In recent years, pumped hydro storage has reduced its share in the energy storage market, but it still maintains its leading position. New types of energy storage, such as lithium-ion batteries, sodium-ion batteries, flow batteries, flywheel energy storage, molten salt thermal energy storage, and air energy storage, have gradually increased their share as their technology matures and investment costs decrease, becoming the focus of the industry.
This article will focus on the current application status of new energy storage in scenarios such as 5G base stations, data centers, subways, and photovoltaic power plants.
5G base station + energy storage
According to data released by the Ministry of Industry and Information Technology, as of the end of September 2022, the total number of 5G base stations in my country had exceeded 2 million, reaching 2.22 million, accounting for about one-fifth of the total number of mobile base stations.
Currently, my country's 5G network is already the world's largest, but its coverage breadth and depth are still somewhat insufficient. As the relevant layout is gradually improved, the number of 5G base stations will continue to increase.
Compared to 4G base stations, 5G base stations have much higher power requirements, with peak power being 3 to 4 times that of 4G base stations.
Therefore, the power supply response of 5G base stations needs to be more proactive in improving the operating efficiency of the power supply system and reducing resource waste.
In response to this requirement, lithium battery energy storage, especially lithium iron phosphate energy storage, will stand out due to its advantages such as high efficiency, flexibility, and mature technology, and become the optimal choice for backup power for 5G base stations.
It is reported that at the beginning of 2020, State Grid Jiashan County Power Supply Company cooperated with companies such as Jiashan Unicom to explore the "5G base station + energy storage" project. By replacing lithium iron phosphate batteries and building a monitoring platform for energy storage equipment, the company has upgraded the energy storage equipment of 5G base stations and improved its working efficiency. The project has already achieved initial results.
In the future, sodium-ion batteries may gain some traction in this field.
Data Center + Energy Storage
Since the launch of the "East Data West Computing" project, data center projects have sprung up all over the country.
The ultra-high energy consumption of data centers is becoming an increasingly pressing issue for the industry, especially given the accelerated implementation of the "dual carbon" policy. The market urgently needs a solution to address the problem of green development.
Data centers combined with energy storage can prevent data loss caused by occasional power outages and enhance the power supply reliability of data centers.
Currently, lead-acid battery energy storage is widely used in data centers as an "emergency power source".
In terms of long-term energy storage, lithium iron phosphate batteries benefit from mature technology, low cost, and high performance, making them the best choice for data center energy storage.
However, lithium iron phosphate batteries also have a problem: once they catch fire, they are difficult to extinguish, which is something that data center operators especially need to pay attention to.
There are many data center + energy storage projects on the market. The Century Internet Foshan Smart City Data Center operates on the model of "data center + energy storage system + photovoltaic", and it is currently in operation.
In the future, sodium-ion battery energy storage and miniaturized flywheel energy storage may see some penetration.
Subway + Energy Storage
Intercity rail transit systems such as subways and light rails consume a lot of electricity and dissipate a lot of energy due to the large number of stations, short intervals, frequent starting and braking during operation.
Flywheel energy storage is a type of physical energy storage. Its working principle is as follows: in a vacuum environment, an electric motor drives a flywheel to rotate at high speed, storing kinetic energy. When needed, the flywheel drives a generator to generate electricity, converting the kinetic energy into electrical energy.
The flywheel energy storage device can be installed in the traction substation inside the subway station to absorb the energy released by the subway's braking upon entering the station, reduce energy dissipation, and enable the flywheel speed to reach 20,000 revolutions per minute.
Then, when the subway accelerates out of the station or encounters an emergency, the flywheel converts kinetic energy into electrical energy, releasing energy for the train to use, thus achieving energy-saving effects.
Currently, the combination of subway and flywheel energy storage has been put into practical use in Qingdao.
On April 11, 2022, two 1MW flywheel energy storage devices were commissioned and officially connected to the grid at Wannianquan Road Station on Qingdao Metro Line 3.
After the flywheel energy storage device was applied, the stability of the subway traction power supply system was significantly improved, and the power quality of the power supply system was also significantly improved.
Microgrid + Photovoltaic Power Plant + Energy Storage
Microgrid + photovoltaic power generation and storage is mainly suitable for areas not covered by the main power grid, such as the Sansha Islands in the South China Sea and remote mountainous areas in the southwest. Depending on the location, pumped storage, lithium iron phosphate energy storage, molten salt thermal energy storage and other technical routes can be selected.
Taking remote mountainous areas in Southwest China as an example, one mountain after another blocks the way, and some villages and towns are surrounded by mountains, making it difficult to connect cables.
By establishing smart microgrids in villages and towns, and making full use of renewable energy sources such as solar and wind power, the use of diesel generators can be reduced to the minimum, thus promoting green development.
Currently, there are already practical cases of microgrids combined with wind, solar and energy storage.
The South China Sea Sansha Smart Microgrid Energy Management System, which was put into trial operation in 2017, is a typical example. The system integrates diesel generators, photovoltaic systems, energy storage systems, seawater desalination, and charging piles, and has achieved remarkable results, with 100% reliable power supply, 100% qualified voltage, and 100% clean energy consumption.
In 2020, the State Grid Ningde Power Supply Company invested 5.06 million yuan to build a photovoltaic energy storage microgrid consisting of two 10KV secondary power supply projects on Beiyu Island in Xiapu County. It can be used as a backup power source for the island or connected in parallel with the mainland main grid to supply power to the troops stationed on the island and villagers.
Future Outlook
In addition to microgrids, subways, data centers, 5G base stations, and other scenarios, energy storage is also being applied in photovoltaic-storage charging stations, zero-carbon smart parks, the petroleum industry, shared energy storage, and wind farms.
Currently, the most widely used energy storage technology is lithium iron phosphate energy storage. With the further improvement of new energy storage technologies such as sodium-ion batteries, hydrogen fuel cells, flow batteries, and air energy storage, as these technologies mature and costs decrease, different energy storage technologies will be used to achieve the most suitable match for different scenarios.
