Standalone Battery Energy Storage: What You Need to Know

Large-scale battery energy storage systems are often associated with other renewable energy assets, especially solar. For some businesses, though, there might be an advantage to standalone battery storage. Keep reading to learn how these systems can reduce operating expenses, increase energy resiliency and independence, and boost sustainability.

How Do Standalone Batteries Work?

A standalone battery energy storage system (BESS) consists of several key components:

• Lithium-Ion Batteries: These batteries are similar to those used in electric vehicles, but larger. BESS batteries are regulated for safety, and systems are carefully designed to avoid fires. The ultimate size of an energy storage system depends on a business' needs.
  

• BESS Enclosure: This is a protective housing that stores and safeguards batteries, preventing them from being damaged by storms and other incidents.
  

• Inverter/Charger: Also called a power conversion system or hybrid inverter, this is a system that takes A/C power from the grid to charge the batteries. (It can also be used to charge batteries using renewable energy assets like solar arrays.)  

• Battery Management System (BMS): Software that controls charging speed, monitors charge levels, and prevents overcharging.
  

• Energy Management System (EMS): Another type of software-enabled system that controls the charging and discharging of batteries.

All these elements work together to create a system that stores energy and then strategically dispatches it to power your facility when needed.

Key Benefits of Standalone Battery Energy Storage Solutions

There are major financial, operational, and environmental benefits to having standalone battery storage on site. Here are some of them:

1. Energy Arbitrage: Some utility companies charge more for energy at times of high usage. Charging your batteries when prices are low and discharging them to power your building when prices are high allows you to avoid this added expense. This also helps remove stress from over-worked grid infrastructure.

2. Peak Shaving: If your utility charges a premium for demand, such as for the highest 15 minutes of electricity usage in a billing cycle, energy management software can help. In a strategy called peak shaving, the software automatically discharges during peak demand periods, creating a flatter draw.
   

3. Demand Response Participation: In areas with demand response programs in place, you can receive financial incentives from your utility company for reducing your grid consumption. A BESS facilitates this by allowing you to use stored energy to power your building instead of drawing electricity from the grid.

4. Improved Sustainability: Reducing your reliance on grid electricity, especially during times of peak usage, helps your company shrink its carbon footprint and meet emission reduction targets. A BESS specifically helps with lowering Scope 2 emissions, which stem from an organization’s purchased electricity.

5. Energy Resilience: A battery system that is part of a microgrid (which will be explained later) can provide clean emergency power if the grid goes down. This ensures continuity of operations, avoids productivity losses, and reduces local pollution.
   

6. Improved Energy Forecasting: Advanced energy management software can measure and help you better understand how much energy you consume and when. An EMS also uses this information to optimize battery charging and discharging schedules.

Standalone vs. Other Types of Battery Storage

Besides operating as a standalone system, a BESS can be paired with other renewable assets. In a solar-plus-storage system, software is used to coordinate battery charging and discharging with solar energy production. For example, if solar arrays produce more energy than the facility needs during daylight hours, the surplus can be stored and then used in the evening when solar production drops off — a strategy called "solar shifting."

A BESS can also be combined with solar arrays and a traditional generator to form a microgrid, which is a system that can “island” itself from the local power grid during blackouts. When configured correctly, a microgrid coordinates these assets to provide backup power during an extended grid failure with minimal energy costs and environmental impact.

How Much Storage Capacity Does Your Business Need?

So, you’re thinking about getting a battery energy storage system, but how big does it need to be? There are a variety of factors that determine your storage capacity requirements, including:

• Energy Consumption Patterns: Do you consume more energy during peak hours, or do you consume more at night? How much total energy do you use? Smart meters give good data here, and an energy audit is vital before implementing any onsite power generation or storage.
  

• Peak Demand: How much energy do you use at your absolute peak, such as the middle of weekday when your office building or warehouse is full and the HVAC system is running at maximum?

• Backup Needs: How much equipment do you have that can't be without power? How reliable is the local grid? (Businesses in rural areas with overhead lines and frequent storms may need more capacity than those located in larger cities where the grid is more hardened.)

• Future Growth: What are your business goals and how do you see them impacting your energy needs down the line? It's often better to overbuild a little now rather than pay for expansions later.

If all these factors make deciding on the size of a system seem complicated, don’t worry. An experienced clean energy provider can walk you through each one and make recommendations based on your specific situation.

Understanding the Lifespan of Standalone Battery Energy Storage Systems

Though battery energy storage systems are a large investment, they also last a long time. A system is typically designed to last at least 25 years, but even longer if retrofitted or upgraded. In fact, since your business’ energy needs will naturally change long before your system “wears out,” retrofitting is a great way to ensure your BESS continues to meet those needs.

Proper maintenance practices help extend the lifespan of a system. This includes ensuring the battery management system prevents overcharging, which can impact the longevity of individual cells and potentially the system.

However, over time, all battery-based systems eventually hold less charge. This is called battery degradation and is primarily caused by reactions between lithium ions as they move, called lithium loss. This is why your three-year-old cell phone no longer has the battery life it did when it was new.  

Another phenomenon, called capacity loss, is caused not by time but by charging cycles – the more your batteries are charged, the faster they degrade. While degraded cells can be replaced, eventually the BESS and other systems will also wear out and/or become obsolete, making it easier to change out the entire system.  

Modern battery and energy management systems are designed to reduce charging cycles as much as possible, but the more you use your battery system, the shorter its life. This is something to consider if you experience a lot of power failures, as it might be more cost effective to overbuild the system to allow for capacity loss.

All that said, it’s important to keep in mind that with proper preventative maintenance, the average customer can get 25 years or more out of a battery energy storage system — making it a smart long-term investment.

Trust PowerFlex for All Your Energy Storage Needs

PowerFlex has the expertise to build you a standalone battery storage system that perfectly meets your company’s needs. We handle the entire process from determining the size of the system to installation and asset management. Contact us today and let our experts help you find the perfect solution to control and optimize your company's energy usage.