Generators, Motors and How We Get Electricity

Topics

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

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

Energy Conversion Options for ElectricityNon-Thermal Paths

• Source to Electrical Source ConverterSun Photovoltaic (photon to electron)Chemical Fuel Cell 

• Source to Potential/Kinetic to Mechanical to Electrical Source Converter Kinetic to Mechanical Mech to ElectricalDam Penstocks Turbine (water) GeneratorTides Machine Turbine (air or water) GeneratorWind N/A Turbine (air) Generator 

Energy Conversion Options for ElectricityThermal Paths

• Heat to Mechanical to Electrical  Source Heat to Mechanical Mech to ElectricalGeothermal Turbine (vapor) GeneratorOTEC Turbine (vapor) Generator 

• Stored Energy to Heat to Mechanical to Electrical  Source Reactor     Heat to Mechanical       Mech to ElectricalFuel Combustor Turbine (gas or vapor) GeneratorU, Pu Reactor Turbine (gas or vapor) GeneratorSun Collector* Turbine (gas or vapor) GeneratorH, H2, H3Reactor Turbine (gas or vapor) Generator

 * More a modifier or concentrator than a reactor

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 = I2xR (watts)

Electric Motor

MElectricalEnergy

MechanicalEnergy

DC Motor

Model Electric Motor

Beakman Motor

What do you need?1. Electric Energy2. Coil3. Magnetic Field

Electric Generator

GMechanicalEnergy

ElectricalEnergy

Stationary magnets - rotating magnets - electromagnets

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

Generator Phases 1 Phase – 2 Phase – 3 Phase…Smooth Power

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035150

100

50

0

50

100

150

200

250220

110−

V t( )

V 1 t( )

V 2 t( )

V 3 t( )

0.0330 t

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035150

100

50

0

50

100

150110

110−

V t( )

V 1 t( )

V 2 t( )

V 3 t( )

0.0330 t

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035150

100

50

0

50

100

150

200155.563

110−

V t( )

V 1 t( )

V 2 t( )

V 3 t( )

0.0330 t

Polyphase Systems 3 phases for smoother torque delivery

Force Driving Motor (Red)

Single Phase Two Phase Three Phase

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

0

1

2

3

4

5

6

7

8

9

USA

Cana

da

Norw

ay

Russ

ia

Japa

nU.

K.

Mexico

China

India

Afric

a

Bang

lade

sh

Energy Usage Per Capita (1999)T

OE

/per

son-

yea

r

*TOE - Tons of Oil Equivalent (~40 Million Btus)

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 highestconsuming nations combined.

U.S. Renewable Energy Resource Assessment

WindSolar

Geothermal

Temperature <90CTemperature >90CGeopressured resources

o

o

10

10

12

12

14

14

16

16

18

1820

20

2224

26

22 2426

16

14

14

1614

12

10

10

12 <10

10-12

12-14

14-16

16-18

18-2020-22

22-24

24-26

26-28

>28

6.0-6.5 m/s13.4-14.6 mph

6.5-70 m/s14.6-15.7 mph

>7.0 m/s15.7+ mph

Megajoules/m2

Biomass

Agricultural resources & residues Wood resources & residues Agricultural & wood residues Low inventory

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

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