Materially Affected Party Comments to awea draft Standard 1 – 2009, “Small Wind Turbine Performance and Safety Standard”




Скачать 226.37 Kb.
НазваниеMaterially Affected Party Comments to awea draft Standard 1 – 2009, “Small Wind Turbine Performance and Safety Standard”
страница4/6
Дата конвертации25.10.2012
Размер226.37 Kb.
ТипДокументы
1   2   3   4   5   6

No. 15: Andrew Tasker, Iskra Wind Turbines (UK) (manufacturer)

Number

Comment

Recommended Response

Rcmd. Action

15.1

Section 1.5.2.3 AWEA Rated Sound Level – This has been replaced by the Noise Map in the BWEA standard. We believe that this would not involve additional testing, but a different way of reporting the test data.

See response to Comment 10.4

None

15.2

Section 3.1.1 The AWEA standard requires a 10 second averaging period for all noise measurements. This was changed in the BWEA standard (Section 3.4.1) to say “The averaging period, t, for noise and wind speed data shall be at least t = 4*D seconds (i.e. 4 * rotor diameter, where D is expressed in metres) subject to a minimum period of 10s. Shorter periods can be used and combined to give a 10 second or longer average consistent with t = 4*D.” The difference in the 2 standards has the following effects:
·         There is an additional overhead in taking measurements every 10s and then combining to present the information in line with the BWEA requirements.
·         More importantly the data gathered for Acoustic Sound Testing would not be valid for Performance Testing as this is required in 1 minute durations (AWEA / BWEA Section 2.1.13). This could affect the timescale for achieving the requirements for the Duration Testing, as any Noise measurement work would be time off the 2500 Hours of Power production.
We currently set the anemometer for a 1 minute sample time and hence we can measure power and noise concurrently. I think that if this section could be changed it would be a major benefit to the Manufacturers, without being detrimental to the Customers.

Since the sampling rates are even faster it doesn’t seem that the averaging period differences should be hard to accommodate and it doesn’t seem that any duration data is excluded. Maybe there’s something I’m missing here so we’ll discuss it at the committee


See response to Comment 10.5

Discuss at Windpower 2009 committee meeting

No. 16: James Doane, et al, AWS Truewind

Number

Comment

Recommended Response

Rcmd. Action

16.1

Referring to Section 1.4:

Allowing manufacturers to collect and submit their own performance data will create conflicts of interest within the performance evaluation process. In order to eliminate this conflict of interest and collect objective performance data, AWS Truewind feels that the turbine manufacturers should be required to use an independent, third party for performance testing. This data can then be reviewed by the certifying agency and will give consumers more confidence in the performance evaluation process and the production capacity of small wind turbines.

The cost/benefit ratio of requiring only independent data is deemed poor and the committee is concerned about setting barriers to entry for small companies. The certifying agency will review the data and will likely vet the test set-up and procedure (this is what SWCC plans to do). The BWEA does required independent testing from certified labs and we have a reciprocity issue to deal with.

None

16.2

Referring to Section 2.1.8:

The guidelines provided for mounting the wind sensors are unclear, and lack several monitoring practices that are essential to arrive at an accurate assessment of turbine performance. AWS Truewind recommends that the standard suggest a minimum boom length to mitigate the tower effects on the wind measurements. Additionally, two measurement levels should be utilized to develop a shear estimate of the hub height wind speed.

Suggested revision:

2.1.8 In Section 2.2.1, Distance of meteorological mast: If it is more practical to mount the anemometer on a long boom that is connected to the tower, a separate meteorological mast is not required. The length of the anemometer boom should be carefully considered in order to minimize the tower effects on the wind measurements. Boom length of 7 diameters for tubular towers and 4 face widths for lattice towers will generally limit wind speed deviations to less than 1% of free stream. However, for large lattice towers, practical considerations may require that shorter boom lengths are used. In this case, a solidity analysis should be performed to determine the uncertainty introduced due to boom length. This uncertainty should be documented in the performance report. Use of two measurement levels is recommended in order to make a shear estimate of the hub height wind speed. The uppermost level should be placed one rotor diameter below hub height. The second level should be placed halfway between the lower level and the ground.


See the response to Comment 10.3. This should be sufficient.


A tower mounted anemometer boom still has to place the anemometer at hub height. No shear correction should be necessary.

None

16.3

Referring to Section 4.2:

The statements made in this section regarding the tendency for harmful dynamic interactions based upon the design of the turbine are broad and unsubstantiated. All small wind turbines should be required to demonstrate that they avoid potentially harmful dynamic interactions.

