字幕表 動画を再生する 英語字幕をプリント Speaker1: With the future of automobiles undeniably electric, the transition is bringing with it some challenges. While they provide a path towards reduced emissions, EVs can be especially dangerous when they catch fire. Speaker2: There have been some really high profile fires at homes in the United States, parking structures in Europe and in China. Speaker3: If that vehicles in your garage and it's charging and this problem occurs, it will likely take the car and the garage and potentially the home. Speaker1: Car fires are nothing new. In 2020 alone, there were 173,000 highway vehicle fires, resulting in 580 fatalities. 1,500 injuries and $1.6 billion in property damage in the U.S. But when an EV catches on fire, it's a different story. Lithium-ion batteries are extremely volatile and incredibly challenging to put out. These fires burn hotter, they burn longer. They take more water. It burned very hot. It melted the roadway underneath it. There was really nothing even left of the shell of the vehicle. And little education is out there to help firefighters. Speaker4: We're still trying to catch up with all this stuff, but it changes almost every day. Speaker5: The industry has rocket launched radically ahead of the preparatory pieces. Speaker2: A lot of the time, firefighters, fire agencies are just expected to kind of figure it out. Speaker1: On top of the challenges for firefighters, carmakers like GM, Ford and Hyundai have had to do massive recalls, so the problem is costly. CNBC explores how automakers and firefighters are going to deal with EV's fire problem. Over the years, lithium-ion batteries have seen significant improvements in energy density. And while this has enabled more powerful batteries, it made them more vulnerable. Speaker4: You had to do lots of things to optimize it, one of them was to reduce the space between the two electrodes, but as you get closer and closer to each other, the chances of short increases. Speaker1: A key ingredient in batteries is liquid organic electrolyte, but it is also one of the most flammable. Speaker4: Liquid electrolyte, like gasoline, is a flammable liquid, and it could get into what's called a thermal runaway situation where it just starts boiling the liquid and it results in a fire. Speaker1: Today's batteries are very safe, and for large ones, such as those in EVs, cells are meticulously controlled through a battery management system. It has to maintain the right operating temperature for the battery. Then within that operating temperature range, the other aspect of it is how fast does it charge or discharge. But there are rare instances where defects or damage cause issues. Speaker6: We don't know the exact frequency of failure for lithium-ion cells. We assume it's somewhere between one and 10 million and one in 40 million. Speaker2: Battery electric vehicle fires can happen due to defects in the actual battery cells or in the pack architecture. The battery pack design matters and so does the quality of manufacturing. Speaker1: And when they're fully charged, that's when they're the most dangerous. Speaker5: Think of it as a fuel tank. If you have a fuel tank in a standard combustion engine and it is completely full and you develop a fire, you have a lot of fuel load, you're going to have a long burning fire. It's the exact same concept with batteries. Speaker3: The battery problem is unique to electric vehicles, but noncash fire risk is not unique to electric vehicles. Speaker1: Car fires are unfortunately nothing new. Internal combustion engine vehicles continued to have issues. Vehicle fires accounted for 16 percent of the 1.3 million fires reported to U.S. fire departments. Most of these are caused by mechanical or electrical failures and malfunctions. But non-crash fires, those that occur when a vehicle is idle or not in use, are extremely uncommon overall. Speaker3: There's only about one claim for every 10,000 insured vehicles, so it's a pretty rare event. Speaker1: Experts are still trying to determine non-crash EV fire incident rates. Speaker3: The data that we've looked at so far doesn't indicate that there is an outsized risk of non-crash fire for electric powered vehicles. We need a lot of them and we need a lot of old ones in order to be able to say anything with confidence. Speaker2: The most famous examples of battery electric vehicle fires have been with the Bolt and various Tesla vehicles. A Model S Plaid burst into flames earlier this week while the owner was driving it. According to the Lower Merion Fire Department in Pennsylvania, copious amounts of water were poured on the vehicle for over two hours in order to extinguish the fire and render the scene safe. Speaker1: Chas McGarvey's department responded to the Pennsylvania Tesla fire. Speaker4: We actually had to lay a supply line, the street line, to feed our engines, and we had two inch and three quarters going trying to extinguish this fire and it doesn't go out right away. It definitely burns a lot hotter and a lot quicker. Speaker1: For most fire departments, they are confronting EV fires for the first time. EV fires require different tactics to effectively fight them. Speaker5: Gas you put water on top of the engine or the interior plastics. With an electric vehicle, you have the interior plastics, so you put water on top, but you're also looking for water to be able to cool the bottom of the battery. You have to get it under about 260 degrees fahrenheit. Speaker6: The big problem is the accessibility of the batteries, the cells inside the battery, because they're usually held within a steel case and they form the chassis of the car, which is largely inaccessible. Speaker5: A number of European cities have adopted a strategy of simply dunking the car in water. Speaker1: These battery pack chemical fires can emit dangerous smoke and gases. Speaker5: It