Academician Du Xiangwan: How the New Power System Realizes the
Time：2021/12/24 8:37:14 Tag：Renewable energy, new power system, energy storage, hydrogen energy, new energy
"It is often seen in discussions that it is difficult for the energy system to meet the three goals of safety, reliability, economic feasibility, and green and low carbon at the same time. The optimization of any one of the three goals may cause problems in other directions. Therefore, the three goals are often referred to as It is the 'impossible triangle' of the energy system." At the "2021 Energy Transformation and Development Forum" held recently, Du Xiangwan, an academician of the Chinese Academy of Engineering, said, "Safety and reliability are the basic requirements for the energy system, and only an economically viable energy society will accept it. , Green and low-carbon is the general direction of energy transformation. The new energy system that carbon peaks and carbon neutrality calls must gradually meet the above three goals, making it a 'possible triangle', which is a high-quality energy system. At the same time, the new power system must also be one that realizes the 'possible triangle'."
Du Xiangwan believes that in the new power system with new energy as the main body, the proportion of new energy will increase significantly, and the green and low-carbon characteristics of the system are relatively clear. reliable".
The economy faces a huge test
"The development of new power systems should take into account the staged affordability of social energy consumption and long-term economics." Du Xiangwan said that with technological progress and large-scale development, wind power and photovoltaic power grid links can already compete with fossil energy, but with the As the proportion of new energy increases, the cost of system balance and security will become the cost increment of the power system.
To this end, Du Xiangwan proposed that on the one hand, flexible resources in various fields should be widely used to solve the balance problem of the power system at a low cost. For example, some coal-fired power plants use renewable energy for peak regulation, which is a realistic and economical flexible resource; another example is to promote the system from using flexible resources such as pumped storage and electrochemical energy storage to developing electric vehicle charging and discharging, heat pump, electric heating, Electric-cooling synergy, electric-hydrogen coupling and other multi-energy complements can improve the efficiency of the system. On the other hand, with the development of distributed power generation, the mode of large power grid can be divided into a combination of large power grid and a series of micro-grid modes, and high-precision prediction technology can be used to achieve local self-balancing and reduce the balance pressure of large-scale systems. , reduce the incremental cost input.
Du Xiangwan said that some studies have shown that it is more economical for electricity to come from "nearby" than from "distant". For the eastern region with a high electricity load, the "nearby" and "distant" can be combined, not just It relies on the traditional and centralized power supply of "West-to-East Power Transmission".
Du Xiangwan said that technological progress will reduce the cost of energy storage and hydrogen energy. At present, the cost of electrochemical energy storage has broken through the economic inflection point. 80%. It is estimated that by 2025, the new energy + energy storage market will enter the 100 billion level.
System safety and reliability is the bottom line
As we all know, ensuring the safety and resilience of the new power system is the bottom line and responsibility for its development and growth. Avoid the risk of large power deficits in the electricity supply, even in extreme weather conditions. So, how can the new power system ensure safe supply?
In this regard, Du Xiangwan believes that the power supply of the new power system, in addition to water renewable energy, needs to establish a multi-energy complementary strategy. For example, coal power, the national policy is very clear, the "14th Five-Year Plan" did not mention the reduction of coal power, but called strict control, and the "15th Five-Year Plan" began to replace coal power. At present, a more practical approach is to arrange the flexibility transformation of coal-fired power units in an orderly manner while generating high-efficiency and clean power generation, allowing them to participate in deep peak shaving to help improve the flexibility of the power system. There should be a compensation policy for coal-fired power peak shaving auxiliary services, that is to say, the "power supply value" and "flexibility value" of coal power should be reflected.
In Du Xiangwan's view, the construction of a new power system requires the further development of hydropower, and my country's hydropower installed capacity and output still have certain potential to be tapped; nuclear power plays a role in stabilizing the base load in the new power system. Under the premise of safety, nuclear power installed capacity is completely possible. It will reach more than 100 million kilowatts by 2030; under the condition of multi-energy complementarity, the problem of peak regulation can be solved through the power trading market, and a certain amount of power plants can be used as backup emergency power sources, and users can provide various power outputs according to big data. Prediction and selection of power sources; for new energy power generation enterprises, they can deeply participate in the balance of power and electricity through self-construction or purchase of peak shaving capabilities to achieve high-quality output.
In addition to the above-mentioned measures on the power supply side to ensure the safety and reliability of the new power system, it is also necessary to develop smart grids and distribution networks on the grid side. Du Xiangwan believes that digital technology can improve the data collection, analysis and application capabilities of the power grid, integrate with traditional power technology, promote the intelligence of all aspects of the power system, and make the power grid observable, measurable and controllable. "The traditional large power grid is changing to the complementary symbiosis of large power grid and micro grid, active distribution network, and local DC power grid. Therefore, we need to build a smart distribution network to adapt to the grid connection of distributed energy, energy storage and electric vehicles. "
In addition, Du Xiangwan said that energy storage has application markets on the power generation side, the grid side and the user side. "The development of commercial energy storage and heat storage technology is the key to the flexibility, inclusiveness and balance of the energy system."
How to implement the "possible triangle"
"Constructing a new power system is not an overnight process, but a process." Du Xiangwan said that in the early stage of the construction of a new power system, with the increase in the proportion of new energy power, a market trading system suitable for new energy power should be gradually formed, so that flexible resources can be obtained reasonably On the other hand, the deep integration of the physical system of electricity and digital technology should be realized, and the role of digital as a productive factor should be brought into full play. "This stage is mainly to accumulate experience in combining new energy with energy storage and flexible resources. At the same time, we will accumulate experience in combining fossil energy and non-fossil energy power generation."
Du Xiangwan predicts that after carbon peaks, the new power system will enter a mature development stage. At this stage, various transformation costs must be solved economically, and in-depth research and risk prevention must be carried out to make it a new national comprehensive foundation that integrates with various infrastructures. facility.
"There is no principle obstacle to the realization of the 'possible triangle' of the power system, but it cannot be completely solved by the existing technical capabilities." Du Xiangwan said that building a new power system is a process of creating new technologies, new industries, and new social values. Needs more in-depth research and more practice. (Source: China Energy Network)