Table 2. Performance of Imputation Models with the Increasing Count of Missing Data for Case D1.

	KNN			ETR
% missing	PVmicro	EC	FR	PVmicro	EC	FR
20%	RMSE: 0.05 MAE: 0.02 R2: 0.97	RMSE: 1.68 MAE: 0.53 R2: 0.90	RMSE: 8.56 MAE: 2.73 R2: 0.81	RMSE: 0.01 MAE: 0.00 R2: 1.00	RMSE: 1.48 MAE: 0.45 R2: 0.92	RMSE: 5.05 MAE: 0.78 R2: 0.93
50%	RMSE: 0.08 MAE: 0.05 R2: 0.91	RMSE: 2.54 MAE: 1.28 R2: 0.76	RMSE: 8.30 MAE: 4.07 R2: 0.82	RMSE: 0.04 MAE: 0.01 R2: 0.98	RMSE: 2.28 MAE: 1.08 R2: 0.81	RMSE: 6.72 MAE: 2.24 R2: 0.88
70%	RMSE: 0.11 MAE: 0.06 R2: 0.85	RMSE: 2.95 MAE: 1.91 R2: 0.68	RMSE: 14.10 MAE: 7.62 R2: 0.49	RMSE: 0.09 MAE: 0.04 R2: 0.88	RMSE: 3.02 MAE: 1.69 R2: 0.67	RMSE: 8.99 MAE: 4.07 R2: 0.79