The structure, problems and trends of China's electric power energy during energy transition

However, even if the leading position of renewable energy development scale determines China's role as a global pioneer in combating climate change, it does not mean that China is in the same position in terms of energy transition. Energy transition, in essence, is a country's internal energy substitution problem. Therefore, the relative amount of renewable energy, that is, the share in the energy system, better reflects the stage of the energy transition. As the share of renewable energy in the energy system increases to different levels, its development characteristics and problems are different.

Internationally, non-water renewable energy (wind power and photovoltaic power generation) accounts for the proportion of total power generation to measure the progress of energy transition, because wind power and photovoltaic power generation is not only the main force of new renewable energy generation in the future, but also the biggest impact on the old power system of renewable energy. As shown in Figure 5, in China, the United States, India, Canada, Japan and other countries, the share of total electricity generation is less than 10%, which belongs to the primary stage of energy transformation.

The structural problems of China's electric power energy are viewed from the energy transition trend

To understand the problems existing in the power supply structure, there needs to be a potential evaluation standard. In other words, what criteria are used to evaluate whether a certain feature is a strength or a problem. It is necessary to think about the power energy structure and even the whole problem of the current power system from the perspective of the trend and logic of energy transformation.

The impact of energy transition on the power sector

This energy transition is driven by the response to climate change, and the ultimate goal is to significantly reduce carbon dioxide emissions from human activities and curb global warming. Energy transformation is the most basic and lasting factor affecting all energy industries, including the power industry, in the next 50 years, and will have a profound impact on the development direction of the power industry, business models and power systems.

Trends in energy transition. By gradually reducing the carbon emissions generated in energy production and consumption, gradually building an energy system based on zero-carbon energy sources. The core task of the transition is to promote the current energy system dominated by fossil energy, to the energy system dominated by renewable energy.

Two pillars of the energy transition. From the practice of various countries, the realization of low-carbon to zero-carbon energy depends on vigorously improving energy efficiency and reducing the total consumption of fossil energy; Second, we will vigorously develop renewable energy. The key to the transformation is the transformation of energy system, of which the transformation of power system is the key.

Impact on the power industry. The requirements of energy transformation are specific to the power industry, and its impact is mainly manifested in two aspects: low-carbon power generation, grid and electricity consumption; The second is the digitization of the entire power system, using digital technology to adapt to the challenges in the process of energy transition and better adapt to the changing needs of users.

Problems existing in the current power structure

Talking about the power structure from the perspective of low-carbon, it is natural to mention that the proportion of thermal power is too high. However, the author believes that this is only a phased feature of China's power industry, because the proportion of thermal power has indeed continued to decline in recent years, and the installed capacity and power generation of non-fossil energy have steadily increased. And the coal-based energy structure, it is impossible to quickly leapfrog to low-carbon electricity.

First of all, the poor flexibility of China's power system is the fundamental problem, which is far from meeting the requirements of energy transformation at this stage.

With the increase of the proportion of wind and electricity with the characteristics of volatility, the power system must be more flexible to cope with this volatility. Based on European experience, there are five common ways to increase the volatility of existing power systems:

The first is to improve the flexibility of other power plants in addition to wind and photovoltaic. Including the flexible transformation of coal-fired generating units, reduce the minimum power of the plant, increase the maximum load gradient increase, shorten the start-up time, etc. Cogeneration power plants can import heat energy into energy storage systems or central heating networks, which can expand the regulation range of their output.

The second is to strengthen the interconnection of regional power grids, give play to the role of adjacent power grids as "indirect energy storage systems", optimize resource utilization, and reduce the overall cost of the system.

The third is to improve the flexibility of the power demand side, mainly by integrating technical means such as energy storage, heat pumps, electric vehicles, and smart meters to improve the adjustability of the load.