scince

1. Generators, Motors and
How We Get Electricity

2. Topics
 What is electricity?
 Energy Conversion
 The Faraday Effect
 Motor vs. Generator
 AC/DC
 Energy Trends - the case for Green

3. What is Electricity?
Electricity is energy transported by
the motion of electrons
**We do not make electricity, we
CONVERT other energy sources into
electrical energy**
Conversion is the name of the game

4. Energy Conversion Options for Electricity
Non-Thermal Paths
• Source to Electrical
Source Converter
Sun Photovoltaic (photon to electron)
Chemical Fuel Cell
• Source to Potential/Kinetic to Mechanical to Electrical
Source Converter Kinetic to Mechanical Mech to Electrical
Dam Penstocks Turbine (water) Generator
Tides Machine Turbine (air or water) Generator
Wind N/A Turbine (air) Generator

5. Energy Conversion Options for Electricity
Thermal Paths
• Heat to Mechanical to Electrical
Source Heat to Mechanical Mech to Electrical
Geothermal Turbine (vapor) Generator
OTEC Turbine (vapor) Generator
• Stored Energy to Heat to Mechanical to Electrical
Source Reactor Heat to Mechanical Mech to Electrical
Fuel Combustor Turbine (gas or vapor) Generator
U, Pu Reactor Turbine (gas or vapor) Generator
Sun Collector* Turbine (gas or vapor) Generator
H, H2
, H3
Reactor Turbine (gas or vapor) Generator
* More a modifier or concentrator than a reactor

6. Faraday Effect
• Faraday Effect
• Basic Concepts
• Voltage – V – Potential to Move Charge (volts)
• Current – I – Charge Movement (amperes or amps)
• Resistance – R – V = IxR (R in =ohms)
• Power – P = IxV = I2
xR (watts)

7. Electric Motor
M
Electrical
Energy
Mechanical
Energy
DC Motor

8. Model Electric Motor
Beakman Motor
What do you need?
1. Electric Energy
2. Coil
3. Magnetic Field

9. Electric Generator
G
Mechanical
Energy
Electrical
Energy
Stationary magnets - rotating magnets - electromagnets

10. AC/DC
(not the band)
 Alternating Current
 Large-scale
generators produce
AC
 Follows sine wave
with n cycles per
second
 1, 2, 3-phase?
 US:120 V,60 Hz
 Europe: 240 V,50Hz
 Transforming ability
 Direct Current
 Batteries,
Photovoltaics, fuel
cells, small DC
generators
 Charge in ONE
direction
 Negative, Positive
terminals
 Easy conversion AC to
DC, not DC to AC

11. Generator Phases
1 Phase – 2 Phase – 3 Phase…Smooth Power
0 0.005 0.01 0.015 0.02 0.025 0.03 0.035
150
100
50
0
50
100
150
200
250
220
110−
ς τ( )
ς 1 τ( )
ς 2 τ( )
ς 3 τ( )
0.0330 τ
0 0.005 0.01 0.015 0.02 0.025 0.03 0.035
150
100
50
0
50
100
150
110
110−
ς τ( )
ς 1 τ( )
ς 2 τ( )
ς 3 τ( )
0.0330 τ
0 0.005 0.01 0.015 0.02 0.025 0.03 0.035
150
100
50
0
50
100
150
200
155.563
110−
ς τ( )
ς 1 τ( )
ς 2 τ( )
ς 3 τ( )
0.0330 τ
Polyphase Systems  3 phases for smoother torque delivery
Force Driving Motor (Red)
Single Phase Two Phase Three Phase

12. Where do we get our
Electricity?
• Fossil – Coal, Natural
Gas, Oil – 550 Gigawatts
(GW)
• Nuclear – 200 GW
• Hydro – 75 GW
• Geothermal – 2.3 GW
• Other Renewable –
Wind, Solar, OTEC – 13.6
GW

13. 0
1
2
3
4
5
6
7
8
9
USA
CanadaNorwayRussia Japan
U.K.
Mexico China India Africa
Bangladesh
Energy Usage Per Capita (1999)TOE/person-year
*TOE - Tons of Oil Equivalent (~40 Million Btus)

14. Oil Resources
Saudi Arabia 26%
Iraq 11%
Kuwait 10%
Iran 9%
UAE 8%
Venezuela 6%
Russia 5%
Libya 3%
Mexico 3%
China 3%
Nigeria 2%
U.S. 2%
U.S. 26%
Japan 7%
China 6%
Germany 4%
Canada 4%
Russia 3%
Brazil 3%
S. Korea 3%
France 3%
India 3%
Mexico 3%
Italy 2%
Have Oil… Use Oil…
The U.S. uses more than the next 5 highest
consuming nations combined.

15. U.S. Renewable Energy Resource Assessment
WindSolar
Geothermal
Temperature <90C
Temperature >90C
Geopressured resources
o
o
10
10
12
12
14
14
16
16
18
18
20
20
22
24
26
22 24
26
16
14
14
16
14
12
10
10
12 <10
10-12
12-14
14-16
16-18
18-20
20-22
22-24
24-26
26-28
>28
6.0-6.5 m/s
13.4-14.6 mph
6.5-70 m/s
14.6-15.7 mph
>7.0 m/s
15.7+ mph
Megajoules/m
2
Biomass
Agricultural
resources & residues
Wood resources &
residues
Agricultural & wood
residues
Low inventory

16. US energy infrastructure is large and deeply entrenched
• 400,000+ miles of gas and oil pipelines
• 160,000+ of high voltage transmission lines
• 176,000 gasoline stations
• 1000’s of oil and gas wells drilled annually in the
US and Canada
Barriers to Change

17.  oil and gas are readily available as a world
commodity at low cost -- equivalent to $ 4 to 5 /
million Btu
 US coal is even more abundant and cheaper –
approximately $1/million Btu
 US electricity prices remain low relative to
other commodities
The average American family spends only 3
to 4% of their income on energy!!
Barriers to Change