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Power Storage Systems ≠ Batteries ,4 Major Cognitive Errors In Electric Energy Storage System
- Jul 11, 2018 -

Recently, lithium storage projects have attracted much attention, especially in Henan and Jiangsu. These projects can be described as "unprecedented" at home when the total installed capacity of lithium batteries reaches 100 MW. While we are excited and happy, we need to be calm. The power industry is the basic pillar industry of the country. It has strict requirements for the safety and reliability of the equipment. We need to have a strict awe attitude to the promotion of power storage. The energy storage project does not mean that the power lithium storage technology is mature.

The biggest feeling since the beginning of the work is that people's understanding of energy storage needs to be deepened.

(1) the power storage system is equivalent to the battery.

There are many applications of energy storage, such as energy storage power station for power system, and backup power supply for communication base station and data room. The backup power technology and power battery technology of communication base stations and data rooms belong to DC technology, and the technical requirements are lower than that of power batteries. Electric energy storage technology contains a lot of contents. Besides DC technology, it also includes converter technology, power grid access technology and power grid dispatching control technology. Therefore, the design of power battery will not necessarily be able to design an electric energy storage system.

At present, the energy storage industry has not clearly defined what power storage is. It is believed that the power storage system should have two characteristics: 1) energy storage system can participate in power grid scheduling (or the energy stored by the storage system can feed back to the main grid); and 2) can provide power services for more than one user.

(2) the performance requirements of lithium batteries for power storage are lower than that of power batteries.

At this point, it is difficult to give a clear judgement. The main reason is that so far there is almost no recognized successful commercial operation of the power type energy storage projects in China, so what kind of battery can meet the application of power storage can not be known.

At present, China is more keen to use the power battery ladder in power storage, and there have been some small-scale demonstration projects, the source of the battery and the actual operation of the project are not known to the outside world.

It is interesting that foreign well-known battery enterprises, such as LGC and Samsung SDI, have several GWh projects in the field of power storage, and they are also the world's recognized power battery leading enterprises, and can not find their reports on the ladder of use in the media. Most of the foreign power companies rely on car companies, such as BMW. Therefore, the application of decommissioned power battery to power storage needs to be verified.

(3) the lithium battery industry generally exists the phenomenon of "power battery" and "energy storage".

At present, there is no independent energy storage R & D team in China, and the research and development of energy storage is generally undertaken by the power battery team in the "leisure" of the power battery project. Even with an independent energy storage R & D team, the number of energy storage teams will be less than that of the power team. Compared with the power battery, the electric energy storage system has the characteristics of high voltage (usually designed according to 1000Vdc), and the characteristics of battery serial and parallel connection. Therefore, the electrical safety and battery condition monitoring of electric energy storage system are more complex.

(4) the industry is optimistic about the maturity of power storage technology.

The success of electric energy storage projects needs to be evaluated from two aspects of functionality and economy. On the one hand, the function of the energy storage system should meet the needs of the customer, such as the function of cutting peak and filling valley, FM and so on. In the economic aspect, the storage system can achieve the cost recovery through operation in the agreed time, and the storage system can be operated steadily for a long time and let the customer gain the profit for a long time.

The functional verification of energy storage system is relatively easy, and economic verification takes a longer time. The economy of the energy storage system is a test of the stability of the energy storage system. Only a long time of observation records can obtain key statistical indicators such as fault free running time, daily maintenance cost and scheduling success rate.

It is often seen in the media that a certain energy storage project has been successfully connected to the network. This kind of report gives people a sense of maturity of power storage technology. But in fact, the success of grid connected energy storage system is only verified by the functionality of the energy storage system. The economy or stability of energy storage system is not supported by operational data at present.

Any technology needs a step-by-step growth and improvement process before the real large-scale promotion. Taking power battery as an example, from 2009 to 2012, the Ministry of science and technology, the Ministry of finance, the development and Reform Commission and the Ministry of industry and information jointly promoted the "Ten City thousand" projects. In 2012, the State Council issued the "energy saving and new energy auto industry development plan (2012 - 2020)", and the industrial and financial policies to promote the development of power battery after 2014. Dense release. It is no exaggeration to say that the power battery is a high concern in the whole society, and the efforts of government, production, study and research have been promoted, and the large-scale application has been basically realized after 10 years.

Look at power lithium energy storage. Although there are demonstration projects in Zhangbei, in the past ten years, electricity storage in China has been in a state of being intermittent. The power storage industry has no clear policy guidance and financial support. The battery scale of the project is small and the operation is opaque. Objectively speaking, from the development process of domestic lithium ion power storage technology, lithium storage energy does not yet have the ability of large-scale application in the power field.