Land Owners Cost Guide

The Alternative Energy Institute has often been been asked to provide an estimate for installing, maintaining and analyzing data from a standard meteorological tower on a landowners property. This data will define the wind resource on and near to the land and determine the viability and expected returns of a potential wind farm located on the site. The factors to be considered are the size of the data collection tower, the length of time that data will be collected and the availability of local support for data collection and site inspection.

The standard agreement between AEI and private individuals is that AEI will work on a cost basis for any work done outside the AEI office (field work) and that in return the monthly wind speed and direction averages are made available for the general public. This removes any chance of having state funds being used to aid selected private individuals only. The true data (hourly averages and individual data observations) remains the property of the landowner. These values will not be made available to any outside group without the expressed consent of the landowner.

AEI also maintains a list of technicians who are familiar and capable of installing these NRG standard towers.  To find companies in your area refer to the following link: Installers.

1. Towers readily available are:  20 m, 40 m, 50 m and 60 m Talltower systems from NRG Systems of Vermont. These are industry standard towers and have the ability to be easily transported and raised with a small crew in one-two days. The sensors and data logger would be supplied by AEI as part of the anemometer loan program for Texas residents. Wiring costs would vary according to tower size and the number of sensors.

	20m	40m	50m	60m
Base cost	$800	$3,700	$5,700	$8,400
Wiring	$72	$220	$250	$300
Sensor supports	$260	$390	$390	$520
Total	$1,132	$4,310	$6,340	$9,220

AEI would supply the gin pole, winch and hardware for tower raising and lowering.

2.  Data should be collected for a full year; collection costs are based on phone service at $50/month and data stored at AEI offices in Canyon. Cost is independent of tower height.

    Phone
    $600 / year

3. Data can then be used to generate expected energy output from many different manufacturers power curves. It should take about 1 hour to do this type of calculations each month. A wind analyst could do this job monthly and it would run $50/hour.

    Energy Estimates by different turbines
    $600/year

4. The data would be delivered in a Microsoft Excel spreadsheet, with printouts showing the hourly average of wind speed and direction from all sensors on the tower and plots showing the wind distribution and energy distribution. Plots of the data streams for all wind data would be printed to show the sensors were working and to aid in identifying periods of poor data or broken sensors.

5. To extend the operation of the site beyond the planned single year would incur phone charges and any maintenance that AEI has to do.

Maintenance trips for AEI would include mileage round trip @ $0.41/mile plus time during travel. Work onsite is at the base cost of $50/hour for senior personnel and $15/hour for students. It normally takes three people on hand to safely raise and lower a tower, if any onsite help is available then less student labor could be used.

6. A typical met tower will have sensors at 10 m (32.8 ft)  and at the upper level of the tower. If the 40 m tower is used a mid-level of 25 m and tower top would be used. Wind direction at the tower top and temperature at 2-3 m is also collected. The 50m tower would have 6 wind speed sensors, 10, 25, 40 (2) and 50 (2) with wind direction at 25 and 50m. Higher numbers of sensors require more signal wire and sensors mounts (booms).

Data will be collected at ten-minute averages for long-term data and to minimize the length of phone calls. This is the international standard now adopted by NRG and is built into the logger.  Once we start working with the data, the information is utilized in 10 minute intervals as well as averaging into hourly intervals to produce easily comprehensible graphs and tables.

Cost for labor to install the tower will be based on the $50/hour and $15/hour for senior/student labor and just what time it takes. For the 20 m tower about 6 hours, for the 40m tower about 10 hours, 12-15 for the 50m, and about 20 hrs for the 60 m. The condition of the soil and surrounding land determines the difficulty of installation and maintenance. Anchors will be the screw type and set with predrilled holes using a posthole digger.

	20m	40m	50m	60m
Labor for installation	$480	$800	$1,200	$1,600
Total costs: 1st year	$3,870	$7,078	$8,915	$10,752
Total costs: 2nd year	$2,115	$2,115	$2,115	$2,115
Tower removal	$385	$385	$385	$385
2 year total	$6,209	$9,578	$11,415	$13,252

The advantage of the 60 m tower is that they are collecting data at nearer to the expected hub height of the turbines that should be installed, the obvious disadvantage is the increased costs of installation. Data can be estimated at upper levels from lower measurements but accuracy is increased with a longer distance between the sensors, as on the taller tower.

We know from long-term examination of data from all over the Texas Panhandle that the data will not be too different from what has been measured at other sites; it will only characterize the local site. The 20 m tower option should give an adequate estimate of the wind conditions. The 40 m tower will be better and give greater accuracy to the upper level estimates (50 m). The 60m tower would be the best in taking actual 60m data and predicting higher hub height wind speeds.

AEI does not have a standard contract for work like this, if you agree to one option or the other we will supply you with the information needed to order the tower, when it arrives we will schedule the installation and then set up the phone service and start the data collection.

At monthly intervals we will compile the data into the standard presentation and mail it to you along with the averages and graphs. Estimates of wind speeds at 60m will be made from the lower levels, or the measured data at 60m. Raw data will be stored onsite at AEI and sent to you along with the hardcopies. Comparisons can be made to the online data at http://www.windenergy.org/ to see how the monthly averages compare to nearby sites.

The only non-budgeted item is if there is damage to the data logger or sensors, in that case the you would be expected to pay for the cost of replacement or repair. Typical values have been $700 for full repair of a completely damaged logger (lightning strike), to sensors ($85 for wind speed, $155 direction and $195 for temperature).  Typical rates for damage have been about 10% loss of sensors per year (hail, lightning, high winds) and a logger every 4 years. But there is no guarantee that damage would not occur more often than that, or that there could be no damage at all, in which case the unscheduled costs would reduce.

The 20 m tower would have 3 wind speed, a wind direction and a temp sensors,  the 40m and 50m towers would have 6 wind speed, 2 wind direction and a temp, extra sensors are at the upper levels for redundancy.

For further information, please contact David Carr or Ken Starcher at AEI.

 

ALTERNATIVE ENERGY INSTITUTE
WT BOX 60248
CANYON TX  79016
806-651-2295
FAX: 806-651-2733
Email:  aeimail@mail.wtamu.edu