Sky Image-Based Localized, Short-Term Solar Irradiance Forecasting for Multiple PV Sites via Cloud Motion Tracking

Table 3

RMSE, MAE, and TS for irradiance forecasts and irradiance forecasts at location 1 (onsite forecasting) with three-level irradiance drop percentages and with 40% irradiance drop assumption (Sn: sunny; Oc: overcast; Pc: partially cloudy).

Date; Sky condition	Time horizon	Forecast with three-level cloud categorization			Forecast with 40% drop assumption [10, 14]			TS/(%)
		RMSE/(Wm^-2)	MAE/(Wm^-2)	SF	RMSE/(Wm^-2)	MAE/(Wm^-2)	SF
07/09/2019 (Sn)	1 min	37	29	-0.63	37	29	-0.63	98
	5 min	37	28	-0.02	37	28	-0.02	99
	15 min	36	28	0.41	36	28	0.41	99
08/09/2019 (Sn)	1 min	20	16	-8.6	20	16	-8.6	99
	5 min	20	16	-0.16	20	16	-0.16	100
	15 min	19	15	0.62	19	15	0.62	100
11/09/2019 (Sn)	1 min	13	10	-3.5	13	11	-3.5	98
	5 min	12	10	0.28	12	10	0.28	93
	15 min	12	10	0.76	15	10	0.76	98
13/04/2019 (Pc)	1 min	157	92	-0.20	164	96	-0.25	70
	5 min	213	143	-0.12	229	157	-0.21	62
	15 min	199	120	0.00	202	123	-0.01	61
08/05/2019 (Pc)	1 min	142	92	-0.13	144	92	-0.15	88
	5 min	142	94	0.10	142	94	0.09	87
	15 min	151	101	0.24	151	101	0.23	84
28/07/2019 (Pc)	1 min	136	86	-0.89	144	90	-0.99	79
	5 min	137	88	0.02	148	95	-0.06	78
	15 min	144	89	0.13	146	89	0.12	75
29/07/2019 (Pc)	1 min	113	69	-1.20	118	79	-1.29	80
	5 min	122	73	-0.04	126	81	-0.07	81
	15 min	157	99	0.13	158	104	0.13	62
30/07/2019 (Pc)	1 min	106	51	-1.71	111	50	-1.85	76
	5 min	107	55	-0.53	114	54	-0.63	65
	15 min	80	42	0.19	76	36	0.23	68
10/09/2019 (Pc)	1 min	162	100	-0.87	162	100	0.87	79
	5 min	167	53	-0.27	167	102	-0.27	63
	15 min	130	75	0.11	129	75	0.12	72
09/04/2019 (Oc)	1 min	230	143	-0.64	240	163	-0.71	72
	5 min	224	141	-0.02	228	155	-0.04	74
	15 min	307	230	-0.20	314	243	-0.23	65
05/05/2019 (Oc)	1 min	160	118	-1.01	160	119	-1.01	81
	5 min	206	153	-0.25	206	152	-0.25	66
	15 min	265	220	-0.11	263	218	-0.10	42
12/09/2019 (Oc)	1 min	168	121	-3.6	166	126	-3.55	61
	5 min	188	136	-1.17	183	138	-1.10	63
	15 min	173	119	-0.26	167	122	-0.23	42