Minnesotans For Sustainability©
Sustainable Society: A society that balances the environment, other life forms, and human interactions over an indefinite time period.
(Part 1 of 3)
Minnesota’s Energy Future:
Minnesota Senate: Commerce and Utilities Committee
Wind Power in Minnesota
February 26, 2003
Minnesota’s Energy Future: Evaluating Windpower©
The power of the wind is promoted as an alternative method of meeting electricity demand. The implication is that it virtually requires no other energy source but free and non polluting “wind”, the ideal perpetual motion notion.
Windpower is a wonderful sounding idea that is fanciful thinking. There are a number of drawbacks that persuade against its development: frequently it is windy when not needed, calm when electrical demands are greatest, and windpower can be only a local or regional and minor electrical contributor at best. Perhaps its greatest positive feature is that windturbines can be relatively quickly constructed. At worst, windpower is yet another energy sink requiring more energy to develop and maintain a site and to deliver its energy than the energy derived from it.
The capital invested and price increases discernible in windcommerce would lead to a more sustainable future using modern efficient coal technologies.
In brief, windpower:
A “farm” growing energy, it’s not. Trying to instill a positive image, “farm” is the wholesome sounding name frequently given to windpower developments. Yet, windfarm is a strange name —imagine miles square of 500’ and larger towers in an otherwise pastoral landscape. Because windpower is not a “farm” and its development dependent on an association of government and industry this paper will frequently use the term “windcommerce” to describe the wind energy industry.
Environmentally “green”, non-polluting with benign global warming effects are important environmental selling points for windcommerce. This should be reconsidered. Windcommerce may exacerbate the very energy problems it claims to resolve because the manufacturing, development, and operating processes all require standard baseline energies. In many respects, windcommerce duplicates existing energies and reallocates funds from existing energy industries, generating facilities, and anti-pollution programs. Thus, windcommerce may have the unintended consequence of actually exacerbating energy and environmental concerns. The (dubious) air pollution benefits come at a high price —spoiling of numerous land based environments while at the same time reducing funds available for environmental and efficiency improvements in existing generators.
Because of its inefficiencies relative to traditional baseline energies and high conversion and processing costs, it is unrealistic to believe windpower can be used as energy to process other alternative energies such as ethanol or hydrogen.
Responding to windcommerce’s most frequently repeated claims, in the “Darmstadt Manifesto”, German scientists found that windpower produced minor quantities of electricity while saving an insignificant quantity of air pollution. German scientists studied its (Germany’s) more than 7,000 windturbines and concluded that, “less than 1% of the electricity needed is produced” and that “the contribution made by the use of wind energy to the avoidance of greenhouse gases is somewhere between one and two thousandths.” In other words, windpower is not an answer to renewable energies.2
The rigorous German study demonstrates that intelligent marketing has preceded science. Claiming environmental benefits while economically unwise and environmentally disruptive, the industry has employed a carefully crafted marketing plan. The plan even extends to the level of the windturbine in the field where windturbines are painted white, symbolizing purity and cleanliness. Yet, even the color can be a problem. The white paint can be glaring and the blades at certain periods in the morning and evening can have annoying strobelight-like reflections as each blade reflects sunlight at certain light angles. The polished surfaces benefiting blade rotation conflict with the requirement of reducing reflecting surfaces from the use of textured and non-glare surfaces.
And, as one can imagine with giant blades, they do make noise.
Windcommerce “studies” are frequently overly selective in the issues studied and data can be difficult to obtain to evaluate its merits. Invariably, sponsors will claim that the data is not public. Thus, rigorous evaluation is not often possible resulting in windcommerce decisions made with incomplete information.
