Convergent development to leverage energy transformation
To achieve the goal of carbon peak and carbon neutrality, large-scale, high-proportion development of zero-carbon energy is an inevitable trend.
The zero-carbon energy represented by water and scenery, especially new energy such as scenery, has many advantages such as clean and zero-carbon, but there are also shortcomings such as intermittent and volatility. Under the background of building a new power system with new energy as the main body, unstable new energy has become the main power source, and peak shaving has become a worldwide problem. Some power experts even believe that once intermittent power sources such as wind and wind become the main force, if there is no good peak shaving method, there may be major risks in the power grid.
How to solve this worldwide problem? Qian Zhimin, Secretary of the Party Leadership Group and Chairman of the State Power Investment Corporation, said that the answer given by the State Power Investment Corporation is two words-"fusion", that is, based on the idea of fusion, the source, network, load and storage interact collaboratively and complement each other through multiple types of energy. Integrated smart energy to achieve the balance and stability of the power system.
Currently, State Power Investment Corporation has launched 420 integrated smart energy projects with a total investment of more than 131 billion yuan. The reporter recently conducted investigations and interviews on the company's trials and demonstration projects in Beijing, Anhui, Shandong, Qinghai and other provinces.
Multi-energy integration——
The water-light complementary project enables photovoltaic power sources that are originally intermittent, fluctuating and random to achieve smooth grid connection
The Longyangxia Hydropower Station in Qinghai Hainan Tibetan Autonomous Prefecture is the first large-scale cascade power station planned for the Longqing section of the upper reaches of the Yellow River. 1700 West Lake in Hangzhou.
Beginning in 2013, SPIC has built 850,000 kilowatts of photovoltaic power plants in Gonghe County, which is 36 kilometers away from Longyang Gorge. This has contributed to the world's largest hydro-light complementary power generation project.
The State Power Investment Corporation has taken great pains to build the photovoltaic power station next to the hydropower station.
The "soft underbelly" of photovoltaic power generation is that it cannot generate electricity at night, while the "short legs" of hydropower are due to changes in wet and dry periods. How to make these two zero-carbon energy sources complement each other and realize "1+1>2"?
SPIC’s solution is "complementation of water and light"-when the sun is strong, photovoltaic power is used more, and hydropower is disabled or less generated; when the weather is bad or the night affects the photovoltaic power, it is adjusted in time through the control system , So that hydropower can do more. In this way, the “bundling” of hydropower and photovoltaic power generation can be used to achieve smooth grid connection of photovoltaic power sources that are originally intermittent, fluctuating and random, thereby reducing the impact on the grid.
On July 23, the reporter saw at the Longyangxia Hydropower Station that the electricity sent by the “bundling” of hydropower and photovoltaic power generation the previous day was 34.55 million kilowatt-hours. Huang Qinggang, Secretary of the Party Committee and General Manager of the Longyangxia Power Generation Branch of SPIC Yellow River Company, told reporters: “The adjustment of hydraulic turbine units is very convenient. It only takes a few seconds to respond to changes in photovoltaic power generation. , The unstable power of the "sawtooth" photovoltaic power supply is adjusted to a balanced, high-quality, safe, smooth and stable power supply, which can reduce the backup capacity required by the power system to absorb photovoltaic power generation."
In the complementation of water and light, hydropower can indeed make up for the gap in photovoltaic power generation at night. However, if photovoltaic power is used during the day, will it squeeze out the benefits of hydropower?
Huang Qinggang said that from the perspective of the operation in recent years, the annual utilization hours of the transmission lines of hydropower stations have increased from 4,621 hours to 5,019 hours. That is to say, after the water is "bundled", the "cake" has become bigger. . Even if there is a drop in hydropower output, if the overall benefit is considered, it is still a good deal. For example, the Longyangxia Reservoir currently ranks only fourth in importance of power generation, and the top three are flood control, snow prevention and water supply. Less power generation means more water storage, which is especially important for the water-scarce northwestern region.
Not only complementary water and light, new beautiful blueprints are spreading-the "14th Five-Year Plan" outline proposes to "build a batch of complementary clean energy bases", the upper reaches of the Yellow River and Jiziwan are also included in large-scale clean energy bases.
"There is also a Laxiwa Hydropower Station not far from here!" Pointing to the downstream direction, Huang Qinggang couldn't hide his excitement: "We rely on the clean energy base on the upper reaches of the Yellow River to explore the construction of a new power system, and prepare to use the altitude difference to build the Longyangxia Clean The energy control hub project uses hydropower to drive the development of new energy. Pumps are used to pump up water when power is low and discharge water for power generation at peak times. Relying on Qinghai’s rich wind and solar resources, we are confident to build a water, wind, and solar energy storage and multi-energy complementary regulation center."
