Wind Resource

1
Wind Resource

• References
• NREL (Tony Jimenez, Neil Kelley)

2
Where Does Wind Come From?

• The differential heating of earths atmosphere
  causes wind.

3
The Jet Stream

• The jet stream is responsible for the transport
  of heat and momentum in the mid latitudes

4
Measuring the wind

• Wind speed is typically measured using
  anemometers.
• How might you measure the speed of the wind from
  a fan without an anemometer?

5
Characterizing the Wind Resource

• How might you characterize the wind?
• average wind speed
• variation in wind speed
• most frequent wind direction (prevailing wind
  direction)
• frequency of other wind directions

6
Probability Distributions

• Create a table like the one below

Range (bin) Number Percent
0 2
2 4
4 6
6 8
8 10
7
Probability Distributions - 2

• Consider this list of numbers.
• 1, 3.5, 7, 6.5, 1.5, 9, 1, 0.5, 8.5, 9.5
• What is the average?
• Fill in the second column of your table with the
  number of numbers in the list that fall within
  each of your bins.
• Fill in the third column of your table with the
  percent of the numbers in each range.
• Create a plot showing the percent in each range.
  Mark the average on your plot.

8
Wind Speed Distribution
9
Turbine Power Curve

• Power is usually limited to a certain maximum for
  real turbines (to ensure safe operation)

10
Power

• Power available in the wind
• r air density
• v wind speed
• A cross sectional area swept by rotor

11
Power Density
Power Density
Wind Class W/m2 at 50 m Wind speed at 50
m 1 0 - 199 0 - 5.9 m/s 2 200 -
299 5.9 - 6.7 m/s 3 300 - 399 6.7 - 7.4
m/s 4 400 - 499 7.4 - 7.9 m/s 5 500 - 599 7.9
- 8.4 m/s 6 600 - 800 8.4 - 9.3 m/s 7 gt
800 gt 9.3 m/s
12
United States Wind Resource
13
Colorado Wind Resource
http//www.eere.energy.gov/windandhydro/windpoweri
ngamerica/images/windmaps/co_50m_800.jpg
14
Activity

• Use the Wind Living Lab to evaluate the wind
  resource at a location of your choosing. Create
  a wind speed probability distribution (like the
  one on slide 6) showing the proportion of time
  the wind spends at each wind speed value.
• Which turbine produces more energy for your wind
  speed distribution?