Energy storage prompts battery of precautions

Energy storage prompts a battery of precautions

Clean tech adopters urged to understand and mitigate fire safety risks
Monday, March 11, 2024
By Barbara Carss

In step with a projected surge in energy storage installations, fire safety advisors are actively working to help clean tech adopters understand and mitigate the risks. The U.S. based National Fire Protection Association (NFPA), a leading developer of standards that are referenced in many Canadian codes and standards, addresses many of those concerns in a dedicated standard, NFPA 855. Other general guidance for fire safety planning, emergency response, construction, operations and maintenance also comes into play.

The U.S. Energy Information Administration reports that 7.7 gigawatts (GW) of new energy storage capacity was installed in that country in the first six months of 2023, representing a 32 per cent increase over the same period in 2022. That growth trend is expected to continue with the planned flow of significant U.S. government spending into clean energy, and, to a lesser, but somewhat proportional degree, similar investment incentives are coming on line in Canada through a range of tax credits and financing options.

“A lot of the installations we see today are battery energy storage systems and particularly lithium ion,” Brian O’Connor, a senior engineer with NFPA, observed during a recent webinar. “We are seeing these installations everywhere. We are seeing more installations and, with that, we’re bound to see more incidents.”

Along with NFPA colleagues, he outlined a recommended approach for reducing that likelihood and more effectively containing events that do occur. That includes fire safety requirements for: building, configuring and equipping energy storage facilities; operational procedures; and emergency response training.

Under NFPA 855, energy storage facilities must be located at least 10 feet away from the lot lines and other structures, storage areas or vegetation on the site or, alternatively, be enclosed behind a wall that extends 5 feet beyond the energy storage system in all directions and is no less than 5 feet distant from other external exposures. Inside the facility, units are to be separated into clusters of no more than 50 kilowatt-hours (kWh), each of which must be placed at least 3 feet from other clusters and any walls.

The standard also includes directions for sprinklers, fire alarms, ventilation and explosion prevention and protection. Where lithium ion, sodium nickel chloride or flow batteries are employed, 600 kWh of energy storage is the triggering threshold for various hazard analysis, training and emergency response requirements that will need to be documented in supporting plans.

O’Connor advises facility developers/owners to begin that process with a series of ‘What if?’ questions related to potential “thermal runaway” in the storage units and the failure of the battery management system (which could cause voltage fluctuations) and any element of the fire protection system. From there, they should consider what precautions and interventions will be needed to achieve the required safety performance.

“You need to make sure that the fire is contained in that energy storage system room for two hours; that any explosion hazards are addressed; and that the products of combustion — being smoke, heat and any toxins associated with those — do not prevent the occupants from evacuating,” O’Connor reiterated.

Plans should identify key operational and emergency response procedures

Safety plan drafters will need to map out various operational and emergency response procedures, as well as the process for verifying that inspection, testing and maintenance of key systems is occurring. Plans should cover: safe shutdown and start-up of the energy storage system; communications, training and drills for on-site personnel, other building occupants and emergency responders; and key contacts, such as service contractors for critical equipment and systems. Attention should also be paid to potential repercussions for the surrounding area and wider community.

“Make sure that staff and occupants know what to do in the event of a fire, in the event they smell smoke or they smell something off with what’s going on in the battery room,” O’Connor said. “Your personnel needs to be able to figure out, not only how to notify the fire department, but when to notify the fire department.”

Likewise, arriving firefighters should know in advance that there are energy storage units on site, and be quickly directed to the mechanisms that will disconnect all electrical charges.

“Don’t be afraid to bring your local authorities in for training, to show them,” suggested Holly Burgess, one of the NFPA’s emergency planning specialists. “Make sure that they understand where to go and what the hazards are.”

Solar photovoltaic arrays can be one of those lurking hazards if that’s the power source for the energy storage. Dean Austin, a senior electrical specialist with the NFPA, explained that installed PV panels are effectively “live” whenever there is sufficient light. Thus, NFPA guidance calls for a single-switch shutoff for all solar PV arrays mounted on a building.

“It has been documented that some of the emergency lights on fire trucks, used for illumination at night, will turn on the solar panels and begin producing energy,” Austin reported. “The disconnect has to be able to isolate the energy storage system from all other wiring.”

Additionally, qualified technicians are a fire safety imperative at every stage of an energy storage facility’s life cycle from installation to decommissioning. Beyond being a licensed electrician, NFPA guidance defines this as having knowledge of and experience with specific types of equipment and systems. That includes required technical skills along with the ability to assess and mitigate hazards, which may involve getting training from the manufacturers of those products.

“I have been a master electrician for 30 years. I’ve done a lot of work myself and I can tell you that I am not qualified to go into a medium voltage application and start doing electrical work in there,” advised Corey Hannahs, another of NFPA’s senior electrical specialists. “So this qualified person requirement is a big part of knowing what the problems could be.”

A poll of webinar participants found most are still at earlier stages of the learning curve, with 51 per cent of respondents indicating that they need a lot more training before implementing an energy storage system in their facilities and just 3 per cent stating they believe they are sufficiently knowledgeable. O’Connor promotes the NFPA standard as a tool for quantifying the risks, identifying gaps and moving forward.

“Decommissioning without failure (at the end of the facility’s life cycle), that’s what we’re all hoping for, but, if there is some kind of failure, we don’t want to have to figure it out on the spot,” he submitted. “We want to make sure that we’ve thought about this earlier and we have a plan in place, so that the failure and whatever damage might be done is limited.”

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