## 3 Applications  
### Statement of Problem  
The BTH region is regarded as China's economic, political, cultural, and technological innovation center, representing the most dynamic urban cluster in the country, including 11 prefecture-level cities of Hebei Province, as well as two megacities (Beijing and Tianjin) [36; 37]. The region has experienced rapid economic development, with a high annual growth rate of 6.64% for gross domestic product (GDP) over the last five years [1; 2; 3]. The BTH region's energy demands have dramatically increased along with its rapid urbanization, industrialization, and economic development. According to the National Bureau of Statistics of the People's Republic of China, the region's electricity demand reached 50.92 million kWh in 2016, representing an increase of 13.31% compared with five years earlier. The domestic energy structure is heavily dependent on coal resources, with coal-based power accounting for 85.04% of the region's electricity power generation, while renewable energy contributes only 8%.  
Fossil fuels in general are the major contributor to air pollution. For example, approximately 50%, 70%, 90%, and 65% of the total CO2 emissions, nitrogen oxide (NO\({}_{x}\)), sulfur dioxide (SO\({}_{2}\)), and particulate matter (PM) are contributed by coal resources [4; 38]. In addition, the BTH region is one of the high-traffic regions of China, with a vehicle population of 20.67 million in 2016, representing an increase of 63% from 2011. Motor vehicles are recognized as a major contributor of regulated pollutants such as CO, NO\({}_{x}\), HC, and PM. Based on several references, vehicular emissions contributed approximately 20-67% of CO emission, 12-36% of NO\({}_{x}\) emission, and 12-39% of HC emissions [5].  
The BTH region experiences severe air pollution due to increasing energy consumption and vehicle population, as well as a \"high coal\" energy mix characteristic. Cities in the region generally occupy more than half of the top-ten spots for the most polluted cities in China [39]. The scale of emissions in the BTH region has exceeded the capacity of self-purification and air-pollutants' diffusion from the atmosphere [25; 33]. This situation has forced local managers to propose ambitious schemes for planning the EES of the BTH region.  
To tackle the above-mentioned problems, several policies and measures have been implemented with regard to the development of renewable energy resources: adjustment of the energy structure; encouragement of the use of EVs; improvement of energy conversion efficiencies; and enhancement of vehicular emission standards. For example, several strategies have been proposed for reducing vehicular emissions, such as the deployment of EVs and the implementation of the China VI vehicular emission standard. However, it remains unclear how much pollution reduction can be achieved by these control measures and policies. As noted earlier, this paper proposed the DRSFO-EES model for the assessment of the impacts of different emission mitigation policies and measures on EES; development of robust optimization solutions for EES planning; determination of the regional atmospheric pollution contributions of different energy sectors such as energy processing, electricity generation, and vehicular traffic.