New Energy Storage is an important technology and basic equipment to support new power system. According to the 2030 Carbon Peak Action Plan, the installed capacity of new energy storage will reach more than 30 million kw by 2025. New energy storage power stations (hereinafter referred to as "energy storage power stations") mainly refer to non-pumped storage power stations with large power levels and superior comprehensive performance, which play an important role in promoting energy transformation and ensuring energy security.
In recent years, how to promote the commercial application of energy storage power station is a common problem to explore at home and abroad. The Guiding Opinions of the National Development and Reform Commission and the National Energy Administration on Accelerating the Development of New Energy Storage put forward specific requirements for improving the policy mechanism and creating a healthy market environment. How energy storage power stations participate in the power market and make profits is the key to its commercial application.
What are the modes of energy storage power stations participating in the electricity market
Participating in the power market is a common business model of energy storage abroad. Countries with relatively developed power markets define the independent market subject status of energy storage power stations through legislation, allow energy storage power stations to participate in all kinds of market segments fairly, improve the market mechanism and formulate a performance-based compensation mechanism reflecting the value of all kinds of resources, so as to provide institutional guarantee for energy storage power stations and other resources to bid on the same stage fairly.
The types of energy storage power stations participating in the electricity market mainly include the electricity market, auxiliary service market and capacity market, giving full play to the comprehensive value of energy storage and realizing multiple income. The U.S. Energy Information Administration (EIA) reports that by the end of 2020, 59% of U.S. utility-scale energy storage systems (capacity greater than 10gw) were dedicated to frequency response, 39% were dedicated to ramp climbing or backup, and 37% participated in the spot market for electricity.
The capacity electricity charge mode refers to the implementation of two system electricity price for pumped storage power station to compensate the capacity of energy storage power station. Most pumped storage power station at present, the implementation of two-part electricity price, electricity capacity to compensate power plant operating costs, electricity price to compensate smoke hair loss (4 KWH electricity can send 3 KWH electricity), capacity and hair loss into local provincial electricity grid or regional power grid operation and unified accounting cost and overall consideration as the sales price adjustment factors. In order to promote the development of energy storage industry, China has proposed "exploring the establishment of energy storage capacity electricity charge mechanism" in the action Plan for implementing the Guidance on Promoting the Development of Energy Storage Technology and Industry 2019-2020 ", but has not issued relevant policies. At present, only a few national demonstration energy storage projects have received capacity compensation.
In the sharing mode, the energy storage power stations configured in the new energy gathering stations adjust peak load for multiple new energy stations through participating in the peak load auxiliary service market. In order to maximize the peak regulation function of the energy storage station, under certain market transaction rules, the energy storage station is allowed to adjust the peak regulation for other new energy stations, so as to realize resource sharing in the whole network. After the security check, the dispatching agency invokes in order according to the clearing result of market transaction. At present, the market operation rules of peak shaving assistance service in Qinghai and Xinjiang allow bilateral transactions between energy storage and new energy power stations, participation in market bidding or direct call by dispatching agencies, so as to realize sharing of energy storage power stations.
Capacity lease/split sale mode is that a single or multiple social third parties purchase and lease the capacity of independent energy storage power stations and share the investment and construction cost of energy storage power stations. The difference between this mode and shared energy storage lies in whether the third party such as the owner of the new energy station has the asset ownership or exclusive right to use the fixed capacity of the energy storage station. In the regions where new energy is required to be configured with energy storage, if it is more economical to buy or lease independent energy storage power stations than to invest in the construction of energy storage by the new energy stations themselves, this mode will have a certain development prospect. New energy station and other owners can purchase or lease a certain capacity of independent energy storage power station to meet the requirements of energy storage configuration at a lower price.
Current situation of energy storage power station participating in electricity market transaction in China
At present, under the existing power market framework and rules, energy storage power stations can participate in medium and long term electricity transaction, frequency modulation and peak modulation auxiliary service market transaction. At the beginning of 2020, Qinghai Haixi Geermu Jingneng New Energy and Happy Technology Energy Storage power Station carried out the first medium and long term energy storage transaction.
