THE NORTH AMERICAN ELECTRICAL
GENERATION, TRANSMISSION AND
DISTRIBUTION NETWORKS
A report submitted to the Department of Electrical and Computer Engineering (ECE), McMaster
University, Hamilton, Ontario, Canada, as part completion of course Elec. Eng. 4PL4.
2013
by
Zeeshan Ashraff
Department of Electrical and Computer Engineering (ECE)
2
CONTENTS
LIST OF TABLES 3
LIST OF FIGURES 3
ACKNOWLEDGEMENTS 4
ABSTRACT 4
CHAPTER 1: INTRODUCTION
1.1 Typical Electric System 5
1.2 Historical Development of the Electric Power Industry 5
CHAPTER 2: GENERATION
2.1 Resources 6
2.2 Electricity Generation in Canada 6
2.3 Electricity Generation in the United States 8
CHAPTER 3: TRANSMISSION
3.1 Energy and Power 8
3.2 System Design and Transmission Lines 9
3.3 Flows Around the Continent 10
CHAPTER 4: DISTRIBUTION
4.1 System Design 11
4.2 Network Configurations 12
4.3 Electricity Distribution 12
CHAPTER 5: FUTURE REQUIREMENTS AND DEVELOPMENTS 14
CHAPTER 6: PERSONAL VIEWPOINT 14
REFERENCES 15
Word count of main text(excluding acknowledgements and abstract): 3, 002
3
LIST OF TABLES Table 2.1 Monthly variations in electricity generation in Canada in 2010 (MWh) 5
Table 3.1 Electric power delivered to other provinces (by each province) in 2020 in MWh 11
Table 3.2 Electric power delivered to the U.S. (by each province) in 2012 in MWh 11
LIST OF IMAGES Figure 1.1 Typical electric system 5 http://www.centreforenergy.com/AboutEnergy/Electricity/Transmission/Overview.asp?page=1
Figure 2.1 Electricity generation in Canada by fuel type (2012) 6 http://www.parl.gc.ca/content/lop/researchpublications/cei-26-e.htm
Figure 2.2 Generation by year and fuel type 6 http://www.electricity.ca/media/Electricity101/Electricity101.pdf
Figure 2.3 Electricity generation in Canada by province and fuel type (2012) 7 http://www.electricity.ca/media/Electricity101/Electricity101.pdf
Figure 2.4 Electricity generation by source in the U.S 8 http://en.wikipedia.org/wiki/File:2008_US_electricity_generation_by_source_v2.png
Figure 3.1 Length of transmission lines in Canada by voltages (kilovolts) 9 http://www.electricity.ca/media/Electricity101/Electricity101.pdf
Figure 3.2 Electrical transmission across North America 10 http://www.eia.gov/todayinenergy/detail.cfm?id=8930
Figure 3.3 2010-2011 Monthly Canadian Electricity Exports to and Imports from the U.S. 10 http://www.neb-one.gc.ca/clf-nsi/rpblctn/rprt/nnlrprt/2011/nnlrprt2011-eng.html
Figure 3.4 Canada U.S. electricity trade volume from 1990 to 2012 11 http://powerforthefuture.ca/data-world/
Figure 4.1 List of the 10 largest Canadian electric utilities in 2009 13 http://en.wikipedia.org/wiki/List_of_Canadian_electric_utilities#cite_note-2
Figure 4.2 Canada U.S. electricity trade revenue 13 http://powerforthefuture.ca/data-world/
Figure 4.3 Price in cents/kWh for different hours in a day (Ontario) 13 http://www.ontarioenergyboard.ca/OEB/Consumers/Electricity/Electricity+Prices#tiered
Figure 5.1 Future electricity generation 14 http://www.neb-one.gc.ca/clf-nsi/rnrgynfmtn/nrgyrprt/nrgyftr/2011/nrgsppldmndprjctn2035-eng.html
Figure 5.2 Forecast of energy demand by sector 14 http://www.globe-net.com/articles/2011/november/23/canada's-energy-future-secure-to-2035/
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ACKNOWLEDGEMENTS
First and foremost, I would like to thank my supervisor, Prof. N. Schofield for being a great
mentor. Prof. N. Schofield’s endless support in the form of supplying a diverse collection of
resources made the successful completion of this report possible. Moreover, I must extend my
gratitude towards the Teaching Assistants for their tireless efforts in passing on their knowledge
of Energy Management and Systems.
