pecos.pv module¶
The pv module contains custom methods for PV applications.
- insolation(G, tfilter=None)[source]¶
Compute insolation defined as:
where
is irradiance and is the time step between observations. The time integral is computed using the trapezoidal rule. Results are given in [irradiance units]*seconds.- Parameters:
G (pandas DataFrame) – Irradiance time series
tfilter (pandas Series, optional) – Time filter containing boolean values for each time index
- Returns:
Insolation
- Return type:
pandas Series
- energy(P, tfilter=None)[source]¶
Convert energy defined as:
where
is power and is the time step between observations. The time integral is computed using the trapezoidal rule. Results are given in [power units]*seconds.- Parameters:
P (pandas DataFrame) – Power time series
tfilter (pandas Series, optional) – Time filter containing boolean values for each time index
- Returns:
Energy
- Return type:
pandas Series
- performance_ratio(E, H_poa, P_ref, G_ref=1000)[source]¶
Compute performance ratio defined as:
where
is the observed energy (AC or DC) produced by the PV system (kWh) divided by the DC power rating at STC conditions. is the plane-of-array insolation (kWh/m2) divided by the reference irradiance (1000 W/m2).- Parameters:
E (pandas Series or float) – Energy (AC or DC)
H_poa (pandas Series or float) – Plane of array insolation
P_ref (float) – DC power rating at STC conditions
G_ref (float, optional) – Reference irradiance, default = 1000
- Returns:
Performance ratio in a pandas Series (if E or H_poa are Series) or float (if E and H_poa are floats)
- Return type:
pandas Series or float
- normalized_current(I, G_poa, I_sco, G_ref=1000)[source]¶
Compute normalized current defined as:
where
is current, is the short circuit current at STC conditions, is the plane-of-array irradiance, and is the reference irradiance.- Parameters:
I (pandas Series or float) – Current
G_poa (pandas Series or float) – Plane of array irradiance
I_sco (float) – Short circuit current at STC conditions
G_ref (float, optional) – Reference irradiance, default = 1000
- Returns:
Normalized current in a pandas Series (if I or G_poa are Series) or float (if I and G_poa are floats)
- Return type:
pandas Series or float
- normalized_efficiency(P, G_poa, P_ref, G_ref=1000)[source]¶
Compute normalized efficiency defined as:
where
is the observed power (AC or DC), is the DC power rating at STC conditions, is the plane-of-array irradiance, and is the reference irradiance.- Parameters:
P (pandas Series or float) – Power (AC or DC)
G_poa (pandas Series or float) – Plane of array irradiance
P_ref (float) – DC power rating at STC conditions
G_ref (float, optional) – Reference irradiance, default = 1000
- Returns:
Normalized efficiency in a pandas Series (if P or G_poa are Series) or float (if P and G_poa are floats)
- Return type:
pandas Series or float
- performance_index(E, E_predicted)[source]¶
Compute performance index defined as:
where
is the observed energy from a PV system and is the predicted energy over the same time frame. can be computed using methods inpvlib.pvsystem
and then convert power to energy usingpecos.pv.enery
.Unlike with the performance ratio, the performance index should be very close to 1 for a well functioning PV system and should not vary by season due to temperature variations.
- Parameters:
E (pandas Series or float) – Observed energy
E_predicted (pandas Series or float) – Predicted energy
- Returns:
Performance index in a pandas Series (if E or E_predicted are Series) or float (if E and E_predicted are floats)
- Return type:
pandas Series or float
- energy_yield(E, P_ref)[source]¶
Compute energy yield is defined as:
where
is the observed energy from a PV system and is the DC power rating of the system at STC conditions.- Parameters:
E (pandas Series or float) – Observed energy
P_ref (float) – DC power rating at STC conditions
- Returns:
Energy yield
- Return type:
pandas Series or float
- clearness_index(H_dn, H_ea)[source]¶
Compute clearness index defined as:
where
is the direct-normal insolation (kWh/m2) is the extraterrestrial insolation (kWh/m2) over the same time frame. Extraterrestrial irradiation can be computed usingpvlib.irradiance.extraradiation
. Irradiation can be converted to insolation usingpecos.pv.insolation
.- Parameters:
H_dn (pandas Series or float) – Direct normal insolation
H_ea (pandas Series or float) – Extraterrestrial insolation
- Returns:
Clearness index in a pandas Series (if H_dn or H_ea are Series) or float (if H_dn and H_ea are floats)
- Return type:
pandas Series or float