Energy Part 4

1
Energy Part 4

• Energy Conservation and Renewables

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Energy Star

• Joint program between the US EPA and the US DOE
• Mission to protect the environment through
  energy-efficient products and practices
• Saved enough energy in 2005 equivalent to 23
  million cars and 12 billion in utility bills

3
Corporate Average Fuel Economy (CAFE) Standards

• Average fuel economy (mpg) of a manufacturers
  passenger cars and light trucks
• Testing follows EPA guidelines
• Result in an estimated 55 billion gallons
  annually and 10 reduction in carbon emissions
• Achieved through better engine design, effciency,
  and weight reduction

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Corporate Average Fuel Economy (CAFE) Standards

• Improvements to CAFE standards could be achieved
  by expanding the standards to include
• Streamlining
• Reduced tire-rolling resistance
• Engine improvements (ex hybrid technology)
• Optimized transmission improvements
• Transition to high voltage automotive electrical
  systems
• Preformance-based tax credits

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Cars

• Cars should
• Drive at least 300 miles between refueling
• Be refueled quickly
• Keep up with other traffic on the road (no moped
  effect)

Pros Cons
Gas Meets above standards Poor gas millage Pollution
Hybrid Electric Almost no pollution Limited range between charges
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Hybrid Electric Vehicles

• Attempt to increase mpg while overcoming the
  shortcomings of an electric car
• Parts of a gas-electric hybrid
• Gasoline engine (smaller than gas only cars)
• Fuel tank
• Advanced electronics allow electric motor to act
  as a generator
• Generator acting only to produce electrical power
• Batteries to store energy

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Types of hybrid electric vehicles

• Parallel Fuel tank supplies gas to the engine
  and batteries supply electricity to the electric
  motor
• Series gasoline engine turns a generator which
  charges the batteries and/or power the electric
  motor the gasoline engine never directly powers
  the car
• Plug-in electric hybrid cars with an added
  battery can be plugged into a 120 volt outlet
  and charged run on stored energy for up to (60
  miles per charge)

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Alternative Fuels (LNG and CNG)

• Natural Gas Vehicle (NGV) uses compressed natural
  gas (CNG)
• In 2010 there were 12.7 million natural gas
  vehicles world wide
• Pakistan had the most with 2.7 million
• Asia-Pacific region 6.8 million
• Latin America 4.2 million

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Alternative Fuels (LNG and CNG)

• CNG require high compression and thick walled
  tanks (adds cost and weight)
• CNG is cheaper than oil
• NGV corrode and wear the engine parts less
  rapidly than gasoline (500,000 miles) on one
  engine is not uncommon
• Emissions are cleaner
• There is less wasted fuel

10
Electric Cars

• Uses an electric motor and electrical energy
  stored in batteries
• Popular in the late 19th and early 20th centuries
  but were replaced by internal combustion engines
• Renewed interest in electric cars due to climate
  change

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Electric Cars

• Cons
• More expensive than conventional vehicles
• Due to cost of lithium-ion battery
• Lack of private and public recharging stations
• Driver fear of running out of energy before
  reaching a recharging station

• Pros
• Significant reduction of urban air pollution
• Reduced green house gasses
• Less dependent on foreign oil

12
Mass Transit

• Types
• Rail
• Bus services
• Subways
• Ferries
• Often determines where people live and work
• How much air pollution people are subject to

• US only 3 frequently use mass transit
• Japan 47
• Land availability determines is cities expand
  vertically (no land NYC) or horizontally (have
  land LA)
• Determines preferred mode of travel

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Mass Transit

• Use rises with population density
• Development of system determines efficiency of
  mass transit system
• Most efficient method promote a user-pay
  approach, where all external costs are factored
  into license fees and/or vehicle taxes

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Types of mass transit

• Light rail trains that share space with road
  traffic and have own right-of-way and are
  separated from road traffic
• Bus rapid transit separate lanes, turnouts,
  signals, etc. for all busses

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Types of mass transit - Car sharing

• short-term car rentals
• Not limited by office hours, reservations, pickup
  and return are self-service
• Can rent by hour or day
• Locations are distributed throughout service area
• Insurance and fuel costs are included in rates
• Near public transportation

• 30 of households participated in car sharing
• Help reduces congestion and pollution
• Reduces demand for parking spaces
• Only in high density areas

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Types of Renewable Energy

• Solar
• Hydrogen Fuel Cells
• Biomass

• Wind Energy
• Ocean Waves and Tidal Energy
• Geothermal

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Solar

• Collecting and harnessing radiant energy from the
  sun to provide heat and/or electricity
• Can be generated at home or in industrial
  settings
• Photovoltaic cells
• Solar collectors
• Solar-thermal plant

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Solar Collectors

• Active collects and uses suns energy to heat
  water or air inside a home or business
• Passive structure is built to maximize solar
  capture
• Large south facing windows

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Solar

• Pros
• Supply of solar energy is limitless (for our
  purposes)
• Reduces reliance on foreign imports
• Only pollution is in the manufacture of
  collectors
• Can store energy during the day and release it at
  night
• Small systems have a low impact on the
  environment

• Cons
• Inefficient where sunlight is limited or seasonal
• Maintenance costs are high
• Systems deteriorate and must be replaced
  periodically
• Current efficiency is between 10 and 25
• Large systems can threaten wildlife vaporize
  birds, etc.

