September 17, 2001

Conclusions in 8/24/2001 Science "Policy Forum" Article on Wind Energy and Coal Are Unsupported and Contradicted by Other Evidence

Catharine M. Lawton*

Executive Summary
August 23, 2001 news reports by MSNBC and others,  called attention to and quoted from a Science "Policy Forum" article titled, "Exploiting Wind versus Coal," by two Stanford University Professors.
The news media reported:  "The authors calculate that, by building approximately 250,000 new turbines, America could eliminate almost two-thirds of its coal-generated capacity. . ."  The news media also reported that such action would allow the U.S. to meet the Kyoto Protocolís 1999 greenhouse gas targets and simultaneously improve health, acid deposition, smog, and visibility problems associated with coal.   Finally, the news media also reported the authorsí claims that wind power is now cheaper than coal, there is no reason not to invest in wind, and that wind could become a leading source of electricity with "the right political support and investment."
The article has been the subject of considerable e-mail discussion between one of the authors and others who questioned the authorsí analysis and doubted the validity of their conclusions.  The authors, however, have refused to respond to some critical questions.
Nonetheless, based on information available thus far it is quite clear that:
* The authorsí have failed to support their central assertions, including conclusions that:
ß Wind power is now cheaper than coal.
ß Wind could satisfy a significant share of U.S. base load electricity demand.
ß The cost of electricity from new, large windmills is less than from smaller windmills.
* One authorís claim that ". . .wind has received no government incentives,"  is false.
* The authors unwisely ignored actual wind energy performance data, wind developer business decisions and other evidence that contradicts their unsupported, theoretical conclusions.
* The authorsí conclusions cannot be independently evaluated because the lead author has, in some cases, refused to answer questions and/or because data cited is not publicly available.
It is unclear why such an inaccurate, unsubstantiated and misleading article would be published at this time. It may be related to the wind industryís attempts to get Congress to extend its lucrative tax shelters. Or, it may be to counteract publicity about the growing opposition to wind energy in Europe and the projected industry downturn.  However, it is quite clear that:
* The Science article was not subjected to adequate review before it was published.
* News media that picked up and reported on the Science "Policy Forum" article apparently do not have the capability to assess the validity of the authorsí claims, but reported them anyway.
In the August 24, 2001 Science "Policy Forum" article, "Exploiting Wind versus Coal," by Stanford University engineers Mark Jacobson and Gilbert Masters, the authors recommended replacing 59% of U.S. coal energy with energy from 214,000 to 236,000 large windmills.   This recommendation reportedly would allow the U.S. to meet the Kyoto Protocolís 1999 greenhouse gas targets and simultaneously improve health, acid deposition, smog, and visibility problems associated with coal.   The authors also claimed that wind power is now cheaper than coal, there is no reason not to invest in wind, and that wind could become a leading source of electricity with "the right political support and investment."
Although the authors claim that the cost of wind energy is now competitive with coalówithout considering the impact of current and significant federal and state government subsidiesóthe authors argue for a very significant federal and state government role in supporting wind energy development in the U.S.  In a press release, the authors asserted that wind ". . .should be promoted and funded by federal and state governments,"  and recommended that:
* "The federal government could either go into the energy business for itself, or it could foster wind energy through tax incentives that would catalyze private-sector investment;"
* "State governments also should take the initiative. . .They point out that energy-strapped California  could obtain 10 percent more electricity from wind by spending less than 10 percent of the state budget for one year on the construction of 5,000 new turbines, then selling the electricity over 20 years to recover all costs."
In the MSNBC news story, it was clear that the authors are recommending massive government intervention in support of further wind energy development in the U.S.óbuilding some 225,000 windmills at an initial taxpayer cost of $338 billion and an annual maintenance costóat further taxpayer expenseóof at least $4 billion per year.
Analysis of the Authorsí Article and Other Claims
The August 24, 2001 "Exploiting Wind versus Coal" Science "Policy Forum" article has engendered considerable discussion (principally by e-mail), debate, criticism, and efforts to obtain clarification, data and justification for the authorsí highly publicized conclusions.  Some requests to the authors have not been answered.
At this point, the authorsí three (3) central conclusions are unsupported, contradicted by other evidence and/or cannot be independently evaluated.  For example:
* The authors have cited data and information sources that are not publicly available.
* In some cases, the author designated to respond to inquiries has refused to answer questions or provide the underlying data.
* The authors dismiss "real world" wind energy performance data, wind developer business decisions and other evidence that tends to contradict the authorsí conclusions, preferring instead unsubstantiated theories, inferences, assumptions and untested engineering estimates.
* The authorsí support for their conclusions is generally limited to presenting the conclusions of others, often without confirmation or supporting data.
* Citations provided by the authors are often to wind industry data that apparently have not been investigated or independently confirmed.  For example, the authors place particular emphasis on information from the Danish Wind Turbine Manufacturerís web site.
The purpose of this paper is to summarize the substantive problems with the "Exploiting Wind versus Coal" Science article, and the authorsí attempts to date to defend it.  This summary is based on the available debate that has occurred since August 24, 2001, and additional research on wind energy issues. Each of the authorsí three (3) central conclusions will now be reviewed.
A. The authors have not justified their claim that the cost of wind power is now cheaper than coal. In summary, the authors estimate the total cost of coal (including claimed "externalities" of "health and environmental costs") at 5.5 to 8.3 ¢/kWh versus the estimated total cost of wind (including claimed "externalities" of "manufacturing and scrapping costs") of 3.0 to 4.0 ¢/kWh.
Some of the sources cited in support of the wind energy cost estimate are not publicly available and therefore cannot be reviewed and analyzed.  In addition, the authorsí claim is contradicted by other evidence and directly conflicts with the authorsí other conclusionóthat very significant federal and state government intervention is required to support further wind energy development in the U.S.