Suggested revision:

4. Strength and Safety

4.2 The wind turbine and tower(s) must be shown to avoid potentially harmful dynamic interactions.

This statement reflects the collective experience of numerous manufacturers and researchers over three decades. This covers hundreds of millions of operational hours, so the lack of incidents makes a compelling case. It can be seen as a testament to the schotastic nature of the wind. In order to drive a structure towards resonance the wind turbine has to dwell on a natural frequency for enough cycles to transfer significant energy. The variability of the wind keeps this from happening on variable speed turbines. On the flip side, how could you prove analytically that a variable speed turbine will not reside on a natural frequency unless the tower was so stiff that max turbine speed was below the first structural frequency. The existing language is deemed adequate.

None

No. 17: Gerald Giroux, Wind Energy Institute of Canada

Number

Comment

Recommended Response

Rcmd. Action

17.1

1.3.2 The limit of 200 m2 will exclude a number of turbines currently available in North America below the generating capacity of 100 kW. In Sections 1.1 – Purpose and 1.2.1 – Overview, the text talks about having a standard that is consumer friendly. It is not clear that the average consumer would relate to the rotor swept area of a turbine. The primary parameter that any consumer will be considering when purchasing a small wind turbine would be its electrical generating capacity. In addition, the parameter of rotor swept area is viewed differently between vertical axis and horizontal axis turbines. By describing a small wind turbine by its generating capacity (ie the electrical generator manufacturer’s nameplate capacity) this definition of a small wind turbine would be consistent across all wind turbine generator types.


One of the goals of implementing a certifying program around this standard is to make wind turbines more affordable and more available to wind turbine consumers. The limit of 200 m2 will force turbine manufacturers that have developed turbines for the small wind market that have rotor diameters greater than 16 m to go through the significantly more expensive testing and certifying process required of large wind turbines. This additional cost will reduce the competitiveness of these turbines in the small wind market. This will be counterproductive to the development of the small wind market because one of the impediments to the growth of the small wind turbine sales is the lack of financial return and these small turbines with larger rotors will to some extent provide a product that will attract consumers who weigh the annual energy production when considering a small wind turbine. This will be particularly true in low wind speed areas that would not be a market for most small wind turbines.

See response to Comment 1.1

Defer issue for next edition or IEC

17.2

1.4.1 This sentence does not read properly.

Don’t see the problem

None

17.3

1.5.2.11 Can the Rotor Swept Area definition be expanded to include Vertical Axis Turbines?

This definition works for VAWT’s.

None

17.4

2.1.5 To minimize differences in power readings a range should be given instead of only the lower limit of 8 rotor diameters.

The committee felt that including realistic wire run losses was important and recognized that smaller turbines tend to have shorter wire runs. It is assumed that manufacturers will use the lower limit since it gives them the lowest losses.

None

17.5

2.1.8 If the met mast is not used, it is critical that the wind measurement instruments be positioned in accordance with IEC 61400-121 to ensure consistency with either method of mounting the instruments. The text should include for mounting a wind direction vane and, also that the anemometer is to be at hub height within the tolerance specified in IEC 61400-121. A figure giving dimensions may also provide a clear description of a typical arrangement.

See responses to Comments 10.3 and 16.2

None

17.6

2.1.14.3 It is not clear whether “..at least 5 m/s beyond the lowest wind speed…” is referring to greater than or less than the limit discussed. Can this wording be edited to state the desired comparison to the limit?

The word “beyond” provides this guidance – it means greater than.

None

17.7

2.2 IEC 61400-121 allows for an analysis of the test site, providing parameters for determining its acceptability and, if not acceptable, for performing site calibration. It would be unfortunate for a turbine to go through a testing program only to have the results not accepted after the testing is completed. If the suitability of a test site, based on its turbulence intensity, is to be decided upon by the reviewers, WEICan strongly recommends that the parameters for acceptability be included in the standard. This would allow for monitoring the wind at a test site in advance of the testing so that all parties can agree on a site’s suitability before installing a turbine and performing the tests.

The committee appreciates that turbulence intensity is a factor in performance, but no one felt comfortable specifying acceptable limits. So the decision was taken to require TI data or serial data be submitted so that the certifying agency technical reviewers would have this information as they passed judgment on the validity of the test results. It is deemed to be the best we can do at this time.

None

17.8

3.1.2 In performing acoustic testing, either a manufacturer doing self testing or through a third party agency, an anemometer would not be a significant additional cost to the overall testing. In most cases the acoustic testing will be in conjunction with a complete testing program with a permanent anemometer. In the interest of promoting consistency across all testing, can this clause indicate wind speed directly measured is required?

