def get_solarposition(time,
latitude,
longitude,
altitude=None,
pressure=None,
temperature=10,
**kwargs):
#calculate the altitude and pressure based on default vales
if altitude is None and pressure is None:
altitude = 0
pressure = 101325
elif altitude is None:
altitude = atmosphere.pres2alt(pressure)
elif pressure is None:
pressure = atmosphere.alt2pres(altitude)
#converting the time into DatetimeIndex
time = pd.DatetimeIndex([
time,
])
#Normalizing the time
t = time.tz_localize(tz='UTC')
spa_python(t, latitude, longitude, altitude, pressure, temperature,
**kwargs)
def get_solarposition(time, latitude, longitude,
altitude=None, pressure=None,
method='nrel_numpy',
temperature=12, **kwargs):
"""
A convenience wrapper for the solar position calculators.
Parameters
----------
time : pandas.DatetimeIndex
latitude : float
longitude : float
altitude : None or float
If None, computed from pressure. Assumed to be 0 m
if pressure is also None.
pressure : None or float
If None, computed from altitude. Assumed to be 101325 Pa
if altitude is also None.
method : string
'pyephem' uses the PyEphem package: :func:`pyephem`
'nrel_c' uses the NREL SPA C code [3]: :func:`spa_c`
'nrel_numpy' uses an implementation of the NREL SPA algorithm
described in [1] (default): :func:`spa_python`
'nrel_numba' uses an implementation of the NREL SPA algorithm
described in [1], but also compiles the code first: :func:`spa_python`
'ephemeris' uses the pvlib ephemeris code: :func:`ephemeris`
temperature : float
Degrees C.
Other keywords are passed to the underlying solar position function.
References
----------
[1] I. Reda and A. Andreas, Solar position algorithm for solar radiation
applications. Solar Energy, vol. 76, no. 5, pp. 577-589, 2004.
[2] I. Reda and A. Andreas, Corrigendum to Solar position algorithm for
solar radiation applications. Solar Energy, vol. 81, no. 6, p. 838, 2007.
[3] NREL SPA code: http://rredc.nrel.gov/solar/codesandalgorithms/spa/
"""
if altitude is None and pressure is None:
altitude = 0.
pressure = 101325.
elif altitude is None:
altitude = atmosphere.pres2alt(pressure)
elif pressure is None:
pressure = atmosphere.alt2pres(altitude)
method = method.lower()
if isinstance(time, dt.datetime):
time = pd.DatetimeIndex([time, ])
if method == 'nrel_c':
ephem_df = spa_c(time, latitude, longitude, pressure, temperature,
**kwargs)
elif method == 'nrel_numba':
ephem_df = spa_python(time, latitude, longitude, altitude,
pressure, temperature,
how='numba', **kwargs)
elif method == 'nrel_numpy':
ephem_df = spa_python(time, latitude, longitude, altitude,
pressure, temperature,
how='numpy', **kwargs)
elif method == 'pyephem':
ephem_df = pyephem(time, latitude, longitude, pressure, temperature,
**kwargs)
elif method == 'ephemeris':
ephem_df = ephemeris(time, latitude, longitude, pressure, temperature,
**kwargs)
else:
raise ValueError('Invalid solar position method')
return ephem_df
def get_solarposition(time,
latitude,
longitude,
altitude=None,
pressure=None,
method='nrel_numpy',
temperature=12,
**kwargs):
"""
A convenience wrapper for the solar position calculators.
Parameters
----------
time : pandas.DatetimeIndex
latitude : float
longitude : float
altitude : None or float, default None
If None, computed from pressure. Assumed to be 0 m
if pressure is also None.
pressure : None or float, default None
If None, computed from altitude. Assumed to be 101325 Pa
if altitude is also None.
method : string, default 'nrel_numpy'
'nrel_numpy' uses an implementation of the NREL SPA algorithm
described in [1] (default, recommended): :py:func:`spa_python`
'nrel_numba' uses an implementation of the NREL SPA algorithm
described in [1], but also compiles the code first:
:py:func:`spa_python`
'pyephem' uses the PyEphem package: :py:func:`pyephem`
'ephemeris' uses the pvlib ephemeris code: :py:func:`ephemeris`
'nrel_c' uses the NREL SPA C code [3]: :py:func:`spa_c`
temperature : float, default 12
Degrees C.