In terms of peak regulation auxiliary service, currently more than 20 provinces or regions in China have issued market operation rules for peak regulation auxiliary service (including trial operation), and most provinces have included energy storage in the power market.
In terms of FM auxiliary services, a total of 6 provinces or regions in China have issued market operation rules for FM auxiliary services. Among them, Guangdong, Fujian, Shanxi and Jiangsu allow energy storage to participate in FM, and energy storage stations can participate in FM auxiliary service market as an independent entity or in conjunction with thermal power units, and obtain compensation according to the regulation effect.
In terms of actual results, the investment and construction cost of energy storage power stations in China is still high, and the utilization rate in the single market is low. It is difficult to fully reflect the multiple value and system value, and it is difficult to compete with other alternative resources in the market.
The application of energy storage power station needs to be strengthened in the following aspects. In terms of development planning, China has put forward quantitative targets of energy storage. The next step is to clarify the layout of energy storage power stations based on the actual needs of the power system, especially the overall planning of power grid, pumped storage and various other flexible resources, integrate the planning of energy storage power stations into the power grid planning, and guide the rational layout and orderly development of energy storage power stations. In terms of market access, the main identity and access conditions of energy storage power stations participating in the electricity spot trading market remain to be clarified, and the trading rules remain to be improved. Energy storage configuration has become an important condition for the priority development of new energy in some regions, and the application scope of energy storage configuration needs to be expanded. In terms of price mechanism, there is a lack of electricity price policies for energy storage power stations. At present, China has not issued policies for charging price, on-grid price and electricity transmission and distribution price related to energy storage power stations. In the process of constructing new power system, the energy storage power station which is used to guarantee the safety and reliable supply of power system is difficult to gain profits from the market. Currently, there are no policies supporting the development of such storage.
Promote the participation of energy storage power stations in the electricity market in stages
According to the construction of the power market, energy storage power stations can be promoted to participate in the power market in stages.
Stage 1: Under the current power market environment, improve the trading mechanism of auxiliary service market, give full play to the advantages of dynamic response technology of energy storage power stations, and focus on improving the competitiveness of energy storage power stations in the auxiliary service market. In order to meet the needs of high proportion of new energy and high proportion of power electronic equipment to connect to the power system, the recently issued Administrative Measures for Auxiliary Power Services has included new energy storage as a new main body of auxiliary services, and added auxiliary services such as moment of inertia and climbing. Should be based on the conventional peak shaving, FM market construction, according to the requirements of the system is running, make the moment of inertia, climbing auxiliary services such as new varieties of trading rules, establish the resource value and the effect of paying compensation mechanism, give full play to the energy storage power station fast response, flexible layout and other technical advantages, to transfer the energy storage power station system regulation ability to create the market conditions.
The second stage: In the primary stage of the electric power spot market, the trading rules of electric energy should be improved, the cross-time adjustment ability of energy storage stations should be brought into full play, and the profitability of energy storage stations should be improved in the electric power spot market. At present, China's first batch of 8 power spot pilot has all completed trial operation, the second batch of 6 pilot is accelerating construction. On the one hand, market mechanism should be improved to allow all kinds of resources including energy storage power stations to participate in electricity spot market fairly. On the other hand, the pricing mechanism should be improved, the charging and discharging prices of energy storage stations and the electricity transmission and distribution policies should be clarified, and the energy storage stations should be mobilized to participate in the peak adjustment of the power grid by using price signals. The marginal cost of new energy should be basically zero, and new energy should be combined to participate in the electricity spot transaction.
The third stage: in the mature stage of electric power spot market, we will expand the application of new business forms and new modes of energy storage power stations, focusing on enabling energy storage power stations to play multiple values in multiple markets. The power spot market will replace the peak - shaving auxiliary service market after mature operation. Energy storage power stations can fully participate in the electricity market, auxiliary service market and capacity market, and provide regulation services at different time scales. When designing the market mechanism, the value of energy storage capacity and quantity should be fully considered, and the energy storage power station should be allowed to participate in multiple markets and realize multiple values through time-sharing utilization. Smart energy, virtual power plants and other new business forms and modes including energy storage power stations should be expanded to realize diversified development of energy storage power stations.
