The energy storage frequency regulation market is gaining momentum

The energy storage industry has existed for a long time, and the relatively new point is that the future trend and space have changed. Now mobile energy storage has entered our lives. The energy storage business has also created many companies, such as using lead-acid batteries as energy storage for base stations. Everyone pays more attention to the current time point because the rapid development of renewable energy, including electricity reform, the increase in the peak-to-valley electricity price difference, etc., will further open the energy storage market. Tesla's layout of new energy vehicles attracts the most attention, but there is also Solarcity on the power generation side, and Powerwall, the energy storage business, is the connection point between clean energy power generation and clean power consumption. In the future, the extension of people can be extended to the car, and the longer-term layout is to realize the integration of clean energy power generation, clean energy storage and clean energy consumption on the car.


How we see the industry


The energy storage industry has existed for a long time, and the relatively new point is that the future trend and space have changed. Now mobile energy storage has entered our lives. The energy storage business has also created many companies, such as using lead-acid batteries as energy storage for base stations. Everyone pays more attention to the current time point because the rapid development of renewable energy, including electricity reform, the increase in the peak-to-valley electricity price difference, etc., will further open the energy storage market. Tesla's layout of new energy vehicles attracts the most attention, but there is also Solarcity on the power generation side, and Powerwall, the energy storage business, is the connection point between clean energy power generation and clean power consumption. In the future, the extension of people can be extended to the car, and the longer-term layout is to realize the integration of clean energy power generation, clean energy storage and clean energy consumption on the car.


First of all, the energy storage industry is a relatively new industry, but the industry has existed for a long time, but the future trend and space have changed. Our current mobile phones, computers, new energy vehicles, etc. all have battery energy storage, which is mobile energy storage.


Second, the energy storage business has also created many companies, such as Narada Power and Sacred Sun, which use traditional batteries—lead-acid batteries to sell to China Mobile, China Unicom, etc. as base station energy storage. Although the industry has existed for a long time, why do people pay more attention to this time point? It is because the rapid development of renewable energy, including electricity reform and the solidification of renewable energy output, is further expanding the energy storage market.


The third point is Tesla, which everyone is concerned about. Tesla’s layout of new energy vehicles is the most interesting thing, but at the same time, there is also Solarcity on the power generation side, and Powerwall is the connection point between clean energy power generation and clean power consumption. In the future, the extension of people can be extended to cars to realize clean energy power generation, clean energy storage and clean energy consumption on the car, which is a more long-term layout.


Key points of energy storage and frequency regulation analysis


1. Energy storage


As the name implies, energy storage is the storage of energy. In fact, energy storage is not only used in the power grid, such as hydrogen storage. There are many sources of hydrogen, and finally to the downstream fuel cells and new energy vehicles, which has nothing to do with the power grid. However, the application scenarios and application markets of energy storage in the power grid are the largest. We believe that there is a certain demand for energy storage, but it needs to be guided by policies. We have divided the application scenarios of energy storage from the aspects of power generation, transmission and distribution, and electricity consumption. In a simple view, there are six application scenarios on the power generation end, three in power transmission and distribution, and five parts on the power consumption side. Another part is new energy vehicles. With the development of new energy vehicles and the emergence of V2G in the future, the linkage between new energy vehicles and the power grid can also be realized. At this time, new energy vehicles can be regarded as a mobile energy storage device.


According to different applicable scenarios, we have made a Lianliankan of energy storage for relatively more suitable scenarios and different technologies, but this does not mean that some other energy storage methods cannot be used in other aspects.


2. FM


From a principle point of view, the first is the generator: including the engine, generator and control system. Most of the generators in our country are synchronous generators, in which the rotor generates a rotating magnetic field, and the stator cuts the magnetic field to generate electricity, so the frequency of the generator and the rotor are consistent. The change of rotor speed is matched according to whether the mechanical power output by the prime mover and the electromagnetic power of the generator are balanced. If the electromagnetic power is greater than the mechanical power, the system frequency will drop.


Users will not consider the frequency of the power plant in the actual use process. From this point of view, the principle of power system operation is that the power generation end is adjusted by the load. How much load and how much power generation is adjusted can the frequency be balanced.


