What is battery energy storage system?

A battery energy storage system (BESS) is a device that can store electrical energy in the form of chemical energy and release it when needed. BESS can provide various benefits and services to the power system, such as enhancing renewable energy integration, improving power quality and reliability, reducing peak demand, and lowering greenhouse gas emissions. However, BESS also faces some challenges, such as high cost, safety issues, environmental impacts, and regulatory barriers. In this blog, we will introduce what BESS is, how it works, what types of batteries are used, what technologies are involved, and what applications and use cases are possible.

Introduction

• What is a battery energy storage system (BESS) and how does it work?
• What are the benefits and challenges of using BESS?
• What are the main applications and use cases of BESS?

!A battery energy storage system)

What is a battery energy storage system (BESS) and how does it work?

A battery energy storage system (BESS) is a device that can store electrical energy in the form of chemical energy and release it when needed. A BESS consists of three main components: a battery, a power converter, and a control system. The battery is the core component that converts electrical energy into chemical energy and vice versa. The power converter is the interface that connects the battery to the grid or the load. It can convert alternating current (AC) to direct current (DC) or vice versa, depending on the direction of the power flow. The control system is the brain that monitors and controls the operation of the BESS. It can communicate with the grid operator, the load, or other energy sources, and optimize the performance and efficiency of the BESS.

What are the benefits and challenges of using BESS?

BESS can provide various benefits and services to the power system, such as:

• Enhancing renewable energy integration: BESS can store excess renewable energy when the generation is high and the demand is low, and release it when the generation is low and the demand is high. This can reduce the curtailment of renewable energy, increase its utilization, and smooth its intermittency and variability.
• Improving power quality and reliability: BESS can provide fast and flexible response to voltage and frequency fluctuations, harmonics, and other power quality issues. BESS can also provide backup power and black start capability in case of grid outages or emergencies.
• Reducing peak demand: BESS can charge during off-peak hours when the electricity price is low, and discharge during peak hours when the electricity price is high. This can reduce the peak demand, lower the electricity bill, and defer the need for new generation and transmission capacity.
• Lowering greenhouse gas emissions: BESS can reduce the dependence on fossil fuel-based generation, especially during peak hours, and increase the share of renewable energy in the power mix. This can lower the greenhouse gas emissions and mitigate the climate change impact.

However, BESS also faces some challenges, such as:

• High cost: BESS is still relatively expensive compared to other energy sources, especially in terms of capital cost, operation and maintenance cost, and lifetime cost. The cost of BESS depends on many factors, such as the type of battery, the size of the system, the application, and the market conditions. The cost of BESS is expected to decline in the future as the technology matures and the scale increases, but it may still be a barrier for widespread adoption.
• Safety issues: BESS involves high voltage, high current, and high temperature, which pose potential risks of fire, explosion, leakage, and electrocution. BESS also contains hazardous materials, such as metals, acids, and electrolytes, which may cause environmental and health hazards if not properly handled and disposed of. BESS requires strict safety standards, regulations, and procedures to ensure safe operation and management.
• Environmental impacts: BESS may have negative environmental impacts, such as resource depletion, land use, water use, waste generation, and pollution. BESS requires a large amount of raw materials, such as lithium, cobalt, nickel, and copper, which are scarce and unevenly distributed in the world. BESS also consumes water and land for mining, manufacturing, installation, and operation. BESS generates waste and emissions during its life cycle, which may affect the air, water, and soil quality. BESS needs to consider the environmental impacts and adopt sustainable practices to minimize them.
• Regulatory barriers: BESS faces some regulatory barriers, such as unclear ownership, valuation, and compensation of the services provided by BESS, lack of standardized codes and standards for interconnection and operation of BESS, and uncertainty of the future market and policy environment for BESS. BESS needs to overcome these regulatory barriers and create a favorable and stable environment for its development and deployment.

What are the main applications and use cases of BESS?

BESS can be used for various applications and use cases, depending on the location, size, and purpose of the system. Some of the main applications and use cases are:

• Grid-scale BESS: Grid-scale BESS is a large-scale system that is connected to the transmission or distribution grid and provides services to the grid operator or the wholesale market. Grid-scale BESS can be used for frequency regulation, voltage support, spinning reserve, ramping support, congestion relief, and renewable energy integration.
• Distributed BESS: Distributed BESS is a small-scale system that is located at the customer’s premises and provides services to the customer or the retail market. Distributed BESS can be used for peak shaving, demand response, power quality improvement, backup power, and self-consumption of renewable energy.
• Microgrid BESS: Microgrid BESS is a system that is integrated with a microgrid, which is a local network of distributed energy resources that can operate independently or in parallel with the main grid. Microgrid BESS can be used for load leveling, islanding, and resilience.

