The battery technologies that most often make industry headlines these days are those that hold promise for integrating renewably generated power. But advances in other applications deserve attention as well, especially when they offer utilities substantial operations and maintenance (O&M) benefits.
Lead-acid batteries have supplied tried-and-true back-up power to utilities for years, and since 2007, compliance with North American Electric Reliability Corporation (NERC) standards has been mandatory for the maintenance of these systems. Typically, compliance has required the regular testing and documentation of battery health. But with advances in Internet-of-things (IOT) sensors, utilities can now benefit from continuous monitoring of their back-up battery systems.
Continuous monitoring provides three major benefits to utilities.
Reduced compliance protocols
Utilities that invest in continuous battery monitoring for their back-up power systems have very little to do to remain NERC-compliant. If continuous monitoring is in place, the standard simply requires that utilities react to any system warnings within 24 hours and document corrective actions.
By comparison, utilities without monitoring systems are required to test and document every individual battery in a back-up system every four months. An average-sized installation of 120 lead-acid batteries would take a single technician about four hours to fully test. That doesn’t include travel time for remote installations or the inventory, training and planning needed to manage ongoing compliance.
“Continuous monitoring is a game changer for utilities,” said Alejandro Leanos, Senior Field Service Engineer for Franklin Electric, which manufactures both battery testing devices and monitoring systems. “Because if batteries are under the watchful eye of a system, the standard specifies no periodic maintenance requirements. That effort and labor can be redirected to other O&M needs.”
Reduced risk of human error
Even a technician with the strongest powers of attention could have difficulty completing the same procedure 120 times in a row. That’s why human error is perhaps the greatest risk to the accurate completion of compliance activities.
“Good battery testers are designed to be intuitive, but even so, they require careful attention and training to use,” Leanos said. “Then there’s also the follow-up step required to properly store the testing documentation — not to mention the safety training, considering the hazards of the environment.”
Continuous monitoring removes the risk of human error. A sensor on each battery confirms its health every few hours and the results are transmitted to a backend or cloud server that automatically stores the necessary documentation. If a battery’s condition moves outside the parameters for healthy operation, the system immediately sends a warning message to O&M staff. Then, when a technician arrives on site, he or she will already know which battery requires maintenance or replacement.
Uptime assurance and risk management
Quarterly battery testing may feel like a brief interval to the O&M staff responsible for maintaining compliance. But four months is plenty of time for a battery to go bad. If the condition degrades between testing, and the back-up system is called into service, it’s a problem.
“If a single battery in a battery string becomes faulty between test periods, the results are always catastrophic,” Leanos said. “There is no best-case scenario. When a link in a chain is broken, the chain becomes unusable.”
In this situation, thermal runaway would occur, and the entire backup system would likely be lost. In addition, whatever critical systems the backup system was there to protect would fail, which would likely be a much greater loss than the backup system. However, with continuous monitoring, reactive maintenance can occur as soon as a battery shows signs of degradation, ensuring availability of the system when the need arises.
In a word, the benefit of continuous monitoring is “automation.” Across the industry, utilities are looking for solutions that help them respond to labor constraints.
Battery monitoring systems do away with labor-intensive compliance testing, while also reducing risk. “Once the system is installed, the data is always going to be consistent,” Leanos said. “The limiting human factors are removed. There’s no risk of the new guy performing the tests incorrectly, and there’s no risk of just bad-luck timing.”
Monitoring systems can be configured to work with existing wired or wireless communication networks. Plus, they can be integrated with back-office enterprise systems or monitored with standalone applications. Ultimately, they increase the reliability of battery systems that — by design — are needed to be fail-safe.