Thermal energy storage system – FAQs&prospect analysis

1. What is thermal energy storage system?
2. Technical characteristics of thermal energy storage system
3. Development status of thermal energy storage system
   1. Grid side
   2. User side
   3. Power supply side
4. Development trend of thermal energy storage system
5. Summary

Energy storage refers to the process of storing energy through a medium and releasing it when needed. And there are some outstanding manufacturers which have rich experience in producing energy storage battery. Here is an article of top 10 energy storage battery manufacturers in China.

According to different storage media, energy storage can be divided into electric energy storage, thermal energy storage, and hydrogen energy storage. Among many energy storage technologies, thermal energy storage system is one of the most promising large-scale energy storage technologies.

What is thermal energy storage system?

Thermal energy storage technology uses heat storage materials as the medium to store solar thermal energy, geothermal heat, industrial waste heat, low-grade waste heat, etc., or convert electrical energy into thermal energy, and release it when needed to solve the problems caused by time, space or intensity. The problems caused by the mismatch between the thermal energy supply and demand, and maximize the energy utilization rate of the entire system.

Compared with other energy storage technology routes such as traditional electrochemical energy storage and industrial electrical energy storage, thermal energy storage system has obvious advantages in energy storage density, installed capacity, service life, and cost technology.

Compared with the two mechanical energy storage technologies, compressed air energy storage and pumped hydro energy storage, thermal energy storage technology has the advantages of small footprint, low cost, no area impact, high energy storage density, small environmental impact, and wide environmental conditions. and many other advantages.

As a large-capacity and large-scale energy storage method with high energy density, high conversion efficiency, and minimized application cost, thermal energy storage technology will play an important role in the construction of a clean, low-carbon, safe and efficient energy system and the construction of new energy-based energy storage systems. It plays a vital role in the new power system and ensuring the safe and stable operation of the power system.

Technical characteristics of thermal energy storage system

At present, the more mature technical routes of energy storage thermal management are air cooling and liquid cooling, among which air cooling is the mainstream in the current energy storage system, and the penetration rate of liquid cooling solutions is expected to continue to rise in the future. Thermal management has become the core of the battery energy storage system, and air cooling and liquid cooling are currently mature technology routes.

The cooling methods of energy storage thermal management mainly include the following three technical routes: air cooling (air cooling), liquid cooling and phase change cooling, in addition to heat pipe cooling.

• Large energy storage capacity, flexible configuration, and no special environmental requirements;
• It has the advantages of large-scale construction and operating costs, and has obvious scale effects;
• According to the needs of users, it can realize the combined supply of cold, heat, electricity and steam with various energy grades;
• It can realize peak shaving and valley filling, two-way adjustment, and absorb intermittent new energy (wind power, photovoltaic, etc.) installed output for the regional power grid, which is the best solution to balance the peak and valley difference of the power grid;
• The number of cycles is large and the service life is long, and the bidirectional regulation function of the energy storage power station will not lead to a decrease in efficiency with a long heat storage cycle;
• There is no chemical reaction in the storage process, the technical parameters and process are controllable, and the system safety is high.

Development status of thermal energy storage system

Thermal energy storage technology can be applied to the power supply side, the grid side, and the user side.

Grid side

At this stage, the power system presents a “double high” feature with a high proportion of renewable energy and a high proportion of power electronic equipment. The frequency regulation and voltage regulation capabilities are insufficient, and the moment of inertia of the system continues to decline, posing severe challenges to the power grid energy output.

Thermal storage can generate electricity. Through the rotation of the steam turbine generator set, the frequency modulation output power can be effectively realized, and the purpose of stable power supply can be achieved.

User side

Thermal energy storage technology can be applied to user’s cold, heat, electricity integrated energy services, seawater desalination and other occasions; in the direct utilization of thermal energy, thermal energy storage technology has higher energy utilization efficiency than electricity storage technology.

Thermal storage technology also includes the storage and utilization of thermal energy below ambient temperature, that is, cold storage technology has been maturely applied in cold chain related fields, and the market scale is also expanding.

Power supply side

In the production output of thermal power plants, thermal energy storage system, power generation technology changes the excess steam heat energy that occurs during unit load operation into heat storage, stores it through the medium, and releases the heat energy when needed, which can increase the peak depth of the power supply unit.

It can also increase the peak load capacity of the generator set, greatly reduce investment and operating costs, and reduce carbon emissions from fossil energy heat generation.

Development trend of thermal energy storage system

Advanced countries in the world have carried out various researches and investments in thermal energy storage system and its power generation technology. High-temperature thermal energy storage and power generation technologies have been widely commercialized in Europe, America, Africa, and the Middle East. By the end of 2021, the installed capacity of CSP stations in the world is about 6.6GW.

In recent years, the scale of thermal energy storage in China has grown rapidly. In 2018, the installed capacity of thermal energy storage projects in China was 1.07GW. In 2019, the cumulative installed capacity of thermal energy storage projects in China was 32.4GW. In 2020, a 100MW heat-conducting oil trough-type CSP station will be built in Wulatezhong Banner, Inner Mongolia, equipped with a 10-hour molten salt heat storage system.

The cumulative on-grid electricity of the project is 205 million KW·h, accounting for 30.48% of the total CSP power generation in China at the same time. In 2021, 3 experimental power stations and 9 commercial power stations have been built and connected to the grid for thermal energy storage power generation, with a total installed capacity of 521MW.

Summary

The thermal energy storage system has high efficiency in comprehensive energy utilization of cold, heat and electricity, and has outstanding advantages in heat storage capacity, large-scale construction and operating costs, operating life, safety, power generation, etc., especially for absorbing intermittent new energy.

In this way, another tool to check the situation of energy storage is energy storage BMS, and here is an article of top 10 energy storage BMS manufacturers in China to help you know more about it.

The installed output of energy (wind power, photovoltaic, etc.) plays an important role in building a new power system with new energy as the main body and ensuring the safe and stable operation of the power system. It is the backbone of large-scale energy storage in the future and has broad development prospects. play an important role in the energy revolution.

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