releases two contents in the smoke that we have to be aware of. One is flammable. The other is toxic. Speaker2: Of the incidents we researched, just under 90 percent the gases that were venting from the traction battery ignited and in about 10 percent of cases, the vapors coming from the traction battery actually exploded. Speaker1: And the battery packs can reignite up to several days later. Speaker5: All it takes is for a little bit of metal in that battery to short circuit. Speaker1: In some instances, the fires have spread to other vehicles. EVs are particularly vulnerable when charging and in close proximity to one another. Speaker5: In China, they lost 55 busses in one amusement park's parking lot because they were all electric, they were on chargers, one caught fire and it daisy chained across the rest of the parking lot. Speaker1: One of the biggest issues is educating firefighters. Speaker5: Not all the manufacturers have up to date and current quick reference guides for their vehicles. The guides are very good at being kind of an all-inclusive representation of the vehicle. The challenges occur when things happen to the vehicle that are outside of the design specifications. Speaker1: Training for firefighters is limited and not widely accessible. Speaker5: The educational campaigns for the fire service, the resource capabilities for the fire service and then the funding for the education and the resource capabilities, none of that's intact yet. Speaker1: And with an ever-changing environment, it is hard to keep up with the latest EVs and technologies. Speaker5: There is not really stringent federal regulatory components in place right now regarding the batteries placed in EVs. Every single vehicle is different, even within a manufacturer. You've got this whole kind of supply chain of people that are potentially at risk until that vehicle is is broken up and scrapped. Whether you are a legacy automaker getting into battery electrics or you're a startup making battery electric vehicles and new types of them, it's going to be expensive. Speaker1: Automakers are already struggling with scaling EV production. Potential recalls could pose major issues. In August 2021, GM recalled its Bolt electric vehicle, the result of issues with battery maker LG Chem's pouch cells. Speaker7: They did a recall of 61,000 Chevy Bolts. They have now expanded that recall to fix two potential defects in the battery packs. Those potential defects will impact 73,000 additional vehicles. The additional cost of this recall? $1 billion. Speaker2: GM recalled all of them. They didn't want to take the risk that any driver could experience a battery fire. However, this problem is by no means limited to the Bolt. BMW, Ford, Hyundai, Mitsubishi and, of course, Tesla. They have all issued fire related recalls. Speaker1: Within the last year, General Motors, Hyundai and Ford have recalled around 132,500 electric vehicles, costing a combined $2.2 billion. Tesla has tried to minimize battery related recalls, instead pushing software updates. However, this led to a lawsuit for throttling the range and charging capacity of some batteries. Speaker2: In the United States that settled out, and they got sued for that also in Norway. Automakers are starting to explore different battery chemistries and approaches that could reduce fire risk and improve the life of these batteries. Speaker1: Tesla recently announced it is switching more of its vehicles to LFP batteries, lithium-ion phosphate. Speaker6: They are generally believed to be a lot safer in terms of abuse resulting in thermal runaway. Speaker4: It does not go to as high of a voltage, so it tends not to have as high of an energy density as the other batteries. But at the same point, because it doesn't go to as high voltage is less likely to have that safety issue. Speaker6: On the other hand, we know of battery energy storage systems, two at least, that involved LFP batteries that have exploded. Speaker1: Researchers are working on technologies that could reduce or completely eliminate the fire hazard. Speaker2: There's also a lot of hope around new solid state battery development, but those are unproven technologies so far. Speaker4: Every automotive company who's doing electric vehicles has a play in the solid state battery, and they either are developing themselves or they're investing in companies that are making solid state batteries. That issue we had with safety or flammable liquid is just completely removed. But also at the same time results in batteries, which can have much higher energy density and also can have much longer cycle life. Speaker1: But it will take time before solid state batteries replace lithium-ion in EVs. Speaker4: 2026 people are talking about it. 2028 sort of in that time frame, you will start seeing solid state batteries in electric vehicles. Speaker1: Until then, much has to change to accommodate the new wave of electric vehicles. Speaker5: We are just starting to scratch the surface of how much infrastructure, networking and support needs to be in place. The new infrastructure bill is all about electric vehicles, battery systems and the electric future. What we need is in that bill to reflect the need for training, Speaker1: And it is important for the public to be aware of the risks. Speaker2: We're going to have to figure out how to deal with this, and most of that responsibility falls on automakers and battery producers. But some of it falls on consumers. The drivers have to follow the recommended usage. Speaker6: We've had a long time to fully understand the risks and hazards associated with petrol and diesel cars. We're going to have to learn faster how to deal with the challenges with electric vehicles, but we will.
B1 中級 米 EV火災問題(Why Tesla, GM And Other EV Companies Have A Fire Problem) 7 0 moge0072008 に公開 2022 年 01 月 28 日 シェア シェア 保存 報告 動画の中の単語