Other keywords are passed to the underlying solar position function.
References
----------
[1] I. Reda and A. Andreas, Solar position algorithm for solar radiation
applications. Solar Energy, vol. 76, no. 5, pp. 577-589, 2004.
[2] I. Reda and A. Andreas, Corrigendum to Solar position algorithm for
solar radiation applications. Solar Energy, vol. 81, no. 6, p. 838, 2007.
[3] NREL SPA code: http://rredc.nrel.gov/solar/codesandalgorithms/spa/
"""
if altitude is None and pressure is None:
altitude = 0.
pressure = 101325.
elif altitude is None:
altitude = atmosphere.pres2alt(pressure)
elif pressure is None:
pressure = atmosphere.alt2pres(altitude)
method = method.lower()
if isinstance(time, dt.datetime):
time = pd.DatetimeIndex([
time,
])
if method == 'nrel_c':
ephem_df = spa_c(time, latitude, longitude, pressure, temperature,
**kwargs)
elif method == 'nrel_numba':
ephem_df = spa_python(time,
latitude,
longitude,
altitude,
pressure,
temperature,
how='numba',
**kwargs)
elif method == 'nrel_numpy':
ephem_df = spa_python(time,
latitude,
longitude,
altitude,
pressure,
temperature,
how='numpy',
**kwargs)
elif method == 'pyephem':
ephem_df = pyephem(time,
latitude,
longitude,
altitude=altitude,
pressure=pressure,
temperature=temperature,
**kwargs)
elif method == 'ephemeris':
ephem_df = ephemeris(time, latitude, longitude, pressure, temperature,
**kwargs)
else:
raise ValueError('Invalid solar position method')
return ephem_df
def test_alt2press():
atmosphere.pres2alt(1000)
def test_pres2alt():
atmosphere.pres2alt(100000)
def basic_chain(times,
latitude,
longitude,
module_parameters,
inverter_parameters,
irradiance=None,
weather=None,
surface_tilt=None,
surface_azimuth=None,
orientation_strategy=None,
transposition_model='haydavies',
solar_position_method='nrel_numpy',
airmass_model='kastenyoung1989',
altitude=None,
pressure=None,
**kwargs):
"""
An experimental function that computes all of the modeling steps
necessary for calculating power or energy for a PV system at a given
location.
Parameters
----------
times : DatetimeIndex
Times at which to evaluate the model.
latitude : float.
Positive is north of the equator.
Use decimal degrees notation.
longitude : float.
Positive is east of the prime meridian.
Use decimal degrees notation.
module_parameters : None, dict or Series
Module parameters as defined by the SAPM.
inverter_parameters : None, dict or Series
Inverter parameters as defined by the CEC.
irradiance : None or DataFrame, default None
If None, calculates clear sky data.
Columns must be 'dni', 'ghi', 'dhi'.
weather : None or DataFrame, default None
If None, assumes air temperature is 20 C and
wind speed is 0 m/s.
Columns must be 'wind_speed', 'temp_air'.
surface_tilt : None, float or Series, default None
Surface tilt angles in decimal degrees.
The tilt angle is defined as degrees from horizontal
(e.g. surface facing up = 0, surface facing horizon = 90)
surface_azimuth : None, float or Series, default None
Surface azimuth angles in decimal degrees.
The azimuth convention is defined
as degrees east of north
(North=0, South=180, East=90, West=270).
orientation_strategy : None or str, default None
The strategy for aligning the modules.
If not None, sets the ``surface_azimuth`` and ``surface_tilt``
properties of the ``system``. Allowed strategies include 'flat',
'south_at_latitude_tilt'. Ignored for SingleAxisTracker systems.
transposition_model : str, default 'haydavies'
Passed to system.get_irradiance.
solar_position_method : str, default 'nrel_numpy'
Passed to solarposition.get_solarposition.
airmass_model : str, default 'kastenyoung1989'
Passed to atmosphere.relativeairmass.
altitude : None or float, default None
If None, computed from pressure. Assumed to be 0 m
if pressure is also None.
pressure : None or float, default None
If None, computed from altitude. Assumed to be 101325 Pa
if altitude is also None.
