Power and Energy

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Power and Energy

• What would you do if the lights went out and we
  ran out of gasoline?

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Essential Question

• EQ1 What are our essential energy needs?
• EQ2 How would your life be made more difficult
  if energy sources were interrupted?
• EQ3 Where does electricity come from?
• EQ4 Where does gasoline come from?
• What is the price of gasoline, adjusted for
  inflation over time?
• How have our oil supplies changed over time?
• What geopolitical factors have played a role?

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EQ1 What are our essential energy needs?

• Electricity
• Powers all homes, businesses
• Many industrial processes
• Heating
• Keeping homes warm
• Industrial process
• Locomotion
• Movement of goods and people

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EQ2 How would your life be made more difficult
if energy sources were interrupted?

• 1965 power outage
• 80,000 sq. miles 2 Canadian provinces affected
• 30 million people affected
• President involved
• Looting was a concern
• Baby boom 1966 many more babies born that year
• 2000 California
• Rolling blackouts the result of bankrupt and
  corrupt power companies
• 2003 blackout in northeast US
• Took all of 9 seconds
• Caused by heat wave and high demand
• 7 states and 1 Canadian province affected
• Earthquake / tsunami wrecked Japanese nuclear
  power plant 2011
• 1000s dead
• nuclear power plants destroyed
• Conclusions
• All brings to mind looming infrastructure crisis
  in the US
• Concerns about terrorists and natural disasters
• Opportunities in power plant ops,
  electrical/civil engineering, security

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Power Grids in the US3 Grids East, West, Texas
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Just What IS the Electrical Grid

• The largest machine ever invented
• Like the internet, its everywhere
• Like the internet, it just happened
• A result of the Industrial Revolution
• Edison and Westinghouse battled over AC vs. DC
• AC won because of Teslas inventing transformers
• AC doesnt lose as much energy over distance
• Consists of
• Power plants 600-1700 Megawatts (MW 1,000,000
  W)
• Step-up Transformers EHV Extra High Voltage
  (270 Kilovolts)
• Transmission lines High Voltage (110 KV )
• Neighborhood Substations (50 KV)
• Power pole transformers (13,000 volts)
• Your house (240V/120V)

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The Power Grid
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The Power Grid
From Power Plant
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EQ3 Where does electricity come from?
Dept of Energy created in 1979 to plan for crises
like the oil shortages of 1973 / 1979. How are
we doing at increasing supplies of renewable
green energy as percent of whole? Answer?
Were not doing that well.
68 fossil 10 nuclear 22 renewable
66 fossil 19 nuclear 15 renewable
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Oil Crises 1973 1979Embargo and Rationing
Notice diesel less than gasoline
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Ration Stamps from World War II
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Oil Consumption by Region / Year
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(No Transcript)
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Oil Consumption by Region / Year
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Where does electricity come from?

• Conventional 95.5
• Coal (44.9)
• Natural Gas (23.4)
• Nuclear (20.3)
• Hydro-electric (6.9)
• Other Renewables 4.5
• Solar
• Wind
• Geothermal
• Wave
• Rounding error

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Solid Fuels Coal

• Carbon-based fuels said to cause global warming
• Coal
• Biggest energy source available in US
• 90 of coal in US used for electricity production
• Supplies 45 of electricity
• Used to produce steam
• Clean Coal techniques being perfected
• Much opposition to strip mining (strip mining
  / mountain-topping
• Coal arrives by train (coal transport)
• Over a mile long
• 100 cars with 100 tons of coal in each one
  (10,000 tons)
• A large plant needs at least one train every day
• Coal consumption
• 6.75 billion tons in world
• USA consumes 14 of world total
• Steam plants only 35 efficient - Rest goes to
  atmosphere

• Many people do not believe in man-caused global
  warming

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A Coal-Fired Power Plant
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Liquid Fuels

• Petroleum
• Can pollute oceans, land much opposition since
  BP oil spill / Exxon Valdez)
• Fuel Oil
• Must be refined (Oil Refinery from jet fuels to
  gasoline to kerosene to diesel (leaving tar)
  lightest fuel goes to top, tar at bottom
• Used for heating (northeast US)
• 1 US Electricity is from oil (emergencies)
• Gasoline
• Powers most vehicles in US (0.35/gal road tax
  one of highest in nation (road tax)
• Diesel
• Ignition comes from compression heat (no spark
  plug)
• On-Road / Off-Road
• Used to power personal vehicles
• Used for larger vehicles trucks
• Used for tractors, bull dozers, cranes
• Off-road diesel dyed red, not charged 0.41/gal
  road tax (also highest)

