RNP wishes to thank Tom Gray for permission to post this article
on our web site. The article addresses many of the myths associated
with utility integration of wind power. This article originally
appeared in RE Insider on March 31, 2003.
Utility
Integration of Wind Power
by Tom Gray
Wind
power is a reality today. More than 2,000 MW of wind generation
- enough to serve more than 600,000 average American homes - were
installed in the United States in the past two years alone. With
continued government encouragement to accelerate its development,
this increasingly competitive source of energy can provide at least
six percent of the nation's electricity by 2020, revitalizing farms
and rural communities - without consuming any natural resource or
emitting any pollution or greenhouse gases.
While wind generates only a small fraction (about 0.3 percent) of
U.S. electricity today, another way of looking at that number gives
a different view: to generate the same amount of electricity using
coal would require a train of coal cars more than 500 miles long,
each year.
Perhaps because of its growing success, wind is increasingly becoming
the target of critics within the traditional energy community. They
are disturbed by the fact that the wind does not blow all of the
time, making a wind plant's generation highly variable and thus
quite different from other utility generating options.
As someone who has been actively promoting wind energy since the
late 1970s - spending the bulk of that time with the American Wind
Energy Association (AWEA), the wind industry's only national trade
group - I've had a unique opportunity to follow the progress of
the "case against wind," in all of its various forms,
over time.
Many of the negative assertions that have been made about wind over
the past two decades have had a grain of truth. Yet despite its
modest drawbacks, the wind energy industry has continued to advance
steadily, weathering a difficult policy environment, and now stands
as the "poster child" of the energy crises of the 1970s.
This is not because thousands of people have been hoodwinked into
ignoring the real facts about wind. It is because those facts are
much more positive than critics suggest. Sometimes, common sense
really is a helpful guide: wind energy is attractive because it
is clean, and it is growing because its costs have declined steadily.
In this article, I would like to look at several common complaints
about wind, and then dwell briefly on some little-recognized benefits
of wind-generated electricity.
Complaint: The wind doesn't blow all the time, so it's unrealistic
to count on it to supply all of our electricity needs.
Response:
Why should we require of wind what we don't require of any other
energy source? We don't expect coal, or nuclear, or hydro to do
it all. Why should we expect that of wind? Why would we not opt
instead for a mixed portfolio of all five renewable energy sources,
taking advantage of their regional availability and their complementary
characteristics?
Simply because it is impractical to generate all electricity from
wind, it does not follow that we should not make reasonable efforts
to increase the amount of wind in the utility generating mix. Wind
is far cleaner than the average of that mix and cheaper than most
new alternatives, and is therefore desirable from a public policy
point of view.
The amount of wind in the U.S. generating mix, and in many regional
portfolios, can be substantially increased with little or no operating
difficulty. Wind today stands atroughly 0.6 percent of national
generating capacity, and 0.3percent of electricity supply. Grids
in California and Texas today operate with roughly 10 times that
level of wind energy without difficulty. Grids in Denmark, Germany,
and Spain operate with roughly 100times that level of wind energy
and only now are beginning to think about "special" investments
in order to allow further expansion of wind energy.
Complaint: Electric utilities need "dispatchable" power
plants (plants that can be turned on and off as required)to respond
to electricity demand.
Response:
Critics often suggest that because of its variability, wind cannot
serve a given, steady amount of consumer demand. But it's not that
simple. In fact, electricity demand is a constantly moving target.
The more accurate picture is one of a number of generating plants
moving on and off-line throughout the day to meet that constantly
shifting target. At any one time, only some15 percent of the total
generating capacity on-line is consciously "dispatched"
to keep load and generation in balance. Obviously, a variable generating
source fits into the latter picture much more readily. In fact,
at relatively low "penetrations" (where wind is providing
less than, say, 10-20 percent of the electricity on a system in
any given hour), its variability is essentially lost within the
larger, shifting variability of the system. The rule of thumb -
admittedly rough - is that until wind provides 10 percent to 20
percent of the electricity on an annual average basis, it can be
accommodated without significant added equipment on most transmission
grids.