1. The authors incorrectly compare the cost of "new" wind with "new" coal-fired generation.  At least two critics have challenged the authorsí use of new coal-fired electric generating capacity as a basis for comparing their estimate of the cost of new wind energy-based generation.   The central question is what energy source would be displaced by new wind energy?  The critics argue that cost comparisons should be made to the marginal capacity that might be displaced by new wind energy, namely, existing ("old") coal-fired capacity that the authors wish to displace, or existing gas-fired capacity.
The authors have conceded that their estimate of the total cost of new natural gas capacityó4.4 to 5.5 ¢/kWhóis substantially less than their claimed total cost (including externalities) of new coal capacity.   The authors have not provided their estimates of the cost of electricity from existing coal or gas-fired units. Others have asserted that wind energy cannot displace coal economically (without pushing up consumersí electricity bills) given coalís estimated variable cost of 2 ¢/kWh.

2.  The authorsí wind v. coal cost estimates are not comparable.  The authors have been challenged as to whether their estimate of the total cost of coal energy is comparable to their estimate of the total cost of wind energy.   In particular, the authors have included a substantial "externality" cost in the total cost of coal energyó2.0 to 4.3 ¢/kWh for "health and environmental costs."   On the other hand, the authors have included only an inconsequential "externality" cost in the total cost of wind energyó0.11 ¢/kWh which is limited to "manufacturing and scrapping costs."   The authors have ignored the other external or social costs associated with wind energy, which can vary significantly depending on the site.  For example, a European study noted noise and visual intrusion (scenic impairment) as the most important "wind farm" impacts.   Other wind energy environmental impacts include moving shadows/"strobe effect," erosion, impact on birds, interference with electromagnetic communications, and personnel safety.

3. The authors ignore the cost of windís intermittency. The authors have been challenged to explain why they ignore other real and significant costs that result from the fact that electricity from windmills is intermittent, unpredictable and unreliable.   Windmills produce electricity only when wind is within certain speed ranges and the electricity output varies within that range.   The added costs imposed by intermittent energy sources like wind energy include the displacement of lower cost generation (e.g., natural gas), requirement of dispatchable backup generation, reduced capacity factors for conventional generation, increased electric price volatility, and decreased system efficiency.  All such factors result in increased costs to consumers.   One expert has estimated the cost of windís intermittency at 3.9 ¢/kWh.   That estimate includes the displacement value of wind (wind substituted for natural gas): 2.0 ¢/kWh; cost of dispatchable backup: 1.4 ¢/kWh; and dispatch inefficiency, transmission overbuilding and transmission operational inefficiency: 0.5¢/kWh.

4. The authors ignore the fact that wind energy would increase consumer electricity costs. If the real total costs of wind energy are considered, then it has been reported that consumer electricity costs would increase significantly.  If 5% of the nationís electricity came from wind, it is estimated that electricity costs would increase by $8 billion;  and at 10% of electricity from wind, it is estimated that electricity costs would increase by $20 billion.