Types of BESS

• What are the different types of batteries used in BESS?
• What are the advantages and disadvantages of each type of battery?
• How to choose the best type of battery for your needs?

!Types of BESS)

What are the different types of batteries used in BESS?

There are many types of batteries that can be used in BESS, but the most common ones are:

• Lead-acid batteries: Lead-acid batteries are the oldest and most widely used type of batteries. They are composed of lead plates and sulfuric acid electrolyte. They have low cost, high reliability, and long lifespan. However, they also have low energy density, low efficiency, and high environmental impact.
• Lithium-ion batteries: Lithium-ion batteries are the most popular and advanced type of batteries. They are composed of lithium metal or compound electrodes and organic electrolyte. They have high energy density, high efficiency, and low environmental impact. However, they also have high cost, safety issues, and limited lifespan.
• Flow batteries: Flow batteries are a type of rechargeable batteries that use liquid electrolytes stored in external tanks. They have low energy density, high efficiency, and long lifespan. However, they also have high cost, low power density, and complex system.
• Other types of batteries: There are also other types of batteries that can be used in BESS, such as sodium-sulfur batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and supercapacitors. They have different characteristics and performance, and may suit different applications and use cases.

What are the advantages and disadvantages of each type of battery?

Each type of battery has its own advantages and disadvantages, which can be summarized in the following table:

How to choose the best type of battery for your needs?

There is no one-size-fits-all answer to this question, as the best type of battery depends on many factors, such as:

• The application and use case of the BESS: Different applications and use cases may require different performance and characteristics of the battery, such as power, energy, discharge time, charge time, cycle life, and response time.
• The cost and benefit analysis of the BESS: The cost and benefit analysis of the BESS should consider not only the initial capital cost, but also the operation and maintenance cost, the lifetime cost, and the value of the services provided by the BESS.
• The availability and accessibility of the battery: The availability and accessibility of the battery may depend on the supply and demand of the raw materials, the manufacturing and transportation capacity, the market and policy environment, and the local conditions and resources.

Therefore, the best type of battery for your needs should be chosen based on a comprehensive and holistic evaluation of the above factors, and may vary from case to case. You can consult with experts, manufacturers, or service providers to help you make the best decision.

BESS Technology

• What are the key components and technologies of a BESS?
• How to optimize the performance and efficiency of a BESS?
• How to ensure the safety and reliability of a BESS?

!BESS Technology)

What are the key components and technologies of a BESS?

A BESS consists of three main components: a battery, a power converter, and a control system. Each component has its own technologies and functions, which can be described as follows:

• Battery: The battery is the core component that converts electrical energy into chemical energy and vice versa. The battery has two main subcomponents: the cell and the module. The cell is the basic unit of the battery that contains the electrodes, the electrolyte, and the separator. The cell determines the voltage, capacity, and chemistry of the battery. The module is a group of cells connected in series or parallel to form a larger unit. The module determines the power, energy, and configuration of the battery. The battery also has other subcomponents, such as the battery management system (BMS), the thermal management system (TMS), and the mechanical structure. The BMS is responsible for monitoring and controlling the state of charge, state of health, temperature, current, and voltage of the battery. The TMS is responsible for regulating the temperature of the battery and preventing overheating or overcooling. The mechanical structure is responsible for supporting and protecting the battery and ensuring its mechanical stability and integrity.
• Power converter: The power converter is the interface that connects the battery to the grid or the load. The power converter has two main subcomponents: the inverter and the transformer. The inverter is the device that converts DC to AC or AC to DC, depending on the direction of the power flow. The inverter determines the frequency, waveform, and quality of the output power. The transformer is the device that changes the voltage level of the power, either stepping it up or stepping it down. The transformer determines the voltage level and the impedance of the output power. The power converter also has other subcomponents, such as the filter, the switch, and the controller. The filter is responsible for smoothing and filtering the output power and reducing the harmonics and noise. The switch is responsible for switching the power on and off and controlling the power flow. The controller is responsible for regulating and synchronizing the output power and communicating with the grid or the load.
• Control system: The control system is the brain that monitors and controls the operation of the BESS. The control system has two main subcomponents: the local controller and the central controller. The local controller is the device that controls the individual components of the BESS, such as the battery, the power converter, and the protection devices. The local controller determines the operating mode, the set point, and the control strategy of the BESS. The central controller is the device that coordinates the multiple BESS units or other energy sources, such as the grid, the load, or the renewable energy. The central controller determines the optimal dispatch, the scheduling, and the aggregation of the BESS. The control system also has other subcomponents, such as the sensor, the meter, and the communication device. The sensor is responsible for measuring and collecting the data of the BESS, such as the voltage, current, power, energy, temperature, and status. The meter is responsible for recording and displaying the data of the BESS, such as the energy consumption, the energy generation, and the revenue. The communication device is responsible for transmitting and receiving the data and the commands of the BESS, such as the grid signal, the market signal, and the user interface.

BESS Application

• How to integrate BESS with renewable energy sources such as wind and solar?
• How to use BESS for peak shaving, microgrids, and backup power?
• How to use BESS for grid support and stability?

!BESS Application)

How to integrate BESS with renewable energy sources such as wind and solar?

BESS can be integrated with renewable energy sources (RES) such as wind and solar to increase their penetration and utilization in the power system. There are two main ways to integrate BESS with RES: co-location and hybridization.

• Co-location: Co-location means that the BESS and the RES are installed at the same location and connected to the same point of common coupling (PCC). Co-location can reduce the transmission and distribution losses, increase the local consumption of RES, and provide ancillary services to the grid. Co-location can be either behind-the-meter (BTM) or in-front-of-the-meter (IFOM). BTM means that the BESS and the RES are connected to the customer’s side of the meter and serve the customer’s load. IFOM means that the BESS and the RES are connected to the grid’s side of the meter and participate in the wholesale market.
• Hybridization: Hybridization means that the BESS and the RES are combined into a single system and operate as a single entity. Hybridization can optimize the operation and control of the BESS and the RES, and enhance their performance and efficiency. Hybridization can be either AC-coupled or DC-coupled. AC-coupled means that the BESS and the RES are connected to the same AC bus and use separate inverters. DC-coupled means that the BESS and the RES are connected to the same DC bus and use a single inverter.

How to use BESS for peak shaving, microgrids, and backup power?

BESS can be used for peak shaving, microgrids, and backup power to reduce the electricity cost, improve the reliability, and enhance the resilience of the power system. Some examples are:

• Peak shaving: Peak shaving means that the BESS charges during off-peak hours when the electricity price is low, and discharges during peak hours when the electricity price is high. Peak shaving can reduce the peak demand, lower the electricity bill, and defer the need for new generation and transmission capacity. Peak shaving can be done by both grid-scale and distributed BESS, depending on the market structure and the tariff scheme.
• Microgrids: Microgrids are local networks of distributed energy resources that can operate independently or in parallel with the main grid. Microgrids can provide reliable and clean power to remote or isolated areas, critical loads, or communities. BESS can be integrated with microgrids to provide load leveling, islanding, and resilience. Load leveling means that the BESS balances the supply and demand of the microgrid and reduces the fluctuations and variations of the power. Islanding means that the BESS enables the microgrid to disconnect from the main grid and operate autonomously in case of grid outages or emergencies. Resilience means that the BESS helps the microgrid to recover and restore its normal operation after a disturbance or a fault.
• Backup power: Backup power means that the BESS provides emergency power to the load in case of grid outages or failures. Backup power can improve the reliability and security of the power supply and prevent the loss of data, production, or life. Backup power can be provided by both grid-scale and distributed BESS, depending on the size and the duration of the load and the outage.

How to use BESS for grid support and stability?

