Example for
energy yield


Energy yields can be calculated with the following user-definable options:

  • Measured wind speeds.
  • Wind speeds extrapolated onto any hub height.
  • Calculated or constant air density.
  • Power curve selection with/without air density adjustment, or constant power coefficient.
  • Any amount of shutdown constraints and/or power curve constraints. All shutdown constraints and power curve constraints with user-definable and freely combinable conditions of:
    • Wind speeds
    • Times of day
    • Times between sunrise and sunset
    • Times between sunset and sunrise
      • Seasonally resolved night fractions tables (e.g. night-tenths) with the thresholds to be used for the shutdown of air temperature and/or of wind speed
    • Seasonal times
    • Wind directions
    • Air temperatures
    • Precipitations
  • One shutdown constraint for shadow flicker shutdown with shadow flicker tables for the shutdown with receptor specific cumulative impacts.

WindDataSuite calculates gross and net yields for the time series in total and month specific as well as the mean annual and monthly gross and net yields. Also the respective total, particular, and proportional energy yield losses due to the assigned shutdown constraints and power curve constraints are calculated.

The results (mean wind speed, mean air density, operating hours, calculated energy yields and energy losses) can be exported in form of a table into a csv-formatted file.

In the following example, the energy yields have been calculated for a time series at the heights of 80 m, 100 m, and 120 m above ground level. Three different constraints have been defined:

  1. A shutdown constraint for the protection of bats: Shutdown will be done
    • when the wind speed is less than 6 m/s,
    • when the air temperature is greater than or equal to 10°C,
    • when the precipitation intensity is less than 0.1 mm/hour,
    • from 2 hours before sunset over night until sunrise,
    • seasonally from 1 April to 31 October.
  2. A turbulence constraint: Shutdown will be done
    • when the wind direction is within the sector from 340° to 20°,
    • when the wind speed is greater than 6 m/s.
  3. A noise reduction: During the night between 22:00 hours MEZ (21:00 GMT) and 06:00 hours MEZ (05:00 GMT), the turbine will be operated in a power-reduced mode with a noise level of 100dB.

Fig.1 shows a time series excerpt of the calculated energy yields.
Fig.2 shows an excerpt of the table with the energy yields and energy yield losses.


Time series of the energy yields
The table with the energy yields and energy yield losses (excerpt)
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