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I always thought any concentration of power represents an opportunity for things to go off the rails; do you happen to have a citation for "not a fire hazard" t

I always thought any concentration of power represents an opportunity for things to go off the rails; do you happen to have a citation for "not a fire hazard" that I could read up on? That's actually one of my bigger concerns with these solar into battery stunts is where to place such a massive array of batteries such that if something caught fire it wouldn't take out my roof or other flamable stuff

jodrellblank 3y ago
Watch for RedFlow batteries, they are made of bromine liquid tracks which is a fire retardant. They’re big, not as cheap as Lithium batteries but can be charged and drained 100% repeatedly without damage. I’m hoping they can scale up manufacturing and lower pricing with time because it seems an option with plenty of desirable strengths in this kind of scenario.
- mdaniel 3y ago
  Thanks for bringing those to my attention, that does sound like something that interests me. The "where can I buy" was notably absent from their website, but some further searching found a comment of someone who did find prices <https://pv-magazine-usa.com/2022/10/06/residential-flow-batteries-and-inverter-updates-from-the-floor-at-re/#comment-206125 https://pv-magazine-usa.com/2022/10/06/residential-flow-batt...> but it wasn't especially the price that made me pause as much as the assertion that the batteries have fluid pumps that must be kept running Since I apparently couldn't buy one then it doesn't matter but I would need to further understand what happens <s>if</s>when those pumps fail
  - jodrellblank 3y ago
    They have a YouTube channel with some case studies and discussions[1] the channel intro shows high level what the battery chemistry and mechanism is - pumping electrolyte past a membrane and either dissolving or precipitating Zinc + Bromine to charge/discharge. They seem to be making a 10kWh cell which they can stack into a shipping container sized larger cell, and then deploy those to make grid-scale storage, rather than home use. Presumably they have an answer for if all the pumps in all those containers need regular maintenance, but I haven't thought about that until now. ('liquid tracks' should have been 'liquid tanks' in my earlier comment). [1] https://www.youtube.com/@redflow-acceleratingacarbo9077/videos https://www.youtube.com/@redflow-acceleratingacarbo9077/vide...
20after4 3y ago
LiFePo4[1] is not 100% safe but it's a much safer chemistry compared to the other common alternatives. This is because LiFePo4 chemistry isn't prone to thermal runaway. Thermal runaway is really bad. Typical lithium rechargeable batteries can't handle overheating without starting a chain reaction: an uncontrollable thermal runaway followed by a literally inextinguishable inferno. If you short circuit the LiFePo battery it still is going to turn into a welder. It can still start a fire. If you don't short circuit it, under normal conditions it shouldn't spontaneously combust. 1. Note: Confusingly LiFePo4 (Lithium Iron Phosphate) looks a lot like LiPo (Lithium Polymer), however, LiPo batteries are some of the most prone to fire while LiFe batteries are the least prone to fire.

jodrellblank 3y ago

Watch for RedFlow batteries, they are made of bromine liquid tracks which is a fire retardant. They’re big, not as cheap as Lithium batteries but can be charged and drained 100% repeatedly without damage. I’m hoping they can scale up manufacturing and lower pricing with time because it seems an option with plenty of desirable strengths in this kind of scenario.

mdaniel 3y ago
Thanks for bringing those to my attention, that does sound like something that interests me. The "where can I buy" was notably absent from their website, but some further searching found a comment of someone who did find prices <https://pv-magazine-usa.com/2022/10/06/residential-flow-batteries-and-inverter-updates-from-the-floor-at-re/#comment-206125 https://pv-magazine-usa.com/2022/10/06/residential-flow-batt...> but it wasn't especially the price that made me pause as much as the assertion that the batteries have fluid pumps that must be kept running Since I apparently couldn't buy one then it doesn't matter but I would need to further understand what happens <s>if</s>when those pumps fail
- jodrellblank 3y ago
  They have a YouTube channel with some case studies and discussions[1] the channel intro shows high level what the battery chemistry and mechanism is - pumping electrolyte past a membrane and either dissolving or precipitating Zinc + Bromine to charge/discharge. They seem to be making a 10kWh cell which they can stack into a shipping container sized larger cell, and then deploy those to make grid-scale storage, rather than home use. Presumably they have an answer for if all the pumps in all those containers need regular maintenance, but I haven't thought about that until now. ('liquid tracks' should have been 'liquid tanks' in my earlier comment). [1] https://www.youtube.com/@redflow-acceleratingacarbo9077/videos https://www.youtube.com/@redflow-acceleratingacarbo9077/vide...

20after4 3y ago

LiFePo4[1] is not 100% safe but it's a much safer chemistry compared to the other common alternatives. This is because LiFePo4 chemistry isn't prone to thermal runaway. Thermal runaway is really bad. Typical lithium rechargeable batteries can't handle overheating without starting a chain reaction: an uncontrollable thermal runaway followed by a literally inextinguishable inferno. If you short circuit the LiFePo battery it still is going to turn into a welder. It can still start a fire. If you don't short circuit it, under normal conditions it shouldn't spontaneously combust. 1. Note: Confusingly LiFePo4 (Lithium Iron Phosphate) looks a lot like LiPo (Lithium Polymer), however, LiPo batteries are some of the most prone to fire while LiFe batteries are the least prone to fire.