WIND ENERGY GENERATION LAB
INSTRUCTOR FACILITATION NOTES:
OBJECTIVES: Self-discovery that direct wind orientation (YAW concept), at higher wind speeds (SPEED concept
and relationship to freq/volt/power), are most efficient as wind source distance varies. Wind profiles are also
impacted by topography. Obstacles such as mountains, trees and buildings cause a turbulent wind flow within
a horizontal distance of 20H (where H = height of obstruction.) and up to 2Hobstruction. Turbulent wind flows
within this envelope do not produce as efficient wind profiles as those outside the obstruction envelope. Thus
the best positions for wind turbines are outside of the 20H envelope at a height above 2H of obstruction.
RECOMMENDED READINGS FOR INSTRUCTOR:
AWEA Siting Handbook (for wind turbine components and siting considerations)
Wind Power: Renewable Energy for Home, Farm and Business (Paul Gipe 2010)
RECOMMENDED LECTURE CONCEPTS TO REVIEW PRIOR TO LAB:
● Wind turbine components
● Efficiency
● Conversion of mechanical energy to electrical energy, i.e. a wind turbine
● Relationship between speed, frequency and period: freq = 1/period or period = 1/frequency
● Voltage
● Relationship between height of wind turbine and wind speeds/efficiency
● Relationship between angle of wind source and wind turbine efficiency; yaw concept
● Mathematical relationships between obstruction height and zone of wind turbulence, i.e. unstable and
unreliable wind flow regimes for wind energy production
● How to use a map scale to determine distances on a map using a ruler and proportionality
PROCEDURAL NOTES:
1. You will need the “Wind Lab Day 1 – student vers.doc” file, “Wind Lab Day 1 – prelab questionnaire.doc”
file, and “Wind Lab Day 1 – post lab questionnaire.doc” file for this lab. You will also use the links to the two
SEED videos that originally accompanied this lab.
2. “Running” the Vernier Logger Pro is not shown nor could I remember how to initiate data collection; you
will need to explain that. We anticipate additional help is necessary when adjusting the data collection
settings in the program.
3. All other aspects of this lab are fairly self explanatory and self-contained.
4. Use the “Wind Lab Day 1 – key.doc” and to evaluate the labs. Pre- and post-assessments will be taken on
the SEED website in the near future.
HERE ARE THE KIND OF QUESTIONS YOU WANT YOUR STUDENTS TO BE ASKING:
1.
What kind of relationship do you think exists between distance from the wind source and power
production? Would shorter or longer turbines distances from the wind source yield the highest power
production?
2.
How do you think the angle of the wind source impacts the wind turbine’s efficiency? Does turbine
and/or blade design matter?
3.
What do you think is the relationship between wind speed and wind turbine efficiency? Do higher
wind speeds always correlate to higher efficiency or is there a point where high wind speeds create unstable
wind turbine operation?
4.
In general, how does the height of the wind turbine affect efficiency, i.e. what do we know about wind
speeds as height increases?
5.
How do you think topographical characteristics such as buildings, trees, and hills impact wind turbine
efficiency? Do you think that at some distance away from such obstructions, these characteristics no longer
matter?
Vocabulary
Anemometer – An instrument that measures wind speed
Convection – The air movement due to density differences as heated air rises
and is replaced by cooler air
Cut-in speed– Speeds at which wind turbines begin generating usable power
Cut-out speed – Max speed allowable before creating unstable turbine operation and performance
Pressure Gradient Force – The difference in air pressure that causes air molecules to move causing wind
Topography – The study and mapping of the shape of surface features of the earth such as mountains, valleys, rivers and
lakes
Turbulence – Irregular or unstable movement of a gas or liquid
Wind Speed – The rate at which air is moving horizontally past a given point
Wind Speed Units – Wind speed is measured in meters/second (m/s) or miles/ hour (mph). 1 m/s = 2.24 mph
FOR THE LAST LAB QUESTION YOU COULD ALSO SIMPLIFY AND ASSUME A UNIFORM H=30’ FOR ALL BUILDINGS.
Map of Alisal Campus: Using the scale indicated in the lower left hand corner, sketch the turbulent region
outside each building envelope. Note there will be overlap in each building’s turbulent region. (Note to
Instructor: use larger landscape oriented map to pass out in class)
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