5. The authors have not documented their wind energy cost estimate.  The authorsí wind energy cost estimate has not been documented and should be considered highly questionable for at least four (4) reasons:
* First, the authors rely on unpublished data (both for estimated windmill cost and estimated windmill energy production) as the basis for their wind energy cost estimate, including two (2) yet to be published textbooks:  Wind Energy in the 21st Century by R. Y. Redlinger,  and an "in preparation" textbook by one of the authors, G.M. Masters.
* Second, the authors appear to rely upon an unsubstantiated and undocumented "rule of thumb" of $1,000 per kW for estimating the cost of wind energy.   The authors assume without confirmation or investigation that $1,000 kW applies to all windmills, both large (1500 kW and larger) and small.
* Third, the authorsí claimed total wind energy cost of 3.0 to 4.0 ¢/kWh is substantially less than some regulated utilities are agreeing to pay "wind farm" developers for electricity; e.g., Wisconsin Energy agreed to pay FPL Energy 7.84 ¢/kWh in year 1 (2000) of a 10-year Power Purchase Agreement.
* Fourth, the actual cost per kWh of electricity produced by a "wind farm" varies widely depending on specific circumstances and/or assumptions; e.g., land costs, capital costs (turbines, towers, substations, meteorological towers), operations and maintenance costs, performance deterioration, backup generation costs, transmission costs, capacity factor (discussed in greater detail later in this paper), financing costs, assumed lifetime of the facility (e.g., 10 yrs., 15 yrs., 20 yrs.), etc.
6. The authors ignore "real world" experience.  The authors ignore published reports indicating that the cost of electricity from wind energy is not competitive with other energy sources.  For example, Chairman Larry Weyers of Wisconsin Public Serviceóthat claims to have done extensive studies of wind-power projectsóstated:  "The initial cost of renewable sources is not competitive.  They are almost double what you could actually build other types of generation for.  In addition, you canít count on the capacity.  If the windís not blowing, you donít have anything."   Furthermore, the objective, real world facts about wind energy have caused U.S. House Speaker Dennis Hastert to conclude:  "Iím not sure that windmills are going to do it."

B. The authors have not justified their assertion that wind energy could supply a significant amountóapproximately 30% of U.S. base load demand for electricity. The authors claim that it would be feasible to replace 59% of current U.S. coal-fired electricity generation with 214,000 to 236,000  (or potentially more than 366,000 ) large windmills.  The authors further claim that if such a massive shift toward wind energy were to occur, it would be feasible for wind energy to supply approximately 30% of U.S. base load demand for electricity.
The authors provide no convincing evidence or justification for either claim.  Both claims are highly doubtful for many reasons.  For example:
1. The authors ignore the inherent limitations of wind energy that undermine the two claims.  Wind energyís potential contribution is limited by the low output of the huge machines and the fact that wind is intermittent, unpredictable and unreliable.  The experts accept the fact that: "Öwind power has struggled to reach the levels of efficiency necessary to supply electricity at prices that can compete with power generated by fossil fuels.  There are several reasons for this.  Wind turbines produce relatively low outputs of electricity, that require a lot of maintenance, and have difficulty handling variations in power [that destabilize the power grid], which are themselves a consequence of variable wind speeds."  In addition, the authors ignore the fact that wind energy has virtually no capacity value to power grid managers.

2. The authors offer no evidence that wind is suitable for providing base load generation.  The authors have been challenged as to whether wind energy could supply base load electricity, or whether wind is really only "extra" and "on the margin."  The authors finally conceded,  "We do not suggest that winds service peak loads."   In addition, when challenged, the authors finally conceded that the windís intermittency is a problem, but claimed "Winds are intermittent in some locations but not others." The authors then claimed that the winds over the ocean are "regular, predictable" and therefore, offshore windmills "would produce predictable energy."   However, the authors have refused to answer questions regarding the technical feasibility, economics, or public acceptance of offshore wind energy development.   Further, the authors seem to have forgotten that their Science "Policy Forum" article counted on North and South Dakota, and "Ölarge tracts of the West, Great Plains, East and NortheastÖ"  to provide the needed windmill sites, while at the same time providing "needed revenue to farmers and ranchers."

3. The authors offer no evidence that their 30% of base load claim is technically feasible.  The authorsí "30% of base load" claim is contradicted by the contention that wind energy systems work only when they supply no more than 10% of the power in a huge grid that can compensate for the power output fluctuations caused by wind speed fluctuations.

