Development of a method and determination of weather indicators for estimating gas consumption for the purposes of the distribution service for non-daily metered gas customers

The article presents the method of billing for non-daily metered customers. Characteristics of the method of estimation and thresholding of gas consumption used in the Polish gas industry up to October 2021 are presented. The principles of additional estimation and forecasting of gas consumption using the temperature method are described. The paper presents the proprietary methodology of gas consumption estimation using the "thermal" method and the method of estimating historical daily gas consumption by consumers based on gas meters readout data. Principles for determining WSK weather indicators in the Polish gas system have been developed. Based on gas consumption data obtained from the Polish Natural Gas Operator Polska Spolka Gazownictwa Sp. z o.o., the implementation of determining the threshold WSK indicators was done. In the supporting application 'WSK' ver. 0.21, calculations of the daily gas consumption of consumers as a function of temperature for each temperature zone were carried out. Based on the calculated daily gas consumption, a regression analysis for two statistical models: the linear model Y = a + bX and the square root-Y model: Y = (a + bX)(2) was performed. The correlation analyses were carried out for main tariff groups and for tariff groups divided into two parts (subgroups a and b). The weather indicators were determined based on the results of the regression analysis. The analysis of the obtained values of the correlation coefficients r and R-2 shows that higher values of these coefficients were obtained in the subgroups than in the case of tariff groups. In statistical terms, this means that a better fit of the model was obtained for the subgroups. Hence, it can be assumed that the use of WSK coefficients in subgroups will provide a more accurate method of determining gas consumption. The developed research and computational methodology allowed for the development of the concept of principles for determining WSK indicators. The paper shows that apart from the influence of climatic conditions on the volume of gas consumption, the nature of gas consumption, i.e. economic factors and the possibility of producing energy in an alternative way, determining the volume of gas consumption, is also important. The linear regression analysis showed a statistically significant correlation between the value of daily gas consumption and the average daily ambient temperature. The methodology adopted in the work allowed for the determination of two independent WSK models. The first one, specifying one value of the WSK index for a tariff group, and the second one with two WSK indexes for sub-tariff groups. Taking into account the higher values of the correlation coefficients, the latter model is recommended for use in practice. The determined WSK indicators have been implemented for use in the Polish gas system for estimating and forecasting gas consumption for non-daily metered gas customers.