1) Lab Experiment Goals
The student will learn how to calculate the average wind energy density over the measurement time frame to assess the suitability of installing a Wind Energy Extraction system. The user can also see how wind speed peaks contribute towards the overall wind energy collected.
2) Lab Apparatus and Equipment
a. This remote trigger experiment collects data from an actual anemometer installed at Amrita University, Amritapui Campus. The geographical coordinates of the anemometer are:
Longitude =76.492016; //units are degrees & Latitude = 9.094258; // units are degrees
For this experiment, it is installed on the Roof of the Engg College Building about 40m above ground.
b. The equipment used for this experiment include:
i. Anenometer – Davis Instruments
ii. Data Acquisition Module - Labjack UE9-Pro over Ethernet
3) Lab Procedures
a. Go to the “RT” tab in this experiment.
b. Click the “Start streaming live data” button
c. Watch how the Wind data changes over time. It is recommended that the user watch the data for some time, in order to see changes in the wind speed and direction.
d. “Stop” the experiment.
e. Export the data to Microsoft Excel / LibreOffice / OpenSpreadsheet or a similar program, or a similar spreadsheet program. The data is exported as a Comma Separated Variable (CSV) file.
f. If it is nighttime when you are performing the experiment, or you want to analyze a longer duration data set, Historical Data is available for download by clicking the Historical Data button.
g. After importing the data into the spreadsheet software:
i. Create a graph of the Wind Speed vs. Time,
ii. Find the peak, minimum, and average wind speed over the data file duration,
iii. Calculate the Energy received by the sensor over the duration of the data file.
1. Create a new column titled “Energy”, to the right of the column titled “Irradiance”. This should be column “C”.
2. In the second row of the new column, cube the adjascent wind speed value and multiply it by 0.5 and 1.2929 (the air density). The formula should look something like “=0.5*1.2929*B2*B2*B2”. You can copy and paste this cell into the other row elements of column “C”, down to the last row of data. Each of these cells approximates the wind energy density available at that point of time.
3. Create a new column to the right of the previous column. You will calculate the Wind Energy per unit time in this column.
4. Find the average Wind Energy Density over the duration of the time by adding up all of the wind energy density energy intervals and dividing by the number of samples. This can be done by using an “Average” formula. The formula should look like =average(C2:Cn), where n is the last row of data. This formula will give you the average wind energy density over the file duration, in units of Watts/meter3.
5. Check your answers against the values given on the experiment webpage. You have just done your first wind energy site assessment. If not, go back and check your calculations until the correct answers are obtained. Of course, for an actual site assessment, data should be collected for a much more extended duration of time.
6. For assessing the potential power production of a wind turbine at that site, it is necessary to multiply the average wind energy density value determined by the anticipated swept area of your rotor. In a real monitoring scenario, the data should be averaged over a one year duration.