Metals That Go Into Battery Energy Storage Systems (BESS)

Battery energy storage systems (BESS) store energy from different sources in a rechargeable battery. The total number of batteries depends on several factors: the number of cells per module, the modules per rack, and the racks connected in series. For instance, a BESS can consist of 5,032 modules containing over 100,000 lithium-ion batteries.

When paired with renewable energy sources, BESS systems play a crucial role in stabilizing the energy grid by leveling out the peaks in demand and supply. They also provide a reliable backup power source for industrial loads, reducing the grid’s strain created by electric transportation demand.

This article explores BESS systems, how they work, their benefits, and how the systems are built.

What is the battery energy storage system?

A battery energy storage system, usually known by its acronym BESS, is a simple technology that stores electrical energy in batteries at a household, industrial, or municipal level. This device enhances grid stability, improves energy efficiency, and enables the integration of renewable energy sources.

A BESS is not precisely like the batteries you use to power your flashlight or home generator, although a storage system could be attached to a home solar array. Generally, these tools are designed as units where computerized systems can send energy to prevent the grid from being overwhelmed.

For example, the City of San Juan Capistrano has proposed building a commercial BESS on 13 acres of undeveloped property currently owned by a nearby church. If approved, the facility would house lithium-iron phosphate batteries and other equipment that would interconnect with the San Diego Gas & Electric’s nearby 138-kilovolt transmission line. The existing power grid would send electric energy to the BESS for storage, which would return the energy to the grid during times of high demand.

The UK has already successfully implemented this concept. Engineers at the country’s national grid built a BESS to store energy created by an offshore wind farm. The project is expected to save UK taxpayers a significant amount of money and contribute to net zero carbon production and energy independence.

What are the different types of battery energy storage systems?

The different BESS types include lithium-ion, lead-acid, nickel-cadmium, and flow batteries, each varying in energy density, cycle life, and suitability for specific applications.

• Lithium-ion Batteries: The most widely used type of BESS, lithium-ion batteries are known for their high energy density, long cycle life, and efficiency. They are commonly used in grid storage, electric vehicles, and consumer electronics. Their advantages include high efficiency (90-95%), fast response times, and declining costs due to widespread use and technological advancements. Sometimes, however, they risk overheating, and some observers have raised environmental concerns related to mining and disposal.
• Lead-acid Batteries: Lead-acid batteries are among the oldest rechargeable batteries. Their low cost, proven reliability, and ease of recycling make them best suited for backup power, off-grid energy systems, and emergency power supplies. However, lead-acid batteries often have lower energy density, shorter cycle life, and longer charging times than other battery types.
• Sodium-sulfur Batteries: Sodium-sulfur batteries are high-temperature batteries that operate by reacting molten sulfur with molten sodium. They are often used for grid-scale energy storage, particularly in stabilizing power grids with sizeable renewable energy inputs. Their advantages include high energy density, long cycle life, and good performance at high temperatures. However, sodium-sulfur batteries require high operating temperatures (~300°C), which can complicate maintenance and safety and result in high costs.
• Flow Batteries: Ideal for large-scale energy storage applications, such as grid support and renewable energy integration, flow batteries use liquid electrolytes stored in external tanks, which flow through the cell stack to generate electricity. The most common types are vanadium redox flow batteries (VRFB) and zinc-bromine flow batteries. Since their capacity can be increased by adding more electrolytes, flow batteries are scalable but complex and require high upfront costs.

How do battery energy storage systems work?

Battery energy storage systems convert electrical energy into chemical energy during charging, storing it, and then converting it back to electrical energy when needed. When controlled by intelligent software, the BESS knows when to deliver additional power and how much is required.

Why are battery energy storage systems increasingly important?

Battery energy storage systems are increasingly important because they enable the efficient use of renewable energy, enhance grid reliability, and support the transition to a more sustainable and resilient energy infrastructure.

BESS systems help offset the effects of climate change by reducing peaks and dips in energy supply and demand and by harnessing green energy for long-term use. This can reduce carbon outputs and deliver low-cost solutions for consumers. BESS systems also help reduce the use of fossil fuels by predicting supply and demand for natural gas plants.

What are the benefits of BESS?

BESS offers many economic, environmental, health, and safety benefits. Commercial users can better manage energy demand and reduce impacts on their grids, while residential users can run their homes on solar energy. They can also access backup power during outages, increasing energy security. Other benefits of BESS include:

• Scalability: Easily scalable to meet varying energy storage needs, from small to large applications.
• Reduced Carbon Emissions: Decreases reliance on fossil fuels by optimizing renewable energy use.
• Black Start: Restores power to part of the grid or an entire power system after a complete or partial shutdown (a blackout) without relying on the external power transmission network. BESS provides the necessary power to kick-start the grid.
• Deferred Infrastructure Investment: Reduces the need for costly transmission and distribution infrastructure upgrades.

What are the disadvantages of BESS?

• High Initial Cost: Expensive to install, with significant upfront investment required.
• Limited Lifespan: Batteries degrade over time, requiring eventual replacement.
• Safety Concerns: Risk of overheating, fire, or chemical leakage, particularly with specific battery chemistries.
• Resource Intensity. Manufacturing batteries requires rare and environmentally sensitive materials like lithium and cobalt. The extraction and processing of these materials can have a significant environmental impact.
• Recycling Challenges: It is difficult and costly to recycle used batteries, leading to potential environmental harm.
• Temperature Sensitivity: Battery performance can be significantly affected by extreme temperatures.

Applications of battery energy storage systems by industry.

