Nuclear and renewable energy, not "rivals" but "teammates"



01

- Smart energy system with nuclear energy and renewable energy -

With the decrease of the proportion of coal power installed and the increase of the proportion of renewable energy generation, nuclear power will play an important role in the long-term safe and stable operation of the power grid. Nuclear energy relies on its stable and reliable operation, long refuelling cycle and other characteristics, as a clean baseload energy can solve the problem of large-scale power supply security and stability, nuclear energy and wind, light and other renewable energy synergistic and complementary development of the situation needs to be formed.

Therefore, starting from the actual situation of China's energy endowment and adapting to the needs of energy transformation, the collaborative intelligent system of nuclear energy and renewable energy takes into account the strategy, necessity, feasibility and economy, and can effectively reduce the abandonment of wind and light, achieve efficient allocation of resources, optimize China's energy structure, break through the constraints of fossil energy, and achieve emission reduction targets under the premise of ensuring energy security. It is an important way for China to achieve the development of clean and low-carbon energy and energy transformation under China's "30·60 goal", which has great value for China to achieve ecological civilization construction and lead global climate governance, and is an important choice to ensure the coordinated development of energy supply, economic development and ecological environment.

Nuclear energy and renewable energy collaborative intelligent system is a smart energy system with power system as the core, smart grid as the basis, nuclear energy and renewable energy as the main body, with an appropriate amount of hydropower and thermal power, to achieve cold, hot, gas, water, electricity and other energy complementary, improve energy efficiency.

The nuclear and renewable energy collaborative intelligent system architecture consists of four main parts: development of the infrastructure system, including nuclear and renewable energy infrastructure; Technical support system, including distributed energy technology, smart grid technology, big data technology, Internet of Things technology and multi-energy complementary technology; Consumption systems, including energy trading, energy services, decision support and optimization control; Standard system, including demand response, energy coordination, energy storage, energy prices, energy trading, network security and a series of standards.

By deeply integrating modern information technology, intelligent control and optimization technology with modern energy supply, storage and transportation, and consumption technology, the system provides a more scientific forecasting, decision-making and interactive platform for energy optimization management and multi-function collaboration, and creates a new way for consumers to obtain energy, store energy and even sell energy. We will promote the increase in the proportion of nuclear energy and renewable energy and the adjustment and optimization of the energy structure, promote the transformation of users' energy use concepts and the improvement of terminal energy efficiency, and achieve energy security, clean, economical and sustainable development under the constraints of energy conservation and emission reduction targets.

In this system, the comprehensive utilization of nuclear energy can provide a variety of secondary energy. For example, in the case that the scenery can not provide effective power supply, nuclear energy exerts the baseload energy characteristics to provide power supply guarantee; In the case that wind provides an effective power supply, nuclear energy through comprehensive utilization, the energy is converted into hydrogen, fresh water, molten salt heat storage and other ways of storage and transportation, improve the overall economy and utilization rate of the system.

Nuclear energy and renewable energy collaborative intelligent system adopts advanced nuclear energy and renewable energy supply and energy conversion technology, energy transmission technology, energy consumption technology, intelligent processing technology, comprehensive system optimization technology, to achieve independent, safe, clean, diversified and efficient energy supply and consumption. The main features of the system include safety, cleanliness, diversity and economy.

Safety: The total amount of energy in the collaborative intelligent system of nuclear energy and renewable energy is stable and abundant, and the sustainability is strong, and the energy supply in the system is low in external dependence.

Clean: The energy supply in the collaborative intelligent system of nuclear energy and renewable energy is low-carbon energy and environmentally friendly.

Diversity: The continuity of energy supply in the collaborative intelligent system of nuclear energy and renewable energy is strong. As the base load, nuclear energy supplements each other through cold, hot, gas, water, electricity and other energy sources, and is applied flexibly to ensure a variety of energy supplies.

Economy: As a mature support power supply, nuclear energy has achieved technical independence, and its cost is controllable and will gradually decrease with the expansion of application scale. Wind, light and other renewable energy sources have also become economically competitive energy varieties. At the same time, the power transmission loss and energy loss in the collaborative intelligent system of nuclear energy and renewable energy are low.