**kwargs
Arbitrary keyword arguments.
See code for details.
Returns
-------
output : (dc, ac)
Tuple of DC power (with SAPM parameters) (DataFrame) and AC
power (Series).
"""
# use surface_tilt and surface_azimuth if provided,
# otherwise set them using the orientation_strategy
if surface_tilt is not None and surface_azimuth is not None:
pass
elif orientation_strategy is not None:
surface_tilt, surface_azimuth = \
get_orientation(orientation_strategy, latitude=latitude)
else:
raise ValueError('orientation_strategy or surface_tilt and '
'surface_azimuth must be provided')
times = times
if altitude is None and pressure is None:
altitude = 0.
pressure = 101325.
elif altitude is None:
altitude = atmosphere.pres2alt(pressure)
elif pressure is None:
pressure = atmosphere.alt2pres(altitude)
solar_position = solarposition.get_solarposition(
times,
latitude,
longitude,
altitude=altitude,
pressure=pressure,
method=solar_position_method,
**kwargs)
# possible error with using apparent zenith with some models
airmass = atmosphere.get_relative_airmass(
solar_position['apparent_zenith'], model=airmass_model)
airmass = atmosphere.get_absolute_airmass(airmass, pressure)
dni_extra = pvlib.irradiance.get_extra_radiation(solar_position.index)
aoi = pvlib.irradiance.aoi(surface_tilt, surface_azimuth,
solar_position['apparent_zenith'],
solar_position['azimuth'])
if irradiance is None:
linke_turbidity = clearsky.lookup_linke_turbidity(
solar_position.index, latitude, longitude)
irradiance = clearsky.ineichen(solar_position['apparent_zenith'],
airmass,
linke_turbidity,
altitude=altitude,
dni_extra=dni_extra)
total_irrad = pvlib.irradiance.get_total_irradiance(
surface_tilt,
surface_azimuth,
solar_position['apparent_zenith'],
solar_position['azimuth'],
irradiance['dni'],
irradiance['ghi'],
irradiance['dhi'],
model=transposition_model,
dni_extra=dni_extra)
if weather is None:
weather = {'wind_speed': 0, 'temp_air': 20}
temps = pvsystem.sapm_celltemp(total_irrad['poa_global'],
weather['wind_speed'], weather['temp_air'])
effective_irradiance = pvsystem.sapm_effective_irradiance(
total_irrad['poa_direct'], total_irrad['poa_diffuse'], airmass, aoi,
module_parameters)
dc = pvsystem.sapm(effective_irradiance, temps['temp_cell'],
module_parameters)
ac = pvsystem.snlinverter(dc['v_mp'], dc['p_mp'], inverter_parameters)
return dc, ac
def test_alt2press():
atmosphere.pres2alt(1000)
def test_pres2alt():
atmosphere.pres2alt(100000)
def test_pres2alt():
out = atmosphere.pres2alt(np.array([10000, 90000, 101325]))
expected = np.array([15797.638, 988.637, 0.124])
assert_allclose(out, expected, atol=0.001)
def basic_chain(times, latitude, longitude,
module_parameters, inverter_parameters,
irradiance=None, weather=None,
surface_tilt=None, surface_azimuth=None,
orientation_strategy=None,
transposition_model='haydavies',
solar_position_method='nrel_numpy',
airmass_model='kastenyoung1989',
altitude=None, pressure=None,
**kwargs):
"""
An experimental function that computes all of the modeling steps
necessary for calculating power or energy for a PV system at a given
location.
Parameters
----------
times : DatetimeIndex
Times at which to evaluate the model.
latitude : float.
Positive is north of the equator.
Use decimal degrees notation.
longitude : float.
Positive is east of the prime meridian.