Technology integration——
"Distributed energy + information technology + energy storage technology" allows new energy to be absorbed locally
If multi-energy integration is expected to alleviate the pressure of new energy peak shaving, then the integration of distributed energy, information technology, and energy storage technology can help new energy to be absorbed locally, and even partially resolve the distribution of new energy resources and load centers in my country The problem of imbalance.
A comprehensive smart energy experiment is kicking off in Xiaogang Village, Fengyang County, Anhui Province, which is well-known throughout the country.
"The roof is installed with photovoltaic panels for free, and the annual electricity bill can be reduced by more than 200 yuan. We are very welcome." One of the leaders of the "big contract", Yan Jinchang, who is more than 70 years old this year, is eager to give it a try.
Not far from Yan Jinchang’s home, ground-source heat pumps provide centralized heating and cooling for visitor centers, retirement centers and other areas. Photovoltaic carports, photovoltaic seats, smart street lights and other facilities have become a new landscape in Xiaogang Village. "In the future, after the entire project is completed, Xiaogang Village can achieve full replacement of clean energy and electricity." said Gao Yang, general manager of SPIC Anhui Xiaogang Village Integrated Smart Energy Co., Ltd.
For a long time, my country’s new energy resources and demand have been in reverse distribution-on the one hand, the northwestern region is rich in "scenery" resources and weak in self-consumption capacity, on the other hand, the east and central regions have limited resource endowments, electricity demand and pressure on emission reduction. huge. If the potential of distributed new energy can be tapped in the eastern and central regions, and the potential of distributed new energy can be tapped nearby and self-use, it can reduce the excessive dependence on long-distance power transmission and relieve the pressure of new energy transmission.
However, a large number of distributed energy sources will also bring challenges to the stability of the power system. For example, in the past, the power grid was like a giant ship. In the future, there will be more distributed power sources. It may be that countless small-tonnage cargo ships, small boats, and giant ships form a fleet. Coordination between them is particularly important. As a result, the need for the integration of new technologies such as energy and the Internet, big data and even the Internet of Things has also surfaced.
"10 o'clock, 4847 kilowatts; 12 o'clock, 14541 kilowatts; 18 o'clock, 43623 kilowatts..." On the "Tianshu No. 1" integrated smart energy management and service platform in Xiaogang Village, the reporter saw a fluctuating photovoltaic daily forecast curve , With a single click of the mouse, you can switch to the forecast curves of electricity load, cooling and heating load, etc.
"Based on historical data and meteorological information, this'smart brain' can predict users' energy needs, optimize the configuration among multiple energy sources, and cut peaks and fill valleys. For example, if photovoltaic output is small, biomass can make up for it. This is equivalent to "bundling" distributed power sources with a wide range of points and random changes into a relatively stable and controllable piece of power, thereby enhancing the stability of new energy sources." Gao Yang said.
Although distributed energy has a bright future, it still depends on breakthroughs in energy storage technology to truly realize self-use, or even off-grid operation. At present, the most mainstream technology routes in the global energy storage technology are pumped storage and electrochemical energy storage, and the use of surplus "wind and solar" electricity to produce hydrogen, and even the use of peak-to-valley electric difference to store heat and cold, are equally promising.
In the Baozhigu International Conference Center in Changping District, Beijing, a large tank with a height of more than 10 meters stands on the west side of the park. This is a "cold and hot dual storage tank" independently developed by the State Power Investment Corporation. A few meters away, there is a "container" nearly 4 meters long and 2.5 meters wide. This is another form of energy storage-the Chaowei sodium salt battery energy storage system, which can store up to 330,000 kWh per year. The peak-to-valley price difference can save more than 350,000 yuan in electricity costs each year. Zhang Yue, general manager of CLP Smart Integrated Energy Service Co., Ltd., said that last year they removed 3 gas boilers and changed them to use the valley electricity period at night for heating or cooling, and during the day peak electricity price period to release heat or cool, and then cooperate with it. Air source heat pumps, sewage source heat pumps and other equipment "can reduce the burning of natural gas by 800,000 cubic meters per year, which can save about 2.8 million yuan per year."
Cross-border integration——
Participate in urban heating and desalination, and the positioning of traditional power stations has quietly changed
With the emergence of new energy, the status of traditional power generation companies such as thermal power plants will inevitably decline. In recent years, thermal power and nuclear power plants in some provinces have been operating at reduced power levels. Whether capital-intensive thermal power and nuclear power companies can successfully adapt to new trends is not only a matter of their own development, but also whether my country can successfully build a new power system with new energy as the mainstay.