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Liquid / Gaseous Fuels

• Natural Gas home meter
• US has large supply
• Cleaner than petroleum
• Home heating in south, power plants, large
  vehicles
• WS city buses (WS diesel-electric buses a big
  PRIUS)
• Some suggest converting large semis to burn NG
• Could also work in trains
• Biodiesel can be used in any diesel vehicle or
  engine
• Chemical process using plant and animal fats and
  alcohol
• 3.8 million tons worldwide, mostly in Europe
• Only 200-800 million gallons in US (2006-2010)
• Ethanol
• From food (corn) in the US
• Raises price of food
• Government gives subsidies () to farmers to
  grow it
• From sugar cane (Brazil)
• Vegetable Oil (not enough to go around ... cant
  grow enough)
• Supplies going down as gas prices rise

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Nuclear Power

• Takes energy from splitting the atom
• Neutrons hit other neutrons causing chain
  reaction
• Uranium decays into different isotope same
  element, different number of neutrons
• Chain reaction controlled
• By moderator water slows chain reaction
• Control Rods stop reaction altogether
• Heats up water in primary loop (power plant)
• Primary water boils water in secondary loop
• Like conventional steam plant after that
• Accidents (details not on test)
• 1979 3-Mile Island (Pennsylvania)
• Unit 2 meltdown
• No loss of life
• The last nuclear power plant built in US in 1979)
• Look for movie called China Syndrome
• 1986 Chernobyl Ukraine/USSR
• Reactor melt down caused steam explosion - lives
  lost at scene from accident and shutdown
• Many people got cancer for years
• Left area a wasteland

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Nuclear Power
Containment Structure blew off in Japanese power
plant from steam explosion
Steam Generator
Secondary Loop
Reactor
Steam is condensed back to water and to feed
steam generator
Primary Loop
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Prime Movers

• Prime Movers (PMs) mechanical equipment that
  turns a driven load
• In electrical production, this is a generator
• Steam Engines
• Gas Turbines
• Diesel Engines
• Water Turbine
• Wind Turbines

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Driven Equipment

• Driven Equipment mechanical equipment using
  power from prime mover
• In electrical production, this is a generator
• Could also be
• Pumps
• Propeller shafts (ships)
• Turbo-fans (airplanes)

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Steam Turbines

• Steam turbine (rotor, rotor1) most common PM
• Long time to get on line / expensive to take out
  of service.
• Steam turbine is external combustion engine
• Steams energy comes from boiler
• Water is condensed, used again in steam power
  plant
• Run on high pressure steam
• Rotor stages act like pinwheels
• Blades are hit with the high pressure steam
• Most rows blades act like nozzles (turbine blade
  type)
• Each rotor gets bigger as energy of steam is used
  up
• Connected to reduction gears to reduce speed but
  increase torque (turning force) (reduction
  gears)

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Gas Turbines (GT)

• Just like engines on airplanes
• Used in remote locations and for emergency power
  needs
• Has compressor, combustor, HP turbine, LP turbine
  (turbine image)
• Rotating and stationary blades (LM2500 opened)
• LM2500 is engine Mr. Goodman worked on for US
  Navy
• Internal combustion engines - all heat
  starts/ends in GT
• Compressor in front (stages get smaller) turns HP
  turbine
• Power turbine in back (stages get bigger)
• Uses up more energy in each stage
• Rows (stages) of blades act like pinwheels
• Compressed air mixes with fuel in combustor
• After HP turbine, combustion gases spin power
  (LP) turbine
• Reduction gears decrease speed, increase torque.