4. The authors fail to explain where wind energyís dispatchable back-up power will come from.  Because wind energy is intermittent, unreliable and unpredictable, it requires immediately available dispatchable backup capacity to supply electricity when wind speeds drop.  In Europe, the highly publicized Danish "wind farms" work on the backbone of Norwayís hydropower.   Hydro plants are uniquely suited to back-up intermittent energy sources like wind energy without losing efficiency.   This is because hydropower can adjust for wind energyís power fluctuations by opening and closing the gates that control water flow.   In contrast, for fossil-fired plants to compensate for wind energyís power fluctuations, the turbine has to heat up and cool down, and the thermal cycling shortens the turbineís life.   In addition, with fossil-fired plants the response to power fluctuations cannot be immediate due to the delay time.
If the authors are counting on hydropower for backup, they should recognize that there are very few, if any, areas in the U.S. where enough hydropower is available to provide back up for the authorsí proposed massive shift toward wind energy.  This is because, a) hydroelectric power accounted for just 7.2% of U.S. net electricity generation in 2000;   b) U.S. hydroelectric power is heavily concentrated in a few statesówith 58% of the nationís hydropower located in three (3) Pacific Northwest states:  Washington, California and Oregon;  and c) hydroelectric generation is variable, and declines when precipitation declines as it did in 2000.
Furthermore, the authors do not seem to recognize that the cost of wind energy should include all the costs, including the costs of the necessary backup generation that is kept in spinning reserve (i.e., generating units connected to the electrical system and ready to take load or operating below rated level) which are directly attributable to the intermittent source that is being backed up.

5. The authors ignore forecasts regarding wind energyís projected contribution to U.S. electricity supply.  The authors ignore the fact that mostóincluding EIAóexpect wind energyís contribution to U.S. electricity supply to remain inconsequential through at least 2020.  In fact, EIA projects that by 2020, wind energy will provide just _ of 1% of U.S. electricity supply.   In June 2000, DOE proposed as a goal that the U.S. obtain 5% of its electricity from wind energy by 2020,  which is a small fraction of what the authors are advocating.  The DOEís proposal has been described as "unrealistic" for many reasons, including the fact that it is 20 times higher than the forecast made by the independent EIA.

6. The authors ignore the fact that wind energy has never achieved 30% of electricity supply anywhere around the world:  The authorsí claim that wind energy could supply 30% of U.S. base load electricity is in stark contrast to real world experience over decadesóand in response to very significant government subsidies. The authors are misleading the public when they couch their 30% wind proposal as "America catch[ing] up with major wind power nations such as Germany, Spain and Denmark."  The facts are clear.  In Denmark and Germanyówith substantial government subsidies and incentivesóthe market has been characterized as "saturated"  with wind energy reportedly accounting for just 7% of domestic supply in Denmark and 2% of domestic supply in Germany.   In the UKóamidst public protests in opposition to almost every proposed wind energy projectówind energy constitutes barely 3/10 of 1% of total electricity supply.   Based on these facts, it is highly unlikely that 30% of total electricity from wind energy could ever be achieved anywhereólet alone achieved in the U.S. where wind energy accounts for less than 1/10 of 1% of Americaís electricity supply.

7. The authors ignore historical windmill reliability problems.  Equipment problems have plagued the wind industry for decades.  As noted in an August 6, 2001 article in The Boston Globe,  "Wind power acquired a flaky image in the 1980s when windmills sprouted from the landscape, spurred in part by federal tax incentives, and began spinningóonly to quickly destruct and grind to a halt.  Giant blades would shear off, entire rotors would fall to the ground, or the machines would just shake themselves to death."   In addition, the wind industry has been plagued by bankruptcies (and near bankruptcies) caused by equipment problems; e.g., Kenentech (blades), NEG Micon (gearboxes). The authors have failed to answer questions regarding the expected reliability and potential equipment problems with these new, unproven 1500 kW, 3 MW and 4 MW and larger windmills that have very limited, if any, actual field experience.

8. The authors ignore the inherent and recognized safety issues posed by windmills.  In recommending a massive policy shift towards wind energy, the authors refused to answer questions regarding inherent and recognized wind energy safety issues including:  blade throws (e.g., a 1-ton piece of blade thrown 500 meters), shattered blades due to lighting strikes, ice throws, towers that have toppled over or been "uprooted," fires caused by electrical shorts and twisted cables, intolerable noise including both audible and low frequency noise, problems for hearing aid users, etc.  Professor Jacobsonís simple retort was:  "Old statistics are not relevant since the technology has changed."

