Analysis on the commercialization and application

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Analysis on the commercialization and application of new energy storage

the resultant force of policy, market and technology seems to be promoting large-scale new energy storage (relative to traditional pumped storage) to the "tuyere"

on the one hand, the policy guidance of the energy storage industry since last year has boosted morale, on the other hand, energy storage can be embedded into the whole links of power supply, electricity and load side of the power system and added to it, and on the other hand, the technical cost has fallen rapidly

however, from the global to the domestic, the traditional pumped storage has dominated the energy storage market for a long time, and the share of new energy storage installed capacity is only 4%, and the degree of commercial application is generally low. In the future, it is worth paying attention to whether the long-standing commercial application of new energy storage can "blossom everywhere" and quickly transition from R & D demonstration to the initial stage of commercialization

At present, energy storage technology is mainly divided into three categories: mechanical energy storage (such as pumped storage, compressed air storage, flywheel energy storage, etc.), electromagnetic energy storage (such as superconducting energy storage, super capacitor, etc.), electrochemical energy storage (such as lithium-ion battery, sodium sulfur battery, lead-acid battery, nickel cadmium battery, zinc bromide battery, all vanadium flow battery, etc.), as well as heat storage, cold storage, hydrogen storage, etc

according to the statistics of Zhongguancun energy storage industry technology alliance, by the end of 2017, the cumulative installed capacity of energy storage projects that have been put into operation worldwide was 175.4 GW, with an annual growth rate of 3.9%, and that in China was 28.9 GW, with an annual growth rate of 18.9%. Among them, the cumulative installed capacity of pumped storage accounts for the largest proportion, with global and domestic installed capacity of about 96% and 99% respectively; The cumulative installed capacity of global electrochemical energy storage projects is 2926.6 MW, and the cumulative installed capacity in China is 389.8 MW, with an annual growth rate of 45%. Obviously, electrochemical energy storage is the "leader" of new energy storage, and it is growing rapidly

different energy storage technologies have different advantages and disadvantages in terms of life, cost, efficiency, scale, safety, etc. In general, the mechanical energy storage scale is relatively large and the service life is long; Electrochemical energy storage develops rapidly, its scale is relatively small, its response time is very fast, its application is comprehensive and extensive, and its safety is slightly inferior

in different countries, there are differences in different levels of technological development. The flywheel energy storage in the United States is generally in a leading position; Japan is absolutely in the lead in sodium sulfur batteries; China is in a leading position in the development of liquid flow batteries; In terms of new compressed air energy storage without fuel and gas storage caverns, China is basically synchronized with the world

at present, electrochemical energy storage (the new energy storage in this paper generally refers to electrochemical energy storage) has formed a certain scale of demonstration or commercial application. Among them, the cumulative installed capacity of lithium-ion batteries accounts for the largest proportion, accounting for 58%, and lead-acid batteries and liquid flow batteries also account for a relatively large proportion; The demonstration of 10 MW compressed air energy storage was completed; The first molten salt energy storage optical thermal power station put into operation in China - the central control Delingha 10MW tower type molten salt energy storage optical thermal power station realized full load and power generation on August 21, 2006, which is the third molten salt energy storage tower type solar thermal power station in the world

in 2018, China actively promoted the construction of started energy storage projects. During the year, it is planned to build Dalian 100mw/400mwh peak shaving power station with liquid flow battery energy storage, Liaoning Suizhong Power Plant 24mw/12mwh thermal power unit joint frequency modulation energy storage, Dalian 30mw/120mwh source friendly wind farm energy storage, Jiangsu Jintan compressed air energy storage and other projects. Research and promote the preliminary work of 100MW compressed air energy storage power station and 100MW lithium-ion battery energy storage power station. From this, we can see the types of energy storage technologies that China focuses on promoting

II. Gradually formed business models and application scenarios

energy storage has the dual attributes of "source" and "load". It is basically used in renewable energy and (specifically refers to the application of energy storage in centralized wind farms and photovoltaic power stations), auxiliary services, power transmission and distribution, distributed power generation, micro electricity and other fields in the power field. In different countries, the mainstream applications of energy storage are different. In domestic practice, the main profit model of new energy storage is single. We are learning from the experience of western countries to explore a variety of commercial application models, and the progress is uneven

1. Peak valley electricity price difference arbitrage

through peak valley electricity price difference, help users reduce capacity electricity charges and electricity charges, which is the most important profit model of energy storage in China at present. Large power users pay a fixed capacity charge to power enterprises every month, and the energy storage system can save this expenditure for users. Reducing the electricity charge refers to charging the energy storage system at the valley price and using the electricity stored in the energy storage system at the peak price, so as to save the electricity charge of users with the same electricity consumption. The peak valley electricity price difference in each region is different. Based on the peak valley price difference of 0.75-0.8 yuan/kWh, it is assumed that the peak valley electricity price arbitrage is the only profit point. It is charged and discharged twice a day, and the static investment payback period of the energy storage power station project is about 7-9 years

2. Supporting renewable energy projects to build centralized energy storage power stations

renewable energy power generation has the characteristics of intermittency and volatility. Careful application of energy storage can track the planned output, smooth output and participate in peak shaving and frequency modulation auxiliary services, so as to promote the consumption of renewable energy. This application scenario has high requirements on the cost, life, scale and safety of energy storage. The 10 MW lithium battery energy storage project in Dingbian, Shaanxi Province is to absorb the remaining electricity through joint operation with the local 1.5 million KW photovoltaic power station, cut the peak and fill the valley according to the photovoltaic electricity price, and promote local consumption

