Energy Efficiency and Renewable Energy by pengxiuhui

VIEWS: 12 PAGES: 92

									Energy Efficiency and
Renewable Energy

          G. Tyler Miller’s
     Living in the Environment
             14th Edition

         Chapter 18
Chapter 18 Key Concepts

Improving energy efficiency
Types and uses of solar energy
Types and uses of flowing water
Uses of wind energy
Types and uses of biomass
Use of geothermal energy
Use of hydrogen as a fuel
Decentralized power systems
Section 1: The Importance of
Improving Energy Efficiency
 • What is energy efficiency? How
   much energy do we waste?
 • What is life cycle cost?
 • What is net energy efficiency?
What is energy efficiency?

Energy efficiency is the
 measure of the useful
 energy produced
 compared to the energy
 converted to low quality-
 -- usually heat.

Using energy to do work,
 not produce heat.
What is energy conservation?
Implementing new
  technology to do same
  work using less energy.
• Heating homes more
  efficiently
• Driving more efficient cars
• Lightning spaces more
  efficiently
SAVES $$$, produces
 less pollution, reduces
 CO2
Energy Conservation

• 84% of commercial
  electricity is wasted in
  U.S.
• 41% of energy is
  automatically wasted
  due to 2nd Law Of
  Thermodynamics
• 43% is wasted
  unnecessarily
Advantages of Reducing Energy
Waste
The Importance of Improving Energy
Efficiency
 Energy efficiency
 Net energy efficiency

    Least Efficient
 Incandescent lights
 Nuclear power plants
 Internal combustion
  engine
                             Fig. 18-3 p. 381
Energy Efficiencies (Fig. 18-5 p. 381)
Life Cycle Costs

Initial Cost plus the
  lifetime cost.
                           Civic Hybrid vs.
Some energy efficient      Conventional Gas
  models may cost more
  up front, but save
  money in the long run.
Net Energy Efficiency
Measure of how much
 useful energy we get
 from energy resource
 after subtracting the
 energy wasted.

How much energy you
 get out given ALL the
 wasted energy.
Comparing Efficiency of 2 Types
of Space Heating
Section 2: Ways to Improve
Energy Efficiency Key Concepts
 • How can we save energy in industry?
 • How can we save energy in transportation?
 • How can we design buildings to save
   energy?
 • How can we save energy in existing
   buildings?
 • Why are we still wasting so much energy?
Ways to Improve Energy Efficiency

Cogeneration
Efficient electric motors
High-efficiency lighting
Increasing fuel economy
Alternative vehicles
Insulation
Plug leaks
How can industry save energy?

• Cogeneration –
  combining heat and
  power systems
• Improving electric
  motor efficiency
  (consumes 1/4th of
  energy)
• Improving light fixtures
How can we save energy in
transportation?
CAFÉ Standards need to
 be increased.

Increase to 40 mpg in
  10yrs would cut
  consumption in half
  (could eliminate
  imports from Middle
  East)
Average Fuel Economy of New
Vehicles Sold In U.S.
Price of Gas in 1993 Dollars
Hybrid and Fuel Cell Cars

 Hybrid electric-internal combustion engine

Hybrid-electric
cars are powered
by a battery and
a small ICE that
recharges the
battery.

                                      Fig. 18-9 p. 385
Toyota Prius
Ford Escape Hybrid
Fuel Cell Cars

Fuel cell cars run on
  hydrogen and produce
  little pollution.

Combine hydrogen and
 oxygen to produce
 electricity and water   Ford Focus Fuel
 vapor.                  Cell Car
Fuel Cells
GM’s prototype future fuel cell car. No engine noise, no
pollution, no greenhouse gasses.
How can we Design More
Efficient Buildings?
Chicago’s Sears Tower
 uses more energy in a
 day than a city of
 150,000

Atlanta’s Georgia Power
 Company uses 60% less
 energy than other
 buildings it size.
How can we Design More
Efficient Buildings?
We can save energy in
  buildings by
• Getting heat from the
  sun
• Insulating well
• Using plants for shade
  and wind blockage
How can we Design More
Efficient Buildings?
Super insulated house:
• Costs 5% more to build
• Can use 90% less
  energy for heating and
  cooling
Green Roofs:
• Plants or gardens on
  roof help insulate from
  heat in summer and
  cold in winter
An infrared photo showing heat loss (red,
white and orange) around windows, doors,
roofs.
How can we save energy in
existing buildings?
We can save energy in
  existing buildings by:
• insulating them
• plugging leaks
• using heating,
  electricity, cooling,
  appliances and lighting
  more efficiently
Insulate and plug leaks
1/3rd of heated air in U.S.
  homes is lost through
  windows, holes and
  cracks.
Insulating and plugging
  holes is the easiest and
  cheapest ways to save
  energy.
Use Efficient Windows

              Double pained,
               insulating windows
               cost more, but can
               save money in the
               long run.
Heat House More Efficiently

Using the most efficient
 heating system
 available.

