def NPV(rho,g,eff,H,q_process,delta_t,p,Q,a,b): integrand = lambda t: np.exp(-r*t)*power(rho,g,eff,H,q_process)*delta_t*p PV = quad(integrand, 0, np.inf) NPVal = PV[0] - cost(a, b, Q) return NPVal