TALL TOWER INVESTIGATIONS OF MIDWEST WIND PATTERNS – MISSOURI
Progress report 8 – July 20, 2007
General
By the end of March 2007, the majority of the towers (4) had now been fully instrumented for more than 6 months. Three of these (Maryville, Blanchard and MoundCity) had been recording data for eight months. These three, along with the Chillicothe tower and two towers that had been instrumented as part of a parallel project funded by Kansas City Power and Light even earlier (Miami and Raytown) were used to compile a comprehensive review of the data collected up to March 31, 2007. This extensive Interim Data Report is being circulated alongside this progress report.
While there have been some problems with data recording and collection enough consistent data has been collected for the establishment and testing of data analysis methodologies. This puts in place standard schemes that can be simply implemented on additional data as it comes in. The fifth tower was instrumented in January and the sixth is ready for installation. This report will describe some of the analyses that will be conducted as standard.
Tower status
Of the six towers required by the project there are currently five towers instrumented and in operation. The remaining one has an agreement in place and should be instrumented in the very near future. There was a significant icing event in mid-January leading to loss of data for periods of up to two weeks for some instruments on some towers.
1.Maryville
The equipment on this tower was installed on 2nd August 2006 and has operated well since that date, although the lack of cellphone connectivity means that data is currently collected sporadically. To date data has been collected up to 21 April, 2007.
2.Blanchard
The equipment on this tower was installed on 3rd August 2006 and has operated well since that date, although the lack of cellphone connectivity means that data is currently collected sporadically. Due to a logger malfunction 3 channels did not record good data from mid-December to March when the logger was replaced. Data was last collected from the tower on 21 April 2007 and appeared to be good for all channels at that time.
3.MoundCity
The equipment on this tower was installed on 6th August 2006, but has had a number of problems. However, at its last visit on 21 April 2007 all channels were operational and the collected data was good.
4.Chillicothe
The tower at Chillicothe was equipped on 4th October 2006. The cellphone connection at this tower is operational and good data has been collected from this site since installation.
5.Santa Rosa
The Santa Rosa tower, located on US69 in DaviessCounty near junction 68 of I35, was set up on 6th January 2007. This tower is owned by the Shepperd Radio Group. Because of some concerns with the tower construction only one boom was installed at each level. Therefore one anemometer and wind vane were placed at heights of 63m, 93m and 121m. The cellphone unit worked when initially set up but did not completed its scheduled calls after that. This cell phone unit was replaced on 21 April 2007 and operated briefly and then ceased again. At that time the instruments seemed to operating well.
6.Lancaster
Everything is in place for instrumentation to be installed on the KTVO tower near Lancaster (north of Kirksville). This is a TV broadcast tower belonging to KTVO. Consultations have taken place with the tower owners and the installation crew to ensure that adequate equipment is available at the time of installation. However, despite constant attempts, we have been unable to set a date for the installation with any of the crews previously used.
Data
Data has been collected from the three operational towers at Maryville, Blanchard and MoundCityup to April 21, 2007. We plan to retrieve data from these sites at the beginning of August, at which time a complete year of data will have been recorded at each site and we will be able to begin producing assessments of the annual characteristics of the wind at these sites for comparison with the wind map.
The tower at Chillicothe is transmitting its data daily. Therefore data has been analyzed up to the end of June. For the three months (April, May, June) a new analysis has been performed which selects the higher wind speed from the two sensors at each height. This is done because it has been noticed that there are times where significant differences are sometimes seen. These are assumed to result from sheltering of the anemometer by the tower and the further assumption is that the higher wind speed at each time comes from the more exposed sensor and is a more accurate observation of the true wind speed. (Further tests of these assumptions will be made by using the directional data collected by the wind vanes at the times of interest.) A similar method is used to calculate the overall mean wind speed in section 9 of the extended data report.
Data from Santa Rosa was last collected on April 21, 2007, and therefore there is still not enough data to present as monthly averages.The tables below present the monthly average wind speeds found to date.