Strategically placed in the middle of the nation's prime wind generation area for example, is the DOE's National Wind Technology Center. This 290 acre site just north of Golden, Colorado is the wind turbine design research and field testing center for the U.S. It is the industry's primary source of testing and source of information for windturbines. Although the existence of this facility is another industry subsidy, a windpower research facility is welcome and necessary if alternative wind energy designs and systems are to be evaluated. This research site has the potential to provide the industry and the public important design information from a near optimal wind location. Unfortunately, the National Wind Center operates as an industry surrogate, available cost data from the center is sparse and operating costs from field trials is infrequently offered or not completely comparable.3
The “load-factor” (actual useable operating time) is the principal reason for windpower's high consumer costs and extensive visual pollution. The majority of time turbines stand unproductive and idle, capital investment earning a negative energy and monetary return. Because the load factor is between one-forth and one-third it suggests that for every three or four expensive windturbines constructed, less than one produces consumer energy.
Very expensive energy storage facilities must be constructed for smaller windmills used by ranches, farms, and individuals. The reasons are identical to commercial windturbines: limited output and unavailability during high demand periods. These energy storage systems are racks of expensive batteries. In addition, for large commercial sized windturbine generators, a backup traditional fuel based generator is indispensable because storage facilities cannot be built to match electrical demands. Most frequently natural gas is the backup fossil fuel for electrical generation. In other words, windpower is another term for significantly increasing consumption of natural gas.
Siting of windturbines is another important consideration. The location must lie in windprone areas without natural or manmade obstacles to impede the free flow of the wind. Wind complexes also have the unavoidable dilemma of visually polluting entire regions.4
The irony for environmentalist and “smart growth” advocates is that while promoting windcommerce as a benefit to the environment, its enormous land requirement aggravates sprawl and development in rural environments, parks, natural, and farm areas. Moreover, by attracting employees from larger metropolitan areas, windpower reduces opportunities to advance “smart growth” concepts in larger cities.
In addition to the other considerations, is a never evaluated but potentially serious problem: the production of ozone destroying gasses. Windturbines are very large generators producing substantial amounts of emissions that destroy the protective ozone. As produced by every lightning discharge, electricity passing through air within the generator produces these environmentally dangerous gasses. There has not been a study quantifying the amount and effects of ozone destroying gases created by the “motors” in windturbines. With the large and growing number of windturbines, further development could have serious air quality impacts.
These are the windcommerce issues discussed in this section. It begins by discussing the potential for wind development in Minnesota and then describes growth in demand and lacking reliability of windpower systems. The basic costs of windturbine systems are discussed followed by an evaluation of the economic impacts and job claims. The substantial energy storage requirement of non-commercial applications is discussed. Several windcommerce issues are illustrated using the largest windcommerce development in Minnesota, southwest Minnesota’s Buffalo Ridge. The consequences of windcommerce include and effects on flying species, noise and visual pollution. This section concludes with a discussion of the subsidies now employed to encourage windcommerce development and its net energy implications. Without substantial subsides the development of windcommerce would be problematic.
Windcommerce is economically possible only under very limited wind conditions, thus statements suggesting the Midwest and Minnesota in particular, has tremendous wind energy potential should be reconsidered. The quantity of electricity produced can fluctuate from one locality to another, in short time periods, and seasonally. Because the quantity of energy produced varies with the wind speed, the speed and pattern of prevailing winds is significant and wind’s characteristic unreliability creates difficulties for managing the entire grid of baseline energies. Windpower requires constant monitoring and modifying the output of the big conventional generators. The energy contained in wind increases at a multiple of the windspeed up to high wind conditions where it trails off. Continuous wind speed in the low to mid teens is the minimum levels for efficient electricity generation with wind speeds into the twenties more productive. Also due to the physics involved, windspeeds above the mid thirties result in the windturbines shutting down. The “plate” ratings –the rated output, is frequently based on windspeeds of approximately 30 mph ―twice the average windspeed at Minnesota’s premier wind prone area. Thus, assuming the wind is blowing, the window of windspeeds for effective wind energy production is narrow.
The eMergy –energy returned on energy invested, of windpower is only positive under relatively high wind conditions and these conditions are seldom found in the U.S. ―certainly not in Minnesota.