3. Participate in the charging of power auxiliary services

power auxiliary services include primary frequency modulation, automatic generation control (AGC), peak shaving, reactive power regulation, standby, black start services, etc., which can maintain the safe and stable operation of the power system and ensure the power quality. Globally, frequency modulation is the main application of energy storage. According to Bloomberg new energy finance statistics, in 2016 and 2017, FM applications accounted for 41% and 50% of the cumulative installed capacity of megawatt energy storage projects. In the energy storage project participated by a domestic enterprise in the UK, the profit composition is 70% of the frequency modulation income, 20% of the peak shaving income, and 10% of the capacity fee income

in China, this profit model will be formed with the construction of power auxiliary market. At present, the southern power region has formulated the auxiliary service compensation table to compensate the AGC service provided by the parallel generator set; If the energy storage power station enters the charging state according to the instructions of the power dispatching agency, it will compensate the charging power according to the statistics of the charging peak shaving service provided by it. The specific compensation standard is 0500 yuan/megawatt hour

4. Distributed energy storage applications

cooperate with the construction of distributed energy, as the main body of electricity sales, it mainly benefits from electricity sales. The guidance on improving the regulation capacity of power system issued in March this year "encourages the application of distributed energy storage"

5. Participate in the power demand side response

directly connect power, and regulate peak and valley in both directions to increase power security and stability. The conditions of energy storage power station in this application are strict. In January, 2018, the 20MW energy storage power station in the Singapore Industrial Park in Wuxi, Jiangsu Province, was approved by the national household appliance company and was in full capacity and operation. During the Spring Festival this year, the energy storage station participated in the power demand side response, and "filled" about 90000 kW load during the low power consumption period, with a total consumption of 576000 kwh. This is the first time that large-scale energy storage power stations in China have participated in the demand side response and charged

III. opportunities for commercial application of new energy storage

1. Continuous improvement of policy and market mechanism

2017 is considered the first year of the release of China's energy storage industry policy. Since last year, the state and some local governments have intensively issued a series of policy documents to give the energy storage market a dominant position, build a market system that fully reflects the value of energy storage, and bring environmental benefit mechanisms, which will accelerate the development of the energy storage industry

among them, on September 22 last year, five departments including the national development and Reform Commission and the National Energy Administration issued the guiding opinions on promoting the development of energy storage technology and industry. As the first guiding government document for the energy storage industry, it puts forward the development goals of China's energy storage industry in the next 10 years. The person in charge of the science and Technology Department of the National Energy Administration recently said in this regard that the role of the guidance is mainly "four clarifications", that is, to clarify the policy guidance to encourage and support the development of energy storage, the identity of the subject of energy storage, the investment management mechanism of energy storage, and the task of energy storage demonstration

later, the Southern Energy Regulatory Bureau and Shanxi Energy Regulatory Office formulated implementation rules for electrochemical energy storage to participate in auxiliary services in the power market, clarifying the compensation standard for auxiliary services of energy storage. At the end of 2017, the South Regional FM auxiliary service market has officially started simulation operation. In 2018, more provinces will successively introduce policies related to the participation of energy storage in ancillary services. By the end of 2018, the first batch of electric power spot pilot projects in eight regions in China will be put into trial operation. In the real-time spot market, when testing rubber materials, the journey of the rubber tensile testing machine is extremely large, and the electricity price is more flexible, which is conducive to improving the yield. With the liberalization of the power selling side and the liberalization of market-oriented transactions, energy storage can be combined with distributed generation to form a power selling entity

2. The technology cost is expected to decline rapidly

according to various calculations of insiders, in recent years, the cost of electrochemical energy storage technology has decreased by 8% - 20% per year. At present, the cost of battery and manual assembly has accumulated, and the cost of some energy storage projects has fallen to less than 2000 yuan per kilowatt hour, or even about 1400 yuan; After the 100 MW compressed air energy storage demonstration project is put into operation in 2021, the project cost is expected to be reduced to 5000 yuan/kW, equivalent to 1200 yuan per kWh. With the development of new energy storage technology and the promotion of demonstration projects, the downward trend of cost is expected to continue

according to the guiding opinions on improving the regulation ability of power system, we should speed up the research and innovation of new energy storage technology and improve the conversion efficiency and service life of new energy storage system. According to the action plan for energy technology revolution and innovation (2016-2030), a number of mature energy storage technologies, such as 10mw/100mwh supercritical compressed air energy storage system, 1mw/1000mj flywheel energy storage array unit, 100MW all vanadium flow battery energy storage system, 10MW sodium sulfur battery energy storage system and 100MW lithium-ion battery energy storage system, will be demonstrated and promoted by 2020

3. Broad market demand

energy storage can enhance the flexibility and adaptability of the power system. With the development of energy interconnection, large-scale centralized renewable energy, distributed power generation, micro electric power generation, FM auxiliary services and other energy storage needs are huge

at the same time, with the popularization of electric vehicles and the large-scale retirement of power batteries, the rise of retired battery energy storage market will accelerate. At present, the cost of new batteries is relatively high, which is an important reason for limiting the large-scale promotion and application of energy storage; The echelon utilization can reduce the engineering cost of energy storage, and is relatively environmental friendly, with good economic and social value

in addition, with the further promotion of the new round of power system reform, the power auxiliary service market and the power spot market gradually play a role, the scope of power market-based transactions is expanded, the value of energy storage projects is fully reflected, and their profitability is increased, which will further increase the investment enthusiasm of social capital and form a good cycle

IV. challenges faced by the commercial application of new energy storage

for a long time, the development of the global energy storage industry has lagged behind, which naturally has its reasons. After years of development, some constraints have become smaller or even eliminated, some constraints still exist, and new challenges are emerging. On the whole, China's energy storage industry faces a variety of uncertainties and challenges on the road of transition from the R & D demonstration stage to the initial stage of commercialization

1. There are different degrees of limitations in technical performance

although energy storage

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