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Energy Efficiency and Renewable Energy Chapter 16 – PowerPoint PPT presentation

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Title: Energy%20Efficiency%20and%20Renewable%20Energy

Energy Efficiency and Renewable Energy
  • Chapter 16

16-1 Why Is Energy Efficiency an Important
Energy Resource?
  • Concept 16-1 We could save as much as 43 of all
    the energy we use by improving energy efficiency.

We Waste Huge Amounts of Energy
  • Energy conservation
  • A decrease in energy use as a result of a
    decrease in the amount of wasted energy Use
  • Energy efficiency
  • The measure of work we can get out of a unit of
    energy we use Use it better
  • Four widely used devices waste large amounts of
  • Incandescent light bulb 95 lost as heat
  • Internal combustion engine 94 of the energy
    from fuel wasted
  • Nuclear power plant 92 of energy is wasted
    through nuclear fuel and energy needed for waste
  • Coal-burning power plant 75-80 of the energy
    released by burning coal is lost

Flow of Commercial Energy through the U.S.
  • 84 of all commercial energy used in the U.S. is
  • 41 wasted due to the 2nd law of thermodynamics.
  • Only 9 of the total energy put into the U.S.
    economy results in useful energy.

Advantages of ReducingUnnecessary Energy Waste
16-2 How Can We Cut Energy Waste?
  • Concept 16-2 We have a variety of technologies
    for sharply increasing the energy efficiency of
    industrial operations, motor vehicles, and

We Can Save Energy and Money in Industry
  • Industry accounts for 38 of U.S. energy
    consumption. It can save energy and money by
  • Produce both heat and electricity from one energy
    source (cogeneration or combined heat and power,
  • Use more energy-efficient electric motors
  • Recycle materials
  • Switch from low-efficiency incandescent lighting
    to higher-efficiency compact fluorescent (CFL)
    and LED lighting
  • Update the old/wasteful electrical grid system
    (how electricity is transmitted from the power
    plant to the consumer)
  • Utility companies promote use of energy
  • Instead, should promote conservation

We Can Save Energy and Money in Transportation
  • Transportation accounts for 2/3 of U.S. oil
    demand and is a major source of air pollution.
  • We can save energy in transportation by
    increasing fuel efficiency and making vehicles
    from lighter and stronger materials.
  • Corporate Average Fuel Economy (CAFE) standards
  • The average fuel economy, in miles per gallon
    (mpg), of a manufacturers fleet of passenger
    cars and/or light trucks
  • Fuel-efficient cars are on the market
  • Tax breaks for buying fuel-efficient cars

Average Fuel Economy of New Vehicles Sold in the
U.S. and Other Countries
  • CAFE standards had not increased since 1985.
  • In May 2009, President Obama increased the
    standards 5 per year towards a goal of 35.5 MPG
    by 2016.
  • This represents an average of an 8 MPG increase.
  • Still well below Europe and Japan.

More Energy-Efficient Vehicles Are on the Way
  • Hybrid vehicles have two types of engines working
    together to achieve higher gas mileage (15-70
    more) and lower engine exhaust emissions
  • A standard gas powered engine
  • An electric motor assist powered by a
    rechargeable nickel-metal hydride (NiMH) battery
  • Gasoline-electric hybrid car
  • Mostly gassome electric
  • Plug-in hybrid electric vehicle
  • Mostly electricsome gas
  • Electric vehicle (EVs)
  • ALL electric

Solutions A Hybrid-Gasoline-Electric Engine Car
and a Plug-in Hybrid Car
Solutions A Hybrid-Gasoline-Electric Engine Car
and a Plug-in Hybrid Car
More Energy-Efficient Vehicles Are on the Way
  • Hybrid cars accounted for 3 cars on the road in
  • Up from than 1 in 2007
  • Typically cost 3-4,000 more than non-hybrid
  • Plug-in hybrids can get twice the mileage of
    gasoline-electric hybrid cars, but
  • How is the electricity generated?
  • Electricity from coal or nuclear power plants
  • Electricity produced by wind or solar energy
  • Analysts estimate that hybrid cars could make up
    as much as 20 of the car market by the year
  • The boost in sales will be pushed by consumer
    demands and stricter government regulations on
    CO2 emissions.