Haiyang City, a small coastal city in the southeast of Shandong Peninsula, is surrounded by the sea on three sides at the top of the headland. Two snow-white "big round pots" are very eye-catching. This is the nuclear island of Haiyang Nuclear Power's first phase 1 and 2 units. Here, the reactor heats the water, produces a large amount of high-temperature steam, and drives a steam turbine to generate electricity. At present, the two most advanced third-generation nuclear power plants in the world have accumulated more than 57 billion kilowatt-hours of power generation.
Wu Fang, chairman of SPIC Shandong Nuclear Power Co., Ltd., talks about it, in addition to the advanced nuclear power unit, there are two white pipelines extending from the conventional nuclear power island.
"These two pipelines are not used to transmit electricity, but to supply heat to the city." Liu Xianling, an engineer at the Haiyang Nuclear Power Design and Management Office, explained that one end of the pipeline is connected to the first heating station in the nuclear power plant, and the other end is connected to the off-site thermal power company. In a nuclear power plant, the high-temperature steam drawn from the nuclear power plant heats the water in the pipeline to 120 degrees Celsius. Subsequently, the hot water is transported to the heat exchange main station of the thermal power company, and then returns to the power plant after releasing the heat. This cycle repeats to achieve a steady flow of heat output.
Why does one of the world's most advanced nuclear power plants make a living for urban heating? "At present, the annual power generation hours of nuclear power plants are not bad, but in the future, nuclear power plants like ours will also have pressure to make way for new energy power generation. Therefore, we must be prepared for danger and cannot just do the article on power generation." Wu Fang said, the second one they thought of. Articles are the "heat" most closely related to electricity.
Any power plant has a large amount of waste heat. Utilizing the waste heat will increase efficiency. "The actual thermal efficiency of nuclear power plants is 10 percentage points lower than that of the most advanced thermal power units, only 36.7%. Taking part of the heat of nuclear power directly for heating can improve the thermal efficiency of nuclear power and have higher overall benefits. Moreover, reducing waste heat emissions is also beneficial. Marine ecological protection can be said to serve multiple purposes in one fell swoop." Wu Fang said.
For Haiyang City, nuclear power heating can also bring carbon reduction dividends.
“Before heating by boilers, the coal-burning boiler room was dark.” Standing in front of the 5-story tall boiler that had been out of service, Pan Shiwei, manager of Fengyuan Thermal’s Lingang Branch, counted the inconveniences of coal-fired heating: “ One is not environmentally friendly, two is not economical, and three is not worry-free. The failure rate of coal-fired boilers is high, and workers must be asked to reload coal in three shifts 24 hours a day. In winter, just temporary recruitment requires 20 people."
Now, next to the boiler room, a clean white plate heat exchanger has solved various problems. According to estimates, after Haiyang realizes nuclear power heating in the city, each heating season can save 100,000 tons of raw coal, reduce 180,000 tons of carbon dioxide, 691 tons of soot, and 1,188 tons of sulfur dioxide, which is equivalent to planting 1,000 hectares of broad-leaved forest. "This winter, Haiyang will become the country's first zero-carbon heating city." Wu Fang said.
"The same production of water and heat" is the third article of Wu Fang and their "cross-border" article.
"Desalination of seawater consumes a lot of heat or electricity. We have jointly developed a'hydrothermal co-production' device with Tsinghua University, which uses the high-temperature steam of nuclear power plants to try seawater desalination." said Zhang Zhen, an engineer at the Haiyang Nuclear Power Design and Management Office. After testing, fresh water It is of high quality and can be consumed directly, and all the energy used for production comes from heating steam without additional energy consumption. It achieves zero-carbon heating and zero-energy water production. “Some areas of Shandong Peninsula are relatively short of water and will be large-scale in the future. The application prospects are broad."
Promote integration-
Seek a win-win situation, so that "the rich spend less, and those who don't have no money"
During the interview, Qian Zhimin told reporters a story that impressed him: A few years ago, the company wanted to install photovoltaic power generation equipment for herdsmen in the Sanjiangyuan area of Qinghai so that they could use electricity to cook and heat. But the herders are not very motivated: “You don’t need a penny for picking up cow dung and cooking, and it costs money to install photovoltaics.”
Qian Zhimin keenly felt that to promote integrated development, it is necessary to find a win-win path for multiple parties, so that "the rich spend less and those who have no money don't spend money", so that the problems that were originally wanted to be solved but cannot be solved can be found. The new solution, in this way, the integration of the "big drama" can be sung and sung well.
"What's the biggest headache in Xiaogang Village?" Before the Xiaogang Village project started, the first question raised by SPIC Anhui Company was whether to build photovoltaic roofs and smart street lights. This made the deputy secretary of the Xiaogang Village Party Committee, Zhou Qunzhi, director of the village committee, immediately became interested: "The burning of straw is the most troublesome thing for us. Can you help solve it?"
