Only reliable in certain areas • Expensive to install (active solar power) • Solar thermal plants require a lot of space (habitat destruction) • Manufacture of solar cells produces water pollution • Electricity must be stored in batteries (expensive)
Solar Domestic Hot Water (SDHW) • An open circuit hot water system heats the domestic water directly on the roof of the building • The water flows from the heat collector into the hot water tank to be used in the house • Integration of solar energy conservation in homes can reduce energy consumption by 75-90%. • www.iea-shc.org www.earlham.edu/~parkero/Seminar/ SOLAR%20AMERICA%5B1%5D.ppt
Photovoltaic (Solar) Cells Provides electricity for buildings www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Inside the PV cell • PV cells are made from silicon alloys • PV module • 1cm by 10cm cells • 36 cells connected www.earlham.edu/~parkero/Seminar/ SOLAR%20AMERICA%5B1%5D.ppt
Solar Thermal Techniques SolarTwo www.earlham.edu/~parkero/Seminar/ SOLAR%20AMERICA%5B1%5D.ppt
Heliostats • Heliostats provide concentrated sunlight to the power tower • The reflecting mirrors follow the sun along its daily trajectory www.earlham.edu/~parkero/Seminar/ SOLAR%20AMERICA%5B1%5D.ppt
Power Tower • Sunlight from mirrors are reflected to fixed receiver in power tower • Fluid transfers the absorbed solar heat into the power block • Used to heat a steam generator Solar One www.earlham.edu/~parkero/Seminar/ SOLAR%20AMERICA%5B1%5D.ppt
Solar-Hydrogen Revolution • Splitting water can produce H2 gas • If scientists and engineers can learn how to use forms of solar energy to decompose water cheaply, they will set in motion a solar-hydrogen revolution • Hydrogen-powered fuel cells could power vehicles and appliances
Energy Efficiency Solar Energy Hydropower Wind Power Biomass Geothermal Sustainability www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
History of Hydroelectric • B.C. - Used by the Greeks to turn water wheels for grinding wheat into flour, more than 2,000 years ago • 1775 - U.S. Army Corps of Engineers founded, with establishment of Chief Engineer for the Continental Army • 1880 - Michigan's Grand Rapids Electric Light and Power Company, generating electricity by dynamo, belted to a water turbine at the Wolverine Chair Factory, lit up 16 brush-arc lamps. www.usd.edu/phys/courses/scst601/ hydroelectric/hydro.ppt
History of Hydroelectric • By 1940 - 40% of electrical generation was hydropower • Between 1921 and 1940 - conventional capacity in the U.S. tripled; almost tripled again between 1940 and 1980 • Currently - about 10% of U.S. electricity comes from hydropower. www.usd.edu/phys/courses/scst601/ hydroelectric/hydro.ppt
Turbine Technologies • Reaction • fully immersed in fluid • shape of blades produces rotation www.usd.edu/phys/courses/scst601/ hydroelectric/hydro.ppt
Hydroelectric – Advantages • Moderate to high energy yield • Low operating and maintenance costs • Long life spans • No air pollution • Control flooding
Hydroelectric - Disadvantages • Destroys habitats • Decreases fish populations below the dam • Changes wildlife populations above the dam • Displaces people (Three Gorges dam in China) • Creates earthquakes • May cause flooding if the dam breaks • Inhibits fish migration (salmon)
Tidal Power Plant www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Wave energy • The motion of wind-driven waves at the ocean’s surface is converted into electricity.
Energy Efficiency Solar Energy Hydropower Wind Power Biomass Geothermal Sustainability www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Rotary Windmill www.usd.edu/phys/courses/scst601/wind_energy.ppt
Vertical Blades www.usd.edu/phys/courses/scst601/wind_energy.ppt
Energy from Wind • Production of electricity and hydrogen gas by wind farms is expected to increase • Western Europe currently leads in the development of wind power • Land used for wind farms also can be used for ranching or crops and most profits stay in local communities • North Dakota
Modern wind turbines convert kinetic energy • Wind turbines: devices that turn wind energy into electricity • Towers are 40–100 m (131–328 ft) tall. http://www.wind.appstate.edu/map/node
Wind is the fastest-growing energy sector • Wind farms: turbines erected in groups of up to hundreds of turbines • California and Texas produce the most wind power in the U.S.
Optimization • Low Torque – Rapid Speed • good for electrical generation • High Torque – Slow Speed • good for pumping water • Small generator • low wind speeds • captures small amount of energy • Large generator • high wind speeds • may not turn at low speeds www.usd.edu/phys/courses/scst601/wind_energy.ppt