Calling out illegal cheap batteries | The Buzz

Jeff Spies, president of Planet Plan Sets, is increasingly concerned that the solar and storage industry is facing the biggest safety challenge of its 50-year history. Solar Builder published “The Lithium Battery MESS” in the Q3 2024 issue, to sum up those concerns. This episode of The Buzz digs deeper into the topic. What are safe and legal home batteries? And how have decisions by California regulators helped set the market conditions giving rise to this Lithium Battery MESS?

Lithium battery topics covered:

• 0:10 – Overview of the lithium battery MESS in California
• 2:15 – How safe are UL 9540 listed batteries?
• 4:56 – Influx of unlisted batteries & deceptive marketing
• 9:08 – The Catch-22 of California battery policy and permitting
• 13:25 – LFP vs. NMC. Is one better than the other?
• 17:46 – Did the CPUC create this MESS?
• 19:16 – What are regulators doing to ensure safe battery installations?
• 21:10 – Can you blame California homeowners for buying unpermitted batteries?
• 25:19 – Legal cheap batteries vs. illegal cheap batteries
• 30:19 – Advice for solar installers navigating all of this
• 34:43 – How to ensure you’re installing a safe and legal energy storage system

Be sure to watch the full episode above, or find the podcast version at Solar Builder Radio, in the podcast player of your choice (and subscribe!) Spotify | Apple Podcasts | Podbean

Crowell: “A lot of this safety discussion hinges on the UL 9540 listing. To this point UL 95 40 listed batteries seem pretty safe, right?”

Spies: “Correct. Keep in mind that a lot of this does happen anecdotally, but we are not aware of very many problems with UL 9540 listed energy storage systems. Just to cite a statistic that I’ve become aware of: I believe that Tesla has manufactured 680,000 Powerwall units, so there’s a lot of those out there in the field. Of those, there’s only one that we’re aware of where there was a thermal event, if you will, in the non-battery compartment of the energy storage system. And there’s been no cells that we’re aware of that have gone into thermal runaway in these Powerwalls. They have also had a number of the homes that had Powerwalls installed, that had fires that were unrelated to the battery system, and interestingly, there doesn’t seem to be any serious safety threat that was perceived after that fire ravaged the home.”

“In some cases the battery wasn’t burnt, in other cases it was burnt, but the perception from the anecdotal information that I’ve heard so far from respected colleagues in the industry is that the fuel load added by that energy storage system really wasn’t any more dramatic than the fuel load presented by the lumber that’s in the framing of the home.

“The good news is 9540 energy storage system certification has been highly effective at validating the safety of those batteries that have gone through the process.”

Is LFP safer than NMC?

Crowell: “As I have understood it, LFP (lithium iron phosphate) batteries — which are kind of on the rise and being promoted a lot and replacing NMC (nickel manganese cobalt) — are safer and less prone to thermal runaway.  But is this all marketing speak that I’ve been duped by? Do you not see LFP batteries as generally safer for stationary energy storage systems?”

Spies: “They way I explain it is the two different chemistries have different safety profiles. NMC is a more energy dense cell, and the presence of nickel and cobalt gives it the properties of going into thermal runaway more quickly than LFP. However, when LFP goes into thermal runaway, it expels upwards of four times the explosive gas of NMC.

“This is one way to think of it: When an NMC battery goes into thermal runaway it can catch on fire and burn out more quickly than LFP.  What LFP does is release all the gas, and if there’s a spark, it goes kaboom. We have seen incidents of this type occur. One in Germany actually collapsed a very thick concrete block wall home. About a quarter of the home was collapsed in as a result of a 5 kWh lithium iron phosphate battery that exploded back in October of 2023. More recently there’s been a 5 kWh lithium iron phosphate battery in California that has suffered that same fate. There was one in the Bahamas I’m aware of where there’s lawsuits going through the federal court system because it burned down a multi-million dollar home after the battery exploded. So, there are certainly safety considerations for LFP.

“One other thing I’ll mention, when you look at NMC energy storage systems, and there’s still a number of major companies use them — those NMC cells are the same battery cells used predominantly in automobiles. We’ve seen, as a general rule, the 9540 listed NMC cell based energy storage systems have had a really good safety track record, and there’s only six or seven companies in the world that make these cells, and they have highly controlled processes of making those.

“Whereas lithium iron phosphate cells are made by literally hundreds of companies, many of them that have very unregulated manufacturing processes. If you buy an NMC cell, it’s going to come from probably one of seven companies, and the likelihood is it’s going to be a solid, reliable cell. If you buy lithium iron phosphate cells, they can be super safe, but they could also be super unsafe because of the hundreds of companies that are unregulated that are making them.”

Legal cheap batteries vs. illegal cheap batteries

Spies: “Most people that are trying to do it in the least expensive way are buying illegal cheap batteries, and obviously if a safety issue occurs, you could be unprotected from a homeowner’s insurance perspective, a liability perspective. We’ve seen already, the inexpensive stuff on the market, many of them turn into useless bricks within a year or two. They’re nonfunctional. Oftentimes you might have them working with an inverter where the inverter firmware changes, or possibly the battery firmware might be upgraded, and now there’s an incompatibility where the two systems aren’t speaking to one another and they don’t work together.

“What do you do with a battery that stops working? And then try to get support from these consumer grade battery companies — it’s non-existent. They may have a support hotline, they may have a frequently asked questions section on their website, but I can assure you that so far, what we’ve seen when people have had problems with these batteries, they’re out of luck. They’ve got a few thousand dollars worth of useless lithium brick that they now have to dispose of. How do you do that?

“Now let’s talk about the legal cheap batteries. You can buy inexpensive batteries that are listed to 9540, but I consider it an issue of price versus cost. A lot of people buy low price. I like to focus on low cost over the life of the system, and the number of years that it lasts is a huge impact on your overall cost of ownership. And I think what most people care about five or 10 years down the road isn’t that cheap initial purchase price, it’s the low cost of operation over the course of the ideally 10 years or more that that battery would serve you.”

Tags: California, The Buzz