Science Focus The Search for Better Batteries
  • Current obstacles to hybrid or electric vehicles
  • Storage capacity of battery
  • Currently about 100 mile range
  • Charging time
  • 8 hours for a Nissan Leaf (available NOW)
  • 3 hours for a Ford Focus EV (available in 2012)
  • Use of rare earth metals for battery construction

We Can Design Buildings That Save Energy and
  • Green architecture
  • Makes use of passive solar heating, natural
    lighting, natural ventilation, rain water
    collection, cogeneration of heat/electricity,
    geothermal heat pumps, and recycled building
  • Living or green roofs
  • Superinsulation
  • U.S. Green Building Councils Leadership in
    Energy and Environmental Design (LEED)

Graded on 100 possible points Certified - 40 -
49 points Silver - 50 - 59 points Gold - 60 - 79
points Platinum - 80 points up
We Can Save Energy and Money in Existing
  • Insulate and plug leaks
  • Use energy-efficient windows
  • Stop other heating and cooling losses
  • Heat houses more efficiently
  • Heat water more efficiently
  • Use energy-efficient appliances
  • Use energy-efficient lighting
  • About 1/3 of the heated air in typical U.S. homes
    and buildings escapes through closed windows,
    holes, and cracks.

Individuals Matter Ways in Which You Can Save
Money Where You Live
Why Are We Still Wasting So Much Energy?
  • Low-priced fossil fuels and few government tax
    breaks or other financial incentives for saving
    energy promote energy waste.

We Can Use Renewable Energy in Place of
Nonrenewable Energy Sources
  • A variety of renewable-energy resources are
    available but their use has been hindered by a
    lack of government support (subsides) compared to
    nonrenewable fossil fuels and nuclear power.
  • Direct solar
  • Moving water
  • Wind
  • Geothermal

16-3 What Are the Advantages and Disadvantages of
Solar Energy?
  • Concept 16-3 Passive and active solar heating
    systems can heat water and buildings effectively,
    and the costs of using direct sunlight to produce
    high-temperature heat and electricity are coming

Solar Power
We Can Heat Buildings and Water with Solar Energy
  • Passive solar heating system
  • Absorbs and stores heat from the sun directly
    within a structure without the need for pumps to
    distribute the heat.
  • House faces South

We Can Heat Buildings and Water with Solar Energy
  • Active solar heating system
  • Pumping a liquid such as water or an oil through
    rooftop collectors
  • Can also be used to provide hot water

Trade-Offs Passive or Active Solar Heating
We Can Cool Buildings Naturally
  • Technologies available
  • Superinsulation and high-efficiency windows
  • Overhangs or awnings on windows
  • Light-colored roof
  • Reflective insulating foil in an attic
  • Geothermal pumps
  • Plastic earth tubes underground

We Can Use Sunlight to Produce High-Temperature
Heat and Electricity
  • Solar thermal systems
  • Sunlight is directed towards a central tower
    where and oil absorbs the heat and is used to
    create high temperature steam to turn a turbine.
  • Large arrays of solar collectors in sunny deserts
  • Costs are high and energy yield is low.

Solutions Woman in India Uses a Solar Cooker
  • Solution to the fuel wood crisis?

We Can Use Solar Cells to Produce Electricity
  • Photovoltaic (PV) cells (solar cells)
  • Convert solar energy to electric energy
  • Can be made in all shapes and sizes and can be
    included in the building design and construction.

We Can Use Solar Cells to Produce Electricity
  • Their costs are high, but expected to fall with
    mass production, new designs, nanotechnology.
  • Solar cells can be used in rural villages with
    ample sunlight who are not connected to an
    electrical grid.
  • Mostly for pumping water

Trade-Offs Solar Cells, Advantages and
  • Solar cells currently only 0.2 of the worlds
  • Solar power has the largest POTENTIAL for
    supplying electrical power to the world.

16-4 Advantages and Disadvantages of Producing
Electricity from the Water Cycle
  • Concept 16-4 Water flowing over dams, tidal
    flows, and ocean waves can be used to generate
    electricity, but environmental concerns and
    limited availability of suitable sites may limit
    the use of these energy resources.

We Can Produce Electricity from Falling and
Flowing Water
  • Hydropower
  • Build a high dam across a large river
  • Water builds up into a reservoir
  • Let water flow through large pipes and turn
    turbines to produce electricity
  • Worlds leading renewable energy source used to
    produce electricity
  • 16 of the worlds electricity
  • 99 in Norway, only 7 in the U.S.

We Can Produce Electricity from Falling and
Flowing Water
Trade-Offs Large-Scale Hydropower, Advantages
and Disadvantages
Tides and Waves Can Be Used to Produce
  • Ocean tides and waves and temperature differences
    between surface and bottom waters in tropical
    waters are not expected to provide much of the
    worlds electrical needs.
  • Few suitable sites
  • High costs
  • Equipment corrosion
  • Only two large tidal energy dams are currently
    operating one in La Rance, France and Nova
    Scotias Bay of Fundy (where the tidal difference
    can be as high as 63 feet).
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