In general, the western half of the nation has greater windpower potential than the eastern half. Minnesota is on the national windpower line dividing acceptable and unproductive regions.5 The large area in the shadow of the Rocky Mountains (lea or eastern side) from Texas to Idaho has only moderate wind potential. The Eastern half of the nation and many regions of the southwest, including much of California and its large valleys, are not in general, capable of economically supporting windcommerce. Notwithstanding environmental considerations, it appears that the higher elevation areas from northern New Mexico to Oregon are best suited for windpower. Although not included in the windpower potential study, it is likely that populated areas of Alaska and much of Hawaii may have areas suitable for windpower. Nationally, Minnesota ranks 9th among the states with a mathematically derived 657 billion kWh of windpower potential. The fact that Minnesota ranks high is a consequence of the generally ineffective windpower potential for the nation. If the “657 gWh” potential were true in practice rather than in theory, Minnesota would never have an energy problem. The 657 gWh calculation will be revisited later. The observation that Minnesota ranks this high, suggests the mediocre windcommerce potential for the nation.6 As Minnesota illustrates, for most regions of the nation, isolated areas and communities with unique local geographic features are the best that can be realized.
The geography and meteorology of Minnesota generally limits windcommerce potential to selected areas of the far western sections of the state. There are approximately 79,600 square miles of land in Minnesota and almost all of it with only modest to fair or poor windpower potential. According to wind study maps, the potential wind region covers approximately one-fourth of the land area in the western and southwestern region of the state. Overall less than 20,000 square miles of Minnesota has even minimal potential for windcommerce development. Data from the Department of Energy (DOE) demonstrate that approximately three-fourths of Minnesota does not qualify for effective windcommerce development. Based on average windspeeds using a “7” point scale, “7” is best, the area from Minneapolis northwest to the Roseau is rated “2”, “marginal”, meaning generally not suitable for windpower development. The area roughly from Mankato northwest to Kittson County has a “4”rating or “good”. The balance of the state is rated “3”, “fair”. Making windcommerce less attractive is that the windprone area(s) are far from population centers. From north to south, the region covers a line just east of the Red River, south to Crookston, Fergus Falls, Morris, Montevideo, and finally to Jackson County. The single best —moderately wind prone— area lies in southwestern Minnesota, the well known and windcommerce developed Buffalo Ridge/Lake Benton region. There are also isolated but minor locations in several other areas, near Duluth in the northcentral or in Winona County in the southeast, for example. There are no large Minnesota regions rated “excellent, outstanding, or superb”.7
In other words, claiming that Minnesota has excellent windpower potential largely overstates the case. DOE data implies that only isolated local areas such as Buffalo Ridge in southwestern Minnesota may at a minimal output level support effective windcommerce development. Minnesota studies confirm the DOE data. DOE data indicate that North and South Dakota have greater windpower potential than Minnesota.8
Wind availability combined with the windturbine load factor has another equally irksome aspect. The basic assumption is that daily and seasonal consumer electricity demand matches wind availability. However, electricity demand rapidly increases every morning as people wake up and prepare for work. Even if windpower could meet the total kWh use for the day, it frequently will not meet rapid daily increases or seasonal peaking demands. This point was punctuated during the summer of 2001. In the hottest day of the summer with a record 8,300 megawatts of electricity demanded, Minnesota's best —the entire imposing Lake Benton windpower complex— could only muster three megawatts! Perhaps no other fact remotely suggests the need and staggering costs for an entire duplicate energy system if alternative energies are developed.9 The prevailing Minnesota wind pattern is, unfortunately, almost the mirror of consumer demands. The prevailing Minnesota (and Midwest) winds are strongest in winter followed by spring, moderate in the fall, and weakest in the summer. Moreover, the highest windspeeds are a consequence of storms; however storm winds will exceed the design capabilities and result in the shutdown of the turbines.10
Moreover, the trend toward constructing higher and bigger windturbines increases the number of periods when wind speeds exceed the production designs of the turbine. The favored wind sites are in the wind alleys most susceptible to high winds that will shut down the turbine. The larger windturbines appear to trade-off higher potential short term capacity for increasing unreliability. Today's larger and taller windturbines are 400’ to 800’ or more higher. The greater the MW design output, the larger the fan and higher the windturbine required. For example, the proposed 400' blades will reach nearly 1,000 feet and the 5-MW, 500 foot blades, almost one-quarter mile. The frequency of unintended shutdowns will increase as a result of the height. The visual pollution will be staggering. “There is” the DOE reports, “already some evidence that conditions related to the nighttime low-level jet-stream may be causing some turbines to shut down because of fault conditions in the early evening hours and then remain off for the balance of the night. Shutting down and remaining shut down applies to gusting wind conditions. The dilemma is that once the turbine’s safeguards shut it down, it can remain non-producing for long periods of time ―frequently requires manually resetting.”11
The wind potential of an area is a secondary consideration with proximity to electricity users a primary consideration. Even if area testing suggests reasonable wind potential, because the distance to population centers is great, many areas will not be suitable for economical windpower development.
