Lake Michigan Wind Assessment
A study of wind speed and direction over Lake Michigan was conducted to determine if there was sufficient energy potential to justify further work toward wind farm development.
A laser wind sensor mounted on a floating platform was located at the mid-lake plateau in 2012, about 6.5 miles from the eastern shoreline near Muskegon, Michigan. Range gate heights were centered at 75, 90, 105, 125, 150, and 175 meters. Wind speed and direction were measured once each second and aggregated into 10-minute averages. Height and location were the primary variables of interest, along with laser wind sensor performance. Results showed that wind direction primarily was from the south-southwest at both locations. Average wind speed stopped increasing between 105 m and 150 m, depending on location, which is inconsistent with current mathematical models that assume wind speed increases with height. Typically, average speed at the mid-lake plateau is no more than 10 percent greater than at the location near Muskegon. Thus, it may be possible to harvest much of the available wind energy at a lower height and closer to the shoreline than previously thought. Based on these studies, the laser wind sensor's ability to measure wind speed appears to be affected by a lack of particulate matter at greater heights.
AXYS Technologies' WindSentinel was selected based on cost, flexibility of hardware installation, and ease of movement to multiple lake locations. The WindSentinel buoy is a Nomad-style platform buoy, 20 ft. long with a 10 ft. beam. The Grand Valley State University (GVSU) configuration includes the following equipment:
- Vindicator Laser Wind Sensor using laser pulse technology (LPT). The Vindicator can be set to measure wind speed and direction at six different heights or range gates. The GVSU's range gates were set at: 75, 90, 105, 125, 150, and 175 meters.
- Watchman 500 data controller that collects more than 200 data parameters per second. The raw data are sorted, and 1 second of data is converted to 10-minute averages for transmission to shore and the project servers.
- Orientation and position system, including compass engine and GPS (D+).
- Data transmission is accomplished using one of three on-board systems: wireless cell phone and the Inmarsat and Iridium satellite systems.
- Onboard power systems include two solar panels, a wind turbine and a backup diesel generator with a 24-volt, 135-amp alternator. A bank of 40 batteries stores the energy. The system was designed to operate without assistance for 6-9 months.
- A Wildlife Acoustics Bird and Bat SM2 sensor.
Other sensors include: a directional wave sensor, relative humidity and temperature, water quality monitor, barometric pressure, two anemometers, water temperature, and an Automatic Identification System (AIS) system.