Use decimal degrees notation.
module_parameters : None, dict or Series
Module parameters as defined by the SAPM.
inverter_parameters : None, dict or Series
Inverter parameters as defined by the CEC.
irradiance : None or DataFrame
If None, calculates clear sky data.
Columns must be 'dni', 'ghi', 'dhi'.
weather : None or DataFrame
If None, assumes air temperature is 20 C and
wind speed is 0 m/s.
Columns must be 'wind_speed', 'temp_air'.
surface_tilt : float or Series
Surface tilt angles in decimal degrees.
The tilt angle is defined as degrees from horizontal
(e.g. surface facing up = 0, surface facing horizon = 90)
surface_azimuth : float or Series
Surface azimuth angles in decimal degrees.
The azimuth convention is defined
as degrees east of north
(North=0, South=180, East=90, West=270).
orientation_strategy : None or str
The strategy for aligning the modules.
If not None, sets the ``surface_azimuth`` and ``surface_tilt``
properties of the ``system``.
transposition_model : str
Passed to system.get_irradiance.
solar_position_method : str
Passed to location.get_solarposition.
airmass_model : str
Passed to location.get_airmass.
altitude : None or float
If None, computed from pressure. Assumed to be 0 m
if pressure is also None.
pressure : None or float
If None, computed from altitude. Assumed to be 101325 Pa
if altitude is also None.
**kwargs
Arbitrary keyword arguments.
See code for details.
Returns
-------
output : (dc, ac)
Tuple of DC power (with SAPM parameters) (DataFrame) and AC
power (Series).
"""
# use surface_tilt and surface_azimuth if provided,
# otherwise set them using the orientation_strategy
if surface_tilt is not None and surface_azimuth is not None:
pass
elif orientation_strategy is not None:
surface_tilt, surface_azimuth = \
get_orientation(orientation_strategy, latitude=latitude)
else:
raise ValueError('orientation_strategy or surface_tilt and ' +
'surface_azimuth must be provided')
times = times
if altitude is None and pressure is None:
altitude = 0.
pressure = 101325.
elif altitude is None:
altitude = atmosphere.pres2alt(pressure)
elif pressure is None:
pressure = atmosphere.alt2pres(altitude)
solar_position = solarposition.get_solarposition(times, latitude,
longitude,
altitude=altitude,
pressure=pressure,
**kwargs)
# possible error with using apparent zenith with some models
airmass = atmosphere.relativeairmass(solar_position['apparent_zenith'],
model=airmass_model)
airmass = atmosphere.absoluteairmass(airmass, pressure)
dni_extra = pvlib.irradiance.extraradiation(solar_position.index)
dni_extra = pd.Series(dni_extra, index=solar_position.index)
aoi = pvlib.irradiance.aoi(surface_tilt, surface_azimuth,
solar_position['apparent_zenith'],
solar_position['azimuth'])
if irradiance is None:
irradiance = clearsky.ineichen(
solar_position.index,
latitude,
longitude,
zenith_data=solar_position['apparent_zenith'],
airmass_data=airmass,
altitude=altitude)
total_irrad = pvlib.irradiance.total_irrad(
surface_tilt,
surface_azimuth,
solar_position['apparent_zenith'],
solar_position['azimuth'],
irradiance['dni'],
irradiance['ghi'],
irradiance['dhi'],
model=transposition_model,
dni_extra=dni_extra)
if weather is None:
weather = {'wind_speed': 0, 'temp_air': 20}
temps = pvsystem.sapm_celltemp(total_irrad['poa_global'],
weather['wind_speed'],
weather['temp_air'])
dc = pvsystem.sapm(module_parameters, total_irrad['poa_direct'],
total_irrad['poa_diffuse'],
temps['temp_cell'],
airmass,
aoi)
ac = pvsystem.snlinverter(inverter_parameters, dc['v_mp'], dc['p_mp'])
return dc, ac
def test_pres2alt():
out = atmosphere.pres2alt(np.array([10000, 90000, 101325]))
expected = np.array([15797.638, 988.637, 0.124])
assert_allclose(out, expected, atol=0.001)