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Hydrogen

• 9 million tons of hydrogen is produce in US each
  day
• Could power
• 20 30 million cars
• 5 8 million homes
• Used by industry
• Refining
• Treating metals
• processing foods

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Hydrogen Fuel Cell

• Operates similar to a battery
• Two electrodes and a cathode separated by a
  membrane
• Oxygen passes over one electrode and hydrogen
  over another
• Hydrogen reacts with a catalyst that converts H2
  gas
• Hydrogen ions combine with oxygen
• Electrons pass out of the battery

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Hydrogen Fuel Cell

• Pros
• Waste product is pure water
• Ordinary water can be used to obtain hydrogen
• Does not destroy wildlife and has minimal
  environmental impact
• Energy to produce hydrogen could come from a
  fusion reactor, solar, or less polluting source
• Hydrogen is easily transported through pipelines
• Hydrogen can be stored in compounds to make it
  safe to handle

• Cons
• Takes energy to produce hydrogen from water or
  methane
• Changing from a current fossil fuel based system
  to hydrogen based would be very expensive
• Hydrogen is an explosive gas
• It is difficult to store hydrogen gas for
  personal cars

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Biomass

• Any carbon-based, biologically active fuel source
• Wood
• Manure
• Charcoal
• Biodiesel
• Methane
• ethanol
• Approximately 15 of world energy is derived from
  biomass
• Burned in large incinerators as an energy source

• Most common in developing countries
• Suitable plants for growing biomass
• Switch grass
• Hemp
• Corn
• Sugar cane
• Can be used for building materials, biodegradable
  plastics, and paper

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Biomass

• Pros
• Renewable as long as used sustainably
• Can be sustainable (control for deforestation and
  erosion)
• Could supply half of worlds energy demand
• Biomass plantations can be located in less
  desirable locations to reduce soil erosion and
  restore degraded land
• Crop residue are available as biomass
• Ash can be collected and recycled
• Reduces impact on landfills

• Cons
• Requires adequate water and fertilizer
• Use of inorganic fertilizers, pesticides, and
  herbicides would harm the environment
• Corn diverted to ethanol production raises food
  prices
• Could cause massive deforestation
• Inefficient burning methods could increase air
  pollution
• Expensive to transport
• Not efficient (70 of energy lost as heat)
• CO2 production would have impact on climate change

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Case Study - Biomass

• Bagasse the fibrous material that remains after
  sugarcane and sorghum stalks are crushed to
  extract the juice
• Used for biofuel, paper, and building materials
• 10 tons of sugar cane yields 3 tons of bagasse
• High moisture content (40 50) makes it hard to
  use as a fuel
• Used widely in Brazil

• Using agricultural by-products for paper off sets
  commercial forestry reduces rate of rain forest
  conversion to commercial tree farms
• Bagasse can be used to soak up oil spills and
  make disposable food containers, replacing
  styrofoam

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Wind Energy

• The wind turns blades that turn a turbine to
  generate power
• Wind farms clusters of wind turbines

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Wind Energy

• Pros
• All electrical needs of US could be met by wind
  from (ND, SD, and TX)
• Can be built quickly and built on sea platforms
• Maintenance is low and farms are automated
• Moderate high net energy yield
• No pollution
• Land underneath turbines can be used for
  agriculture

• Cons
• Steady wind is required to make investment in
  wind farms economical few suitable places
• Back up systems need to be in place when wind is
  not blowing
• Visual and noise pollution
• Interfere with flight patterns of birds and bats
  killing some
• May interfere with communication such as TV and
  cell phone

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Small-scale hydroelectric

• Utilizes small turbines connected to submerged
  power generators to create electricity
• 100 kW or less capacity
• Factors to consider
• Amount of consistent water available
• Amount of drop between intake and output
• Regualtory issues

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Small-scale hydroelectric

• Pros
• No pollution
• Does not impede stream flow
• Does not stop fish migrations
• Many economic incentives for installing, grants,
  loans, tax incentives

• Cons
• Low energy out put
• Suitable more for remote areas than large scale
  energy production

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Ocean Waves and Tidal Energy

• Uses natural movement of tides and waves to spin
  turbines
• Only a few in operation world wide
• Pros
• No pollution
• Minimal environmental impact
• Moderate net-energy
• Cons
• Construction is expensive
• Few suitable sites
• Equipment can be damaged by storms or erosion

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Geothermal

• Heat contained in underground rocks and fluids
  from magma, dry-rock zones, and warm-rock
  reservoirs produce pockets of warm water or wet
  or dry steam
• Steam drives a turbine engine
• Supplies less than 1 of world energy
• Known resources tend to follow tectonic plate
  boundaries

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Geothermal

• Pros
• Moderate net-energy yield
• Limitless and reliable source if managed properly
• Little air pollution
• Completive cost

• Cons
• Reservoir sites are scarce
• Source can be depleted if not managed properly
• Noise, odor, and land subsidence
• Can degrade ecosystem due to corrosive, thermal,
  or saline waste

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Relevant Law

• Renewable Energy Law, China (2007)
• Requires power grid operators to purchase
  resources from registered renewable energy
  producers
• Offers financial incentives and discounted taxes
  and lending practices for renewable energy
  products
• Designed to help protect the environment, prevent
  energy shortages, and reduce dependence on
  imported energy
• Includes penalties for non compliance

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Case Study Bloom Boxes

• Collection of solid oxide fuel cells that use
  liquid or gaseous hydrocarbons to generate
  electricity on site
• 20 of cost savings results from avoiding
  transfer cost over grid
• Used by eBay, Google, Staples, Wal-Mart,
  Coca-cola, and Bank of America