Problems to be solved in connection with the grid

2022-08-08
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The construction personnel installed wind power generation equipment in Hebei Chengde Weichang wind farm. Photo by Niu Lu

Obama's new deal may indirectly promote the development of China's new energy industry. Recently, the actions at the policy level of China's new energy industry can be directly degraded by thermal oxygen. In order to regulate the management of wind power prices, the national development and Reform Commission recently issued the notice on improving the tariff policy for wind power generation. On the other hand, the "emerging energy industry plan" is being stepped up, and many officials said in public that it will be issued as soon as possible

"the merger problem has been perplexing the development of new energy industry. If this problem cannot be solved in the energy planning being formulated, the merger problem will continue to perplex the development of new energy." A senior person in the industry pointed out the concerns of most people in the industry

why is wind power so difficult? What are the problems facing China? In order to solve the mystery, an exclusive interview was made with jiangliping, deputy chief engineer of Beijing Institute of economics and technology

the project is not matched with the power planning

: most enterprises obviously do not have the problem of sales reflection and merger between subsidiaries and parent companies. Some projects will be delayed for months or even years, which is very detrimental to enterprise investment. What do you think is the reason for the delay

jiangliping: to a large extent, it is because the planning and project approval of new energy and electricity are not coordinated and matched, resulting in a gap. The development of electricity is based on the plan, and the construction of electricity projects still needs to be approved by the relevant national departments

for example, the development plan of the wind power industry has been adjusted repeatedly in recent years, reaching a high growth rate of doubling year after year, but the power planning has not been adjusted accordingly, so the power planning can not keep up with the results of power construction

a recent survey shows that within the business scope of the State Grid Corporation of China, all wind farms approved for construction according to the prescribed procedures have been built and put into operation simultaneously. However, in some areas where the development of wind power projects is relatively concentrated, due to the need for long-distance transmission of 500 kV and 750 kV power transmission and transformation projects, the early approval cycle of such transmission projects is relatively long for high-end products, and there are problems that need to be further coordinated with the development and construction progress of wind farms

loss of new energy supporting power projects

: as a supporting project of new energy, how about the profitability of electricity in such projects

Jiang Liping: Nowadays, renewable energy development policies are characterized by "emphasizing development over transmission and use" and "emphasizing policy encouragement over technical specifications". Many subsidy policies are mostly aimed at power generation enterprises, while the state's subsidies to power companies are too small to make up for the losses caused by their power investment to cooperate with new energy power generation. For example, according to the renewable energy electricity price subsidy fee standard, the difference between electronic universal testing machine and hydraulic universal testing machine per kilowatt is 1 cent for less than 50 kilometers, 2 cents for 50~100 kilometers, and 3 cents for more than 100 kilometers. After calculation, the power company believes that the subsidies for 25, 75, and 120 kilometers of transmission lines should be 1.2 cents, 3.3 cents, and 5.4 cents per kilowatt hour respectively. Therefore, subsidies can only make up for part of it

according to the current system, power enterprises survive in the price difference between the sales price and the upper price. The annual compulsory "lessons" of power companies are still mainly in the construction of large-scale hydropower and coal-fired power bases and the tasks of many new users. In terms of wind power development, this extra expenditure makes power feel relatively difficult

the return on investment of coal-fired power plants will be damaged

: what are the impacts of intermittency of renewable energy such as wind power and photovoltaic power generation on the economy of electricity

Jiang Liping: wind power and photovoltaic power generation have intermittent characteristics, mainly in the safe and stable operation of the power system, and intermittent renewable energy power generation means that the interests of coal-fired power stations and other power producers will be redistributed

this is because in order to solve the problem of intermittent energy, thermal power stations with almost the same installed capacity need to be matched. Once the wind stops or the sunlight weakens, thermal power stations with the same installed capacity need to be started to generate electricity to ensure the safety of electricity

when wind power and other renewable energy sources increase in an area, it does not mean that thermal power is no longer needed. In fact, thermal power plants have to be built, but their utilization hours will become less, which will directly affect the income of coal-fired power plants, that is, the return on investment will be reduced and the investment recovery cycle will be longer in the same time

encouraging the development of renewable energy is good for the society in the long run. It is not only consumers who are paying the bill, but also power enterprises, such as coal-fired power plants, who are also paying the bill. Therefore, the national policy should take into account the interests of the relevant parties

safety accidents occur frequently due to inadequate technology

: what power companies mention most is that the intermittence of new energy such as wind power and photovoltaic power generation has caused hidden dangers to power safety. What are the main aspects of this

jiangliping: the hidden dangers to power safety are mainly caused by some problems caused by the current control performance of most wind turbines that cannot meet the requirements of power system operation

the output of wind power and photovoltaic power generation fluctuates greatly and has poor adjustability, which increases the uncontrollability of electricity and peak shaving pressure. For example, in Baicheng District, Jilin Province, about 400000 kW wind turbines have been out of operation due to the lack of low-voltage ride through performance of wind turbines and transient failure of power distribution; In Sanmenxia area of Henan Province, 25000 kW wind turbines were out of operation when electrified trains passed because the power quality performance of wind turbines did not meet the requirements

power system is a system of instantaneous balance, sometimes it is critical to pull one engine. Therefore, it requires that the units connected to the system should meet the requirements of system operation in terms of technology and management specifications, and be matched with electricity, otherwise it will have a great negative impact on the safety and stability of the whole system

the State Grid Corporation of China has been calling for and implementing technical standards and management planning. However, at present, these standards are internal to the enterprise, and power generation project developers can not comply with them. Therefore, the state needs to issue management standards. These mandatory requirements not only include the technology provided by the upstream developers, but also the upstream equipment manufacturers should operate in accordance with such technical guidelines. This is a problem that must be improved in development

whether it is low-voltage ride through or frequency modulation, it can be overcome when the proportion of new energy is small, but when the proportion is large to a certain extent, especially when it develops into the main energy, we must bear our own responsibility and ensure the quality of the power supplied

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