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Grid Power Storage
- 1.Large-scale energy storage
- Electrical energy is stored during times when production (from power plants) exceeds consumption and the stores are used at times when consumption exceeds production.
- Ex. Pumped HydroelectricPower and Compressed Air Energy storage
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Intelligent Grids
- 1.Transport electrical power
- -use high voltage transmission lines to minimize resistive losses
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Supergrids and Hypergrids
- 1. 1970s, R.Buckminster Fuller proposed linking the world's electrical grids
- 2.Creation of a worldwide grid is now underway
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Penguins vs Hummingbirds
- 1. Penguins
- -dont have to fly, can store energy in form of fat
- -can survive in harsh conditions
- 2.Hummingbirds
- -move constantly
- -need to eat constantly
- -body can decrease to 65F
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Compressed Gas
- 1.Natural gas or hydrogen fuels
- 2. viable for motor vehicles
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Advantages of Compressed Gas
- 1.Very low pollution
- 2.Reduced maintenance
- 3.Simialr performance
- 4.Similar cost
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Disadvantages of Compressed Gas
- 1.Gas must be highly compressed, which requires 20% of the energy it contains
- 2. Tank weight and tank bulk are significant
- 3. Vehicle range can be limited
- 4. Refueling infrastructure is limited
- -best utilized in vehicle fleets
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Liquefied Gas products
- Natural gas is converted to liquid form for ease of storage or transport
- -1/1000 of the volume
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Disadvantages of Liquefied Gas products
- 1. Significant energy required to liquefy
- 2. Evaporative loss of gass, contributes to greenhouse effect
- 3. Enormous energy density is a safety concern
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What are the dominant non-fossil fiel mobile energy storage technology?
Batteries
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Hydrogen reaction
2H2 + O2 =2H2O
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Advantages of Hydrogen
- 1.Specific energy: 142 Mj/kg
- 2. No carbon
- 3. No other emissions except water and some hydrogen
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Disadvantages of Hydrogen
- 1. No free hydrogen on Earth
- 2. Energy storage material, not a net energy
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Making Hydrogen
- 1.Produced from fossil fuels through steam formation with methane
- -Electrolysis uses electric current to dissociate H2O to form H2 and O2 gas
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Energy efficiency of hydrogen electrolysis is
50%
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Fuel cells
- 1.Work like batteries
- 2. Import fresh H2 and O2 and expel H2O
- 3. Provide efficiencies of up to 80%
*Cost is very high due to the engineering required
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Fuel cell vehicles limited by...
- 1.The need to store hydrogen
- 2. Require significant energy
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Batteries store electrical in the form of....
chemical energy
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Battery composition
- 1. Voltaic cells
- -consist of two half-cells
- 2.One half cell: anode(-)
- -where postive ions migrate
- 3. Other half-cell: cathode(+)
- -where negative ions migrate
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How can a battery be charged?
by forcing a current at a higher voltage in the opposite direction
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Reducing or Oxidizing:Lithium vs Chlorine
- 1. Reducing:donating electrons(Left side of Periodic Table)
- -Lithium
- 2.Oxidizing:accepting electrons(Right side of Periodic Table)
- -Chlorine
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Maximum possible voltage of a single battery cell
5 or 6 volts
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The Baghdad battery
- 1. One of the oldest batteries (2000 years old)
- 2. Consists of a clay jar with a stopper made of asphalt
- 3.when filled with vinegar, produces 1.1 volts
- 4. Probaly used for electroplating gold and silver
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Limitations to Battery performance
- 1. Secondar reactions limit the lifetime
- 2. High cost for better batteries
- 3. Structure is many times the mass of the electrochemically active materials
- 4. Inefficiences in the electrochemical process
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High-Tech batteries
- 1. Nickel-Hydrogen Batteries
- -Orbiting spacecraft use
- 2. 18650 form factor; Li-ion cells
- -TheTesla Roadster electric vehicle uses
- -375 V, up to 200KW
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Yuneec International E430
- 1. The world's first commericially produce electric aircraft
- 2. Produced in China
- 3.Flying time of 3 hours
- 4. $5 per flight
- 5. Top speed: 80 mph
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