ABSTRACT
This report focuses on the North American electrical generation, transmission and distribution
industry. Although mentions of the industry are made, due to report length limitations, technical
data is only presented from the Canadian industry. This report comprises of mainly the technical
attributes of the industry, in addition to economic, geopolitical and societal aspects. Firstly, the
origins and evolution of the industry is examined. Subsequently, various methods of Electrical
generation, and the value of the accompanying generated power and voltage levels are examined.
Comparisons of levels of energy generated in different provinces (Canada) and states (USA) are
made, along with annual variations. The distinction between electrical energy and electric power
is made, and differing methods of transmission are discussed. Next, the technical as well as
economical issues are covered, exploring the financial structures. Future requirements are
mentioned and solutions to meet those requirements are stated. Finally, the author’s personal
viewpoint on how to ensure successful development of the industry concludes the report.
5
CHAPTER 1: INTRODUCTION
1.1 Typical Electric System
Figure 1.1 Typical electrical distribution system
Figure 1.1 captures the essence of a
typical electrical system. The electric
delivery system comprises of generation,
transmission, and distribution. Chapter 2
focuses on the generation aspect,
whereas, chapters 3 and 4 illustrate the
transmission and distribution of
electricity, respectively. [10]
1.2 Historical Development of the Electric Power Industry
One of the key figures behind the realization of the first centrally located power station is the
celebrated inventor Thomas A. Edison. Shortly after completion of his light, the induction of
Edison’s Pearl Street Station (New York City) on September 4, 1882, launched the electric utility
industry [1]. At first, steam driven direct current (dc) generators, called dynamos, provided a load
of 30 kilowatts (kW) for incandescent lighting to 59 customers. Voltage issues caused by
increasing loads and transmission lines were resolved by the development of a commercial
transformer by William Stanley. In 1893, Nikola Tesla’s, three-phase induction motor further
encouraged the growth of ac systems, eventually becoming a staple in the industry. As time has
progressed, the load requirements have grown at a rapid rate, leading to “increases in sizes of
generating units” [1].
Meanwhile, in Canada, 1883 marked the lighting of several major Canadian locales, in addition
to Canada’s first single-phase AC generators being commissioned in Calgary and Ottawa.
Subsequently, in 1891, the Canadian Electrical association was formed, followed by the
construction of the world’s largest generating station in Niagara Falls. 1901 began the electricity
trade between Canada and the United States [2]. Later, in 1921, Ontario Hydro’s Sir Adam Beck
No.1 in Niagara falls was erected to be the world’s largest power plant. Two decades later, the
Quebec Hydro-Electric Commission and the British Columbia Power Commission were formed
in 1944 and 1945, respectively. Ontario’s (and Canada’s) first nuclear power plant became an
6
active member of Ontario’s Hydro grid in 1962. Eventually, the number of power plants in
Canada would grow to 22, 20 of which are situated in Ontario [2].
CHAPTER 2: GENERATION
2.1 Resources
As previously mentioned, the first step in electricity delivery is the generation. This chapter
covers the various resources and methods used for electricity generation in different parts of the
continent. To this day, hydroelectricity remains the key source of Canada’s electric supply
(63.1%). Advantageous geographic locations near large bodies of water, have allowed Quebec,
British Columbia, Ontario and Manitoba have allowed for the existing hydropower to have a
Figure 2.1 Electricity generation in Canada by fuel type (in 2012)
capacity of over 80 million kilowatts [3]. In
2009, coal was responsible for 17.4% of
Canada’s electricity, whereas natural gas
produced 4.1%. Fossil fuels are vital for
electricity generation in Alberta and
Saskatchewan. Making use of the CANDU
reactor, nuclear power accounted for 14.8% of
electricity generation in 2009. Lastly, biomass
and non-hydro renewable resources such as
wind and solar power account for the remaining share. Figure 3 illustrates the different fuels used
for electricity generation in 2012 [3].
2.2 Electricity Generation in Canada
Figure 2.2 displays the levels of generation by
fuel type ranging from 2000 to 2012. It can be
inferred from the graph that electrical generation
in Canada is fairly steady from year to year. In
2012, Canada produced 594.9 TWh of electricity,
nearly the same amount produced in 2000. The
utilization of hydro has been fairly constant.
