www.canelect.ca
ENVIRONMENTALLY PREFERABLE POWER
CHALLENGES TO DEVELOPMENT:
WIND TECHNOLOGY
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INTRODUCTION
In the wake of increasing environmental concerns, Canadians are becoming more conscious of their electricity sources. Many
provinces are beginning to introduce Renewable Portfolio Standards (RPS) or directing utilities to issue specific requests for
proposals for renewable energy to ensure that there is a certain percentage of renewable energy in the power generation
fleet. In all of these processes, wind is considered an eligible resource. Wind power is a renewable and indigenous source of
energy, making it appealing, particularly given current societal concerns related to global warming. It is important, however,
to recognize that like any other energy generating technology, wind power faces challenges to its deployment.
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UNDERSTANDING WIND TECHNOLOGY
Wind
Wind power is created by a combination of the energy from the sun with the rotation and tilt angle of the earth. This
combination creates constantly changing temperature differentials within the earth’s atmosphere. These differentials cause
the air to circulate, thereby creating kinetic energy in the form of wind. Oceans and land are also factors as they absorb,
release and reflect heat from the sun.
Wind Power Basics
The two basic wind turbine designs are vertical and horizontal axis turbines. Vertical axis turbines are used for some smaller
distributed energy application while horizontal axis turbines are the most commonly used design world wide. Wind turbine
generators (WTGs) work by capturing the kinetic energy of wind and converting it into electricity. Wind turbines are composed
of three main components: the blades, the tower and the nacelle, which contains the shaft, gear box and generator. The
amount of potential energy is determined by the speed of the wind. The height of the tower will determine the wind resource
available, with wind speeds generally increasing with height. When wind blows, it moves the blade, causing a change in pressure between the two sides and stimulating a lift effect. The blades in turn move the shaft, which connects the blades with
the gear box. The gearbox rotates the generator, creating a magnetic field which produces electricity. The electricity from each
WTG is then collected on a distribution feeder line that ties into the local transmission power system. Control equipment adjusts
the phase and frequency of the electricity produced to transmission grid requirements.1
1. Canadian Electricity Association, Handbook on Electricity Generation Technologies (May 1, 2006)
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WIND POWER
IN CANADA
Existing Plants in Canada
Like in many other countries, wind power in Canada is on the
rise. Canada’s installed capacity has experienced an annual
growth of 51% between the years of 2001 and 2006. In 2006
alone there were 776 MW of new installed capacity. By the
end of 2007, Canada’s installed capacity was 1,846 MW. With
an assumed average capacity factor of 30%, this provides
enough energy to power 560,000 Canadian homes, or the
equivalent of 0.7% of the total demand.2
Potential in Canada
There are many factors that make Canada a good candidate for
developing wind energy. The geographic landscape of Canada,
for example, is ideal for many reasons. Canada’s landscape is
a diverse one, from mountains to prairies, as well as having the
longest coastline of any country in the world. This landscape
provides much potential for wind power. Also, wind blows the
strongest in cold winter months – the months when energy
demand is often at its highest in many parts of Canada.
The Canadian Wind Energy Association (CanWEA) has set
itself a target of 10,000 MW of wind energy capacity installed
or contracted by 2010. Initiatives undertaken by Canadian
provinces and utilities are now projected to lead to the installation of several thousand megawatts of WTGs by 2016. The
total amount of wind power that can be added to the Canadian
electricity grid is a function of the technical potential for wind
power in Canada, the cost of wind power as compared to other
options, transmission capacity available to incorporate these
resources and the need to balance the variable nature of wind
power. The Canadian potential has not yet been assessed in
2. Canadian Wind Energy Association (CanWEA) www.canwea.ca
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detail, although many jurisdictions are now undertaking wind
integration studies to determine what levels of wind energy
penetration are possible.3
What further aids the development of this technology is support
from the Canadian government. In the interest of supporting
3. Canadian Electricity Association, Handbook on Electricity Generation Technologies
(May 1, 2006)
renewable sources of energy, the Government of Canada has
provided financial incentives for producers of wind technology.
Canada recently implemented the ecoENERGY Renewable
Incentive (formerly WPPI) program. This program, designed to
support the installation of 4,000 MW of renewable energy
projects in Canada, has already received applications from
10,000 MW of renewable energy projects and is now expected
to fully allocate all of its funding two years before the original
target of 2011.
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BENEFITS OF WIND –
ENVIRONMENTAL AND ECONOMICAL
Environmental
Wind energy’s popularity is due in part to its environmental benefits. Wind is a clean source of energy that does not emit
pollutants into the air or produce toxic or radioactive waste during operation. It is also a renewable source of energy that,
compared to other sources, has fewer environmental impacts. Further, wind has little impact on the surrounding area, with
the exception of aesthetic concerns related to visibility. For these reasons, wind power is touted as a preferred alternative to
other non-renewable energy sources.
Economic:
The cost of power generation from wind has been steadily decreasing in the past decade. In the
1990’s wind energy cost over $0.25 per kilowatt-hour (kWh). Today the cost of wind power is in the
range of $0.08/kWh and up with government subsidies of about $0.01/kWh for qualifying projects.
There are several factors that contribute to this decrease, such as larger scale wind turbines (>1MW)
that decrease the cost per installed kW, more developed technologies and improved (lighter) materials
which make manufacturing more efficient, and reductions in maintenance costs. 4
Economic
Depending on turbine availability and permitting, a wind turbine can be constructed quickly and at a variety of scales (1 MW–
200 MW). With electricity prices on the rise, wind energy is becoming cost-competitive.
Wind energy also provides significant economic benefits to the rural communities where wind projects are constructed. These
take the form of investment, jobs, municipal tax payments and land lease income for landowners.