9. The authors ignore growing public opposition and difficulty in siting wind energy.  The authors ignore the factóand refused to answer questionsóregarding growing public opposition to wind energy development that is forcing wind energy development offshore in many parts of the world.   The authors concede that a mix of onshore and offshore development is inevitable, but refused to state how important offshore wind energy development might become, or disclose the costs of offshore developmentóalthough they did admit that offshore development would not be cheap.   In Denmark, where wind energy reportedly accounts for just 7% of electricity, there is already a shortage of suitable land-based wind energy sites. As a result, the Danish authorities acknowledge that Denmarkís longer-term wind energy development through 2030 will take place largely offshoreówith more than 70% of Denmarkís projected new wind energy capacity additions (4,000 of 5,500 MW forecasted through 2030) located offshore.

10. The authors ignore the land use issues.  Dr. Howard Hayden highlighted the important public policy issue of land use for energy production back in 1981 and stated:  "I doubt whether society will tolerate either the expense or the dedication of large amounts of land area to energy sources, even if the Sun is the primary source."    There is no dispute that wind energy would occupy large land areas under the authorsí policy proposal.  This is because the amount of wind energy produced per square meter of land is extremely lowóestimated at just 0.51 to 1.22 W/m_.   For example, in order for wind energy in Connecticut (assuming enough suitable sites could be located, and that transmission facilities would be available) to produce the same power produced by Connecticutís two nuclear reactors (located on less than 1 square mile) it is estimated that windmills would cover 700 to 1,600 square miles or approximately 13 to 31% of the state of Connecticut.

11. The authors fail to explain where all the new windmills would be sited.  The authorsí proposed scale of wind energy development is unprecedented; and, the authors fail to explain where all of these new windmills would be located.  To provide some further context to the authorsí implausible proposal, the total worldwide installed wind energy capacity at the end of 2000 was only 17,300 MW.   According to the authorsí proposal, the number of windmills in the U.S. would have to increase more than 12,000% (or almost 21,000% in the case of Glenn Schleedeís 366,000 windmill estimate) from the current level 2,554 MW,  and 1,700 windmills (equivalent number of windmills assuming 1.5 MW windmills); to the authorsí goal of 214,000 to 236,000 new windmills and 321,000 to 354,000 MW of new wind energy capacity.

C. Will the cost of energy from large windmills be lower than the cost of energy from small windmills?  In the Science "Policy Forum" article, the authors imply, but do not expressly state that the cost of energy from large windmills (i.e., 1500 kW and larger) is lower than the cost of energy from smaller windmills.   The importance of this conclusion, however, was highlighted in the subsequent e-mail exchanges when Professor Jacobson stated:  "First, the real issue is the cost of energy from large versus small turbines."   The authors seek to prove this conclusion by attempting to analyze windmill capacity factor ("CF").

"Capacity factor" is an important consideration for windmills because the rated capacity of a windmill (e.g., 1,500 kW) has little meaning when assessing wind energyís potential contribution in supplying electricity.  Windmills produce electricity at their rated capacity only when the wind speed is at an optimum level for that windmill (e.g., 13 meters per second (m/s)óabout 29 miles per hour (mph)).  Otherwise windmills produce at less than rated capacity, or produce no electricity at all.  To calculate the capacity factor of a windmill or other electric generating unit, the actual output in kilowatt-hours (kWh) over, say, a year, is divided by the windmillís rated capacity times 8760 (hours per year).   Few "wind farms" in the U.S. have achieved capacity factors as high as 30%, with many ranging between 20% and 30%.
The authors, however, claim that the new, larger windmills will achieve higher CFs (and correspondingly higher power production), and this is assumed to be associated with lower per kWh costs.  The authors theorize that the "capacity factor of a turbine is a function primarily of wind speed, rated power, and turbine diameter. . .the height of the turbine also plays a factor."   Based on this CF work, the authors conclude that "a new turbine with a 1500 kW rated power and 77 m diameter provides a higher CF than the smaller turbine."
This claim is based on faulty logic and conflicts with real world wind energy developer business decisions and actual operating experience.  Finally, the authors have not permitted independent review and testing of their capacity factor (CF) equationówhich they now concede is "not statistical."   More specifically:

