Estimating Solar Insolation and Power Generation of Photovoltaic Systems Using Previous Day Weather Data

Table 7

Accuracies of the optimal predicted values as compared to the measured values.

Month	Number of valid days	RMSE (kWh/m^2/day)	MBE (kWh/m^2/day)	MAE (kWh/m^2/day)
January	31	0.717	−0.376	0.580
February	28	1.133	−0.246	1.003
March	31	1.112	−0.356	0.917
April	28	1.742	−0.595	1.581
May	31	1.753	−0.797	1.536
June	30	2.034	−0.901	1.744
July	31	1.760	0.029	1.485
August	31	1.753	−0.439	1.491
September	29	1.650	−0.432	1.455
October	30	0.925	0.559	0.643
November	26	0.668	0.609	0.481
December	31	0.767	0.521	0.595