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Extracting Energy from Wind. Matt Aldeman Senior Energy Analyst Center for Renewable Energy Illinois State University. Overview. Where does wind come from? Where is it windy? Wind Assessment Power in the wind. Where does wind come from?. On a macro/global scale, wind is a result of:
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Extracting Energy from Wind Matt Aldeman Senior Energy Analyst Center for Renewable Energy Illinois State University
Overview • Where does wind come from? • Where is it windy? • Wind Assessment • Power in the wind
Where does wind come from? • On a macro/global scale, wind is a result of: Uneven heating of earth’s surfaces • Jet streams and circulatory cells • Equator – 30 degrees: Hadley cell • 30 – 60 degrees: Ferrell cell • 60-90 degrees: Polar cell
Where does wind come from? • On a macro/global scale, the direction of the wind is a result of: Coriolis Effect: in the Northern Hemisphere, moving bodies veer right http://tinyurl.com/yvurcs
Where does wind come from? • On a micro/regional scale, wind magnitude and direction are a result of 1) Storm systems and fronts Air is pushed from areas of high pressure to areas of low pressure
Where does wind come from? • On a micro/regional scale, wind magnitude and direction are a result of 2) Uneven specific heat capacity of various surfaces, especially water v. land -Water has a higher specific heat capacity than land. Warm air over land rises during the day. Warm air over water rises at night.
Where is it windy? • Windy areas can be: • Wide open spaces (pasture, fields) • Plateaus (moraines) • Elevated areas (ridgelines) • Mountain passes (funneling effect) • Offshore
Wind Assessment • Tools used for wind assessment • Visual observation • Wind modeling & Wind maps • Airport data & AWOS stations • SODAR & LIDAR • Meteorological towers
Airport & AWOS Stations • http://www.ncdc.noaa.gov/oa/reds/ • Important to visit the anemometer!
SODAR • Emits sound “chirps” at defined intervals (~1-2 seconds) • “…both the intensity and the Doppler (frequency) shift of the return signal are analyzed to determine the wind speed, wind direction and turbulent character of the atmosphere. A profile of the atmosphere as a function of height can be obtained by analyzing the return signal at a series of times following the transmission of each pulse. The return signal recorded at any particular delay time provides atmospheric data for a height that can be calculated based on the speed of sound.”
LIDAR • Same principle as SODAR (Doppler shift of echo return), but with laser light
Met Towers • Anemometers • From NRG product literature: A four-pole magnet induces a sine wave voltage into a coil producing an output signal with frequency proportional to wind speed. The #40C is constructed of rugged Lexan cups molded in one piece for repeatable performance. A rubber terminal boot is included.
How to get (free) wind data • Airports: http://www.ncdc.noaa.gov/oa/reds/ • Illinois met tower loan program: http://www.illinoiswind.org/ • Meteorological tower search: http://www.windalert.com/#search • ISU met tower: email Matt maldema@ilstu.edu
What can students do with wind data? • Opportunity for learning Excel! • Opportunity for learning Windographer