# Dispatching Strategy for Low-Carbon Flexible Operation of Park-Level Integrated Energy System
## 5 Case Study
### Optimal Operating Scheme  
Figure 5 demonstrates the optimal operation strategy of the PIES electric power supply system. It shows that the system reduces PIES' power purchase from the grid by increasing the MT output and reducing the carbon capture power in the event of high time-of-use electricity prices of the grid, thereby improving the PIES operation economy. Moreover,  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Equipment** & **Parameters** & **Values** & **Equipment** & **Parameters** & **Values** \\ \hline \multirow{4}{*}{ESS} & Charge/Discharge efficiency & 0.9 & & thermal & \\  & lower/upper limit of capacity & 40/360 kW & & efficiency & \\  & Installed capacity & 400 kW & GB & Installed capacity & 300 kW \\  & The upper limit of output & 120 kW & & \\ \hline \multirow{4}{*}{HSD} & Charge/Discharge efficiency & 0.9 & & thermal & \\  & lower/upper limit of capacity & 30/270 kW & & efficiency & \\  & Installed capacity & 300 kW & EB & Installed capacity & 300 kW \\  & The upper limit of output & 80 kW & & \\ \hline \multirow{4}{*}{MT} & electrical efficiency & 0.83 & & \\  & & & & \\ \cline{1-1} \cline{3-5}  & & & & \\ \cline{1-1} \cline{3-5}  & Installed capacity & 500 kW & & \\ \hline \hline \end{tabular} The time-sharing tariff for PIES’ electric power is shown in Table 2.  
\end{table}
Table 1: Equipment Parameters.  
Figure 4: WT and PV power output and electricity and heat load demands.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Periods** & **Specific Time Period** & **Electricity Prices (\%/kWh)** \\ \hline Peak period & 8:00–11:00, 18:00–21:00 & 0.804 \\ Flat period & 6:00–7:00, 12:00–17:00 & 0.550 \\ Valley period & 1:00–5:00, 22:00–24:00 & 0.295 \\ \hline \hline \end{tabular} Flexible load parameters: the electric and heat loads have both SL and IL characteristics, accounting for 15% of the total load; Stepped carbon trading parameters in [11]; CCE parameters: \(u^{CCS}=0.9\), \(g^{ccS}_{\text{T}}=1.5\) kW/kg; Interruption compensation parameters: \(\omega_{el}=0.8\frac{5}{\text{kW}}\cdot\text{h}\), \(\omega_{hl}=0.6\)\(\$\,\text{kW}\cdot\text{h}\).  
Wind-Solar expected output values and load data are shown in Figure 4:  
\end{table}
Table 2: TOU ELECTRICITY PRICES.  
the controllable load variable indicates the unconsumed power of new energy in PIES. It is evident in Figure 5 that the controllable load power remains at 0 throughout the dispatching cycle, which implies that the renewable energy is 100% consumed by the PIES system with no curtailment of wind or solar generation.  
Figure 6 shows the optimal operation strategy of the heating equipment within PIES. It can be observed that, as an electrical energy replacement device, EB bears most of the heat load during the period of 1:00-4:00, which reduces the heating power of GB in this duration while bringing down the consumption of gas in PIES. In contrast, during the peak hours of the electricity price, gas is consumed by GB to supply most of the heat load, reducing the heating power of EB while lowering the consumption of electric power. This analysis shows that GB and EB have complementary characteristics in meeting the heat demand of PIES while further reducing the operating cost of PIES by improving the utilization of electric energy during low-load hours.