1. The authorsí theory is based on faulty logic, not systematic analysis.  In arriving at their conclusion, the authors rely on indirect analysis, inference and assumption. In fact, the authors have conceded that they have not directly and systematically analyzed the relationship between windmill size and wind energy cost.   Instead, the authorsí theory that the cost of energy from larger windmills will be less than the cost of energy from smaller windmills is based on faulty logicóthat relies on unsupported inference and two critical assumptions.  First, the authors infer that windmills with a higher CF will necessarily have a lower cost of energy.  Next, the authors assume (apparently based on the authorsí CF equation that is of questionable validity) that new high-power, large diameter windmills (e.g., Enronís 1.5 MW, 77 m diameter windmill) will achieve higher CFs.  Finally, the authors assumeóapparently without any investigation or analysisóthat the cost of wind energy is constant for all windmills, both large and small, at $1,000 kWh. If, as appears likely, either the inference or the critical assumptions are false, then the theory is also false.
2. The authorsí emphasis on larger windmills does not appear justified.  The authors have not demonstrated that the new, large diameter, 1.5 MW windmills that they favor will actually achieve either the claimed higher CFs, or the assumed lower cost per kWh.  Furthermore, the authorsí claim that the new, large diameter 1.5 MW windmills will achieve higher CFs may simply reflect the fact that windmill manufacturers are now offering machines with larger diameter blades for a given generator size.
  The authors, however, seem to ignore the fact that windmills are designed for different applications.  For example, Enron offers three (3) 1.5 MW windmillsóeach with a different blade diameter.  Based on Enronís machine specification data, however, it appears that the largest blade diameter windmillówith lower rated wind speeds (11.8 m/s v. 13 m/s for the smallest blade diameter windmill) and lower cut-in and cut-out wind speeds (3 and 20 m/s v. 4 and 25 m/s for the smallest blade diameter windmill)ómay be designed for slower wind speed locations.   Given these statistics, it is unclear whether these new, larger diameter windmills that the authors are advocating are even suitable for the high wind speed locations that the authors concede are the only sites suitable for wind energy development.

3. The authorsí theory about capacity factors appears to be overly simplistic.  Furthermore, the authorsí theory appears to be overly simplistic, and ignores the fact that wind energy development and economics are more complicated than simply looking at CF. This was demonstrated when Professor Jacobson conceded that Enron sells three (3) different 1.5 MW wind turbinesóeach with a different blade diameter ranging from 65 m to 77 m, with author-claimed CFs ranging from 25% to 36%.   If minimizing wind energy cost per kWh was as simple as maximizing CF (based on the authorsí unsubstantiated CF equation), then there would be no business reason for Enron to sell three (3) 1.5 MW wind turbinesóif, as the authors claim, the two (2) smaller blade diameter machines are allegedly clearly inferior (with assumed lower CFs and assumed higher cost per kWh).

4. The authorsí theory is contradicted by "real world" wind developer business decisions.  The authors were also challenged to explain why wind energy developers were opting to install small windmills in major projects currently under development rather than the 1500 kW and larger machines that the authors claim are plainly superior.    For example, an EIA official questioned the authorsí theoretical conclusions regarding the alleged superiority of large windmills on the basis of FPL Energyísówhich claims to be the nationís leading wind energy developeródecision to use 660 kW machines in the Oregon/Washington Stateline wind project.
I have also challenged the authorsí theoretical conclusions regarding the alleged superiority of large windmills on the basis of a commercial wind energy developerís analysis of both 900 kW and 1500 kW windmills on constant height towers, and wind speeds at a specific siteóand the wind energy developerís statement that the 1500 kW machines were not economic.   Again, the authors dismissed real world wind developer business decisions in favor of their theoretical conclusions and the contention that the wind energy developers are unaware of their CF equation and do not understand the "fundamental physical characteristics of wind turbine efficiency."

5. The authorsí capacity factor claims are contradicted by "real world" operating experience.  The authors claim that the CF for new, large windmillsó35.8% to 39.6%óis substantially greater than the CF for old, smaller windmills.   The authors dismissed actual reported CFs for smaller windmillsówhich generally have been 30% or less, and often in a range from 20% to 30%.   Furthermore, the authors refused to acknowledge that actual "real world" experience has any application to their theoretical analysis, or reconcile the actual, real world CFs to their estimated CFs.  The authors simply dismissed actual reported field CFs as irrelevant and not valid because they allegedly apply only to short, "low-power turbines with small diameters in slow-wind areas [less than 7 to 7.5 m/s annual winds]. . ."   The authors, however, fail to explain why the higher power windmills with large diameter blades were not available before, if indeed this combination is wind energyís economic panacea.