The cost of transferring wind generated electricity is economically prohibitive. The reason is that transmitting its energy over any but short distances becomes an energy and money losing development. Windcommerce must be located adjacent to important transmission lines and be subsidized for energy transmission in order to be viable. This is especially evident for windpower because wind generators produce DC current, requiring somewhat different lines to distribute, and requires expensive conversion to AC current prior to transmission and use. The DC current generated by windturbines requires either converters on site or closely spaced substations to maintain the current. The energy used for the conversion process is either derived from the windturbine reducing its output, or normal AC baseline generating facilities.
Due to the energy costs of conversion and line losses, transmission of electrical energy beyond 100 miles becomes a critical efficiency factor: an inefficient and wasteful use of energy. The costs of distribution and transmission bring the issue of subsidies to the forefront. The non-utility use of or averaging of utility costs of existing transmission and distribution facilities without additional compensation to the ratepayers who bear the expense of those facilities is a significant subsidy to windpower users. For windcommerce owners to construct nearly a duplicate transmission or distribution system would be prohibitively expensive and misuse of resources.
The cost of transmission must be included in the price to the correct users. The appropriate energy policy would be for windcommerce beneficiaries (or other alternative electrical energies) to in effect “rent” the transmission and distribution lines constructed for conventional baseline energy consumers which they must utilize. The “rent” would be used to offset transmission costs borne by consumers other than from the wind generating site.
Growing Demand, the Load Factor and Capital Investments
The American Wind Energy Association estimates that approximately 300 MW of additional windpower will be located Minnesota, Iowa and Wisconsin with more planned for North and South Dakota. Although it seems unlikely, these Midwest states will account for almost half of all U.S. new wind developments. Windcommerce proponents are assuming that windpower can meet increasing electricity demand from growing populations and the retirement of some of the existing fossil and nuclear fuel generating plants.
The unreliability and lackluster economics of windcommerce suggests otherwise. Those interested in understanding windpower may locate material in their search, material that mischaracterizes Minnesota's wind possibilities. In light of the wind potential described earlier, the accuracy of the statement that Minnesota has 657 gWh of wind potential should be questioned.
For example, one widely circulated report —which will remain anonymous to protect those who should know better, stated that 2.5 acres of land selling for $100 in Wyoming “could yield $25,000 worth of electricity” every year. These three figures are probably accurate. However, no cost data was given. The implication is that for every $100 invested a windturbine owner could receive $25,000 every year.
In reality, the annual cost of generation and transmission very likely exceed the revenues. The $100 would be the market rate an investor is willing to invest now for the $25,000 income stream, discounted at an appropriate rate, e.g., 10%. If the stated income stream accurately portrayed windpower then an investor would be willing to pay more than $235,000 for the land in order to earn a 10% return on the investment. (Note that in the “report” mentioned above, the capital, operating and transmission costs were overlooked.) The land is inexpensive because it is unproductive for most economic purposes, little in demand, and in a sparsely populated area.
A further examination of the economic possibilities of windcommerce to meet the rising Minnesota electricity demand is in order. The windpower load factor (actual productive operating time) assumed by Xcel Energy is 34% ―while national studies show a 22.8% load factor. The significant difference is probably explained by noting that the Xcel experience is based on the state's premier wind development region. Perhaps some of the difference also lies in the definition assumed for load. For example, turbine blades may revolve 60% to 70% of the time but because the windspeed is insufficient to generate useable quantities of electricity, it cannot be said to drive load, produce electricity for the consumer.
To demonstrate windcommerce, loading and the arithmetic of Minnesota electricity growth, the following assumptions will be used:
· Load factor of 30% (0.3);
· 12,700 kWh average use (actual year 2000, see Table 16);
· 85,000 annual Minnesota population increase; and
· Each additional windturbine produces 2 MW of electricity.
Therefore the annual electricity requirement is:
1. 85,000 x 12,700 kWh = 1,080,000,000 kWh (or 1,080 MW);
And windcommerce will produce (“Y” -MW):
2. 0.3 x 8,760 hrs x Y = 1,080,000,000 kWh (24 hours x 365 days = 8,760);
3. then, Y = 1,080,000,000 kWh ÷ (0.3 x 8,760 = 2,628) = 410,960 kWh;
Y = 411 MW.
Using the design capacity of windmills yields approximately 1/3rd of annual Minnesota kWh growth. If meeting 1/3rd of Minnesota’s energy growth is the objective, then assuming 2 MW windturbines are constructed, the annual construction of 411 ÷ 2 MW = 205 windturbines are required. Because of growth, the construction of three additional turbines the following year (208 total), six additional turbines the next (214 total), and so on would be necessary. Obviously, the required sprawling acreage use of 40 to 50 acres per windturbine has dramatic siting and land consequences —an issue worthy of public discussion.
Perhaps another illustration would help clarify the ability of windcommerce to satisfy growing Minnesota energy demand. Assume that meeting 100% of the annual energy demand increases were derived from windcommerce. In that instance, the one-year construction requirement would be 1,080 MW times 3 ÷ 2 MW turbines = 1,620. This proposal would result in the construction of 1,620 windturbines this year, 1,635 the next, and 1,650 the following year due to additional growth. (x 3 = 3,240; 3,240 ÷ 2 MW = 1,620.)
A reasonable estimate of the cost of each 2 MW windturbine is $2.2 million. American Electric Power, for example, purchased on December 31, 2001 the 160 MW Indian Mesa Wind Power Project from Enron Wind Company paying $1.094 million per megawatt. Applying this cost to the quantity to be built indicates that the total construction cost for these windturbines would be $3.56 billion in the first year (1,620 x $2.2 million), $3.6 billion the next and $3.63 billion the following year, assuming no inflation in construction costs. The annual increments of additional construction will continue until either increases in total energy use (not per capita use) or population growth stops.
Perhaps the $3.56 billion in annual windturbine construction costs (at a minimum) and 81,000 acres of land required are manageable by Minnesotans? It should be obvious from this illustration the impossibility of windcommerce to match any but a minor fraction of Minnesota's (or the nation's) electricity demand growth.
Moreover, these cost estimates are only a fraction of the actual capital requirements. The reason for this is that the generating life of windturbines is approximately one-half to one-third the useful life of existing conventional generating facilities. The design lives of windturbines is about 20 years, while that of nuclear plants 30 to 40 years and for coal plants up to 60 years. This indicates that the core generating facilities of the windcommerce system require reconstruction every approximately 20 years. It implies that in addition to the annual construction increment is the annual replacement of approximately 5% of the total of all operating windturbines. In the 100% windcommerce scenario, it implies the construction of more than 80 additional windturbines annually at a cost exceeding $177 million. The larger the MW capacity constructed and replaced each year, the greater the compounding financial costs involved and environment damaged.
The capital requirements fail to consider another substantial cost of constructing a windturbine project: cost of removal and demolition. Removal of the tower and associated infrastructure are self-evident; however the tower is held in place by a concrete slab the size of a small house ―environmentally sensitive disposal of the slab must be accomplished. Incorporating the high costs of removing these items is an appropriate cost of a wind project. Perhaps a “cost of removal” sinking fund should be established for each windturbine. To assure the necessary funds and to avoid conflicts of interest, the fund should be fully funded within ten years; the management of the fund should be independent of the owner, and not under direct state control. An alternative would be to require owners to provide an insurance policy for removal, require liability insurance, and “business interruption” insurance in case of failure or accident.