4. World Energy Council (www.worldenergy.org)
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CHALLENGES TO DEVELOPMENT
Public Acceptance
Before undertaking the construction of a wind farm, it is necessary to ensure that all stakeholders in the project are properly
informed. As with any energy development, the project cannot be developed without the support of landowners, municipal
government and the local community. Given the nature of the project, the developer needs to receive approval and written
agreements from the affected parties, as well as meet provincial, federal and electrical system regulatory requirements. It is
especially difficult for the public to understand the impact of a wind power project if no precedent has been set in the area.
Important steps must be taken to assure the community of project safety standards and to mitigate Not in My Backyard
(NIMBY) concerns.
Economics
There are many economic factors that need to be considered in
order to assess the true cost of wind generated electricity. First,
capital costs of the facility – including grid interconnections
and operational costs – need to be considered. Further to that,
the impact of having to back-up an intermittent source of power
such as wind on a utility’s ability to control the flow of power
in the grid is also an important economic factor.
Although the cost of wind power has been steadily decreasing, even wind proponents are skeptical that this decrease
will continue at such a high rate, given the higher demand
for wind turbines and rising commodity prices such as steel.5
What’s more, countries with a high number of wind projects
have federal support systems which make the projects more
financially viable. At the same time, however, many countries
are now putting in place measures to put a price on carbon
dioxide emissions. This could ultimately diminish or eliminate
the need for direct government support and enhance the costcompetitiveness of wind energy.
5. World Energy Council (www.worldenergy.org)
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Forecasting, Operations and Grid Integration
The first major challenge of operating a turbine is monitoring the wind. Wind farms need precise wind forecasting to guarantee
that back-up generating units on standby take up the load as wind backs off, and that extraneous units are deactivated as wind
comes on-line. Quite simply, accurate wind forecasts maximize the capability of operating plants to support the fluctuations
of wind power.
Moreover, because wind is a variable source of energy, it is vital to understand the true operating capacity factor of a wind
farm before its construction. As well, other conventional generating technologies must substitute for or offset any changes
in demand. This means that wind will always require a stable energy source, like hydro-power or natural gas generation that
can be ramped up and down as a back-up. Further, wind typically blows the hardest when demand on the system is light –
at nighttime, for example, rather than during peak demand time in the afternoon.
Given the intermittent nature of wind, integrating the electricity into the grid can pose many challenges and limit the
output that can be successfully integrated into a power
system. It is important to know how the variability of the
output matches up with the system load throughout the year.
For example, obtaining accurate computer models that forecast wind resources is essential for use in grid interconnection studies. These models, however, are not always available
or are currently under development. Successful integration
with the electrical system requires close communication and
cooperation between numerous groups, including the developer, the off-take utility, the wind turbine manufacturer, the
third party supplier of reactive compensation equipment and
the consultants. This is an effort that should not be underestimated. In many systems, it has been determined that the
maximum output which can be incorporated is about 10-20%
of total installed capacity. That said, some jurisdictions
(e.g., Denmark and Spain) already get more than 10% of their
electricity from wind energy and have significantly higher
wind energy penetration rates in terms of installed capacity.
The Independent Electricity System Operator, however, did a
recent study in Ontario where one year of experience with
400 MW installed had an overall monthly average capacity
factor of 28%. In this study, the month of February had the
highest monthly capacity factor of 43%.6
6. Independent Electricity System Operator “Wind Integration in Ontario” 2007
(www.ieso.ca)
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Backing-up wind
Each power utility is required to have spinning and operating reserves available to quickly replace the loss of the largest
operating unit in their system. With the increased use of wind power in modern systems, this back-up capacity must now be
re-evaluated in order to incorporate wind’s variability. Back-up options can be very expensive to maintain and operate. This
subsequently impacts unit commitment and economic dispatch of operating units. Load following and ramp rates also need to
be considered, so that units can efficiently ramp up and down as well as support the grid system as the wind load fluctuates.
The Utility Wind Interest Group has reviewed wind integration studies across North America and has published documents
that summarize the “state of the art” knowledge with respect to the costs and challenges associated with wind integration.
Maintenance
Frequent start-up and shut-down cycles can negatively impact wind turbines and generate extra maintenance costs. The
complexity of wind technology means turbine technicians and service personnel must be multi-disciplinary, able to perform
numerous tasks from electrical to instrumentation to mechanical work and properly certified in accordance with provincial
legislation. Formal wind turbine technician training programs are required to provide a qualified pool of service technicians
and several such programs are currently operated by wind turbine manufacturers and are now being established at community
colleges across Canada.
Availability (constructability, reliability, availability of materials)
The extremely rapid growth of global wind energy capacity has led to a situation in which the demand for wind turbines
significantly exceeds supply. As a result, the parts for wind turbines are becoming increasingly more difficult to purchase.
There can be long waiting lists for the necessary turbine components, significantly adding to project lead times. Manufacturing
capacity is now being added around the world to address this issue.
Small Power Producer Communities
An increasing trend in wind technology is development in small power producer communities. This presents certain difficulties
because wind power is an expensive technology when used on a small scale. Wind projects are more economical on a larger
scale – typically greater than 20-50 MW.
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CONCLUSION
Although there remain certain limitations to wind power, the technology is continually advancing. Projects are underway in a
variety of companies to develop, for example, large scale storage units that would store energy from turbines to be used when
electricity demand and prices are highest. This would make the large scale use of wind power more economically feasible.
At this time, however, utilities view wind generation as another alternative in the suite of technology options necessary to
maintain diversity in the nation’s power generation fleet. Utilities recognize that diversity is essential, as it helps to deliver
reliable, affordable, and sustainable supplies of electricity to Canadians. It permits the industry to balance the strengths and
weaknesses of various technologies in meeting electricity needs.
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