When nuclear power was first introduced in large amounts to the
U.S. utility system, a number of "special "investments
and changes in operations procedures were required to accommodate
it and the possibility it brought, of large, "lumpy" plants
suddenly going out of service and imperiling system stability. Wind
power is simply another new energy source, with different operating
characteristics, that will require its own set of changes to be
fully integrated.
Complaint:
Because it is too costly, wind energy is being heavily subsidized.
Response:
Wind is not too expensive for widespread commercial application
- new wind plants can and do compete with new generating plants
using other technologies. Today, most new generating plants constructed
in the United States are fueled by natural gas. Yet, new wind plants
are cheaper than new gas plants once the existing stores of natural
gas (roughly seven years)are used up and new capital must be spent
to discover more domestic natural gas or import it from areas of
the world with a surplus.
Utilities in Texas, required by state law to install 400 MW of new
renewable generating capacity by January 1,2003, instead installed
more than 900 MW of wind alone a year early. Why? Because it cost
less than they had anticipated and less than other alternatives
they were considering.
Federal subsidies for wind are dwarfed by those for competing sources.
One recent study[1], for example, found that federal subsidies of
all types for wind, solar, and nuclear over the past 50 years had
totaled US$150 billion - and that nuclear received 95 percent of
the total.
Complaint:
Since a wind plant would generate only 30-40 percent of its total
rated electric capacity over a given period of time, the capital
and operating costs of a conventional plant for the other 60-70
percent of its operation should be included in wind's costs.
Response:
Is this how the economics of, for example, a gas peaker plant that
operates, on average, less than 10 percent of the time are calculated?
No.
The correct way to assess the cost of a wind plant is, first, to
calculate its life-cycle levelized cost of energy (total kWh generated
over the plant lifetime, divided by total costs, adjusted for inflation),
and second, to add or subtract any additional utility system costs
that are specifically required to modify the system to achieve the
same reliability as would have existed but for the wind plant. The
latter incremental costs will indeed slowly rise as more and more
wind is added to a system, and that is as it should be.
A real-world example of a high-wind utility system can be seen in
western Denmark, where the utility ELTRA obtains more than 100 percent
of its electricity from wind during some low-load hours of the year
(the surplus is exported), and where wind constitutes more than
50 percent of required system capacity and non-dispatchable small
combined-heat-and-power plants constitute another 30 percent. If
the criticism were correct, such a system should be either inoperable
(due to its lack of dispatchability), fantastically expensive, or
both. Neither is the case. ELTRA is indeed planning to make changes
to its system to improve its operations and to accommodate new offshore
wind farms, but there is no indication that a wholesale shift away
from wind is needed or desired.
Complaint:
When the wind blows, other power plants must be throttled back in
response. Such throttle-backs cost consumers and should be included
as an extra cost of wind energy.
Response:
In fact, the "throttle-backs" ALWAYS SAVE money. The plant
that throttles back is, by definition, the highest-cost, least-efficient
plant on the system at the time the wind picks up. The incremental
wind energy, by definition, costs almost zero and avoids the expense
of fuel consumption on these "marginal" plants.
In addition, the criticism assumes that emissions reductions have
no value. If in fact they do have value - in reduced human health
and environmental cleanup costs - then the throttle-backs doubly
BENEFIT us all. The plants that are throttled back to make room
for the "free" incremental wind energy are almost always
the dirtiest as well as the highest cost plants. When the average
U.S. utility generating mix is used to generate as much electricity
as a single 1 MW wind turbine, 10 tons of sulfur dioxide and 6 tons
of nitrogen oxides are emitted each year, as well as2,000 tons of
carbon dioxide, the leading greenhouse gas.
As indicated above, power plants must throttle back anyway, and
shut down, and come on-line again, to meet fluctuating customer
demand during the course of a normal day. The question is, what
additional variability does a new wind plant contribute to that
already-dynamic situation? Only that added variability - and any
operations costs associated with it - can fairly be assessed against
the wind plant.
These
are some common complaints about wind. But this promising new energy
source offers a series of benefits for utilities that are often
unrecognized. For the benefit of policymakers, here is a brief check
list to be considered [2]:
1. Wind's fuel cost is constant, providing added value as a hedge
against sudden, unexpected increases in the cost of other fuels
such as is currently occurring with natural gas.
2. Cost-competitive with traditional generation technologies.
3. No emissions to manage.
4. No flammable or hazardous fuels to manage.
5. No high-pressure steam to manage.
6. No water resources to manage.
7. Breeds new life into a power business that is otherwise matured
(leading to new innovations, etc.).
8. Will require that the national transmission grid be improved,
making power in general more reliable.
9. An upgraded transmission network(required for the wind industry)
will allow the competitive wholesale market to work more effectively.
10. A new industry attracting a well-paid professional work force
(engineers, skilled technicians, etc.).
11. Wind power offers new opportunities in rural areas, many of
which are in economic decline.
12. The limited onsite operations support required by wind farms
will not overtax the limited resources available in a rural setting.
13. Wind farms bring new opportunities for tourism to local rural
communities.
14. Wind farms create a new tax base in rural areas.
15. Wind farms will create demand for new support organizations
(more heavy lift cranes, more independent electricians, etc.).
16. An expanded U.S. wind industry will attract manufacturers that
are currently overseas.
17. The wind industry will create new ways to look at grid power
management that will open the door for other emerging technologies
(electricity storage, etc.).
18. Wind power will create the demand for more education support
systems ("wind smith" training programs expanded engineering
programs, etc.).
19. Wind farms will help to safeguard the nation's energy supply
by increasing the number of dispersed generation stations (not an
attractive target for terrorists).
20. The wind industry will lead to new alliances that will create
greater understanding overall (alliances between environment groups
and energy companies, etc.).
21. Successes with government wind policies will lead to similar
policy innovations for other industries.
22. Wind plants improve the nation's energy security because they
do not require imported fuel.
23. Wind plants improve the nation's energy security because they
do not require a fuel transportation infrastructure.
24. No fuel waste residues to manage.
25. Wind plants are compatible with existing land uses (farming,
ranching) in many rural areas.
26. No fuel resource depletion.
27. Wind farms are modular and can be installed as demand expands,
reducing investment risk.
28. Wind farms are modular, reducing the probability of overall
plant outages due to equipment failure.
29. Wind plants can be installed quickly if required in response
to energy market conditions.
30. No fuel resource extraction (with attendant management issues
and costs).
31. Adds diversity to generation portfolio, reducing business risk.
32. Wind farms can help preserve family farms by providing added
income.
33. Where hydro is the dominant generation source, wind farms can
help to extend hydro supplies in times of drought.
The
bottom line? Wind energy's success in the marketplace, quite simply,
reflects the attractiveness of the technology. On balance, it is
the most attractive new energy source available to the utility industry
today.
****
References:
[1] Federal Energy Subsidies: Not All Technologies Are Created Equal,
Marshall Goldberg, Renewable Energy Policy Project 2000. Available
on the Web at
http://www.repp.org/repp_pubs/articles/resRpt11/subsidies.pdf
[2] Many of the items in this list were originally suggested in
2002 by Steve Williams, a communications consultant formerly employed
by American Electric Power.
****
About the Author: Tom Gray is Deputy Executive Director and Director
of Communications for the American Wind Energy Association, which
he joined in 1980 as manager of its then newly-developed wind energy
standards program. He has served AWEA in a number of capacities
over the years, including a nine-year stretch as Executive Director
(1981-1989). He currently directsits communications operations (newsletters,
news releases, publications, Web site, Internet chat lists, etc.)
and is also responsible for following avian-wind power interaction
issues. Gray has a B.A. from Haverford (Pa.) College and a J.D.
from the Catholic University of America. He can be reached at: tgray@awea.org
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