6. The authorsí explanation of their capacity factor equation defies common sense.  The authors claim to have developed an equation that allegedly provides a "very accurate" (but not quantitatively defined)  fit of the data.  However, the lead author then claimed "the analysis is not statistical,"  and admits that they have not tested the accuracy of the equation or otherwise confirmed it with real world data.  The authorsí refusal to answer questions regarding the statistical validity of the model or to provide the model statistics and data add to the doubts about the theory.  If, as appears to be the case, the CF equation is not statistically significant, then it cannot properly be used to justify the authorsí capacity factor equation and claims or the conclusions based on them.
7. The authorsí capacity factor equation is of questionable validity.  The validity of the authorsí theoretical CF conclusions has been questioned by an EIA official on several grounds.   First, based on whether the CF equation is statistically significant.  Second, based on "real world" data collected by the DOE/EPRI Technology Verification Program.  Third, based on the observation that as windmills have increased in size they have decreased in efficiency.  And fourth, that such observed reductions in efficiency appear to be due to the blade reinforcement necessary to compensate for blade deflection in the longer blades associated with the larger windmills.

What Was the Purpose of the Science "Policy Forum" Article?
In view of the fundamental problems with the August 24, 2001 "Exploiting Wind versus Coal" Science  "Policy Forum" article, it unclear why the article was written and published.  However, given the news stories cited earlier, it seems clear that the authors were seeking to influence public policy in favor of increased government support for wind energy development.  The article appears to have two possible objectives:

A. Perhaps, the objective was to assist the wind industryís current lobbying effort that is seeking to extend the industryís very lucrative U.S. tax shelters.  U.S. wind energy developers now benefit from two extraordinary federal income tax shelters.  Specifically:
* Accelerated depreciationófive-year double declining balanceówhich permits wind energy developers to recover 52% of their capital investment within 18 to 24 months of project completion, and the remainder within the ensuing 36 to 48 months.
* A production tax credit of $0.017 per kWh for the first 10 years of windmill project operation.
A representative of BP Solar recently reported that these two federal tax benefits alone have a value equal to an astounding 42% of project costs.   Many state governments also provide additional subsidies.  The effect of all of these subsidies is to shift costs from wind energy developers to taxpayers or electricity customers.
Under current law, the federal production tax credit would expire for wind projects that commence operations after December 31, 2001.  The wind energy industry has a massive effort underway to lobby the Congress to extend this credit, and is encouraging news media in the U.S. to run stories favorable to wind energy.
The authors of the Science "Policy Forum" article do not explain why such massive federal and state government tax shelters and other subsidies for wind energy development are necessary if they truly believe that wind energy is cheaper than coal and that there is no reason not to invest in wind energy.  The authors fail to explainóassuming their claims are trueówhy private sector initiatives and market forces without further government subsidies are inadequate.
One of the authors of the article seems quite confused about subsidies and even made the false claim that wind energy receives no subsidies: ". . .wind has received no government incentives, Jacobson said."  Lucrative subsidies for wind energy are not confined to the U.S.  For example, The Wall Street Journal Europe reported on the importance of the lucrative wind energy subsidies, stating: "Those subsidies have created juicy returns (between 15% and 20%) for wind farm operators."

B. Perhaps, the objective was to attempt to counteract recent news stories reporting growing public opposition to wind energy and predicting an industry downturn. An August 13, 2001 article by Keith Johnson published in The Wall Street Journal Europe  forecasted a slowdown in wind energy development in the wind energy subsidy-rich nations of the U.S., Germany, Spain and Denmark which together account for more than 75% the worldís installed wind energy capacity:
. . .But now, it seems, the glory days may be past.  Saturation in such key markets as Denmark and Germany has limited growth forecasts and prompted regulators to take a closer look at wind powerís subsidies.  It also has helped spur an ecological backlashóenvironmental groups oppose wind power, arguing it kills migrating birds and spoils the landscapeóalready familiar in England, Ireland and Spain, and compelled the industry to start building offshore wind farms, which are still unproven and more expensive than the onshore installations.
Meanwhile, in the U.S., the worldís second-biggest wind market, after Germany, question marks still surround the renewal of the Production Tax Credit for wind farms.  Analysts expect wind power to take a breather next year in the U.S. after a record-setting 2001. . .
But few think France, Italy or other countries newly won over to wind power will take up the slack from the coming slowdown in Spain, Germany and the U.S.  Which puts the onus on the likes of Brazil, North Africa, India and Chinaóall which need new sources of electricity.  But unlike Western Europeans, these countries arenít prepared to offer generous subsidies to promote clean generation.

