At the ees Europe 2022 in Munich, Germany, the fire safety of battery energy storage systems became the primary topic of concern for many energy storage suppliers and their customers.
There were many new products on display, and various macro topics were discussed - such as the need for a coherent EU policy strategy on energy storage and continued supply chain tensions. But industry experts participating in the meeting commented that it is crucial that stakeholders want to be able to ensure the fire safety of lithium-ion battery energy storage systems.
Kai-Philip Kairies, chief executive of battery analyst ACCURE Battery Intelligence, said in an industry interview, “To be really useful, future battery storage systems need to be safer. If people are concerned about battery safety, that’s not good for batteries. The energy storage industry continues to grow.”
ACCURE develops software to help monitor and evaluate battery performance, aging and operational safety in electric vehicles and battery energy storage systems. As a battery technologist, Kairies noted that of the three main functions of the analysis suite, safety has received the most attention recently.
There have been some high-profile fire safety incidents in the global energy storage battery sector, including a fire at Tesla's VictorianBig Battery battery storage system in Australia and a thermal runaway at Moss Landing's storage system in California: and these are Australia and the world's largest battery energy storage project.
The 10MW/40MWh battery storage system deployed by Arizona utility Salt River Project (SRP) also reportedly caught fire recently. The market for residential energy storage systems in Germany is also growing rapidly. Kairies said that as far as he knows, Germany has reported five residential energy storage system fires in the past month alone.
Thankfully, no one seems to have been harmed during these events, and they are still rare relative to the vast array of battery storage systems deployed around the world, but not to be taken lightly, especially customers or the general public.
Saft, a battery storage maker that has been supplying containerized battery storage systems to the global market since 2010, claims to have never experienced an equipment failure that led to a fire, said Michael Lippert, vice president of innovation and solutions at the company. Proud of this.
Lippert said there are still potential risks to battery storage systems that must be taken seriously in terms of safety assessments. For Saft, safety has been a holistic and intrinsic consideration from the very beginning of the design of the grid-scale battery product, the Intensium Max.
One way Saft's approach may differ from its competitors is that the Intensium Max is a standardized, repeatable energy storage system that doesn't fundamentally change in design from project to project.
Lippert said, “At the beginning of the design, we analyzed any possible risks, including the impact of cooling systems, such as humidity due to condensation. In a 1500V battery energy storage system, excessive humidity can cause a short circuit in the battery. We need to ensure that the temperature is set above the condensation point before the staff opens the door of the containerized energy storage system. Therefore, we enhance the function and safety from the beginning. Sex takes a lot of things into consideration."
The design of Saft's energy storage system integrates a combination of detection systems, fire suppression and hazard management, which Lippert claims is a unique design in the world.
The Intensium Max energy storage system is the cornerstone of all of Saft's energy storage projects, with two independent fire suppression systems. The company also learned from incidents at other manufacturing companies with energy storage safety projects that it needed to manage the buildup of potentially explosive gases inside containers.
"We're going to make sure that the crew, as well as the firefighters who put out the fire, are familiar with the equipment, and they have the tools to make the right decisions," Lippert said. "That means they don't need to open the container to see what's going on, they're trained. , and have external diagnostic tools to look at the temperature inside the energy storage system to see if there is a possibility of an explosion.”
Intilion, a Germany-based manufacturer of battery energy storage systems, has introduced a battery energy storage system with built-in fire safety features for the industrial and commercial markets.
Martin Peters, product manager at Intilion, pointed out that although lithium-ion batteries have many advantages, they are also accompanied by fire and explosion risks, which means that lithium battery fires cannot be extinguished.
There are three main reasons for lithium battery fires: electrical risks from overvoltage, overcurrent, or overheating; thermal risks from high temperatures external to the battery system; and mechanical risks from externally unidentifiable physical damage or manufacturing defects.
"Perhaps after years of use, there is some problem inside the battery. For example, dendrites on the separator may increase, causing an internal short circuit in the battery, which then leads to thermal runaway, leading to a fire," he said.
In the German market, battery energy storage systems for indoor use need to meet the certification standards set by the German Association of Electrical Engineers (VDE). These include the requirement that fires cannot spread or spread between adjacent battery modules and that there should be no flames outside the battery modules.
Intilion has designed an additional housing for each battery module with calculated air channels to release gases in a prescribed manner. It is therefore necessary to compress the gas to a level that is not flammable, and that it can be vented from the front of the energy storage system.
The product has been certified by a laboratory in Germany. Peters pointed out that the fire risk of lithium-ion batteries cannot be completely eliminated, but the damage may be limited to one battery module. Each battery of Intilion's battery energy storage system is also equipped with a tray to collect electrolyte that may leak and prevent groundwater contamination.
ACCURE's Kai-Philipp Kairies said the battery's data could be an effective tool for preventive maintenance once the energy storage system is actually in service.
"Every battery has a battery management system that generates some data like voltage, current and temperature, and we use that data to basically reverse engineer what's going on inside the battery," Kairies said.
Certain internal states of battery health cannot be directly measured, nor can they be calculated. How these internal states develop over time, ACCURE is able to tell if the battery module or cell performance is healthy and similar to the rest of the battery pack.
For example, if the analysis software finds a battery showing bad signs, it can be taken out of service before the battery becomes dangerous. With experience managing 1.5GWh of battery assets in EVs and battery storage, ACCURE has demonstrated that this can be done at scale, ensuring the safety of energy storage systems and next-generation lithium-ion battery storage systems, Kairies said.