2021-03-12
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【Why we chose this article】Green energy is an industry actively developed by governments of various countries, but green energy has the characteristics of unstable power generation, so it is necessary to build energy storage equipment in the grid to stabilize power supply. Although the concept of energy storage is very simple, it is to use a large number of batteries to store the excess electricity of the power plant, but in fact, the energy storage system is a complex multi-layer system.
Below, we will understand the 7-layer structure of the energy storage system. (Editor in charge: Guo Jiahong)
The stock market hits new highs frequently, and the whole people are crazy about stocks. Many media took advantage of the trend to propose some star industries and concept stocks. A few days ago, my friend came to ask me which stocks to buy because he knew that I worked in the energy storage industry. It is found that energy storage concept stocks have been ranked at the top of the investment advice list!
Energy storage concept stocks are popular, but the truth is that you don’t know much about energy storage at all, and you don’t know much about the upstream, midstream and downstream supply chain of the energy storage system. You don’t know any business opportunities for energy storage, so you just take your own Money jokes.
In the best years of my life, I have participated in the construction of Taiwan's first large-scale grid-level energy storage system during the explosive period of commercial application of energy storage systems in the past few years. I am one of the few qualified to speak for energy storage. Therefore, from the perspective of practical experience, I will construct a systematic energy storage system knowledge framework for you, help you correctly judge the location of business opportunities, and assist you who are not in the energy storage industry but want to share dividends through investment. In addition to investment, this article will also be very helpful to companies that want to purchase energy storage systems. It can assist in making correct decisions and greatly reduce your exploration and trial and error time, money and other costs.
A large-scale energy storage system is like a reservoir in the middle for "peak shifting and valley filling" regulation. Reservoirs are a complex system, and energy storage is no exception. The energy storage system can be divided into seven layers from raw materials to the system, and some will be split into fewer or more. I suggest that you don’t need to spend time entangled in how many layers are divided. This kind of entanglement can be used to achieve considerable academic achievements. But here is mainly for your convenience to understand. We will focus on the most widely used lithium battery energy storage system. If you want to know more about other types of energy storage batteries, you can refer back to the Green Academy series of articles.
Let's unbox the energy storage system right now! Please take a minute to look at the picture below:
Energy storage systems require batteries as a foundation. The raw materials are mainly mining areas. Battery materials refer to positive electrodes, negative electrodes, electrolytes, and diaphragms. Figure 1 does not show them, but it is in "How to judge whether the breakthrough in battery technology is the big scam of the century or a real revolution?" " article has a complete description of various materials and principles. Basically, each company has its own position here, competition is not easy, and the capital intensity of the upstream is very high. To survive here, the pockets are very deep. There may be opportunities to fall on the electrolyte and the diaphragm.
Combining these battery materials together becomes a battery core. Although each design is very different, for simple understanding, a 1 MW energy storage system will have about 14,000 batteries (take 20 Ah as an example), which is about the capacity of 80,000 batteries in 10 Tesla electric vehicles, but The batteries used in energy storage systems are much larger than those used in electric vehicles.
In the current application scenarios of power grids and electric vehicles, the positive materials of lithium batteries can be roughly divided into three categories: lithium cobalt oxide (LCO), lithium iron phosphate (LFP) and ternary materials (NMC). Taiwan and mainland China mainly use lithium iron phosphate, commonly known as lithium-iron batteries, because of the pursuit of CP value; Japan’s Panasonic and South Korea’s LG/Samsung use ternary materials, commonly known as lithium ternary, which makes them very popular in the electric vehicle market. In addition to the different classification of materials, batteries of the same brand can be differentiated into different specifications and grades to adapt to different application scenarios. If you are not an insider, you must be dazzled.
Many people like to imagine that a world-class battery cell factory can emerge in Taiwan, which is unrealistic. The market in Taiwan is small, and there is no market for R&D, and batteries require a large number of orders to have opportunities for trial and error and adjustment. In addition, the competition for battery cells in mainland China is already very fierce, and it is too late to overtake in a corner.
Each battery cell is like an individual soldier in the army. It is impossible to rely on a single soldier to act, but many battery cells can be connected in series to form a module. A battery module usually has at least 100 batteries. Management is more convenient.
The module factory is responsible for the assembly technology of this section. When they make the module, they will build the first layer of small battery management system, and also design the fire protection mechanism to prevent the battery cells from burning. It is also an important part of passing international safety certification such as IEC and UL. The capital demand is also high here, because this is the only way to have economies of scale and price competitiveness, and you have to know where to sell, otherwise, the company will easily fail to turn over if it accumulates a large amount of inventory.
Put away the 14~21 series battery modules like a drawer, which is the battery cabinet. In order to manage the battery cells and modules, a higher-level battery management system is required. Only by giving commands to the battery can it know how to act, and the battery management system also The status of each battery cell will be checked from time to time, and the balance between the battery cells will be maintained as much as possible. Most of the companies that produce battery cabinets will provide a battery management system as part of the service. Buyers do not need to develop it themselves, lest you accidentally burn it after using it indiscriminately, and everyone will quarrel over compensation.
The power conditioner is the key to connect the battery cabinet to the grid application. It can convert bidirectionally. Discharging is to convert the DC power of the battery into AC power of the general power company, and charging is to convert the AC power of the general power company into the DC power of the battery for storage. Machines and equipment that need to communicate with the grid all need the function of two-way conversion. It just depends on how it is done. For example, electric vehicles rely on charging piles to convert AC power to DC power, or vice versa.
The power conditioner needs to connect various communications between the battery management system and the energy management system mentioned below, and the complexity of data collection and transmission is quite high. There are only a few companies selling power regulators in Taiwan, and there are many mature brands in foreign countries to choose from, so the chances are relatively small.
Whether it is energy saving, energy creation, energy storage, or smart system integration, as long as it involves the integration of many electrical equipment, power generation equipment, and energy storage equipment, an energy management system is required, and energy storage systems are no exception.
In the energy storage system, the energy management system is a complete monitoring system covering the controller. In addition to managing when the power regulator is charged and discharged, it also includes monitoring the ambient temperature and humidity of the battery storage, fire protection system, access control system, etc., which is equivalent to the energy storage system. brain. The energy management system must be able to communicate with the battery management system and power regulator. If the scheduling is not good, there may be loopholes in the safety design. This is one of the reasons for the fire accident of the Korean energy storage battery.
Various application scenarios require different energy management systems, and few battery factories or module factories can stretch their arms so far. Therefore, energy management systems can be regarded as a segment with more business opportunities. It should be noted that sometimes we will see some headlines similar to "EMS factory seizes business opportunities", at this time, we must be careful to distinguish whether it refers to electric vehicle EMS or energy storage EMS. The electric vehicle EMS factory produces automotive electronics. Components, such as the instrument panel and touch panel on the car, are different from the energy storage EMS that communicates with the grid.
Buying an energy storage system is not like buying an electric car. More often than not, you need a customized design. After all, each application scenario that requires an energy storage system is different. So you need to choose a system integrator to assemble the entire energy storage system for you. A system integrator typically develops an energy management system to ensure that the various components it procures perform well.
Congratulations, you have fully understood the energy storage system! In the next article, let's share how to successfully persuade the boss to buy an energy storage system.