BESS can be used for grid support and stability to provide various ancillary services to the grid operator or the market, such as frequency regulation, voltage support, spinning reserve, ramping support, congestion relief, and renewable energy integration. Some examples are:

• Frequency regulation: Frequency regulation means that the BESS adjusts its output power to maintain the grid frequency within a certain range. Frequency regulation can improve the power quality and the system stability, and compensate for the imbalance between the generation and the load. Frequency regulation can be provided by both grid-scale and distributed BESS, depending on the market mechanism and the participation scheme.
• Voltage support: Voltage support means that the BESS injects or absorbs reactive power to maintain the grid voltage within a certain range. Voltage support can improve the power quality and the system stability, and compensate for the voltage drop or rise caused by the line impedance or the load variation. Voltage support can be provided by both grid-scale and distributed BESS, depending on the grid configuration and the control strategy.
• Spinning reserve: Spinning reserve means that the BESS reserves a certain amount of output power to respond to a sudden increase or decrease of the load or the generation. Spinning reserve can improve the reliability and the security of the power supply, and prevent the system from collapsing or blacking out. Spinning reserve can be provided by grid-scale BESS, depending on the market requirement and the availability of the BESS.
• Ramping support: Ramping support means that the BESS increases or decreases its output power to follow the ramping up or down of the generation or the load. Ramping support can improve the efficiency and the flexibility of the power system, and smooth the intermittency and variability of the renewable energy. Ramping support can be provided by both grid-scale and distributed BESS, depending on the grid condition and the renewable penetration.
• Congestion relief: Congestion relief means that the BESS reduces the power flow on the congested lines or nodes of the grid. Congestion relief can improve the operation and the economics of the power system, and avoid the overloading or the curtailment of the generation or the load. Congestion relief can be provided by grid-scale BESS, depending on the grid topology and the congestion level.
• Renewable energy integration: Renewable energy integration means that the BESS stores excess renewable energy when the generation is high and the demand is low, and releases it when the generation is low and the demand is high. Renewable energy integration can reduce the curtailment of renewable energy, increase its utilization, and smooth its intermittency and variability. Renewable energy integration can be provided by both grid-scale and distributed BESS, depending on the location and the size of the renewable energy.

Conclusion

• What are the current trends and future prospects of BESS?
• What are the best practices and tips for using BESS?

What are the current trends and future prospects of BESS?

BESS is a rapidly growing and evolving field that has many opportunities and challenges in the power system. Some of the current trends and future prospects of BESS are:

• Increasing demand and deployment of BESS: The demand and deployment of BESS are expected to increase significantly in the coming years, driven by the growing penetration of renewable energy, the rising electricity prices, the improving cost and performance of batteries, and the supportive policies and incentives. According to a report by BloombergNEF, the global cumulative installed capacity of BESS is projected to reach 741 GWh by 2030, a 31-fold increase from 2019.
• Diversifying applications and use cases of BESS: The applications and use cases of BESS are expected to diversify and expand in the future, covering various sectors and services, such as transportation, industry, buildings, and agriculture. BESS can also enable new business models and value streams, such as virtual power plants, peer-to-peer trading, and transactive energy.
• Innovating technologies and solutions of BESS: The technologies and solutions of BESS are expected to innovate and advance in the future, enhancing the performance and efficiency of BESS, and reducing the cost and environmental impact of BESS. Some of the emerging technologies and solutions of BESS are solid-state batteries, second-life batteries, hydrogen storage, and blockchain.

What are the best practices and tips for using BESS?

BESS is a complex and dynamic system that requires careful planning, design, operation, and management. Some of the best practices and tips for using BESS are:

• Conduct a feasibility study and a cost-benefit analysis of BESS: Before installing or using a BESS, it is important to conduct a feasibility study and a cost-benefit analysis of BESS, to evaluate the technical, economic, and environmental aspects of BESS, and to compare the alternatives and options of BESS. This can help to determine the optimal size, type, location, and configuration of BESS, and to estimate the return on investment and the payback period of BESS.
• Choose the right type of battery and the right supplier of BESS: As discussed earlier, there are many types of batteries that can be used in BESS, each with its own advantages and disadvantages. It is important to choose the right type of battery that suits your needs and preferences, and to consider the factors such as the performance, the cost, the lifespan, the safety, and the environmental impact of the battery. It is also important to choose the right supplier of BESS, who can provide reliable, high-quality, and customized products and services, and who can offer warranty, maintenance, and support for BESS.
• Optimize the operation and control of BESS: The operation and control of BESS are crucial for maximizing the benefits and minimizing the risks of BESS. It is important to optimize the operation and control of BESS, by using smart algorithms, data analytics, and artificial intelligence, and by considering the factors such as the grid condition, the market signal, the user demand, and the battery state. It is also important to monitor and manage the BESS, by using sensors, meters, and communication devices, and by collecting and analyzing the data and the feedback of BESS.