Evaluating spatiotemporal patterns of urban electricity consumption within different spatial boundaries: A case study of Chongqing, China

The timely and effective evaluation of spatiotemporal patterns of urban electricity consumption is a critical prerequisite for establishing policy on sustainable electricity utilisation in China. However, calculating urban electricity consumption in China is difficult due to the confusion generated by the various city definitions and corresponding urban boundaries. Using Chongqing as a case study, this study was the first attempt to evaluate and compare the spatiotemporal patterns of urban electricity consumption within different spatial boundaries. Four urban boundaries, including the city administrative area, city district, urban centre, and urban built-up area, were defined using the administrative boundaries and urban built-up area data. Then, the electricity consumption was estimated at a 1-km spatial resolution from 1992 to 2013 using the nighttime light data and statistical electricity consumption data. Finally, the temporal and spatial evolution of urban electricity consumption within different boundaries were evaluated and compared from multiple perspectives. The results showed that a rapid increase in urban electricity consumption occurred in the four urban boundaries in Chongqing from 1992 to 2013. The urban electricity consumption in urban built-up area accounted for 34.34%–45.69% of that in city administrative area from 1992 to 2013, which indicated that urban built-up area was still the centre of electricity consumption in Chongqing. There was a very low-gridded urban electricity consumption with significant spatial variability in city administrative area, city district, and urban centre; however, there was a wide distribution from 10.03 to 20.21 million kWh in urban built-up area. Special attention should be given to urban built-up area, which presented the highest per capita urban electricity consumption among the four urban boundaries, with values from 18,470 kWh in 2005 to 20,370 kWh in 2010. Our results also noted that the urbanisation rate has become the strongest driver of urban electricity consumption within the different urban boundaries in Chongqing, with R2 values larger than 0.95. This study suggested that decision makers should explicitly state the accounting boundaries to avoid data gaming and inaccurate results when designing benchmarks or plans or when analysing the performance of urban electricity consumption.