Navigating the Battery Energy Storage Systems (BESS) world can be a bewildering experience. The whole is greater than the sum of its parts, but choosing the right parts is critical. Considering performance, compatibility, and costs while advancing toward sustainability goals can be a delicate balancing act.
At the center of this balancing act is battery chemistry. There’s a growing number of options and variants, and each battery type has advantages and disadvantages. Ultimately, your organization’s BESS application goals and usage requirements should determine the best solution.
There's no one-size-fits-all BESS. Every project has different variables, so it’s important to start by taking stock of your needs and goals. Here are a few key questions to consider before making a decision:
The battery may be the most important component of a BESS. The type you choose will impact upfront costs, capacity, geographical footprint, maintenance requirements, and battery lifespan.
Let's take a closer look at the current top five battery types used in battery energy storage systems and consider the pros and cons of each one.
An older technology, lead acid batteries are commonly used in the automotive industry. They’re low-cost, relatively easy to recycle, and work well in a wide range of temperature conditions.
However, they cannot store as much energy per unit volume compared to other battery types, such as lithium-ion — meaning you’ll need a larger system to achieve the same capacity. Lead acid batteries also tend to have a shorter lifespan than lithium batteries and, since they contain highly toxic lead, cause environmental concerns around their disposal. These downsides make lead acid a less popular choice for BESS than other types.
Advantages: Low upfront costs, recyclability, and well-established technology.
Disadvantages: Low energy density, shorter lifespan, and slow to charge.
Nickel-based batteries containing Nickel-Hydrogen (NiH2) have a lengthy lifespan — potentially 20 years or more, with up to 30,000 charging cycles.
While lead acid batteries degrade quickly when charged and recharged, nickel-based batteries maintain high performance over many cycles of use, including deep discharges. They also function well in both hot and cold temperatures and are more environmentally friendly than lead and cobalt-based batteries.
Advantages: Lengthy lifespan, functionality in hot and cold temperatures.
Disadvantages: Low energy density, high upfront cost, slower rates of energy discharge compared to lithium batteries.
While most traditional rechargeable batteries utilize solid electrodes for energy storage, flow batteries use dual tanks of liquid electrolytes with electrodes between them. The electrodes used in flow batteries are non-flammable, making them a safer choice, and they can facilitate high rates of discharge with no negative impacts.
Flow batteries have long-duration capabilities and, because of their modular design, they’re easy to scale up or down depending on capacity needs.
Advantages: Scalability, long cycle life, and inherent safety features.
Disadvantages: Lower energy density, higher upfront costs, and electrolyte management challenges.
Many people are familiar with lithium batteries because of their frequent use in electric vehicles (EVs). Two main types are commonly used in BESS: lithium nickel manganese cobalt oxide (NMC) and lithium iron phosphate (LFP or LifePO4). Let’s take a look at the pros and cons of each one.
NMCs are a popular choice for BESS solutions because of their high energy density and safety from thermal runaway situations. They rely on mined minerals — in this case, cobalt, and nickel, which are costly and environmentally detrimental to collect. NMCs also have the disadvantage of a shorter battery life compared to many other lithium-based battery options.
Advantages: High energy and power density, safety, low upfront cost.
Disadvantages: Environmental impact, shorter lifespan, less stability.
The best-known and most widely used batteries in BESS solutions today, LiFePO4s (also known as LFPs) rely on iron, a more sustainable metal than the nickel or cobalt used in other lithium batteries.
LiFePO4s are also inexpensive compared to most other lithium-based batteries and are less susceptible to hazards such as thermal runaways. While power density is low, that isn’t as much of an issue for BESS applications, as long as your use case provides sufficient physical space for the battery capacity you need.
LiFePO4s also have a longer life cycle than many other lithium-ion batteries. On the downside, LiFePO4 batteries rely on mined minerals, meaning their manufacturing has a negative environmental impact, and improper disposal of used LiFePO4s can contaminate water and soil.
Advantages: High energy density, reliability, long cycle life, safety, fast charging, and wide availability.
Disadvantages: Environmental impact, higher upfront costs, and potential resource constraints.
In addition to battery chemistry, the Battery Management System (BMS) is a crucial component of any BESS. The BMS monitors and manages battery voltage, temperature, state of charge, and overall health. It also protects against thermal runaway and ensures battery safety and longevity.
Look for a BMS that’s scalable, powerful, secure, and able to carry out cell balancing and manage battery safety to avoid potential issues. A battery management system that has been UL 1973 Recognized for functional safety can significantly reduce your UL certification efforts, in addition to providing reassurance that it will keep your batteries safe.
Also, seek out a BMS that’s configurable from the operator side. Nuvation Energy’s battery management systems allow users to adjust settings within an intuitive interface to meet specific application requirements. They also include intelligent features that go beyond the basics, including control loop tuning, built-in fan controls, and self-diagnostic tools. Battery status can be accessed and viewed anytime through a secure web portal.
The BMS software should be protected with tight protocols for security, including hardware authentication, data encryption, and comprehensive testing for all firmware updates.
The R3Di® System is a utility-grade, onsite power generation system that delivers conditioned, uninterrupted power to end users. R3Di® relies on a self-contained, turnkey power platform installed without requiring an interconnection agreement or costly public utility upgrades. It’s capable of providing instantaneous full-load pickup in the event of an outage and sustaining power during long-duration blackouts.
Relying on safe and sustainable lithium iron phosphate (LiFePO4) battery chemistry for energy storage, R3Di® can store and provide up to 1 MW of power and includes a natural gas generator for additional support.
To learn more, read our whitepaper: "Why Lithium Iron Phosphate Batteries (LiFePO4) Are Taking Charge in the World of Battery Chemistry"