*5.2. Scheduling Results*

Taking Place 1 as an example, Figures 8–10 show the electricity balance and heating balance of the CCHP system obtained by the IAO algorithm under different schemes.

**Figure 8.** The electricity balance and heating balance under scheme 1.

**Figure 9.** The electricity balance and heating balance under scheme 2.

**Figure 10.** The electricity balance and heating balance under scheme 3.

The electricity balance shows that all three operating schemes can meet the electricity demand of Place 1 during the day. For scheme 1, from 01:00 to 19:00, the ESS regulates the electrical energy balance of the CCHP system by selling and purchasing electricity. ESS and MT work together to meet the electricity demand of the system when weather conditions do not allow for PV generation. When the PV can generate electricity, ESS, MT, and PV together meet the electricity balance of the system. From 20:00 to 24:00, ESS, MT, and the grid work together to meet the electricity demand of the system. For scheme 2, the scale of self-configured energy storage equipment in CCHP systems is smaller. Therefore, its adjustable range for electricity reduces accordingly. As a result, the electricity required from the grid increases. For scheme 3, the lack of energy storage equipment prevents the system from configuring large-capacity photovoltaic power generation equipment. The system still requires a significant amount of electricity from the grid to meet demand. In summary, ESS can guarantee the electricity balance of the CCHP system by taking advantage of its scale. I In addition, it makes a profit by selling electricity and charging service fees. Meanwhile, the CCHP system reduces economic costs by eliminating energy storage equipment and selling surplus electricity.

The heating balance shows that all three operating schemes can meet the heating demand of Place 1 during the day. The heat production from 1:00 to 11:00 and 15:00 to 24:00 is essentially the same for the different equipment under the three schemes. From 12:00 to 14:00, PV produces sufficient electricity. Due to the electricity regulation by energy storage equipment, the system can be configured with higher capacity photovoltaic generation equipment when operating through scheme 1 and scheme 2. As a result, the percentage of the cooling load allocated to EC will increase. Consequently, less heat will be required to meet the cooling load, indirectly reducing the heat production of GB, thus reducing the emission of polluting gases. On the contrary, when the system is operating

with scheme 3, the capacity of the configured photovoltaic power generation equipment is less due to the lack of energy storage equipment. Hence, EC receives less electricity and reduces its cooling production, and more heat is needed to meet the demand for AC. More heat needs to be provided by GB, thus increasing the emission of polluting gases.

Table 8 shows the electricity generated by different equipment under the three operating schemes. With Scheme 1 operation, the PV and the grid provide 34.38% and 15.08% of the total electricity. When run with scheme 2, the corresponding values are 29.19% and 28.27%. When run with scheme 3, the corresponding values are 17.92% and 44.76%, respectively. The percentage of electricity provided by energy storage equipment under the three schemes is 17.95%, 8.04%, and 0%, respectively. Therefore, for the same load demand, increasing the proportion of PV can reduce the pressure on the grid to supply electricity. Compared with scheme 2 and scheme 3, the electricity provided by the grid is decreased by 43.29% and 61.09% when operating with scheme 1. The intermittency of PV needs to be balanced by energy storage equipment. ESS purchases excess electricity during the peak generation period of PV, and sells electricity preferentially when the system lacks electricity. The combined model of ESS and PV produces almost zero pollution in the production and utilization of electricity. The scheme also makes more sense for environmental protection.

**Table 8.** The electricity production of the equipment.


In summary, the CCHP system based on ESS service proposed in this study has more competitive advantages. The system is more economical and emits fewer pollutant gases. Moreover, ESS has room for profitability. The energy storage space provided by ESS can better alleviate the intermittency of PV, regulate the electricity balance of the system, and reduce the pressure on the grid.