In order to realize the intelligent collaboration between nuclear energy and renewable energy, the flexible operation capability of nuclear power is the basic guarantee. At present, China's three generations of nuclear power generally have a certain flexible operation capability, and the high energy density and adjustability of nuclear power can escort renewable energy online to meet the needs of safe and stable power grid operation.

02

- Nuclear and renewable energy collaborative application scenarios -

1. Energy base delivery scenario

By the end of the third quarter of 2020, the total installed capacity of new energy power generation in Qinghai exceeded 57.1%. Due to the inherent randomness, volatility and intermittency characteristics of renewable energy such as wind and light, its large-scale grid connection has an impact on the power grid, coupled with the shortage of peak load capacity of the power grid, resulting in grid absorption difficulties, so the new energy base must consider stable base load power supply when it is connected to the grid. In addition, the long-term oversupply of Qinghai province's power market, in order to solve the problem of large-scale new energy consumption, we must rely on the delivery channel. Therefore, the development model of "clean energy base + delivery channel + matched peak power supply" has become the only way to develop new energy bases.

Qinghai Province plans to build UHV DC channels for its second large-scale new energy base, but due to the inability to solve the problem of power support points, the planning is slow to land. In order to make full use of the best light resources and large areas of desertification land in the country, and promote the construction of comprehensive pilot projects for the nearby consumption of renewable energy in the Qaidam circular economy Pilot Zone, it can be considered to choose a suitable location to build nuclear power units, provide stable support power points for the new energy base, and promote the construction of new energy bases and delivery channels. This application scenario can be extended to regions with abundant renewable energy resources and unbalanced energy supply and demand such as Inner Mongolia and Xinjiang.

2. Comprehensive energy utilization scenario

Shandong Province is an important region of China's coastal economic belt, and the clean, efficient and safe energy system is the solid foundation for its rapid and stable development. By the end of 2020, the installed capacity of new energy and renewable energy in the province has reached 48 million kilowatts, accounting for 30% of the total installed capacity of electricity. At the same time, the planning and construction of nuclear power has been steadily advanced, and the cumulative power generation has exceeded 48.5 billion KWH, and the installed power capacity of nuclear power under construction in the province has reached 5.7 million kW. Shandong Province's geographical conditions and energy endowment have the natural conditions for the development of renewable energy and nuclear energy smart synergy.

While generating electricity, the Haiyang nuclear power Plant that has been built not only meets the clean heating needs of nearly 700,000 square meters of residents around it through nuclear heating, but also participates in the regulation of offshore wind power to make up for the intermittent shortcomings of offshore wind power to a certain extent.

Schematic diagram of the comprehensive utilization system of nuclear energy

For the scenarios in coastal areas, the comprehensive utilization system of nuclear energy can also be promoted, and through the innovation of the thermal system of nuclear power plants, various functions such as power generation, hydrogen production, seawater desalination, heating, cooling, steam supply and energy storage can be integrated and coordinated. The energy released after nuclear fission is initially shown in the form of heat energy, and the direct comprehensive utilization of nuclear heat energy can effectively improve the economy of the energy system. In addition, nuclear energy hydrogen production has no greenhouse gas emissions, high efficiency and many other advantages, nuclear energy desalination can ensure the lack of coastal areas of water safety, nuclear energy heating and cooling can provide clean economic residential heating and industrial heat, cold, to meet the regional economic development and people's needs of various forms of energy use.

3. Isolated network operation scenario

For remote areas such as isolated islands at sea far from the mainland, due to special geographical factors, the power loss from the main grid is large and the cost is high, which requires the construction of off-grid energy supply system according to local conditions.

As a stable, controllable and high energy density energy form, nuclear energy is the best choice of baseload energy in this scenario mode. By combining any one or several types of small nuclear energy systems with solar energy, wind energy, ocean energy, etc., combined with comprehensive utilization technology of nuclear energy, a more secure, economical and efficient energy supply can be obtained.

In this mode, on the one hand, the supply side of the scene uses nuclear energy and renewable energy to generate electricity together to achieve a stable supply of green power; on the other hand, zero-carbon replacement is carried out for terminal energy equipment, such as electrification of urban household energy terminals; transportation, logistics, ship terminals, municipal sanitation and other systems adopt hydrogen energy operation, and electrified replacement of cooling, heating and power terminals is fully realized. It can achieve a zero-carbon intelligent and efficient energy system for the isolated network operation scenario.