The IEC 61400-11 standard, in Section 4.3.1, allows both anemometer and power curve methods. It states a preference for the power curve method. In 3.1.2 we are saying that unlike the IEC, we prefer the direct use of an anemometer. We don’t require it because the committee anticipated the need for acoustic tests in rural areas with few trees to minimize background noise and though small manufacturers might be burdened if their only option was the installation of a conforming anemometer mast.

None

17.9

6.1.8 All other information listed in 6.1 are results of tests. It could be interpreted that the design loads need to be measured or at least calculated by a third party. Are tower top design loads as calculated and supplied by manufacturers acceptable? If so, a note to this effect would be helpful.

Requiring the tower top design loads is a way to “police” the inputs to the tower structural analyses conducted for local permits. We assume they will be calculated by the manufacturer in many cases, just as the strength calculations will be. The certifying agencies should be able to pass judgment on the validity.

None

No. 18: Sean Whittaker, CanWEA

Number

Comment

Recommended Response

Rcmd. Action

18.1

Following review of the draft standard, CanWEA and our small wind committee would like to ask that AWEA reconsider Section 1.3.2 which states that “this standard applies to wind turbines having a rotor swept area of 200 m2 or less. In a horizontal-axis wind turbine this equates to a rotor diameter of ~ 16 m”. We believe that the standard’s applicability should be based on rated electrical power of the generator rather than swept area.


By basing the standard’s applicability on swept area, we believe that the standard limits the incentive to reduce power loading and unfairly excludes turbines that use a larger rotor to extract greater power at lower wind speeds. This is particularly important for small projects with marginal wind resources who cannot afford to build power lines any significant distances to better wind sites. In these circumstances it makes sense to put additional monies into larger rotors (and taller towers) and we believe that the manufacturer and/or buyer should not be discouraged from exploring this option.


We recommend instead that the threshold be set as a function of rated electrical power of the turbine generator. The figure should be at least 100 kW inclusive (to include turbines rated at 100 kW).

See response to Comment 1.1

Defer issue for next edition or IEC
1   2   3   4   5   6

Похожие:

Materially Affected Party Comments to awea draft Standard 1 – 2009, “Small Wind Turbine Performance and Safety Standard” iconPerformance analysis and design of a small wind turbine for developing countries

Materially Affected Party Comments to awea draft Standard 1 – 2009, “Small Wind Turbine Performance and Safety Standard” iconConstructing the Standard from the Non-standard: Algerian Arabic within French Literature

Materially Affected Party Comments to awea draft Standard 1 – 2009, “Small Wind Turbine Performance and Safety Standard” iconCrew Training and Safety (Standard Operating Procedure 2)

Materially Affected Party Comments to awea draft Standard 1 – 2009, “Small Wind Turbine Performance and Safety Standard” icon2-c compilation Engagements―Draft International Standard on Related Services isrs 4410 (Revised)

Materially Affected Party Comments to awea draft Standard 1 – 2009, “Small Wind Turbine Performance and Safety Standard” icon24-hour standard: a daily standard of 70 µg/m

Materially Affected Party Comments to awea draft Standard 1 – 2009, “Small Wind Turbine Performance and Safety Standard” iconDraft : American National Standard Methods of Measurement of Compatibility between Wireless Communications Devices and Hearing Aids

Materially Affected Party Comments to awea draft Standard 1 – 2009, “Small Wind Turbine Performance and Safety Standard” iconThis draft document is not an api standard; it is under consideration within an api technical committee but has not received all approvals required to become a

Materially Affected Party Comments to awea draft Standard 1 – 2009, “Small Wind Turbine Performance and Safety Standard” iconThis draft document is not an api standard; it is under consideration within an api technical committee but has not received all approvals required to become an

Materially Affected Party Comments to awea draft Standard 1 – 2009, “Small Wind Turbine Performance and Safety Standard” iconKeywords: Wind, Mars, aerodynamic coefficients, Vertical-axis wind turbine (vawt), cardaav, Transition modeling, Computational Fluid Dynamics (cfd)

Materially Affected Party Comments to awea draft Standard 1 – 2009, “Small Wind Turbine Performance and Safety Standard” iconRegulation Impact Statement for the Fuel Standard (Petrol) Determination 2001 and the Fuel Standard (Diesel) Determination 2001


Разместите кнопку на своём сайте:
lib.convdocs.org


База данных защищена авторским правом ©lib.convdocs.org 2012
обратиться к администрации
lib.convdocs.org
Главная страница