In any case, the authorsí proposal is clearly implausible.  In December 2000, the total wind energy capacity installed worldwide was just 17,300 MW óachieved with significant government subsidies and incentives at taxpayer expense over the past 20 years.  In contrast, the authors are proposing that the U.S. install 321,000 to 354,000 MW of new wind energy capacity in the U.S. aloneówhich is staggering and unrealistic in view of current (2000) installed U.S. wind energy capacity of just 2,554 MW.

Based on the foregoing, the authorsí conclusions set out in the August 24, 2001 Science "Policy Forum" article "Exploiting Wind versus Coal," and related news reports, have not been substantiated and are contradicted by other evidence.  In particular, the authors have failed to demonstrate that:

* Wind could replace a substantial proportion of U.S. coal-fired electricity generation.  The authors have failed to demonstrate that it is reasonable, technically feasible or economically viable to attempt to replace 59% of U.S. coal-fired electricity generation with hundreds of thousands of windmills that are intermittent, unpredictable and unreliable in an attempt to increase wind energyís contribution to U.S. electricity supply from less than 1/10 of 1% to 30%.
* The cost of wind energy is less than the cost of energy from coal-fired electricity generation.  The authors have failed to demonstrate that the cost of wind energy is less than the cost of coal-fired generation, or that the cost comparison between coal and wind is even relevant, comparable, and includes all of the costs associated with wind energy.  Assuming that the cost of wind energy is competitive, the authors have failed to explain why continued government subsidies and/or massive federal and state government intervention is necessary to support further wind energy development in the U.S.

* The cost of energy from the latest generation of large windmills will be less than the cost of energy from smaller windmills.  The authors have failed to demonstrate that the cost of energy from new, large windmills (1500 kW) would be less than the cost of energy from smaller windmills. Assuming that larger windmills are more efficient, the authors have failed to explain why major U.S. wind energy developers are continuing to choose smaller windmills (e.g., 660 kW) instead of the larger 1500 kW windmills.

* It is feasible to site hundreds of thousands of new windmills.  The authors have failed to demonstrate that sites for hundreds of thousands of new windmills could be located where average wind speeds exceed 7 to 7.5 m/s, transmission facilities are available, and the windmills would be acceptable to the public and local residents.

* The authorsí conclusions reflect real world reality.  The authors have failed to demonstrate that their conclusions can be reconciled to real world wind energy performance data, wind energy developer business decisions and other evidence.
* The authorsí conclusions can be independently verified.  The authors have failed to demonstrate that their conclusions can be independently verified.  Indeed, so far, the authors have refused to permit independent review and evaluation of their analysis and the underlying data.

Furthermore, it is clear that:
* The Science "Policy Forum" article was not subjected to adequate review before it was published.
* News media that picked up and reported on the Science article apparently do not have the capability to assess the validity of the authorsí claims, but reported them anyway.

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*About the Author:  Catharine M. Lawton is a founder and Managing Director of a national independent economic, valuation, and strategy-consulting firm that specializes in technology and intellectual property issues.  She has testified many times as an expert witness on a variety of economic, financial, accounting and market issues involving a wide range of industries.  She has spoken a number of times on intellectual property valuation and other issues.

Her interest and investigation in wind energy, however, is not on behalf of any client or other interest, but rather arose in 1999 when a major U.S. IPP proposed to locate a 30 MW "wind farm" near her home.  Her initial investigation discovered that the information publicized by the wind industry is highly misleading and incomplete.  Her work in the wind energy area during the past two years has been dedicated to investigating and researching the claims, and separating the facts from the highly misleading and highly publicized fiction about wind energyówhich is the goal of this self-financed article.

The author welcomes comments and can be contacted at: Catharine M. Lawton, 7039 Mt. Pleasant Dr., West Bend, WI, 53090.  Fax:  (262) 629 ­ 4190, e-mail: