What is BESS (Battery Energy Storage System)? Battery energy storage systems are key in the renewable energy era
A battery energy storage system (BESS) is a system that stores electricity and supplies it when needed, and is an essential technology for expanding the use of renewable energy. In this article, I will explain the definition, components, structure, advantages, types, market trends, implementation examples, technological innovation, environmental impact, and future prospects and issues of BESS.
1. What is BESS?
- Definitions and basic concepts
A battery energy storage system (BESS) is a large-scale electric storage facility connected to a power system. Specifically, it refers to a system that stores surplus electricity and supplies electricity as needed. As the introduction of renewable energy expands, the role of adjusting the balance between electricity supply and demand is becoming increasingly important. BESS is attracting attention as a key technology that not only supports a stable supply of electricity, but also contributes to the optimization of electricity charges.
- BESS components
BESS mainly consists of the following elements:
Storage battery (battery): A device that stores electricity as chemical energy and converts it into electrical energy as needed. There are various types, such as lithium-ion batteries, flow batteries, etc.
Power conditioner (PCS): A device that converts AC power and DC power. When the battery is charged or discharged, it is converted to an appropriate voltage/frequency between the power system and the power system.
Battery management system (BMS): A system that monitors and controls battery charge status, temperature, voltage, etc. It is essential for extending battery life and ensuring safe operation.
Control system: It is a system that controls the operation of the entire BESS. Battery charging/discharging is optimized according to power supply and demand conditions.
2. How does BESS work
- Energy storage and supply processes
BESS stores electricity supplied from the power system as chemical energy in batteries. This process is called “charging.” Charged electricity is supplied to the power system as electric energy when demand for electricity increases or when the amount of renewable energy generated is low. This process is called “discharge.”
- Charge/discharge cycle mechanism
When charging, PCS converts AC power into DC power and supplies it to the battery. Inside a battery, electricity is stored through chemical reactions. During discharge, the reverse process occurs, and the chemical energy inside the battery is converted into electrical energy, then converted back into AC power by PCS and supplied to the power system. This repetition of charging and discharging is the basic operating principle of BESS.
3. Types of BESS
- lithium ion battery
Lithium-ion batteries have high energy density and excellent charge/discharge efficiency, making them the mainstream of BESS. It is widely used in various applications such as smartphones and electric vehicles. In the case of Nidec, it was used in a system capable of supplying 10 MW of power equivalent to approximately 100 electric vehicles.
- Flow batteries
A flow battery is a type of battery that stores electricity by circulating an electrolyte solution. It has the characteristics of long life and excellent safety. It is suitable for large-scale power storage and is effective when power supply over a long period of time is required.
- Other battery technologies
In addition, various battery technologies are being researched and developed, such as lead-acid batteries, all-solid-state batteries, and sodium-sulfur batteries. It is thought that the application and scale of BESS will be optimized according to each characteristic.
4. Advantages of BESS
- Integration with renewable energies
BESS will promote the expansion of the introduction of renewable energy, such as solar power generation and wind power generation, which tend to fluctuate in output. It contributes to stabilizing the power system by storing surplus power when the amount of power generation exceeds demand and discharging when the amount of power generated is low.
- Stabilizing the power grid
BESS adjusts the balance between electricity supply and demand, and plays a role in suppressing frequency fluctuations and voltage fluctuations in power systems. This ensures a stable supply of electricity and reduces risks such as large-scale power outages.
- Cost reduction and efficiency
BESS can reduce electricity charges by storing electricity during times when electricity charges are low and discharging during times when electricity is high. Furthermore, by suppressing peaks in electricity demand, investment in power systems is suppressed, and efficient power management is realized.
5. BESS market trends and growth forecasts
- Market size and growth rate
The size of the BESS market is rapidly expanding as the introduction of renewable energy expands and the need to stabilize power systems increases. Going forward, the introduction of BESS will continue to progress globally, and it is predicted that the market size will expand further.
- Demand trends by region
Demand for BESS varies by region. Since the introduction of renewable energy is progressing in Europe and North America, the introduction of BESS is also active. In the Asian region, the introduction of BESS is progressing to stabilize power systems as demand for electricity increases. In particular, large-scale BESS projects are being planned in China and India.
6. BESS case study
- Examples of uses of residential BESS
Residential BESS is often used in combination with photovoltaic power generation systems. Electricity charges can be reduced by storing surplus electricity generated by solar power generation and using it at night or on cloudy days. It can also be used as an emergency power source during power outages.
- Examples of use in commercial facilities
Commercial facilities have introduced BESS to curb peak electricity demand. Electricity costs can be reduced by using stored electricity during times when electricity charges are high. It can also be used as an emergency power source in the event of a disaster.
- BESS's role in large-scale power plants
In large-scale power plants, BESS has been introduced to absorb fluctuations in renewable energy output. This will contribute to stabilizing power systems and promote the expansion of renewable energy adoption. In the UK, there is an active movement to install BESS on the site of a thermal power plant, and Akeisha Energy's “Olana BESS Project” is attracting attention as one of the largest examples in terms of capacity scale.
7. Technological innovation at BESS
- The latest technology and trends
BESS technology is constantly evolving. The development of batteries with higher efficiency and longer life, the advancement of BMS, and energy management systems utilizing AI are attracting attention. In particular, the development of all-solid-state batteries and next-generation lithium-ion batteries is expected to greatly contribute to improving the performance of BESS.
- Energy management through AI and data analysis
By utilizing AI and data analysis, BESS operations can be optimized. AI is being used in various aspects, such as predicting power demand, monitoring battery status, and optimizing charging/discharging schedules. This enables BESS to operate efficiently and reduce costs.
8. Environmental impact and sustainability
- Contributing to CO2 reduction
BESS will contribute to reducing CO2 emissions by promoting the expansion of the use of renewable energy. Since renewable energy does not emit CO2 during power generation, power generation that relies on fossil fuels can be reduced.
- Environmental protection and energy efficiency
BESS promotes efficient use of energy and reduces wasteful electricity consumption. Furthermore, the development of battery recycling technology is also underway, contributing to reducing environmental impact.
9. Future prospects and challenges
- Policy and regulatory impacts
The introduction of BESS is greatly influenced by the policies and regulations of each country. Renewable energy introduction targets and measures to support the introduction of power storage systems are important in promoting the spread of BESS.
- Technical challenges and solutions
There are also technical issues with implementing BESS. Future issues include reducing battery costs, extending life span, and ensuring safety. Technology development and research are continuing to solve these issues.
