On the one hand, due to the lack of large-scale storage in the electric industry, supply is adjusted to match consumption in real time. High forecasting errors will produce an imbalance between electricity supply and consumption. Underestimating electricity consumption will lead to an electricity shortage, and an overestimate would waste precious energy resources [43]. In addition, the normal power grid operation should increase the capacity reserve, which is an
additional supply to account for transmission losses. Grid operators have the capacity in reserve to respond to electricity high consumption periods and unplanned power plant outages. A high forecasting error will lead to inaccurate capacity reserve estimates and then to an administrative risk for the power grid and increased operation costs . Bunn and Farmer
noted that a 1% increase in a forecasting error may lead to a £10 million increase in the operating costs [44].Therefore, it is significantly important to forecast electricity demand
accurately.Accurate electricity consumption forecasts can aid power generators in scheduling their power station operations to match the installed capacity. Small and stable errors in forecasting approaches are certainly necessary. Although the average ARIMA error is the lowest among the four forecasting methods, ARIMA is unsuitable for forecasting electricity consumption in this case. The CSGM forecasting performance is superior to the other models, and the GM
forecasting performance is similar to IAGM.