reskit.wind.core.power_curve#

Attributes#

Classes#

PowerCurve

Creates a wind turbine's power curve represented by a set of (wind-speed,capacity-factor) pairs.

PowerCurve

Creates a wind turbine's power curve represented by a set of (wind-speed,capacity-factor) pairs.

Functions#

synthetic_power_curve_data()

Reads the data used for creating a synthetic power curve.

compute_specific_power(capacity, rotor_diam, **k)

Calculates the corresponding specific power for a wind turbine in W/m2 from values of capacity in kW and rotor diameter in m.

Module Contents#

class reskit.wind.core.power_curve.PowerCurve#

Bases: tuple

ws#
cf#
reskit.wind.core.power_curve._synthetic_power_curve_data = None#
reskit.wind.core.power_curve.synthetic_power_curve_data()#

Reads the data used for creating a synthetic power curve.

Returns:

DataFrame with the data to create a synthetic power curve.

Return type:

pandas DataFrame

reskit.wind.core.power_curve.compute_specific_power(capacity, rotor_diam, **k)#

Calculates the corresponding specific power for a wind turbine in W/m2 from values of capacity in kW and rotor diameter in m.

Parameters:
  • capacity (float or array-like) – Turbine’s nominal capacity in kW.

  • rotor_diam (float or array-like) – Turbine’s hub height in m.

Returns:

Specific power in W/m2

Return type:

float or array-like

class reskit.wind.core.power_curve.PowerCurve(wind_speed, capacity_factor)#

Creates a wind turbine’s power curve represented by a set of (wind-speed,capacity-factor) pairs.

Initialization:

Parameters:
  • wind_speed (array-like) – The wind speeds values

  • capacity_factor (array-like) – The corresponding capacity factor

Return type:

PowerCurve object

wind_speed#
capacity_factor#
__str__()#
_repr_svg_()#
static from_specific_power(specific_power, cutout=25)#

Creates a synthetic wind turbine power curve based on observed relationships between turbine specific power and known power curves according to Ryberg et al. [1].

Parameters:
  • specific_power (float) – Turbines’s specific power in m/s

  • cutout (int, optional) – Cut out wind speed in m/s, by default 25

Returns:

  • PowerCurve

  • Sources

  • ——-

  • [1] Ryberg, D. S., Caglayan, D. G., Schmitt, S., Linßen, J., Stolten, D., & Robinius, M. (2019). The future of European onshore wind energy potential (Detailed distribution and simulation of advanced turbine designs. Energy. https://doi.org/10.1016/j.energy.2019.06.052)

static from_capacity_and_rotor_diam(capacity, rotor_diam, cutout=25)#

Creates a synthetic wind turbine power curve based on observed relationships between turbine’s capacity, rotor diameter and known power curves according to Ryberg et al. [1].

Parameters:
  • capacity (numeric) – Baseline turbine capacity in kW.

  • rotor_diam (numeric) – turbine rotor diameter in m

  • cutout (int, optional) – Cut out wind speed in m/s, by default 25

Returns:

  • PowerCurve

  • Sources

  • ——-

  • [1] Ryberg, D. S., Caglayan, D. G., Schmitt, S., Linßen, J., Stolten, D., & Robinius, M. (2019). The future of European onshore wind energy potential (Detailed distribution and simulation of advanced turbine designs. Energy. https://doi.org/10.1016/j.energy.2019.06.052)

simulate(wind_speed)#

Applies the invoking power curve to the given wind speeds.

Parameters:

wind_speed (array_like) – Local average wind speed close to or at the hub height.

Returns:

CorrespongDing capacity fators for the given wind speeds

Return type:

array_like

expected_capacity_factor_from_weibull(mean_wind_speed=5, weibull_shape=2)#

Computes the expected average capacity factor of a wind turbine based on a Weibull distribution of wind speeds.

Parameters:
  • mean_wind_speed (int, optional) – mean wind speed at the location in m/s, by default 5

  • weibull_shape (int, optional) – Weibull shape parameter, by default 2

Returns:

Average capacity factor

Return type:

numeric

expected_capacity_factor_from_distribution(wind_speed_values, wind_speed_counts)#

Computes the expected average capacity factor of a wind turbine based on an explicitly-provided wind speed distribution

Parameters:
  • wind_speed_values (numeric or array-like) – wind speed values in m/s

  • wind_speed_counts (numeric or array-like) – corresponding counts (number of occurrence) of the given wind speed values. Counts will be normalized within the function

Example

pc.expected_capacity_factor_from_distribution(

wind_speed_values=[ 1, 2, 3, 4, 5, 6], # Units of m/s wind_speed_counts=[0.1, 0.3, 0.5, 0.3, 0.1, 0.025 ] # Units of “counts” )

Returns:

Average capacity factor

Return type:

numeric

convolute_by_gaussian(scaling=0.06, base=0.1, extend_beyond_cut_out=True, _min_speed=0.01, _max_speed=40, _steps=4000)#

Convolutes a turbine power curve by a normal distribution function with wind-speed-dependent standard deviation.

Parameters:
  • scaling (float, optional) – scaling factor, by default 0.06

  • base (float, optional) – base value, by default 0.1

  • extend_beyond_cut_out (bool, optional) – extend the estimation beyond the turbine’s cut out wind speed, by default True

  • _min_speed (float, optional) – minimum wind speed value in m/s to be considered, by default 0.01

  • _max_speed (int, optional) – maximum wind speed value in m/s to be considered, by default 40

  • _steps (int, optional) – number of steps in between the wind speed range, by default 4000

Returns:

The resulting convoluted power curve

Return type:

PowerCurve

Notes

The wind-speed-dependent standard deviation is computed with: std = wind_speed * scaling + base

apply_loss_factor(loss)#

Applies a loss factor onto the power curve. It can be a single value, or a function which takes a ‘capacity factor’ array as input.

Parameters:

loss (numeric or function) –

If numeric, the value is applied at all capacity factors with:

new_capacity_factors = [1-loss] * previous_capacity_factors

If a function, it must take a numpy array representing capacity factor values as input, resulting in the equation:

new_capacity_factors = [1-loss(previous_capacity_factors)] * previous_capacity_factors

Returns:

The corrected power curve.

Return type:

PowerCurve