From the perspective of energy, when the generator generates less power, the power system will instantaneously draw energy from the rotational potential energy of the generator set, which will cause the speed of the generator set shaft to slow down. On the contrary, the excess load of power generation will transfer the excess energy to the potential energy of the rotor, and the frequency will increase. In the system, the synchronous generator has inertia, the smaller the inertia, the faster the frequency becomes. Therefore, a certain amount of generator sets need to be kept online so that the frequency does not change too fast. The frequency in our country is 50Hz, and the tolerance of the large power grid is ±0.2Hz. If the load changes rapidly and exceeds the range, the generator set will be disconnected from the grid, and the power generation end will cause a chain reaction and the grid will collapse. From this point of view, wind power and photovoltaics have disadvantages, because they do not provide system inertia, which makes it easier for the grid system to trigger the 0.2Hz standard, and the system reliability becomes weaker. This is also the main reason why people abandon wind and light. Taking photovoltaics as an example, the technology of virtual synchronous generator is now used, which is connected to the grid through electronic converters. The differences between electronic converters and traditional synchronous generators include the characteristics of fast dynamic response, small overload capacity, low moment of inertia and low short-circuit capacity, which have a non-negligible impact on the stability of the grid. The traditional synchronous generator has relatively good characteristics and natural advantages. It is necessary to learn from the tradition to realize the friendly access of the inverter grid.


For the power grid, the supply of the power generation end and the demand of the power consumption end must maintain a real-time balance. In the actual process, the disordered use of users and the volatility characteristics of new energy generation at the power generation end make the power grid unable to ensure a real real-time balance. By adjusting supply and demand The grid can be made to fluctuate within a small range, so as to achieve a relatively balanced state. Taking the frequency reduction caused by the generator cut off as an example, the current three-period framework is a relatively common balance mechanism: within 30s after a large number of units are cut off, the power plant controls the frequency offset through the unit inertia and governor response, automatically Suppress frequency attenuation, this time is primary frequency modulation; in the period of 30s~10min, secondary frequency modulation equipment represented by frequency modulator intervenes in frequency modulation, this is secondary frequency modulation, secondary frequency modulation is what we call the auxiliary service of the power grid, it is Can generate income; the third time period starts from the 5th minute, and the economic dispatch of resources provides a three-level control mechanism through the real-time situation of 5 minutes, and at this time, frequency regulation is performed three times.


The conversion process of thermal energy, mechanical energy and electrical energy of synchronous generator sets is relatively slow, but if energy storage devices are used, the conversion time of chemical energy and electrical energy is shorter. Energy storage + VSG technology combines the fast response of energy storage and the inertia of traditional generator sets. , the frequency of the grid will be quickly balanced. Energy storage (especially electrochemical energy storage) has a fast frequency modulation speed and adjustable capacity, so it has become a very good frequency modulation resource. On average, the frequency regulation effect of energy storage is 1.7 times that of hydroelectric units, 2.5 times that of gas-fired units, and more than 20 times that of coal-fired units. In theory, the difference between the best frequency regulation effect and the worst frequency regulation effect can be nearly 8,000 times. In practical applications, the average values of K2 and K3 before investment were around 1.4 and 1.5, respectively, and rose to around 1.5 and 1.6 after investment, and the Kp value rose from 2.98 to around 3.2. Later, through further optimization, the Kp value was raised to close to 5, reflecting the The energy storage has superior performance in frequency regulation.


The market space for frequency regulation is huge, and the demand for frequency regulation is about 2% of the total installed capacity. We estimate that the scale of the national stock frequency regulation is about 33GW, and we conclude that the annual new frequency regulation demand is about 1.5-2GW.


The economy of frequency modulation is far more than peak shaving and valley filling: IRR can reach 11%, and the payback period is about 5 years. In the future, with the further increase of the proportion of new energy in the power supply, and the further deepening of the power market, the opening of the auxiliary service market will further release the demand for frequency regulation. By applying the same energy storage to different scenarios, more benefits can be obtained by stacking multiple scenarios, and the payback period can be further shortened.


Viewpoint sharing


Focus 1: The market cycle, market space and development trend of power plant frequency regulation


Kelu Electronics: Follow the power plants. The market will be completed within two or three years, because it has a great impact on the power plants. Once there are about 5-10 power plants in the first batch, the pressure on other power plants will be very high. large, the certification time will be greatly shortened. The market space for the basic level of power plants is limited, and to a certain extent, the best is the best. Some battery storage projects have a life cycle of about eight years.


Concern 2: Will the cost of choosing lithium batteries be reduced? What is the difference between them and lead-acid batteries?


