1. ECE 476 POWER SYSTEM ANALYSIS Lecture 1
Alejandro D. Dominguez-Garcia
Material borrowed from Prof. George Gross

2. OUTLINE The importance of electricity
The US electricity industry – past and present
Electricity generation
Nature of electric demand
The energy supply and demand picture
A brief overview of renewables

3. CRITICAL IMPORTANCE OF ELECTRICITY
Energy is the lifeblood of modern society
The importance of electricity is on the rise, e.g., electrification of transportation
Efficient and environmental electricity services are key or the nation’s global competitiveness
Electricity is a $247 billion plus business annually in the U.S.

4. U.S. ENERGY AND ELECTRICITY DEMAND
300
1980 = 100%
250
200
electricity use
150
CO2 emissions
energy use
100 50
historical
forecast
1980
1990
2000
2004
2010
2020
2030

5. Professor of Electrical Engineering, MIT
A VIEW OF THE POWER GRID
Fred C. Schweppe ( )
Professor of Electrical Engineering, MIT
US Power grid
“I worked on aerospace problems for many years before converting to power systems, and, in my opinion at least, power problems are tougher in many respects.
...
The number of variables [in a power system] is huge, and many types of uncertainties are present.
Few if any aerospace problems yield such a challenging set of conditions.”
– Fred. C. Schweppe, 1970 5

6. IMPACTS OF ELECTRICITY
The National Academy of Engineering, the U.S.’s most prestigious collection of outstanding engineers, named electrification – the development of the vast networks of electricity that power the world – the most important of the twenty engineering achievements that have had the greatest impact on the quality of life in the twentieth century
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7. IMPACTS OF ELECTRICITY
Electricity ranked ahead of the automobile, airplane, safe and abundant water, electronics, computers and space exploration
The widespread electrification implemented in the twentieth century gave us power for our cities, factories, farms and homes, forever changing the lives of people
huston-no this page

8. OUTLINE The importance of electricity
The US electricity industry – past and present
Electricity generation
Nature of electric demand
The energy supply and demand picture
A brief overview of renewables

9. THE BEGINNINGS
Commercial use of electricity began in the late 1870’s with the development of arc lamps for street lighting and lighthouse illumination
The first complete electric power system, comprising a generator, cable, fuse meter and loads, is considered to be Edison’s Pearl Street Station in New York in 1882
DC system with a DC generator supply
59 customers in a 1 mile radius area

10. 1882 EDISON POSTER ON ELECTRIC LIGHTING
You can find this plate in the washrooms of the Courier Café in downtown Urbana.

11. THE BEGINNINGS
Actually, George Roe had founded in 1879 an electric company in San Francisco, which later became part of PG&E
the first plant in the nation to offer central station electric service to the public
two brush arc-light dynamos supplied 21 lights for service from sundown to midnight – Sundays and holidays excluded – for $ 10 per lamp per week

12. MAJOR DEVELOPMENTS
Frank Sprague developed electrical motors in 1884; within a short time, he incorporated them into the electricity system
The major limitations of DC systems became apparent by 1886:
ability to deliver power over only short distances
need for high voltages for longer distance transmission; such voltages were too high for generation and consumption

13. MAJOR DEVELOPMENTS
Gaulard and Gibbs developed the transformer and AC transmission, the forerunners of the AC transmission systems in use today
George Westinghouse bought U.S. rights immediately to the technological developments of Gaulard and Gibbs
In 1889, the first AC transmission line in North America was put into operation between Willamette Falls and Portland – a single phase –kV 21–km line

14. MAJOR DEVELOPMENTS
A major important development was Tesla’s invention of induction motors and polyphase systems
Westinghouse purchased the rights to Tesla’s inventions on AC motors, generators, transformers and transmission systems
Westinghouse was instrumental in the construction of the basis of today’s AC grid

15. MAJOR DEVELOPMENTS AC won out over DC because
the ease of transformation of voltage levels thereby providing the flexibility of using different voltage levels for generation and transmission consumption
the increased simplicity of AC over DC generators
the increased simplicity and lower costs of AC over DC motors
AC replaced DC over a very brief time period

16. MAJOR DEVELOPMENTS
In 1893, the first three–phase transmission line in North America went into service; it was a 2.3–kV, 12–km line in Southern California
Niagara Falls was connected to Buffalo – a 30–km distance – using AC since DC was not practical

