The China Meteorological Administration said that due to the uncertainty of the climate system exacerbated by global warming, China’s extreme high temperature and extreme heavy precipitation events are becoming more frequent and stronger.
Since the Industrial Revolution, greenhouse gases produced by human activities have driven abnormal global high temperatures, rising sea levels, and extreme weather such as rainstorms, floods, and droughts have occurred in different regions with higher density and frequency.
The World Health Organization pointed out that rising global temperatures and excessive burning of fossil fuels have become one of the biggest threats to human health. Not only the threat of heat stroke, heat stroke, and cardiovascular disease, climate change may cause more than 50% of known human pathogens to worsen.
Climate change is a major challenge facing mankind in the contemporary era. As a major greenhouse gas emitter, China announced the “carbon peak and carbon neutrality” goal in 2020, made a solemn commitment to the international community, demonstrated the responsibility and commitment of a major country, and also reflected the urgent need for the country to promote the transformation and upgrading of the economic structure and promote the harmonious coexistence of man and nature.
Turbulence challenges of the power system
The energy field is a highly watched battlefield for the implementation of “dual carbon”.
For every 1 degree Celsius increase in the global average temperature, coal contributes more than 0.3 degrees Celsius. To further promote the energy revolution, it is necessary to control fossil energy consumption and accelerate the construction of a new energy system. In 2022-2023, China issued more than 120 “dual carbon” policies, especially emphasizing the key support for the development and utilization of renewable energy.
Under the strong promotion of policies, China has become the world’s largest country in the use of new energy and renewable energy. According to data from the National Energy Administration, in the first half of 2024, the country’s new installed capacity of renewable energy power generation was 134 million kilowatts, accounting for 88% of the new installed capacity; renewable energy power generation was 1.56 trillion kilowatt-hours, accounting for about 35% of the total power generation.
More wind power and photovoltaic power are incorporated into the power grid, bringing cleaner green electricity to people’s production and life, but also challenging the traditional operation mode of the power grid.
The traditional power grid power supply mode is instant and planned. When you turn on the power, it means that someone has calculated your needs in advance and is generating electricity for you at the same time somewhere. The power generation curve of the power plant and the power transmission curve of the transmission channel are planned in advance according to historical data. Even if the demand for electricity suddenly increases, the demand can be met in time by starting the backup thermal power units, so as to achieve safe and stable operation of the power grid system.
However, with the introduction of a large number of wind power and photovoltaic power, when and how much electricity can be generated are all determined by the weather, which is difficult to plan. When the weather conditions are good, the new energy units run at full capacity and generate a large amount of green electricity, but if the demand does not increase, this electricity cannot be connected to the Internet; when the demand for electricity is strong, it happens to be rainy and cloudy, the wind turbines do not turn, the photovoltaic panels do not heat up, and the power outage problem occurs.
Previously, the abandonment of wind and light in Gansu, Xinjiang and other new energy provinces was related to the seasonal shortage of electricity in the region and the inability of the power grid to absorb it in time. The uncontrollability of clean energy brings challenges to the dispatching of the power grid and increases the operating risks of the power system. Today, when people are highly dependent on stable power supply for production and life, any mismatch between power generation and power consumption will have serious economic and social impacts.
There is a certain difference between the installed capacity of new energy and the actual power generation, and the power demand of users and the power generated by power plants cannot achieve “source follows load” and “dynamic balance”. The “fresh” electricity must be used in time or stored, which is a necessary condition for the stable operation of a well-organized power grid. To achieve this goal, in addition to building an accurate clean energy prediction model through accurate analysis of weather and historical power generation data, it is also necessary to increase the flexibility of power system dispatching through tools such as energy storage systems and virtual power plants. The country emphasizes “accelerating the planning and construction of a new energy system”, and energy storage is an indispensable technology.
“Green Bank” in the New Energy System
Under the energy revolution, the important role of pumped storage power stations has become increasingly prominent. This technology, which was born in the late 19th century, was originally built to regulate seasonal water resources in rivers to generate electricity. It has developed rapidly and gradually matured against the background of accelerated industrialization and nuclear power plant construction.
Its principle is very simple. Two reservoirs are built on the mountain and at the foot of the mountain. When the night or weekend comes, the demand for electricity decreases, and the cheap and surplus electricity is used to pump water to the upstream reservoir; when the electricity consumption is at its peak, the water is released to generate electricity, so that the electricity can be readjusted and distributed in time and space.
As a century-old energy storage technology, pumped storage has been given a new task in the process of “dual carbon”. When the power generation capacity of photovoltaic and wind power is strong and the user’s electricity demand is reduced, pumped storage can store excess electricity. When the demand for electricity increases, the electricity is released to help the power grid achieve supply and demand balance.