Canada’s impressive hydroelectric industry is the
2nd largest one in the world, ranked just after
Figure 2.2 Generation by year and fuel type. China’s. The usage of nuclear and wind power have experienced an increase. Contrastingly, the
decline in usage of conventional steam is also obvious. Figure 2.3 illustrates the electricity
7
generation in Canada by province as well as fuel type. Due to its expansive hydroelectric
industry, Quebec comfortably leads the way in electricity generation, producing 197.6 TWh in
2012. Next in line is Ontario, making use of its nuclear and hydropower, producing 140 TWh in
the same year [4]. British Columbia, Newfoundland, and Manitoba produce vast majority of their
electricity employing hydropower as well. Alberta and Saskatchewan depend mainly on
conventional steam. The Maritime Provinces rank relatively low on the electricity generated
table, whereas the northern territories are nearly negligible.
Figure 2.3 Electricity generation in Canada by province and fuel type (in 2012)
Table 2.1 Monthly variations in
electricity generation in Canada
in 2010 (MWh)
Shifting our attention to table 2.1, the trend in Canada’s monthly variations in electrical
generation by month can be identified. As expected, due to Canada’s harsh winters, demand for
electricity reaches its peak in the winter months. In 2010, January and December were the most
prolific months for electrical generation. However, as the temperature gradually becomes milder
until June, so does the demand for electrical generation. This value rises again slightly during the
hottest months of the summer. Table 2.1 clearly shows the correlation between the temperature
and electricity generation in Canada.
The pattern of daily variations in demand of electric power is a predictable one. For instance, as
previously mentioned, Ontario uses nuclear and hydroelectric stations to fulfill its baseload
requirements. Typically, demand for electricity is at its lowest point during the earliest hours of
the day (2 AM to 7 AM) [4]. However, once business hours commence, the demand increases
until reaching its peak in midday. To accommodate this rise in demand, Ontario utilizes thermal
generating stations. Unlike nuclear stations, thermal stations are able to adjust their level of
electricity output [4]. It is important to note that electricity, when leaving a generating plant, is at
8
a relatively low voltage. Generally, in Ontario, electricity is generated at less than 25 000 V [5]. It
is only after this point that the voltage is stepped up, allowing for transmission over long
distances.
2.3 Electricity Generation in the United States
The proportions of methods of electrical generation and resources in the U.S. differ from the ones
in Canada. A large portion of power in the U.S. is generated via fossil fuels, with coal
accounting for 42% of the 4 trillion kilowatt hours [6]. Additionally, 25% of U.S.’s electric
Figure 2.4 Electricity generation (%) by source in the U.S.
power is generated through natural gas. Nuclear power
is responsible for approximately 1/5 of the electricity in
the U.S. In stark contrast to Canada, where hydropower
is accountable for approximately 60% of the generated
electricity, U.S.’s hydropower contributes just 8%. The
remaining portion comprises of biomass, wind power,
geothermal and solar power [6].
CHAPTER 3: TRANSMISSION
3.1 Energy and Power
The distinction between energy and power is not one that is easily made. “Energy is a measure of
how much fuel is contained within something, or used by something over a specific period of
time” [9]. As far as electricity is concerned, the kilowatt hour (kWh) is the measure of energy.
“Power is the rate at which energy is generated or used” [9]. One unit of power is termed the
kilowatt (kW). It is important to note that technically speaking, energy is neither generated, nor
is it used, but converted from one form to another. Consider the case of two households. “House
1” uses a 100-watt light bulb over a period of 10 hours. On the other hand, “House 2” uses ten
100-watt light bulbs over a period of 1 hour. In both cases, 1 kWh of energy is consumed. Since
“House 1” is using a single 100-watt light bulb, the electric utility must be capable of providing
0.1 kW of power. In the case of “House 2”, ten 100-watt light bulbs demand a readily available
power of 1 kW [10].
3.2 System Design and Transmission Lines
Following the generation, the intermediate step in electricity delivery is the transmission. The
major loss of electricity during transmission occurs in the form of heat loss in the lines, due to
9
high current. Knowledge of the equation P = VI reveals that a low voltage paired with a high
current produces the same power as a high voltage paired with a low current. So, to
diminish the loss levels, electricity is transmitted with high voltage and low current.
High voltage transmission lines, ranging from 69 kilovolts to 735 kilovolts, are employed in
junction with transformers to carry electricity efficiently over long distances. After the initial
generation, step-up transformers located in substations are used to increase the voltage, before
entering the transmission lines. Similarly, after passing through the transmission lines, the
electricity passes through step-down transformers, located at utility substations, so it can be
distributed domestically, commercially, and industrially.