Kelu Electronics: The essence is the evaluation of investment cost. There are differences between manufacturers, and it is recommended to measure each type of battery by the cost of electricity. Bidding is based on capacity, and subsequent risks must be borne by oneself. In the case of bidding and promising the usable part, the risk to the enterprise is relatively small, and no one knows all the batteries. For commercial applications, the uncertain part is excluded, and only the available part is required to be promised. In the future, energy storage will be more about selling and discharging services, which is relatively low for investors.


Concern 3: Lithium batteries are mainly used for energy storage?


Kelu Electronics: Lead-acid is also available. In plateau and other regions, lead-acid batteries are still used, and the starting cost is lower.


Focus 4: Peak-to-valley electricity price difference


Kelu Electronics: The power reform in the pilot areas is adjusted towards the demand-side response. When the response policy is launched, the policy response needs a process. If the peak and valley electricity price is adjusted in real time, the electricity price will be broken even more.


Dynavolt Technology: The view from the power grid is that the electricity price gap will expand, and the electricity price will not necessarily rise. With the release of electricity sales, there may be negative electricity prices, and the economy may be better for the user side.


Focus 5: Is the start of new energy vehicles a node of energy storage?


Kelu Electronics: Regarding the development of electric vehicles, according to the consumption of refined oil products of Sinopec and PetroChina in 2015 and 2016, about 3/4 is used for transportation. Converting how many kilometers an electric vehicle runs per hour, and then converting the total apparent fuel consumption into electricity, it accounts for about one-tenth of the country's power generation. If it is counted as 5 million vehicles in 2020, it is still far from one-tenth of what I just said. Even if all charging piles are replaced by V2G piles in 2020, the impact on the power grid will not be large.


Concern 6: Wind power generation projects have a long payback period. Why can't you charge and discharge multiple times within a day to improve equipment utilization? How to reduce costs?


Kelu Electronics: Photovoltaics can’t be sent up during the day, and wind power is relatively flat, but higher at night. When there is a gap in the transmission grid, it can be sent upwards. The demand model for several wind power is only one time. The real value of wind power and photovoltaic energy storage lies in increasing the proportion. If the proportion is increased, the same power grid can double the transmission capacity. For the local area, wind power and photovoltaics are incapable of digesting, such as Gansu and Qinghai, which are big provinces that transmit electricity. At present, 10% energy storage can only change the transmission capacity of photovoltaic and wind power to improve the stability. In terms of cost, the calculation method of each enterprise is not uniform. Now the cost of electricity is about 4-5 cents. Everyone strives to reduce the cost to 3 cents, which means that the price of the system is reduced to 1.5 yuan/Wh. You can refer to photovoltaics, but the amount of energy storage has not yet increased, and there is still room for cost reduction.


Cinda Securities New Energy and Power Equipment Team: We are optimistic that after the number of new energy vehicles and the establishment of a recycling system, the cost may exceed expectations. It is entirely possible that the cost of lithium battery energy storage is more than 200 cents, which can be seen in 3-5 years. Photovoltaic efficiency has improved, including technological changes far beyond expectations.


Focus 7: Selling electricity


Cinda Securities New Energy and Power Equipment Team: Electricity sales are related to energy storage. Driven by electricity reform, some new changes have occurred. Selling electricity is a starting point, not a way, but an action, not a link that carries hardware. The pace of marketization is lower than expected, and electricity sales have not yet been fully implemented. At present, the release of electricity reform dividends is still mostly confined to the industry. We expect that all aspects will be deeply involved in the future.


This time, the focus is on energy storage, and electricity is sold as a service. This problem involves electricity reform. In terms of electricity sales, the core of electricity reform is to ensure the stability and reliability of the power grid system. On this basis, improve upstream and downstream, improve system efficiency, and reduce electricity prices. In addition, the electricity reform also needs to be clear about what kind of spot market we are going to take, is it a bilateral trading market or a strong power pool market? From overseas experience, the United States is a bilateral trading market, and there must be electricity sales in this market. If you follow the Australian route, since there is only a unified wholesale price under the strong power bank model, there is no need for the existence of electricity sales companies. First of all, the spot market model must be determined before further development. In addition, electricity sales itself should pay more attention to value-added services. In the future, the response part of the demand side is the electricity sales side, and companies should work hard to do it well. For large-scale industrial electricity, it can directly negotiate with the upstream. If it is for household use, the family does not have the ability to negotiate, and the electricity sales side can provide services here.


Please feel free to give your inquiry in the form below. We will reply you in 24 hours.
Message