It is flexible and reliable, with fast start and stop. It takes less than 4 minutes from start to full load power generation. If a large-scale accident occurs in the power grid, pumped storage can start quickly and restore power supply to the power grid. It is regarded as the last “match” to light up the dark power grid.
As one of the most mature and widely used energy storage technologies, pumped storage is currently the world’s largest “battery”, accounting for more than 86% of the world’s energy storage installed capacity. Compared with new energy storage such as electrochemical energy storage and hydrogen energy storage, pumped storage has the advantages of stable technology, low cost and large capacity.
A pumped storage power station has a design service life of 40 years. It can work for 5 to 7 hours a day and discharge continuously. It uses water as “fuel”, has low operation and maintenance costs, and is not affected by price fluctuations of raw materials such as lithium, sodium and vanadium. Its economic benefits and service capabilities are crucial to reducing the cost of green electricity and reducing carbon emissions of the power grid.
In July 2024, my country’s first provincial implementation plan for pumped storage to participate in the power market was officially issued in Guangdong. Pumped storage power stations will trade all electricity in spot in a new way of “quoting quantity and quotation”, and “pump water to store electricity” and “release water to obtain electricity” efficiently and flexibly in the power market, playing a new role of storing and accessing new energy “green electricity bank”, and opening up a new path to obtain market-oriented benefits.
“We will scientifically formulate quotation strategies, actively participate in electricity trading, improve the comprehensive efficiency of units, and strive to obtain incentive benefits from electricity and electricity charges while promoting the increase in the proportion of new energy consumption.” Wang Bei, deputy general manager of the Energy Storage Planning and Finance Department of the Southern Power Grid, said.
Mature technology, huge capacity, flexible storage and access, long-lasting output, low cost throughout the life cycle, and increasingly improved market-oriented mechanisms have made pumped storage the most economical and practical “all-rounder” in the process of energy revolution, playing a key role in promoting the effective use of renewable energy and ensuring the safety and stability of the power system.
Controversial large projects
Against the background of national energy structure adjustment and rapid development of new energy, pumped storage power stations have ushered in a construction boom. In the first half of 2024, the cumulative installed capacity of pumped storage in China reached 54.39 million kilowatts, and the investment growth rate increased by 30.4 percentage points over the same period last year. In the next ten years, my country’s investment space for pumped storage will be close to one trillion yuan.
In August 2024, the CPC Central Committee and the State Council issued the “Opinions on Accelerating the Comprehensive Green Transformation of Economic and Social Development”. By 2030, the installed capacity of pumped storage power stations will exceed 120 million kilowatts.
While opportunities come, they also cause the problem of overheated investment. The construction of pumped storage power stations is a rigorous and complex system engineering, involving multiple links such as regulations, preparatory work and approval. In the investment boom, some local governments and owners often ignore the scientific nature of site selection and capacity saturation, and excessively pursue the speed and scale of project development, bringing a series of negative effects.
The site selection of pumped storage power stations needs to consider geological conditions, geographical location (close to the load center, close to the energy base), ecological red line, head drop, land acquisition and immigration and other factors. Unreasonable planning and layout will cause the construction of power stations to be out of the actual needs of the power grid or unusable. Not only will the construction cost and operating cost be difficult to digest for a while, but there will even be problems such as encroachment on the ecological red line during construction; after completion, if the technical and operation and maintenance levels are not up to standard, it will cause safety risks.
“There are still some cases where the site selection of some projects is unreasonable.” Lei Xingchun, deputy general manager of the infrastructure department of the Southern Grid Energy Storage Company, said, “The essence of a pumped-storage power station is to serve the needs of the power grid and ensure the access of new energy to the grid. The site selection and capacity of the pumped-storage power station must be determined based on the characteristics of power distribution, power grid operation characteristics, power load distribution, and power structure.”
“The project is large in scale and requires a lot of initial investment. It is even more necessary to strengthen communication and coordination with natural resources, ecological environment, forestry, grassland, water conservancy and other departments, and to do a good job in connecting with the ecological protection red line and related plans.” Jiang Shuwen, head of the planning department of the Southern Grid Energy Storage Company, added.
The construction investment of tens of billions or even tens of billions, the construction area of hundreds of hectares of reservoirs, and the construction period of 5 to 7 years are also the reasons why many people criticize pumped storage for not being “economical and environmentally friendly” compared to other energy storage.
But in fact, compared with the limited discharge times and 10-year operating life of chemical energy storage, the actual service life of pumped-storage power stations can reach 50 years or even longer. With large-capacity energy storage, unlimited pumping frequency, and lower cost per kilowatt-hour, its economic efficiency is still much higher than other energy storage.
