Short-Term Photovoltaic Power Generation Forecasting Based on Multivariable Grey Theory Model with Parameter Optimization

Table 1

Analysis of forecasting results on August 23.

	Date	Real value (kWh)	Ordinary model		Optimization model
			Recovered value (kWh)	Percent error (%)	Recovered value (kWh)	Percent error (%)
Sample data	8.15	520	520	0	520	0
	8.16	554	457.99	17.33	527.63	4.76
	8.17	506	566.16	11.89	512.51	1.28
	8.18	493	527.17	6.93	508.11	3.06
	8.19	443	443.45	0.10	402.98	9.03
	8.20	420	425.27	1.25	387.56	7.72
	8.21	518	454.49	12.26	443.20	14.44
	8.22	332	389.29	17.26	330.28	0.52
Forecasting data	8.23	263	381.01	44.87	310.80	18.17