To better understand the trade-off between the two objectives, we refer to the economic breakdowns of several Pareto points, which are selected based on GHG emissions reduction at -24%, 0%, 15%, 30% and 42%. As shown in Figure , improving GHG emissions reduction leads to a gradual growth of utility costs and dropping revenue. Table indicates that the increasing utility cost is caused by the rising percentage of heating electrification, because the energy price of low-carbon heating can be over four times that of fuel or steam (SI, Figure ).