import numpy as np
import math
from numpy import *
import matplotlib.pyplot as plt
plt.style.use('ggplot')

r = 50
Vpv = np.linspace(0,0.6,r) # Vpv = panel voltage

Rs = 0  # series resistance
Rsh = math.inf  # parallel resistance
n = 2       # ideality constant depends on semiconductor material
m = 1.5     # another constant depends on dopping
T = 298    # temperature in kelvin
Eg = 1.14   # band gap energy in ev
K = 0.13      # constant
Vt = T/11600  #thermal voltage
Io = K*(T**m)*exp(-Eg/(n*Vt))   # Io = diode current
print(Io)
Isc = Io*(10**9)

def current():
    current = []  #initializing current array as null
    for t in Vpv:
        Ipv = np.zeros(r)  #initializing panel current(Ipv) as zero

        Ipv = Isc - Io *(exp((t + Rs*Ipv)/(n*Vt)) - 1) - (t + Rs*Ipv)/Rsh
        current.append(Ipv)
    return np.array(current)

Icurrent = current()
power = Vpv * Icurrent
plt.plot(Vpv,power,'b')
plt.plot(Vpv,Icurrent,'r')
plt.xlabel('Panel VOltage(V)')
plt.ylabel('Panel Current(A) and Power(W)')
plt.show()