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Diesel Engines

• Internal combustion engines - all heat starts
  and is used in the diesel
• In electrical production used for
• Peak loads (diesel generator)
• Emergencies
• Small, remote operations
• Mobile operations
• Commonly have 6/8/12 cylinders (large diesel
  engine)
• Fuel is ignited from heat of compression
• Can run on a variety of fuels
• Different designs for different speed / torque
  needs
• May or may not have reduction gears
• Best left running starting / stopping not
  efficient
• Used on ships/trains to drive wheel motors or
  propellers

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Water Turbines

• Used in hydro-electric power plants
  (hydro-electric plant)
• Famous ones in US
• Hoover Dam (Lake Meade, Las Vegas)
• Tennessee Valley Authority (Depression work
  project)
• Large one in China Three Gorges Dam
• Only 7 of power in US is hydro-electric 3.4
  worldwide
• Positives
• Clean, renewable, quiet (picture of water
  turbine)
• Controls flooding, provides for irrigation
• helps navigation with locks and dams
• Negatives
• Floods valleys where people live
• Disturbs natural lives (spawning) of fish
  (Northwest salmon)
• Causes problems with natural flow and build-up of
  silt in river

Many dams have fish ladders where fish can
use to climb back up to spawn
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Wind Turbines (Internal Parts)

• 3-bladed fans drive generators up to 7.5
  megawatts (million watts)
• Built in stages
• Base, mid-tower, top, power head
• Blades up to 130 ft)
• Towers 200 - 300 ft
• Dependent on regular weather patterns
• Located on land or sea (power from wind)
• Heating/cooling rates of land vs. water
• North American wind corridor in US Midwest
  (wind corridor)
• 3.35 of worldwide power by 2013, 8 percent by
  2018)
• Could lower use natural gas use for electricity
  by 20.
• Saving used for electricity or transportation
• Used in US
• Very expensive to build, takes a long time to
  develop
• Complex gearing spins blades and adjusts pitch
  (angle to wind) of blades

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Geothermal

• Draws heat from earth
• Only works in certain parts of planet
• Iceland has a LOT of Geothermal
• Creates steam from water in earth as hot as 180C
  / 350F
• Drives turbines like other steam plants
• Sends water to cooler part of earth

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Solar Power

• Sun hits panels made of semi-conductor
• Mostly Silicon
• Creates DC direct current
• Electronic inverters change DC to AC
• Transformers step up and reduce voltages
• Enters grid like other power
• Small of US power
• Expensive to create
• Large solar farms exist but are expensive
• Must store energy in batteries at night
• Government offers subsidies to
• encourage use

Not Mr. Goodmans house
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Solar Farm
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What will be on the test?

• Energy needs
• Blackouts (cause / effects / lessons)
• Electrical grids
• Sources of energy / energy use / effects of
• Factors affecting energy prices
• Power plants (types, processes, machinery,
  terminology)

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Basic Facts About Electricity

• Everything seeks a lower energy state
• Water will go from high to low if allowed to flow
• Electricity is the movement of electrons
• Electricity seeks the path of least
  resistancethe way water will leak out of a tank

• Think of electricity as having energy like water
  has energy
• Water flowing in a river is called current and
  so is the movement of electrons through a wire
• Water pressure built up in a balloon is like
  voltage stored in a battery

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How does water have energy?

• If this bag of water is left alone, the water
  will fill up some shape of the bag.
• If a weight is dropped on the bag, the water will
  go from high pressure to low pressure

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Generating Electricity Chemically

• Metals give off a negatively charged particles
  called electrons, some more than others
• Sometimes acids (electrolyte) help the electrons
  move easier
• When 2 different metals are placed next to each
  other electrons to move to the more positively
  charged
• The more electrons that are moved, the higher the
  voltage generated

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Using That Electricity

• When all the electrons are on one side of a
  battery ...
• And that battery is connected across a circuit
  ...
• The electrons will try to get back to a place
  where there are too few electrons.
• In the mean time it may light a lamp

Just like that water will fall to the ground
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Ohms Law - The Basic Fact

• Ohms law (E I x R) is the basic fact of all
  electricity
• It is to electricity what Newtons second law (F
  m x a) is to moving objects

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Calculating Resistance

• A voltmeter is place across (in parallel with)
  the resistor
• An ammeter is place in line (in series) with the
  resistor
• Using Ohms law, the resistance can be calculated

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Heat Resistance

• Resistance changes with temperature

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Resistance Changes with Length
DC Ohms
Diameter
Small

• This chart at right shows that resistance of a
  wire
• goes up with size
• can be standardized for a given length.
• If you double a wires length, you double its
  resistance.

Large
Zoom in as needed to see ratings