Chinese public building area accounts for 13.6% of the total building area, but its energy consumption ratio is as high as 21.7%. As typical public buildings, the commercial buildings have huge energy-saving potential. Meanwhile, the load of commercial buildings has large fluctuation. Therefore, to realize the stable operation of local grid, it also requires the energy storage system to act as the load balancing device.

Energy Storage R&D Center of Institute of Engineering Thermophysics sets the comprehensive building of the institute as the research object, and measures and follows its electrical load with an electricity recorder within one year. Meanwhile, a typical battery energy storage technology is selected in line with the 16% peak shaving ratio and the requirement of 2-hour energy releasing. The analyses of technical economy and social benefit are carried out on such basis. Generally, the evaluation model of traditional technical economy only considers static or dynamic evaluation indexes such as net present value (NPV), internal return rate (IRR) or static investment payback period (IPP), and seldom comprehensively considers other changing conditions, and the factors to be considered when calculating the evaluation indexes are still need to be perfected. As for social benefit, previous researches pay more attention to the benefit of environmental protection or emission reduction of CO₂, and lack of quantized calculation models for emission reduction of other pollutants and the auxiliary benefits brought by the energy storage system to the grid. In view of this, Energy Storage R&D Center of Institute strives to propose a more perfect evaluation model of technical economy on the basis of current national conditions. Meanwhile, it also strives to propose a more comprehensive evaluation model of social benefits on the basis of considering quantized auxiliary benefits and emission reduction of CO₂ as well as other pollutants, thus providing references for subsequent relevant researches.

The research results show that: the maximum load of the comprehensive building can reach 30.8kW, and its minimum load is 8.8kW, its average annual load is 18.7kW. To cater to the need for electrical load, the battery energy storage with the power rate needs of 5.15kW-6.5kW and capacity of 10.4-12.7kWh is selected. Based on the new model of economic evaluation and the calculation period of 30 years, the maximum values of the NPV and IRR of the comprehensive building can reach 2577.1$ and 28.1% respectively, and the minimum value of static IPP is 6.2 years. Meanwhile, through sensitivity analysis, the research finds that the discount rate, annual increase rate of equipment costs and purchasing subsidy will all affect the economic indexes of the energy storage systems, of which the effect of discount rate is the largest. In addition, based on the new model of social benefits, apart from CO₂, the emission reductions of CO, SO₂ and NO_x are 3.6kg, 12.5kg and 2.1kg respectively, which shows more obvious emission reduction efficiency, making it more persuasive.