Great Britain's Royal Academy of Engineering on August 30, 2002 released its energy evaluation of windpower. The study evaluated the state proposal to require 22,000 MW of windturbine generated electricity by the year 2020. Similar legislation is seen in Minnesota and other states. In appraising windpower, the Royal Academy stated that, “the Government’s energy policy is hopelessly unrealistic”. The researchers found wind energy unreliable, producing less than a third of the installed capacity and would be an impractical intermittent generator —“not dependable” in their words. If the proposed 22,000 MW of capacity were fully developed, the research concluded that it could produce not more than 600 MW under many UK wind conditions. If the proposal were reduced to 7,300 MW, the figure would be 200 MW. In the language of the report, correlating a “hypothetical wind power capacity of 7,300 MW installed throughout the country with actual Met Office wind data” concludes that the “most likely power output nationally is seen to be less than 200 MW.”
The conclusion was that because 75 – 85% of installed capacity is not useable, the 22,000 MW proposal would require the construction of another 16 – 19,000 MW of conventionally fueled generating plants. The study also cautioned that windpower's intermittent quality requires that the standby generators be on-line at all times. The identical situation applies to Minnesota: the idling plants would generate minor quantities of electricity while generating greenhouse emissions.12
The implication of the load factor is that for every three or four expensive Minnesota windturbines constructed, only the equivalent of one windturbine produces consumer energy ―during the best of circumstances. In brief, under the best circumstances for windpower, 100 kWh of electricity requires 300 kWh of other baseline energies to be produced. A “windpower society” would be an energy intermittent society requiring conventional baseline energies to be functional.
It should also be clear that the “benign environmental” claim understates windpower's environmental impacts. Because of its unreliability and modest production, baseline energies must simultaneously be online and prepared to generate additional electricity. Because windturbines generate on an intermittent basis, an entire backup or reserve system must be in place and operating at all times. The dependency on traditional baseline energies implies that windpower embeds the emissions involved in global warming. Moreover, because the online generators will be the most efficient –certainly hydro, nuclear, and the most modern coal plants, the use of resources and production of emissions are clearly overstated by the proponents of windcommerce. The older, even “grandfathered” coal generating plants are included when comparing the reduction in emissions while those are the plants least likely to be online. In addition, costs include the typical baseline energy costs for construction, steels, plastics, lines, cement, vehicles used, transport and equipment energy of labor, and ozone produced by the turbine “motor”.
The energy inefficiencies, transmission losses, and environmental and economic costs of the backup generators must be included in assessing the economics and environmental impacts of windcommerce. Generators will be using resources and producing polluting emissions, even if not actually generating consumer electricity.
In other words, the energy produced by windpower is unnecessary while contributing the equivalent of an entire electrical energy system to global emissions. This is a serious cost of windpower seldom considered. Baseline electricity generators would produce a great deal more electricity at less environmental and resource costs than windpower.
In summary, with less than one-third the capital investment, modern clean coal generators will annually produce more electricity reliability over a much longer period of time and at considerably less expense and environmental impact. In consumer terms, windturbine development suggests unnecessarily higher energy cost and up to three times the capital outlays of typical baseline generating facilities borne by ratepayers.
Because substantial employment gains are said to accompany windcommerce development, these claims will now be evaluated. The mind-boggling land requirements and impacts are introduced in the section discussing the Buffalo Ridge ― Lake Benton project and at greater length under the heading “visual and land pollution”.
[Continue to Part 2 of 3.]
“Minnesota’s Energy Future©”, Dell Erickson, October 10, 2001.
See at < www.mnforsustain.org/authors_erickson_d_minn_energy_future.htm >.
Please send mail to
email@example.com with questions or comments about this web site. Minnesotans For Sustainability
(MFS) is not
affiliated with any government body, private, or corporate entity.
Copyright © 2002, 2003, 2004
Minnesotans For Sustainability