Intro Tutorial

This page contains introductory examples of cpvlib usage.

Here you can find an example based on a Jupyter notebook ready to be launched:

The example code is detailed below:

# -*- coding: utf-8 -*-
import matplotlib.pyplot as plt
import pvlib

from cpvlib import cpvsystem
from module_parameters import mod_params_cpv, mod_params_flatplate

heat_dissipation_params_CPV = {'model': 'pvsyst', 'u_c': 9.5, 'u_v': 0}
heat_dissipation_params_flatplate = {'model': 'pvsyst', 'u_c': 24, 'u_v': 0.05} # insulated is 15, freestanding is 29

lat, lon = 40.4, -3.7

data_pvgis = pvlib.iotools.get_pvgis_tmy(lat, lon)

data = data_pvgis[0].rename(columns={
    'Gb(n)': 'dni',
    'G(h)': 'ghi',
    'Gd(h)': 'dhi',
    'T2m': 'temp_air',
    'WS10m': 'wind_speed',
})

data = data.set_index(
    data.index.map(lambda t: t.replace(year=2010)))

location = pvlib.location.Location(
    latitude=lat, longitude=lon, altitude=695, tz='utc')

solar_zenith = location.get_solarposition(data.index).zenith
solar_azimuth = location.get_solarposition(data.index).azimuth

# %%
# StaticHybridSystem
static_hybrid_sys = cpvsystem.StaticHybridSystem(
    surface_tilt=30,
    surface_azimuth=180,
    module_cpv=None,
    module_flatplate=None,
    module_parameters_cpv=mod_params_cpv,
    module_parameters_flatplate=mod_params_flatplate,
    modules_per_string=1,
    strings_per_inverter=1,
    inverter=None,
    inverter_parameters=None,
    temperature_model_parameters_cpv=heat_dissipation_params_CPV,
    temperature_model_parameters_flatplate=heat_dissipation_params_flatplate,
    # racking_model="freestanding", #not used because temp model parameters are already defined
    losses_parameters=None,
    name=None,
)

# get_effective_irradiance
data['dii_effective'], data['poa_flatplate_static_effective'] = static_hybrid_sys.get_effective_irradiance(
    solar_zenith,
    solar_azimuth,
    dii=None,
    ghi=data['ghi'],
    dhi=data['dhi'],
    dni=data['dni'],
    spillage=0.15 # Percentage of direct irradiance allowed to the flat plate within AOI range. This number comes from module 120.
    # Spillage is highly dependent on the tracking accuracy of each module.
)

# pvsyst_celltemp
data['temp_cell_35'], data['temp_cell_flatplate'] = static_hybrid_sys.pvsyst_celltemp(
    dii=data['dii_effective'],
    poa_flatplate_static=data['poa_flatplate_static_effective'] + data['dii_effective'], # It is very important to add direct light as well
    temp_air=data['temp_air'],
    wind_speed=data['wind_speed']
)

# calcparams_pvsyst
diode_parameters_cpv, diode_parameters_flatplate = static_hybrid_sys.calcparams_pvsyst(
    dii=data['dii_effective'],
    poa_flatplate_static=data['poa_flatplate_static_effective'],
    temp_cell_cpv=data['temp_cell_35'],
    temp_cell_flatplate=data['temp_cell_flatplate'],
)

# singlediode
dc_cpv, dc_flatplate = static_hybrid_sys.singlediode(
    diode_parameters_cpv, diode_parameters_flatplate)

# uf_global (uf_am, uf_temp_air)
data['am'] = location.get_airmass(data.index).airmass_absolute
uf_cpv = static_hybrid_sys.get_global_utilization_factor_cpv(
    data['am'], data['temp_air'])

# Power
cpv_days = dc_cpv['2010-06-15':'2010-06-20']
uf_cpv_days = uf_cpv['2010-06-15':'2010-06-20']
flatplate_days = dc_flatplate['2010-06-15':'2010-06-20']
data_days = data['2010-06-15':'2010-06-20']

fig, axs = plt.subplots(2)

(cpv_days.p_mp * uf_cpv_days).plot(ax=axs[0], legend=True, label="CPV")
flatplate_days.p_mp.plot(
    ax=axs[0], secondary_y=True, legend=True, label="Flat plate")
data_days[['dni', 'dhi']].plot(ax=axs[1], linewidth=1)

# Energy
energy_cpv = (dc_cpv['p_mp'] * uf_cpv).sum()
energy_flatplate = dc_flatplate['p_mp'].sum()

print(f"E_CPV={energy_cpv:.0f} Wh", f"E_diff={energy_flatplate:.0f} Wh")