Industrial and commercial user-side energy storage is moving forward amid doubts and developing amid hesitation. It is becoming one of the most active application scenarios in the market, attracting manufacturers from all walks of life in the industry chain to flock in. Under the current business model, industrial and commercial energy storage still mainly relies on time-of-use electricity prices to make profits based on the difference between peak and valley electricity prices, supplemented by multiple benefits such as demand-side response, demand-side cost saving, capacity-increasing cost saving, and backup power. However, due to many uncertainties and constraints in auxiliary benefits, such as limited demand-side response calls, mismatch between load curves and charging and discharging strategies, industrial and commercial energy storage still mainly relies on the difference between peak and valley electricity prices to make profits. As the most "market-oriented" market segment, with the reduction in energy storage equipment prices and the improvement in equipment performance, as well as the improvement of the difference between industrial and commercial peak and valley electricity prices, industrial and commercial energy storage has ushered in a golden period of vigorous development.

The time-of-use electricity price mechanism is the basis for the profitability of industrial and commercial energy storage. As the main means to achieve the balance between electricity supply and demand, the time-of-use electricity price is mainly based on the time value of electricity. It guides power users to shave peaks and fill valleys through price signals to ensure the safe and stable operation of the power system. The state and various regions have issued a number of documents to promote the improvement of the time-of-use electricity price mechanism. In particular, in July 2021, the National Development and Reform Commission issued the "Notice on Further Improving the Time-of-Use Electricity Price Mechanism", which greatly promoted the development of industrial and commercial energy storage by scientifically dividing peak and valley time periods, reasonably determining the price difference between peak and valley electricity prices, and establishing a peak electricity price mechanism. Taking Zhejiang Province as an example, after the Zhejiang Provincial Development and Reform Commission issued relevant policies on time-of-use electricity prices at the end of 2021, it became the region with the best profitability conditions for industrial and commercial energy storage in China. With the construction of new power systems, the supply and demand balance characteristics of the power system have also undergone profound changes due to the widespread access of new energy and diverse loads to the power grid. In traditional power grids, the noon period is mostly the peak period of electricity consumption, and the industrial and commercial electricity prices show peak electricity prices. However, with the increase in the penetration rate of new energy, especially photovoltaics, the power load curve shows a "duck curve", and the noon period shows a "low valley" of electricity load. Nearly 20 provinces and regions across the country have adjusted the noon time to the valley time electricity price. At the same time, the changes in the peak, flat and valley of time-of-use electricity prices throughout the year have an impact on the charging and discharging of user-side energy storage. Industrial and commercial energy storage only has the conditions of " one charge and one discharge" in the month. In addition, various regions are promoting power users to directly participate in the market for electricity transactions, and electricity prices are changing more frequently. Since the operation cycle of industrial and commercial energy storage projects can generally reach ten years or even longer, investors are worried that the adjustment of time-of-use electricity price policies will cause a decline in future profits. The sustainability of the existing profit model is a concern for investors, and the profits of industrial and commercial energy storage show more volatility and uncertainty. The main feature of time-of-use electricity prices is that they dynamically adjust their prices and time-of-use periods according to the electricity price cost and the balance characteristics of electricity supply and demand. Changes in boundary conditions will have an impact on the level of income. With the accelerated advancement of the power market, the power market is establishing a full-form power market system that coordinates the medium- and long-term market, the spot market, and the ancillary service market. The power market will restore the commodity attributes of electricity. Industrial and commercial users, virtual power plants, load aggregators, and energy storage can all serve as members of the power market. In the future, industrial and commercial energy storage will explore participating in the power market as an independent energy storage under the conditions of independent metering and dispatching. It can also participate in the power spot market, ancillary service market, demand-side response and other power market services through virtual power plants, load aggregators and other models. The participation of industrial and commercial energy storage in the power spot market is expected to become the main business model in the future. In March 2023, the Guangdong Energy Bureau and other departments issued the "Notice on Issuing the Implementation Plan for the Participation of New Energy Storage in Power Market Transactions in Guangdong Province". The document proposes that industrial and commercial energy storage can participate in the power spot market in conjunction with users and participate in transactions in the spot market by reporting quantity but not quotation. At present, the electricity spot market in Shandong, Shanxi, Guangdong and Gansu has been officially put into operation. The price difference and volatility of the spot market have a great impact on the future income of industrial and commercial energy storage. Observing the price fluctuations of the electricity spot market in the formal operation or trial operation areas, the price difference level and volatility in various markets vary greatly, which brings certain uncertainty to the income of industrial and commercial energy storage. The trend of the price difference and volatility of the electricity spot market in the future will be the key to the profitability of industrial and commercial energy storage. In short, with the advancement of the electricity market, the income model of industrial and commercial energy storage will be diversified, changeable and complex. The advancement of the electricity market will bring more space to the income model of industrial and commercial energy storage. At the same time, industrial and commercial energy storage will also need to adapt to the market mechanism of "can rise and fall" .