17. TECHNOLOGICAL DEVELOPMENTS
Pressures to transmit larger amounts of power over larger distances led to higher voltages
early systems: 12, 44 and 66 kV (RMS line–to– line)
1922: 165 kV
1923: 220 kV
1935: 287 kV
1953: 330 kV
1965: 500 kV
1966: 735 kV (Hydro Quebec)
1969: 765 kV (American Electric Power)

18. TECHNOLOGICAL DEVELOPMENTS
Standardization of voltage levels led to voltage classifications
115, 138, 161 and 230 kV are high voltage ( HV )
345, 500 and 765 kV are extra high voltage ( EHV )
The development of mercury arc valves in the early 1950’s makes HVDC economical in specific cases: transmission of larger blocks of power over longer distances

19. TECHNOLOGICAL DEVELOPMENTS
Eventually, the various frequencies in use – 25, 50, 60, 125 and 133 Hz – standardized to 60 Hz in North America; there are many parts of the world where the frequency is 50 Hz today
DC becomes economic over AC for distances greater than
500 km for overhead lines
50 km for underground/submarine cables

20. ELECTRIC TRANSMISSION LINES IN THE U.S.
Legend
Cooperatives
Federal
Independent Transmission Companies
Other Public Power
Shareholder-Owned
Copyright 2003 Edison Electric Institute. Source: POWERmap, © Platts, a Division of the McGraw Hill Companies. 20

21. THE ELECTRIC POWER SYSTEM21

22. INDUSTRY STRUCTURE
Brutal and inefficient competition was rife in electricity
24 central station power companies were established in Chicago between 1887 and 1893
exhaustive duplication and fierce competition led to high costs

23. INDUSTRY STRUCTURE
Samuel Insull built a monopoly over all central station production in Chicago and is considered the father of the regulated monopoly:
“exclusive franchises should be coupled with the conditions of public control, requiring all charges for services to be based on a cost plus a reasonable profit”
In 1907, New York and Wisconsin set up commis–
sions to regulate electricity

24. THE VERTICALLY INTEGRATED UTILITY INDUSTRY STRUCTURE
customers
customer service
Customer Service
distribution
Distribution
transmission
Transmission
self-
generation
Independent power producers
generation
Generation

25. COMPETITION IN THE GENERATION MARKET
The 1978 Public Utility Regulatory Policies Act (PURPA) unleashes competition through the introduction of qualifying facilities (QFs)
PURPA mandates each investor–owned utility to purchase power at avoided cost from QFs located in its service territory
Implementation of PURPA was left to individual states resulting in non-uniform implementations
The once fledgling private power enterprises constitute today a multibillion dollar industry whose role in the electricity business is critically important

26. ENERGY SOURCES OF NON UTILITY GENERATION (NUG) CAPACITY
geothermal 0.7%
waste 1.5%
wind 1.7%
hydro 2.1%
natural gas 59.0%
nuclear 8.3%
other 3.1%
coal 17.8%
oil 5.7%
Source :Energy Information Administration, Existing Electric Generating Units in the United States, 2005

27. INCREASING ROLE OF NUG billion kWh 1000 2000 3000 4000 5000 1994 1995
non-utility
utility
1000
2000
3000
4000
5000
1994
1995
1996
1997
1998
1999
2001
2002
2003
2004
2005
billion kWh
Source : EIA, Net Generation by Energy Source by Type of Producer, 2006

28. U.S. ELECTRICITY CUSTOMERS
140
120.76
120
total consumers = million
100 80
million consumers 60 40
16.87 20
0.73
0.001
commercial
other
residential
industrial
Source : Energy Information Administration, Form EIA-861, “Annual Electric Utility data” released November 2006

29. US ELECTRICITY SALES IN 2005
total sales: 3,660 million MWh
residential
1,356 TWh
industrial
1,275 TWh
commercial
1,019 TWh
other
7.5 TWh
total revenues: $ 228 billion
other
$ 0.6
billion
commer-cial $ 58 billion
residential
$ 128 billion
industrial
$ 110 billion
Source : Energy Information Administration, Form EIA-861, “Annual Electric Utility data” released November 2006

30. U.S. ELECTRIC UTILITY INDUSTRY
2,015
2000
total number = 3,285
number of entities
884
1000
219
158 9
coope-rative
investor
owned
publicly
owned
power
marketer
federal
Source : Energy Information Administration, Form EIA-861, “Annual Electric Power Industry Report,” November 2005