Chapter 9 Transmission loss in EGAT power system

A transmission loss data is obtained from Power System Control and Operation Division (ฝ่ายควบคุมระบบกำลังไฟฟ้า (อคฟ.)), Power Generation and Purchase Data Processing Department (กองประมวลผลข้อมูลการผลิตและซื้อขายไฟฟ้า (กผฟ-ส.)) website (EGAT intranet only).

The transmission loss is calculated by an equation (9.1) as follows:

\[\begin{equation} TRNLSS_{t} = \frac{LSS_{t}}{EGATSLE_{t}} \tag{9.1} \end{equation}\]

Where, \(TRNLSS_{t}\) denotes a transmission loss in year \(t\) in percentage.
\(LSS_{t}\) denotes a transmission loss in year \(t\) in GWh. \(EGATSLE_{t}\) denotes a EGAT electricity sale in year \(t\) in GWh.

tran_loss_percent <- 
  
  read_excel("raw_data/01 EGAT_20Oct2022_งบ66 67_Final.xlsx",
             sheet = "C_LossUse",
             range = "C321:D348",
             col_names = c("year_th", "percent_loss")) %>% 
  mutate(year = year_th - 543)

The transmission loss decreased from 1.94% in 2010 to 1.57% in 2021. It is assumed that the loss would be similar to those in 2019. The reason is that the EGAT electricity sale in 2020 and 2021 was in a pandemic situation. The transmission loss would be 1.65% from 2022 onwards (see Figure 9.1.

Figure 9.1: Transmission loss in EGAT power system