Figure 3.1 Length of transmission lines in Canada by voltages (in kilovolts)
In Canada, overhead AC transmission
lines (carrying 3 phase currents in three
lines) and underground cables are
employed for the transmission of
electricity. Although underground cables
are employed in urban areas or in cases
where bodies of water must be crossed,
most of Canada relies on overhead
transmission. Figure 3.1 shows the
lengths of transmissions lines by voltage.
Contrastingly, underground cables are
simply buried with either no protection or
placed in conduits, trenches or tunnels
[12].
High Voltage DC (HDVC) lines are used for transmission of large amounts of power over long
distances. The reason HDVC lines are preferred for this is due to the power loss over long
distances in AC lines, as well as the lower costs associated with direct current [15].
3.3 Flows Around the Continent
Canada’s transmission system boasts of over 160, 000 kilometers of transmission lines,
10
capable of carrying electricity at high voltages. Interconnected grids, traversing provincial and
international boundaries allow for the buying and selling of power from various suppliers [12].
The three Canadian power grids are the Western grid, the Eastern grid and the Quebec grid.
Canada’s transmission lines follow a north-south pattern, to allow northern generation sites to
transmit electricity to more populous areas to the south. Although east- west provincial
Figure 3.2 Electrical transmission lines across North America
transmissions do occur, they are much rarer
than their north-south counterparts. Similarly,
the three grids in the U.S. grids are called the
Western, the Eastern, and the Texas
Interconnections. Logically, the Western
Canadian grid is tied to U.S.’s Western
interconnection, whereas the Eastern grid is
tied to the Eastern interconnection [12].
Figure 3.3 Monthly Canadian Electricity Exports to the U.S. and Imports from the U.S.
As can be seen in figure 3.3, Canadian electricity exports to the U.S. exceed the imports from the
U.S. on a monthly basis. This can be explained by excess production on Canada’s part, as well as
the U.S.’s high demand for electric power. Clearly, the exports to the U.S. are far greater
throughout the year, barring the months of September, October and November, where the import
is relatively close to the export. The rise in exports in 2011 when compared to 2010 is explained
by higher precipitation, which resulted in a much higher supply of hydroelectricity. In 2011, total
exports equaled 53 gigawatt hours (worth C$2.1 billion), whereas imports totaled 17 gigawatt
hours (worth C$385 million) [14]. Trading allows for increase in revenue for sellers by selling
excess energy that would go to waste.
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Seasonal conditions often dictate trading. Generally, demand for electric power peaks during the
winter in Canada and during the summer in the U.S. Additionally, hydroelectric utilities may
increase production during peak demand hours to sell electricity at a more profitable price.
Accordingly, they would reduce production during off-peak hours and import electricity at a
lower cost. In 2012, Canada exported 57.9 TWh of electricity to the U.S., and in return, imported
10.9 terawatt hours, making Canada a net exporter. This North American electricity trade allows
for more efficient operation of generators [7][8].
Figure 3.4 Canada U.S. electricity trade volume from 1990 to 2012
Table 3.1 displays how much electricity was delivered by each province to other provinces in
2012. Similarly, Table 3.2 shows the electricity delivered to the U.S. by each province.
Table 3.1 Electric power delivered to other provinces (by each province) in 2020 in MWh1
Table 3.2 Electric power delivered to the U.S. (by each province) in 2012 in MWh1
CHAPTER 4: DISTRIBUTION 4.1 System Design
Distribution substations act as the interface between transmission and distribution lines. Using
substation transformers, distribution substations reduce the voltage from high transmission levels
(115-735 kilovolts) to much lower levels (less than 39 kilovolts). In addition to the step down
transformer, substations comprise of four major components, including circuit switches, high
voltage breakers, voltage regulators, and capacitors [16]. Once the substation has accomplished 1 ‘…’ indicates not applicable in tables 3.1 and 3.2
12
its task, the electricity is ready to be distributed to end-users via the distribution line. Primary
distribution lines at voltages circa 39 kilovolts supply electricity directly to large industrial and
large commercial customers. For residential and small commercial/industrial users, the
distribution transformer comes into play, stepping down the voltage even further. The standard
voltage level for most industrial facilities is 480 volts and the corresponding value for residential
services ranges from 120 to 240 volts (at 60 Hz). The lines used to carry power from the
distribution transformers to the customer’s meter is called the secondary distribution line [16].
