Researchers at the US Department of Energy’s Pacific Northwest National Laboratory (PNNL) have developed a sensor system called IntelliVent that can prevent dangerous conditions from developing in outdoor battery cabinets.

Although energy storage systems with cabinet-type enclosures can be advantageous due to capacity, footprint and access, the cabinets leave little room for exhaust fans which would vent flammable gases that can result from failed cells and lead to explosion.

IntelliVent is a patent-pending, deflagration-prevention system for cabinet-style battery enclosures. IntelliVent is designed to open cabinet doors intelligently to vent the cabinet interior at the first sign of explosion risk. This functionality provides passive dilution of accumulated flammable gases, minimizing the potential for catastrophic explosion and reducing the risk of personnel injury.

The deflagration-prevention system combines automatically controlled door locks with a smart controller that manages signals from fire safety inputs, such as smoke, heat, or gas detectors. The system can cause all doors to automatically open simultaneously and immediately when necessary to help ensure personnel and facilities are safe.

Beyond the door locks and controller, the system can include inputs from a fire alarm panel, door sensors, smoke and heat detectors, and mechanisms to open the doors automatically or manually. Requirements in NFPA 855 and the International Fire Code now necessitate explosion mitigation measures for cabinets. IntelliVent is the first system of its kind designed to address these requirement.

Recent fires at battery storage facilities in Surprise, Arizona, and Liverpool, England, highlighted the dangers these kinds of fires can present. The April 2019 incident in Arizona at an energy storage facility left four firefighters injured, two seriously. In September 2020, fire crews in Liverpool, England, were called to a 20 MW battery storage plant after an explosion had occurred to find a large grid battery system container on fire.

When a lithium-ion battery reaches a critical temperature, the liquid electrolyte inside the battery can vaporize and release toxic, flammable gases including hydrogen, carbon monoxide, methane, and propylene. This process is called thermal runaway.

Depending on the size of the cell, these gases can come out at very high volume, very quickly, and can lead to fire or even an explosion.

—Matthew Paiss, technical advisor for energy storage safety at PNNL and one of the inventors of IntelliVent

Scientists at PNNL developed IntelliVent for cabinet-style battery enclosures to vent the cabinet interior at the first sign of explosion risk. (Video by Mike Perkins | Pacific Northwest National Laboratory)

This is absolutely in the right direction. Getting all doors open early before gas buildup will make the incident safer. It will also increase situational awareness by being able to see if the batteries are smoking or are on fire. And, if extinguishment is needed, we can direct the water right at the modules from a safe distance.

—Bobby Ruiz, the fire chief in Peoria, Arizona, whose firefighters were injured in the Surprise, Arizona, explosion

The Snohomish County Public Utility District’s new Arlington Microgrid and Clean Energy Center, in Everett, Washington, will be the first to install the safety technology when it retrofits a 1.2 MW battery with the IntelliVent system.

IntelliVent designers developed the versatile system to work with a variety of sensors. Further, its simple operation provides an early warning system for pushing the gases out. It is intended to reduce the risk of explosion, but due to limitations of the product standard, is not designed to NFPA-69 (Standard on Explosion Prevention Systems).

IntelliVent is available for low-cost, nonexclusive licensing as PNNL pursues broad and rapid adoption of this safety technology.