Battery energy storage systems (BESS) are an essential technology that will help to enable the transition toward renewable energy. BESS facilities make it possible to capture the energy produced from wind and solar photovoltaic and deploy it when needed, balancing the intermittency of these renewable energy sources and improving the stability of the grid.
In the US alone, large-scale battery storage capacity is forecast to grow from just 1 GW in 2019 to 98 GW in 2030. By that same year, the International Energy Agency estimates that global installed capacity will reach 967 GW.
But though the expansion of BESS facilities will support the growth of renewable energy, it will also introduce new operations and maintenance challenges. Utilities must ensure that both the batteries and the supporting infrastructure, including the transformers, inverters, switchgear, and ancillary systems are operating safely and reliably.
This article is part of a series that looks at how utilities can meet the safety, inspection, operation, and security requirements of battery energy storage systems. To learn more, download the recent white paper (registration required): Continuous Monitoring For Battery Energy Storage Systems.
The Limits of Time-Based Physical Inspections
Utilities have long relied on time-based physical inspections and scheduled maintenance to ensure that equipment is in good condition and operating efficiently.
However, BESS facilities are made up of a mix of high-value assets and components. As electrical infrastructure becomes more complex, these physical inspections are no longer enough to ensure the health and performance of critical BESS and renewable generation assets.
Physical inspections are time-consuming and expensive. Technicians must travel to the facility and manually inspect hundreds or thousands of components. They must be on-site and measuring the component when the fault occurs, meaning they are likely to miss intermittent failures or issues that occur only under specific conditions.
Further, the periodic nature of these inspections increases the likelihood that a fault goes undetected and unrepaired between visits, leading to catastrophic failure that results in significant damage or injury to equipment and personnel.
The Challenges of Maintaining Battery Energy Storage Systems
Introducing new technologies to the grid also introduces more complexity, which in turn creates new challenges for the Operations & Maintenance department.
Already there have been accidents, fires, explosions, and arc flashes that have occurred at BESS facilities and have damaged equipment or put workers at risk.
These incidents, if not avoided in the future, will pose serious threats to the development and adoption of BESS.
Thermal Runaway
Thermal runaway is a chain reaction that occurs when increased temperatures lead to the prolonged release of energy within the lithium-ion battery, resulting in further uncontrolled temperature increases, fire, and explosions.
As energy storage facilities transition to a higher density and smaller footprint, with more units packed more closely together, the risk of a thermal runaway spreading to multiple batteries increases.
Physical damage to the battery cell, degradation, aging, and poor battery maintenance can all result in a thermal runaway event. Many of these issues can be mitigated using thermal monitoring sensors that detect the change in temperature before the unstoppable failure occurs.
Toxic and Hazardous Gases
Lithium-ion batteries have the potential to release toxic and hazardous gases that negatively impact human health and damage surrounding ecosystems. A recent analysis of smoke from a battery fire found high levels of hydrogen fluoride, hydrogen cyanide, hydrogen chloride, sulfur dioxide, and various fluorinated phosphorus and lithium-based compounds.
Labour Shortages
Compounding these risks is the reality that many utilities are struggling to attract and retain talent. The industry is facing a shortage of skilled and experienced personnel, especially among those who have the specialized training needed to deploy, manage, and maintain BESS facilities. Today, the average age of a US utility worker is over 50, while more than 50 percent of workers are expected to retire within the next decade.
Site Security
Renewable generating and BESS facilities are often located in remote areas far from cities and utility offices. Physical security measures such as fences, barbed wire, and other barriers provide some level of protection, but the sites remain highly vulnerable to thieves, vandals, or other intruders. Utilities will need to ensure these remote sites have security monitoring to protect valuable assets and ensure their reliable operation.
Overcoming the Challenges With Continuous Monitoring for BESS
Instead of relying on time-based physical inspections, utilities should implement visual & thermal monitoring solutions that provide continuous, 24/7 coverage of critical BESS and renewable generating assets.
Visual and thermal sensors can be deployed throughout the facility to monitor assets on both the AC and DC side of the BESS, including battery module enclosures, inverters, transformers, switchgear, relays, circuit breakers, cabling, and ancillary systems. Visual sensors can also be used for continuous security monitoring applications.
With continuous coverage, decisions about maintenance and repairs can be made based on the actual health and performance of the BESS asset. By taking a proactive approach, utilities can reduce operations & maintenance costs, improve reliability and uptime, and enhance the long-term performance of the asset.
To learn more about how utilities can effectively maintain battery energy storage systems, download our recent whitepaper (registration required): Continuous Monitoring For Battery Energy Storage Systems.