Standard primary distribution levels include 4.16 kV, 7.2 kV, 12.47 kV, 13.2 kV, 14.4 kV, 23.9
kV and 34.5 kV. Secondary standard voltage levels are 120/240 (single phase), and 120/208 (3
phase), 277/480 (3 phase).
4.2 Network Configurations
Currently, three basic designs, radial systems, loop systems and network systems, are the models
of choice when it comes to planning distribution systems [17]. The radial system, the most
inexpensive system to construct, is also the most unreliable one. In this system a single power
source is employed for a group of distribution customers. Next, the loop system literally loops
through entire service areas. Apart from its primary source a loop system is also connected to an
alternative power source, allowing for the distribution utility to supply electricity to customers
from either power source. Finally, a network system is the most complex of the three systems. A
network system is an interconnected loop system capable of supplying electricity from two or
more different power suppliers. This design is used in areas with high population densities.
However, the network system’s reliability comes at a price, making the network system the most
costly of the three systems [17][18].
4.3 Electricity Distribution
Distribution companies in Canada are owned by either different levels of government, or by
private investors. Major changes in provincial structures are being implemented, separating
generation, transmission and distribution. This will result in greater competition, leading to lower
costs and more options for customers. For instance, over 90 publicly and privately owned local
electricity distribution companies carry out electricity distribution in Ontario, where each
company manages their own area’s network distribution wires and customer billing [19]. Figure
4.1 presents a list of the 10 largest Canadian electric utilities.
13
In Canada, electricity pricing is determined by location, volume, type of generation and whether
prices are market-based or regulated. Alberta has shifted the furthest away from regulation,
Figure 4.1 List of the 10 largest Canadian electric utilities in 2009 restructuring towards more market-based electricity prices, whereas Ontario has partly
restructured its electricity market, moving away from regulation. However, the remaining
provinces and territories have stayed with electricity regulation. Generation, transmission,
distribution (within the province), restructuring, and electrical prices are controlled provincially.
Figure 4.2 Canada U.S. electricity trade revenue
Figure 4.3 Price in cents/kWh for different hours in a day (in Ontario)
Most electricity users in Ontario are required to pay time-of-use prices, off-peak, mid-peak, and
on-peak, as seen in figure 4.3. Using smart meters, utilities can determine the exact usage of
electricity, as well as time of usage. The other option available to Ontario users is fixed contracts
from electricity retailers, involving a fixed rate separate from time-of-use or tiered pricing [21].
CHAPTER 5: FUTURE REQUIREMENTS AND DEVELOPMENT
Electricity supply projections are demand-driven. Canada’s steadily rising population paired with
economic growth increases the electric energy demand [22]. As figure 5.1 shows, Canada’s
electricity generation is expected to rise under various projections. Despite significant
14
investment, ultimately costs will rise for customers [23]. Additionally, the total generation
capacity is expected to increase by 27% by 2035, from 133 GW in 2010 to 170 GW in 2035.
Figure 5.1 Future electricity generation
Although increases will occur in each
province, the larger generators of
electricity (Quebec, Ontario, British
Columbia and Alberta) will
experience the most increases [23].
Figure 5.2 displays the projected
increase in export (to the U.S.) and
interprovincial demands. Also, “If
large hydro developments in
Newfoundland and Labrador, Quebec,
Manitoba and British Columbia are
constructed, these projects will require
substantial additions to the transmission
systems.” [24].
Figure 5.2 Forecast of energy demand by sector
CHAPTER 6: PERSONAL VIEWPOINT
The goal for the future should involve a shift towards utilization of more renewable resources.
Further development in solar and wind power, along with an increase in the usage of hydropower
should be Canada’s objective by 2050. Presently, usage of solar and wind power are deterred by
high costs and lack of reliability, accounting for less than 2% of total electricity generated.
Through heavy investment in research of these two resources, they should account for roughly
10% by 2050. More hydroelectric plants would allow for more export of energy to the U.S., as
well as provinces that rely on non-renewable resources. Increased exports of hydroelectricity
would reduce the U.S.’s reliance on coal. More east-west transmission lines should be
constructed to allow for interprovincial trade, and Alberta and Saskatchewan would be
encouraged to shift away from the usage of fossil fuels. This would be accomplished by better
transmission lines carrying electricity from B.C. More provinces would follow Alberta’s
example, by stepping away from regulation and towards markets. Simply, this allows more
options for the end user, letting them choose which method of payment suits them best.
15
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