The Role of Batteries in Grid-Scale Energy Storage – EQ Mag

As the world shifts towards greener energy production, there is a growing need for grid-level energy storage systems to balance power generation and consumption. One solution to this challenge is using batteries in grid-scale energy storage systems. In this article, we will explore the role of batteries in grid-scale energy storage and their potential applications for improving grid management.

Importance of Grid-Scale Energy Storage

Grid-scale energy storage has the potential to revolutionize the electric grid by making it more adaptable and capable of accommodating intermittent and variable renewable energy sources. In addition, it provides significant system services such as short-term balancing, grid stability ancillary services, establishing a sustainable low-carbon electric pattern, long-term energy storage, and restoring grid operations following a blackout.

Researchers have explored various energy storage systems, such as hydroelectric power, flywheels, capacitors, and electric batteries, to facilitate the operation of the power grid.

Electric batteries have emerged as the most viable option because of their rapid response time, flexibility, and short construction cycles. However, when integrating them into grid-level energy storage systems, the capacity, lifetime, energy efficiency, power, and energy densities must be considered.

Types of Batteries Used in Grid-Scale Energy Storage

Lithium-ion batteries are preferred for their high energy efficiency, density, and long cycle life. They are currently the primary battery technology for stabilizing the grid in the United States, with 77% of electrical power storage systems relying on them.

Flow batteries offer a promising alternative to Li-ion batteries for grid-scale energy storage due to their scalability, ability to increase duration without compromising power density, and use of a wider range of materials. They also have a longer lifespan (100,000 cycles over a 20-year lifespan) and pose fewer risks of explosion or fire.

New options based on organic metal-free materials, vanadium, zinc, and other alternatives are emerging, making flow batteries an exciting area of research for grid-scale energy storage.

The Role and Potential Applications of Batteries in Grid-Scale Energy Storage

Grid Monitoring and Control

Renewable energy sources like wind and solar are intermittent, and old rotating generators can’t entirely compensate for the fluctuation in their output. Therefore, batteries are used to balance the power more quickly without involving heavy mechanical parts that wear out quickly.

Batteries are also good at providing a quick response and scalability, making them suitable for managing power. Li-ion batteries are particularly useful in managing peak loads for up to four hours and can replace gas-fired power plants. Also, batteries can provide flexibility to the transmission grid, maintaining stable system operation even during contingency events.

Power Backup System

Batteries are essential for maintaining power backup systems and ensuring grid stability. They possess flexibility and can be adjusted in terms of location and scale as needed. Batteries can also absorb energy and function as a fast-acting load, which helps manage the balance between power supply and demand. In addition, their deployment increases the operational capacity of existing transmission lines without additional towers or lines.

Peak Shaving

Battery systems in electric grids are designed to provide energy during high peak demands and recharge during off-peak electricity hours. Lithium-ion batteries are a promising option for such applications due to their high energy density and round-trip efficiency.

These batteries help maintain frequency and voltage stability in islanded applications and large-scale deployment, especially when there is a disparity between power generation and consumption.

Operating Reserves and Ancillary Services

Maintaining a stable power system requires generation to match the demand for electricity at all times, which requires various operating reserves and ancillary services operating on different timescales.

Batteries are well-suited for short-term reliability services, such as primary frequency response and regulation, due to their rapid charging and discharging capabilities, which are faster than traditional thermal plants. Additionally, appropriately sized battery systems can provide longer-duration services, such as ramping and load-following, to ensure a stable electricity supply meets demand.

Recent Development

Giving Electric Vehicle Batteries a Second Life: 1300 Recycled EV Batteries Power Grid-Scale Storage System

Electric vehicle (EV) batteries that no longer meet standards for EV use can still retain up to 80% of their total usable capacity.

B2U has built a 25 MWh stationary storage system using 1,300 recycled EV batteries from Honda and Nissan and tested Tesla Model 3 batteries for grid-scale energy storage. In addition, the company’s patented EV pack storage system significantly reduces the storage cost and automatically disconnects batteries if they deviate from operating specifications.

The system charges from a connected solar farm and provides grid services to California’s wholesale grid market 24/7. In addition, the technology increases grid storage capacity and allows end-of-life EV batteries to be taken to recycling facilities.

A study suggests that end-of-vehicle-life EV batteries plus in-use vehicle-to-grid could supply the world’s short-term grid energy storage requirements by 2030 and up to 32-62 terawatt-hours of short-term storage globally by 2050.

MIT Modeling Framework Accelerates Development of Flow Batteries for Grid-Scale Energy Storage

Flow batteries are a more efficient and safer alternative to Li-ion batteries in grid-scale energy storage systems. However, current flow battery technology predominantly relies on vanadium as its active material, and scientists are exploring alternative chemistries due to concerns over its reliability and availability.

MIT researchers have developed a techno-economic modeling framework that estimates the “levelized cost of storage” for different chemistries and provides general guidelines for choosing between finite-lifetime and infinite-lifetime materials. While there is no clear winner among the different chemistries, the framework allows for the estimation of capital and operating costs over the system’s lifetime, helping to make informed decisions on which option to pursue.

The modeling framework provides a valuable tool for assessing the economic viability of new and emerging energy technologies for flow batteries. This will be crucial for grid-scale energy storage, requiring long-duration, large-scale electricity storage to support renewable energy sources.

Challenges and Future Outlooks

Electric batteries hold promise as a significant element in attaining grid-scale energy sustainability. However, several challenges must be addressed to ensure their successful integration into grid-level energy storage systems. These challenges include decreasing costs further, building an effective battery recycling scheme, exploring novel battery technologies, and establishing comprehensive assessment standards.

Looking ahead, ongoing research and development on Li-ion and other battery technologies can lead to further improvements in energy density, cost reduction, and the development of safe battery systems. This presents a vast range of possibilities for the application of batteries in various fields, indicating a promising future for their role in grid-scale energy storage.

Source: azom