1Maryville
Month / Ch 1 / Ch 2 / Ch 3 / Ch 4 / Ch 5 / Ch 6August 2006 / 4.96 / 5.04 / 5.73 / 5.74 / 6.09 / 6.03
September 2006 / 6.19 / 6.05 / 6.86 / 7.01 / 7.20 / 7.30
October 2006 / 6.70 / 6.54 / 7.51 / 7.64 / 7.98 / 8.04
November 2006 / 6.60 / 6.26 / 7.17 / 7.44 / 7.41 / 7.79
December 2006 / 6.80 / 6.49 / 7.52 / 7.80 / 8.04 / 8.21
January 2007 / 7.45 / 7.05 / 8.10 / 8.42 / 8.51 / 8.62
February 2007 / 6.71 / 6.57 / 7.35 / 7.44 / 7.72 / 7.71
March 2007 / 7.63 / 7.50 / 8.46 / 8.58 / 8.96 / 8.91
Table 1: Monthly average wind speed (in m s-1) for each channel of the Maryville tower.
2Blanchard
Month / Ch 1 / Ch 2 / Ch 3 / Ch 4 / Ch 5 / Ch 6August 2006 / 5.63 / 5.60 / 6.40 / 6.30 / 6.78 / 6.77
September 2006 / 6.32 / 6.26 / 7.08 / 7.16 / 7.70 / 7.56
October 2006 / 7.12 / 7.07 / 7.92 / 7.97 / 8.64 / 8.48
November 2006 / 6.98 / 7.03 / 7.82 / 7.83 / 8.36 / 8.18
December 2006 / 7.02 / 6.92 / 7.79 / 8.00 / 8.67 / 8.37
January 2007 / 8.06 / 7.16 / 8.84 / 8.21 / 9.31 / 8.69
February 2007 / N/A / 6.70 / N/A / 7.52 / N/A / 7.82
March 2007 / N/A / 7.72 / N/A / 8.51 / N/A / 9.05
Table 2: Monthly average wind speed (in m s-1) for each channel of the Blanchard tower.
3MoundCity
Month / Ch 1 / Ch 2 / Ch 3 / Ch 4 / Ch 5 / Ch 6August 2006 / 4.45 / 4.48 / 4.96 / 4.94 / 5.31 / 5.36
September 2006 / 5.05 / 5.43 / 5.96 / 5.67 / 6.10 / 6.56
October 2006 / N/A / N/A / N/A / 6.52 / 6.90 / 7.35
November 2006 / N/A / N/A / N/A / 5.88 / 6.15 / 6.92
December 2006 / N/A / 5.76 / N/A / 6.42 / 7.40 / 7.39
January 2007 / 5.82 / 6.71 / 7.24 / 6.56 / 7.68 / 7.13
February 2007 / 6.10 / 6.10 / 6.58 / 6.58 / 6.99 / 6.98
March 2007 / 6.77 / 6.90 / 7.42 / 7.33 / 7.90 / 7.78
Table 3: Monthly average wind speed (in m s-1) for each channel of the MoundCity tower.
4Chillicothe
Month / Ch 1 / Ch 2 / Ch 3 / Ch 4 / Ch 5 / Ch 6October 2006 / 5.52 / 5.56 / 6.21 / 6.25 / 7.01 / 6.96
November 2006 / 5.76 / 5.73 / 6.54 / 6.55 / 7.35 / 7.27
December 2006 / 5.82 / 5.88 / 6.67 / 6.61 / 7.53 / 7.53
January 2007 / 6.04 / 5.81 / 6.50 / 6.66 / 7.50 / 7.15
February 2007 / 5.84 / 5.81 / 6.39 / 6.43 / 7.12 / 7.01
March 2007 / 6.41 / 6.58 / 7.31 / 7.23 / 8.10 / 8.15
April 2007 / 6.32 / 7.03 / 7.74
May 2007 / 5.43 / 6.06 / 6.73
June 2007 / 4.90 / 5.51 / 6.11
Table 4: Monthly average wind speed (in m s-1) for each channel of the Chillicothe tower.