Some natural gas furnaces
  can reach 85-98%
  efficiency
Heat Water More Efficiently

               There are several new
                 technologies to heat
                 water more efficiently:
               • Tankless, instant
                 heaters
               • Well insulated tank
Use Energy Efficient Lighting and
Appliances
                 Microwaves,
                  refrigerators, washers,
                  driers, lights all come
                  with energy star labels

                 ¼ of electricity bill is
                  lighting
Cut Off Electrical Devises Not In
Use
 When not using lights,
  computers, TV’s and
  other electrical
  devises they should
  be turned off.
Review Section 2

 • How can we save energy in industry?
 • How can we save energy in
   transportation?
 • How can we design buildings to save
   energy?
 • How can we save energy in existing
   buildings?
 • Why are we still wasting so much
   energy?
Section 3: Producing Energy
With Solar Power: Key Ideas
 • What are the main types of renewable energy?
 • How can we use direct solar energy to heat and
   cool homes?
 • How can we use solar energy to produce
   electricity?
 • What are solar cells?
 • What are advantages and disadvantages of
   solar cells?
What are the main types of
renewable energy?
The next several sections
  we will go through:
• Solar Energy
• Flowing Water
• Wind
• Biomass
• Geothermal
• Hydrogen
• Other possible renewable
  energy sources.
What are the main types of
renewable energy?
                • EU by 2020: 22%
                  renewable
                • CA gets 12% from
                  renewable (20% by
                  2020)
                • Union of Concerned
                  Scientists study said
                  20% by 2020 is
                  possible
Using Solar Energy to Provide Heat

Passive solar heating: absorbs and stores
  heat from the sun directly within the structure
Has been used for thousands of years.
Using Solar Energy to Provide Heat

Active Solar: absorbs heat
 energy from sun by
 pumping heat absorbent
 fluid through collectors.

Great for hot water
 heaters in warmer
 climates
Using Solar Energy for Electricity
Solar energy can be
converted directly into
electricity using
PHOTOVOLTAIC
CELLS (PV) or “Solar
Cells”

Sunlight energizes electron
to flow in a semi conductor
producing an electrical
current
Using Solar Energy for Electricity
                    Solar Cells can be
                    incorporated into
                    roofing and windows.

                    High costs are
                    expected to fall

                    Currently only supply
                    0.05% of world
                    electricity
Using Solar Energy for Electricity
Great for rural locations


BP in 2004 began to mass
produce cells


With increased R&D and
government help --- 25%
by 2040???
Using Solar Energy for Electricity

Solar Thermal Systems:
  large solar arrays in
  sunny areas can
  produce high-
  temperature heat for:
• Electricity
• Hot water
• Heating
• Wash Machines
Using Solar Energy for Electricity

 Solar thermal systems

 Photovoltaic (PV) cells
Producing Electricity From the
Water Cycle: Section 4 Key
Concepts

 • How can we produce electricity from
   flowing water?
 • What are advantages and disadvantages
   of hydropower?
 • What is tidal and wave power?
Producing Electricity from Moving Water

  Large-scale hydropower

  Small-scale hydropower

  Pumped-storage hydropower

  Tidal power plant

  Wave power plant
Renewable Hydropower
Water flowing in rivers
 and streams can be
 trapped in reservoirs
 behind a dam and
 released to spin turbines
 to produce electricity.
In 2002, hyrdro accounted
  for 20% of world
  electricity (Norway
  99%, U.S. 7% -- 50% in
  west)
Renewable Hydropower

According to UN only
 13% of potential
 hydropower has been
 developed

Large Scale Hydro Power
  has been curtailed
  recently by
  environmental concerns
Large-
scale
Hydroelec
tric
Power:
Trade-offs
Reviewing the Trade-offs of
Hydropower Dams




                              Fig. 15-9 p. 313
Hoover Dam
Tidal Power

Using the twice daily
 natural rise and fall of
 tidal waters to produce
 power.
Newer concept
Lot of potential in certain
 tidal regions.

Problems???
Tidal Power
Wave Power

Using the constant wave
 action along shorelines
 to produce power.

Another form of wind
 power.

Problems???
Producing Electricity from Wind
Section 5 Key Concepts
Producing Electricity from Wind




            Fig. 18-23 p. 396   Fig. 18-24 p. 397
Altamont Pass California
Atlantic City
http://www.eere.energy.gov/windandhydro/windpoweringamerica/where_is_wind_n
ew_jersey.asp
Producing Energy from Biomass
Biomass and biofuels
Biomass plantations
Crop residues
Animal manure
Biogas
Ethanol
Methanol        Fig. 18-25 p. 398
Geothermal Energy

Geothermal heat pumps
Geothermal exchange
Dry and wet steam
Hot water
Molten rock (magma)
Hot dry-rock zones
The Hydrogen Revolution

 Environmentally friendly hydrogen
 Extracting hydrogen efficiently
 Storing hydrogen
 Fuel cells
The Hydrogen Revolution




                          Fig. 18-31 p. 403
Entering the Age of Decentralized
Micropower

 Decentralized power systems
 Micropower systems




                                Fig. 18-32 p. 405
Solutions: A Sustainable Energy
Strategy




                            Fig. 18-35 p. 407

								
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