A Grey NGM(1,1,𝑘) Self-Memory Coupling Prediction Model for Energy Consumption Prediction

Table 2

Comparison of four different models for total energy consumption in China (unit: 10,000 tce).

Years	Actual values	GM model		GM + three-point model		NGM model		NGM + self-memory model
		Simulative values	APE𝑡 (%)	Simulative values	APE𝑡 (%)	Simulative values	APE𝑡 (%)	Simulative values	APE𝑡 (%)
1999	140568.82	140568.82	0.00	145078.39	3.21	140568.82	0.00	—	—
2000	145530.86	154097.54	5.89	153607.37	5.55	121587.39	16.45	—	—
2001	150405.80	166155.76	10.47	166470.28	10.68	142213.09	5.45	145441.98	3.30
2002	159430.99	179157.54	12.37	179496.67	12.59	162614.72	2.00	160778.73	0.85
2003	183791.82	193176.71	5.11	193542.38	5.31	182794.71	0.54	197959.80	7.71
2004	213455.99	208292.90	2.42	208687.18	2.23	202755.47	5.01	209398.51	1.90
2005	235996.65	224591.93	4.83	225017.06	4.65	222499.39	5.72	229729.69	2.66
2006	258676.30	242166.37	6.38	242624.77	6.21	242028.81	6.44	253872.41	1.86
2007	280507.94	261116.02	6.91	261610.29	6.74	261346.08	6.83	276202.44	1.53
2008	291448.29	281548.49	3.40	282081.44	3.21	280453.49	3.77	296765.50	1.82
2009	306647.15	303579.81	1.00	304154.47	0.81	299353.33	2.38	314095.98	2.43
2010	324939.15	327335.10	0.74	327954.72	0.93	318047.84	2.12	327720.81	0.86
2011	348001.66	352949.25	1.42	353617.35	1.61	336539.26	3.29	341540.94	1.86
2012	361732.01	380567.72	5.21	371361.56	2.66	354829.80	1.91	358909.33	0.78
MAPE (%)			4.95		4.74		4.42		2.30

There are no simulative values from year 1999 to 2000 owing to the retrospective order 𝑝=1.