Zheng Jing, a senior engineer at the China Institute of Water Resources and Hydropower Planning and Design, has done a study: “Analysis of the economic efficiency of the project shows that the levelized cost per kilowatt-hour of pumped-storage power stations is 0.207 yuan/kWh. The levelized cost per kilowatt-hour of electrochemical energy storage is 0.563 yuan/kWh, which is 2.7 times that of pumped-storage power stations.”
“Electrochemical energy storage has grown rapidly in scale in recent years, but there are various hidden dangers. It is necessary to continuously extend the life cycle, reduce the unit cost, and increase the scale of the power station and configure the phase adjustment function from the perspective of ensuring safety, so that it can be comparable with pumped-storage power stations.” Zheng Jing pointed out.
Build a power station, beautify the land
According to the data from the Southern Power Grid Energy Storage, in the first half of 2024, the cumulative power generation of pumped-storage power stations in the southern region was nearly 6 billion kWh, equivalent to the electricity demand of 5.5 million residential users for half a year, an increase of 1.3% year-on-year; the number of unit power generation startups exceeded 20,000 times, an increase of 20.9% year-on-year. On average, each unit of each power station generates peak power more than 3 times a day, making an important contribution to the stable access of clean energy to the power grid.
On the basis of helping the power grid to improve its peak-shaving energy storage capacity and provide clean electricity for social and economic development, the Southern Power Grid Energy Storage is committed to the construction of beautiful power stations and providing “green, open and shared” ecological and environmental products for local people.
Every spring, the mountains are full of cherry blossoms. Cyclists and hikers go to Shenzhen Yantian District to check in. Reflecting the lake and mountains, strolling in the sea of cherry blossoms, as if they were in a paradise. This is the upper reservoir of Shenzhen Pumped Storage Power Station, the first pumped-storage power station built in the city center in the country, and the “mountain and sea park” in the mouth of tourists.
Shenzhen Pumped Storage Power Station incorporated green ecological concepts at the beginning of its planning. Environmental protection and water conservation facilities and equipment were designed, constructed and put into operation simultaneously with the project. The project has won awards such as “National Quality Project” and “National Soil and Water Conservation Demonstration Project”. After the power station was put into operation, China Southern Power Grid Energy Storage upgraded the “de-industrialization” landscape of the upper reservoir area with the standard of ecological park, and cooperated with the Yantian District Government to plant cherry blossoms around the upper reservoir, creating the “mountain, sea and flower city” Yantian business card.
The emphasis on ecological protection is not a special case of Shenzhen Pumped Storage Power Station. China Southern Power Grid Energy Storage has formulated strict green construction management systems and evaluation standards throughout the entire project construction process; each project combines the surrounding natural environment, cultural characteristics and relevant plans of the local government, and sets special expenses for ecological environment restoration and improvement in the environmental protection budget to ensure the harmonious integration of the project’s industrial landscape and the surrounding ecological environment.
“Pumped-storage power stations have relatively high requirements for site selection. On the basis of avoiding ecological red lines, if there are rare protected plants or ancient trees in the construction area, it is necessary to communicate with the forestry department in advance and take protective measures under the guidance of the forestry department to carry out on-site protection or migration protection.” Jiang Shuwen said.
At each pumped-storage power station of Southern Power Grid Energy Storage, you can see a huge electronic display screen, which publishes real-time data such as negative ion content, air quality, ultraviolet rays, temperature, humidity, etc. in the environment. “This is what we asked to monitor ourselves, so that stakeholders can clearly see the environmental quality of the power station.” Jiang Shuwen said, “After the construction of Yangjiang and Meizhou pumped-storage power stations, egrets, known as ‘environmental monitoring birds’, came to roost in groups, which is the most intuitive recognition of the ecological environment quality such as air and reservoir water quality in the power station area.”
Since the construction of the first large-scale pumped-storage power station in China in Guangzhou in 1993, Southern Power Grid Energy Storage has accumulated mature experience in how to implement green projects throughout the life cycle. In 2023, the company launched the “Green Construction Management Methods and Evaluation Indicators for Pumped Storage Power Stations”, which clarified the responsibilities and evaluation standards of green construction of all participating units in the project during the construction process. It has practical goals and implementation methods, which is of great significance for guiding the industry to implement ecological protection.
Pumped storage power stations have been built from scratch, and many technologies and management have no precedents to follow. It relies on industry leaders such as Southern Power Grid Energy Storage to drive the upstream and downstream industrial chains to continuously innovate, explore, and verify, and promote industrial upgrading step by step. Ecological protection is also an indispensable part of the sustainable development of the pumped storage industry. It not only represents the company’s responsibility, but also highlights the “green” value and gold content of this green energy storage project.
The carbon neutrality clock is ringing, and the development of renewable energy continues to achieve new breakthroughs. The role of pumped storage power stations as “regulators”, “power banks” and “stabilizers” in the load balance of the power grid is becoming increasingly prominent.
Post time: Feb-05-2025
