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Lecture

Electricity.docx


Department
Geography
Course Code
GEOG 3EE3
Professor
Maureen Padden

Page:
of 4
Electricity:
Electrical Current = flow of electrons
Metals: release and transmit electrons easily good conductors
Charge = Coulomb = 6.25 x 1018 electrons
Current = I = Ampere = coulomb per second
Volt = 1 Joule / 1 Coulomb = potential difference
Resistance = volts / I
Volts = R x I
Generating Electricity:
1. Magnetic field induced by current
2. Current induced by magnetic field
3. Charged particles experience force when travelling in certain directions in a magnetic field
Power Delivered = I2R
1 watt = 1 volt x 1 amp
Electic Generators:
- Pushes steam through turbines and spins rotor through a magnetic field to generate
electricity
Wind Farm development in Minnesota:
What is the difference between community based and commercial renewable energy projects?
Local ownership
Owned and operated locally
5 10 x more value
Community receives the benefits
Electricity from Wind:
Power output = 2.83 x 10-4D2v3 kWh
V= wind speed
D= Diameter
- AC current sent to grid or to a home
- DC current stored in battery
Issues with wind:
Noise
Aesthetics
Birds and bats
Health
Rural vs. urban
Property value
$
Off-shore wind Moratorium:
- Introduced in Feb. 2011
- Lake Ontario proposed site
To reach Target Capacity:
Need to come up with incentive policies
Keep some nuclear and increase renewable switch coal to more cogeneration
Decrease demand through conservation
Photovoltaic Cells:
- Can be used in cloudy climates
- 10-20% efficiency
- Solar energy knocks electrons loose and creates current
- Boron and phosphorous added to silicon
- High costs due to materials required
- Efficiency: double up glass layers to absorb different wave lengths too expensive
- Solar-grade silicon ways to bring down cost, lower temps so cheaper to produce
- Cheaper types of PV cells have less efficiency
- Eg. Solar shingles promoted in developing countries