Analysis of Data
The accompanying report provides an in depth analysis of the data collected to the end of March 2007. While there is much still to do and many interesting analyses that have not yet been undertaken, the primary finding is that the mean wind speeds observed by the towers are lower than those provided by the AWS Truewind wind map of Missouri. There are a number of possible reasons for the differences. The first is that the wind map could be genuinely overestimating the available wind. Second is that the present year is a quiet period for wind and that more data needs to be collected to see if this is the case.
Also revealed by the report, and of concern, is that the stronger winds generally occur during the nighttime hours when energy demand is lower. Again a more detailed analysis is intended to determine the proportion of the time that the wind is observed to be above certain threshold values at each hour of the day, once a complete year’s worth of data has been collected at the towers.
Appendix 1: Examples of the record of missing data for the towers at Blanchard, Chillicothe and Maryville.
Tower Site / Blanchard / Chillicothe / MaryvilleData Record Start Date / 8/4/2006 at 0200 / 10/4/2006 at 1500 / 8/3/2006 at 0000
Data Record End Date / 3/27/2007 / 3/31/2007 / 3/27/2007
Missing Data Times
Aug.2006 / 15th at 3, 4, 5, 13 and 14 hours, Ch 3: 28th at 5 hours / NA / 15th at 4 & 5 hours, 21st at 21 hours, 22nd at 4 hours
Missing Data Times
Sept.2006 / 22nd at 19-23 hours / NA / 6th at 23 hours, 7th at 1hour
Missing Data Times
Oct.2006 / none / 4th from 10-14 hours, 9th from 0-7 hours, 11th from 0-4 hours, 14th from 0-11, 8th at 20 hour for Ch. 5 & 6 / 11th at 0 hours, 17th at 5 hours
Missing Data Times
Nov.2006 / 27th at 16 and 17 hours / 30th from 0-23 hours, 29th from 16-23 hours and for hour 15 for Ch 3, 4, 5, and 6, 24th Ch 5 & 6 for hour 17, 15th from 20-23 hours, 11th hours 16 & 17, 6th at hour 21 / 27th from 14-17 hours
Missing Data Times
Dec.2006 / All Channels: 12th at 22 hours, Ch 6: 1st at 0 hours to 2nd at 15 hours, 24th at 2 hours, Ch 5: 1st at 0 hours to 2nd at 16 hours, 24th at 2 hours, Ch 4: 1st from 0-14 hours, 24th at 2 hours, Ch 3: 1st at 0 hours to the 2nd at 15 hours, 24th at 2 hours, Ch 2: 1st at 0 hours to the 1st at 16 hours, Ch 1: 1st at 0 hours to the 2nd at 9 hours / none
Missing Data Times
Jan. 2007 / Ch 1: 2nd at 2 and 3 hours, 14th at 4 hours to 18th at 14 hours, Ch 2: 2nd at 2 hours, 14th at 4 hours to 18th at 20 hours, Ch 3: 14th at 4 hours to 18th at 10 hours, Ch 4: 14th at 4 hours to 18th at 14 hours, Ch 5: 14th at 4 hours to 18th at 8, Ch 6: 14th at 4 hours to 18th at 12 hours / Ch 1: 14th at 12 hours to 15th at 12 hours, Ch 2: 14th at 8 hours to 17th at 3 hours, Ch 3: 14th at 13 hours to 17th at 0 hours, Ch 4: 14th at 13 hours to 16th at 4 hours and the 16th at 21 hours, Ch 5: 14th at 10 hours to 16th at 10 hours and the 16th at 10 hours
Missing Data Times
Feb.2007 / All Channels: 22nd at 9 hours to 19 hours, Ch 1: 4th at 0 hours, 27th at 9 and 10 hours, Ch 2: 4th at 0 hours / none
Missing Data Times
March 2007 / All Channels: 27th at 14 hours and no data past the 27th at 16 hours at this time