With its flexibility and adaptability, BESS can be used in various applications across different industries. These systems work in virtually any geographic area and can be easily optimized for specific situations, making them a versatile energy storage solution.

Commercial Applications

Peak shaving is a strategy that involves reducing electricity use during periods of high demand (peak hours) to lower energy costs and reduce strain on the power grid. This is often achieved using energy storage systems, such as batteries, to supply power during peak times, thus avoiding higher peak electricity rates.

BESS contributes to peak shaving by storing energy during low-demand periods and releasing it during peak demand, thereby reducing the need for additional grid power and lowering energy costs.

Continuous energy supply ensures a steady and uninterrupted flow of electricity to meet constant demand, preventing disruptions in power delivery. It relies on a mix of generation sources, energy storage, and grid management to maintain balance and reliability, even during fluctuating conditions or equipment failures, safeguarding critical infrastructure and operations.

BESS stores energy during periods of low demand and discharges it during interruptions or high demand, ensuring a stable and reliable power flow.

Renewable integration involves incorporating renewable energy sources like solar and wind into the power grid. This process requires balancing variable and intermittent energy production with demand, often using technologies like BESS and advanced grid management to ensure stability, reliability, and efficient use of renewable resources.

BESS houses excess energy generated from renewable sources like solar and wind and releases it when production is low or demand is high. This stabilizes the grid and enables greater reliance on clean energy.

Residential Applications

Self-consumption optimization involves maximizing the use of locally generated energy from solar panels within a home or business. This has the dual benefit of reducing reliance on the grid while also lowering energy costs. BESS plays a crucial role in storing surplus energy to use later during low-production periods.

Reducing electricity costs by storing energy during off-peak periods and using it during peak periods when electricity rates are higher.

BESS also allows partial or complete off-grid operation by combining storage with renewable energy sources like solar panels, a concept known as grid independence. Grid independence refers to the capability of a home, business, or facility to operate autonomously from the traditional power grid through on-site energy generation, such as solar panels and storage systems like BESS, which provide a reliable and self-sufficient energy supply.

Home Energy Management involves integrating with smart home systems to optimize energy usage and enhance efficiency. This includes using technology to monitor, control, and automate energy consumption in real time, leading to cost savings, reduced energy waste, and improved overall energy performance in residential settings.

Utility Applications

Energy storage systems enhance grid stability and efficiency through various functions.

By rapidly charging or discharging, these systems can respond to deviations in grid frequency, ensuring that the grid remains balanced. This quick response helps prevent potential outages and maintains the reliability of the power supply.

Grid voltage levels must be kept within specified ranges to ensure the proper functioning of electrical equipment. BESS assists in supplying or absorbing reactive power and stabilizing voltage levels. This support helps avoid voltage drops or surges that can cause equipment damage or operational disruptions.

Integrating renewable energy sources like wind and solar into the power grid presents challenges due to their intermittent nature. BESS smooths out these fluctuations by storing excess energy generated during periods of high production and supplying it when generation is low.

How are BESS systems manufactured?

BESS manufacturers assemble battery cells into modules, integrate them with power management systems, and house them in protective enclosures. Each component is optimized for energy efficiency, safety, and scalability.

What metals go into BESS systems?

BESS components typically include metals like lithium, cobalt, nickel, manganese, and sometimes iron and graphite, each chosen to enhance energy density, stability, and battery performance.

The most prominent metal in BESS is lithium, used in lithium-ion batteries and widely favored for its high energy density and efficiency. Lithium-ion batteries also incorporate cobalt and nickel, which help enhance the battery’s energy capacity and stability. Manganese and aluminum are often used in the cathodes of these batteries, contributing to improved durability and safety.

Lead is a crucial metal in lead-acid batteries, a traditional but widely used BESS technology, especially in applications where cost is critical. Vanadium is central to vanadium redox flow batteries, a type of BESS known for its ability to store large amounts of energy and long cycle life, making it ideal for grid-scale applications.

Copper is essential in the electrical components of all BESS technologies, and it is used in wiring and connectors due to its excellent electrical conductivity. Finally, iron is emerging in newer battery technologies, such as iron-flow batteries, which are being developed for cost-effective and sustainable energy storage solutions.

Protective enclosures for BESS are typically made from a combination of metals chosen for their durability, fire resistance, corrosion resistance, and overall structural integrity. The key metals used include:

Galvanized steel sheet is often used for its cost-effectiveness and corrosion resistance due to the zinc coating. Stainless steel is preferred for environments where higher corrosion resistance is required, as it contains chromium, which forms a protective layer. Aluminum is lightweight and naturally resistant to corrosion. It’s commonly used in BESS enclosures where weight reduction is a priority. Finally, carbon flat roll steel is used in parts of the enclosure where high strength is needed, but it is usually coated or painted to prevent rust.

Kloeckner Metals supplies galvanized, aluminum, and stainless sheet—plus the whole range of product lines—for battery energy storage systems (BESS). These metals are often combined or treated with additional coatings to enhance specific properties like fire resistance or thermal management, which are crucial for the safe operation of BESS.

Each metal contributes to BESS systems’ overall functionality and efficiency, making them integral to modern energy storage.

How much does a BESS system cost?

The cost of a battery energy storage system varies widely based on its size, technology, and application. Diverse factors affect costs, including geopolitics, raw material prices, and consumer demand. In February 2024, average prices dropped from $184/kWh to $148/kWh, following a similar decline in 2023. With solar generation predicted to outpace wind energy by December 2025, the need for energy storage has never been stronger or its future brighter.