## 1 Introduction  
In the context of current energy shortage and environmental degradation, the proportion of energy resources, such as distributed generation, ES and flexible load, is increasing in the power grid; these resources are widespread existent on the demand side, thus are called demand-side energy resources (DSER). In China, the National Development and Reform Commission and other departments have issued a series of policies on distributed photovoltaic (PV) and decentralized wind power generation (WG) since 2007. DSER plays an increasingly important role in the transformation of new energy systems in China. By the end of 2017, the newly installed capacity of PV in China is 53.06 million kilowatts, and the cumulative installed capacity is 130.25 million kilowatts. The cumulative installed capacity of ES is 28.9 million kilowatts, an increase of 19%. In addition, according to the global distributed energy technology report, the installed capacity of global distributed energy in 2017 is about 132.4 million kilowatts. At the same time, to support the development of energy resources such as WG and distributed PV, many countries have formulated relevant policies. Brazil, Canada, Spain, the United States and other countries have formulated a localization rate policy for WG equipment. The European Union (EU) has set a target that renewable energy will account for 27% of the energy demand structure in 2030, promoting PV development. Nowadays, urban power grids are facing severe challenges including increasing load density, increasing peak and valley difference, shortage of power grid construction land and difficulties in raising funds for construction. At the same time, DSER receives attention from all sectors of society and policy support from the government, and its penetration rate in the power grid, especially in the urban power grid, is constantly increasing, providing a huge potential for the implementation of various demand-side projects. At this time, how to fully tap and exploit the potential of DSER, furthermore, ensuring their participation in the planning, construction, and operation of urban power grids, has become a key issue in solving the current difficulties existing in urban power grids [1; 2; 3; 4; 5]. It can be seen that the rational development and the effective use of DSER will have a far-reaching impact on China's energy power industry. The evaluation model of demand-side energy resources can be used to explore the status, characteristics, and development prospects of DSER. It is an important tool to develop and use DSER rationally. Therefore, the establishment of an evaluation model of demand-side energy resources is very important for the development and utilization of DSER as well as the energy power industry. Therefore, many literature works discuss the evaluation of DSER. In literature [6], the meteorological data of Kahnuj in Iran have been measured at an altitude of 10 m, over a four-year period. Also, the monthly, annual and seasonal wind speed variations are investigated, and the economic feasibility is determined of installing wind turbine at the site. Literature [7] proposes a method to simulate a large wind farm and determine its capacity value, taking into account the mechanical failure of the wind turbine and the influence of the transmission system, and evaluate and compare the wind capacity values under different conditions. Literature [8] presents a study of the installation of a hybrid PV-WG system for social interest houses in the city of San Luis Potosi, Mexico. To assess the benefits of the implementation of this type of system, a technological, economic, and environmental evaluation is carried out based on the available renewable energy resources and considering a typical load profile of consumers. Literature [9] obtained a probability model for system power output by analyzing the structural characteristics of the PV power system and by examining its component failure mode and the effect of the component failure mode on the output power.