It turns out that in Xiaogang Village, there are nearly 30,000 tons of straw to be processed every year, because of environmental protection requirements, it cannot be burned at once. Therefore, it is either deep ploughing and burying, but the cost per mu requires 30 to 50 yuan; or it is delivered to a power plant 15 kilometers away, and transportation is inconvenient. "We once introduced a reward policy for villagers who don't burn straw, but some villagers said,'Don't give me money, just get the straw away for me.'" Zhou Qunzhi said.
In response to this pain point, the State Power Investment Corporation has planned a 20,000-ton straw comprehensive utilization production line in the comprehensive smart energy project to make full use of local biomass waste such as straw, garbage, and manure to generate electricity, and realize the transformation of waste into treasure.
The exploration of comprehensive smart energy projects has also brought more possibilities for the industrial development of Xiaogang Village. When the reporter came to the agricultural and light complementary project on the west side of Reform Avenue in Xiaogang Village, he saw a small house "producing" plants. Without soil, without chemical fertilizers, the green lettuce is growing vigorously in layers of white cultivation plates...
"We intend to use photovoltaic power to develop hydroponic vegetable production, which will not only grow faster than outdoors, but also greatly reduce the occupation of land." Gao Yang said that in the next step they will also plan to plant black beans or Jerusalem artichoke under photovoltaic panels to help Xiao Gangcun develops industries and increases income. It is understood that projects such as agricultural and solar complementation, rooftop photovoltaic, and comprehensive utilization of straw are expected to increase the income of the collectives and villagers of Xiaogang Village by about 5.3 million yuan each year.
A group of sheep graze leisurely in the Qinghai Tala Beach Ecological Photovoltaic Park, which is more than 2,000 kilometers away from Xiaogang Village. Xiang Zhankui, a 41-year-old herder from Mahantai Village, rides a motorcycle every day to raise "photovoltaic sheep" and earns 3,000 yuan a month.
"Photovoltaic panels can reduce wind speed and water evaporation, which is very suitable for the growth of grass. Therefore, the Gobi Desert in the past has now grown green grass. However, too long grass will affect power generation and have fire hazards. Then we simply raised sheep. I came to'weeding', but an industry was created in the end," said Wu Shipeng, the person in charge of the photovoltaic park. Now, more than 5,000 sheep have been bred on this land of more than 600 square kilometers, which has brought tangible income to more than a dozen herders including Xiang Zhankui.
In the future, how to comprehensively promote integrated development? Qian Zhimin believes that the key is to find technical paths and business models from the exploration of comprehensive smart energy demonstration projects such as Xiaogang Village and Baozhigu.
"Especially the business model. In the past, power companies didn't pay much attention to it. Everyone thinks that it is just to build a power plant, invest tens of billions of yuan, tens of billions of yuan, and it will be enough to generate electricity after it is built, and what business model is needed. But integrated development must take into account. A variety of interests will be explored for business models that benefit all participants and are motivated.” Qian Zhimin said that SPIC will actively cooperate with the supply side, the user side, and the agricultural , Transportation, construction and metallurgy, etc. to carry out cross-border "big integration" development, and strive to continue to lead.
"Integrating" a new chapter in energy applications (reporter's notes)
To achieve carbon peak and carbon neutrality is of great significance and the task is arduous. The State Power Investment Corporation, one of the leading companies in my country's power generation industry, takes the initiative, actively explores, and strives to establish a model for my country's future energy application scenarios with multi-dimensional and in-depth integrated development ideas.
Integration must be high and far-sighted. Only by adhering to a high starting point, high standards, high positioning, long-term, systematic planning, and overall design, can we better break the old pattern and create a new situation. For a long time, my country’s power system has clearly divided sources, grids, and loads. The hydro-photovoltaic complementary photovoltaic power station built by the State Power Investment Corporation has "bundled" hydropower and photovoltaic power generation, successfully achieving stable grid connection and comprehensive benefits. It is the benefits of integration.
To merge, we must break the old and create the new. There is no ready-made experience to build a new type of power system integration. How to integrate and who to integrate needs to be explored step by step. From the integrated smart energy network of Xiaogang Village to the “photovoltaic sheep” of the photovoltaic industrial park on the deserted Gobi, to the first zero-carbon coastal new city for energy transmission by nuclear power plants... The “clean energy +” integration practice of the State Power Investment Corporation has explored New ideas have also led to the development of new technologies and new industries, giving people a broad prospect.
Fusion, relying on everyone to collect firewood. Achieving carbon peak and carbon neutrality faces many challenges. It is impossible to succeed by fighting individually and alone. It requires more parties to leverage each other and work together to play a good game of chess together. From the central to the local, from government departments to related enterprises, all parties concerned will take action to finally establish a new power system with new energy as the main body, which not only meets the energy demand of the whole society, but also protects the blue water and blue sky of the motherland.