Seems like they supply each person with 2 Tesla powerwalls for the $55/month and get a reduction in their bills that depends on how much power they choose to share to the grid during power outages.
They've already closed down 2 peaker power plants because of this, so it doesn't seem to just be about handling power outages, but also handling fluctuating power usage instead of firing up extra power plants.
Lithium is not the way to go for home batteries. As size/weight are not an issue for a basement or shed install, oldschool lead-acid are much cheaper and can be easily recycled once at end of life.
Those tesla wall packs will be a massive headache when they give up the ghost. Read the contract carefully. Who is responsable for end-of-life disposal? Where/how are they to be disposed of? Lead acids can be taken to any number of recycling centers, some will even pay you for them.
I was looking into this stuff early this year in India, and found LiFePO₄ more compelling on paper: two or three times the cost, but lasting two or three times as long, allowing deeper discharge so it should be equivalent to slightly higher capacity, and requiring no maintenance. I could easily have overlooked or misunderstood something, and am interested in counterarguments.
The lifespan numbers are lies. I have personal knowledge of deep cycle lead batteries lasting 10+ years, thousands of cycles. Many websites actually cite numbers for sealed batteries as used in cars. "Flooded" batteries last longer than sealed because they can be inspected and maintained. There are also "deep cycle" and "marine" units which are also different than car batteries and can be discharged more.
I’ve seen and heard of a lot of lead-acid battery home inverter and desktop UPS setups in India (extremely common due to grid unreliability). Desktop UPS batteries sound to consistently be completely useless (<10% capacity, typically 0%) in 3–5 years, and the larger home inverter batteries are typically in poor shape by around 5 years.
I haven’t known any Lithium-ion batteries yet, so I have no personal figures on them. But what I’ve heard is generally more like “they said 8–10 years but it’s still fine after 12”.
lead-acid does not like deep discharge. Also a UPS is typically going to have maintenance free batteries which don't last as long. Many UPSes don't have good chargers and will overcharge your batteries.
You can get decades our of a proper lead-acid battery, but only if you correctly account for all those factors. Start with batteries that you add water regularly (I'm not sure if this is monthly or yearly). Then make sure you have more than enough so that even in the worst case power outage they finish at 30% charge (meaning most don't get close to 50% discharge - the 30% an educated guess but needs more research for your conditions since this needs to be a rare event, the more often you get the worst case outage the more charge needs to remain after). Finally make sure you have a good chargers - modern "battery tender" (a brand name - there are others) makes a big difference.
Lead-acid has been used in major large installation and have a long history of lasting for 20 years when treated properly.
Lithium batteries are still new enough that we don't have a history. We have educated guesses, but those guesses tend to be conservative. Maybe they will turn out to last just as long or even longer. Only time will tell if they are as good or not. However we also know you can abuse lithium batteries and get much worse life. (the Nissan Leaf is famous for significantly worse capacity at 8 years)
The whole depth of discharge thing does make it harder to compare them. I said upthread “slightly higher capacity” for LiFePO₄, but I feel like by recommendations I’ve heard it’s more like 20–40% higher, which is really quite a bit.
hettygreen · · focus · HN ↗
<a href="https://electrek.co/2026/07/28/vermonts-largest-energy-source-is-now-a-virtual-power-plant/" rel="nofollow">https://electrek.co/2026/07/28/vermonts-largest-energy-sourc...
Seems like they supply each person with 2 Tesla powerwalls for the $55/month and get a reduction in their bills that depends on how much power they choose to share to the grid during power outages.
They've already closed down 2 peaker power plants because of this, so it doesn't seem to just be about handling power outages, but also handling fluctuating power usage instead of firing up extra power plants.
sandworm101 · · focus · HN ↗
Those tesla wall packs will be a massive headache when they give up the ghost. Read the contract carefully. Who is responsable for end-of-life disposal? Where/how are they to be disposed of? Lead acids can be taken to any number of recycling centers, some will even pay you for them.
chrismorgan · · focus · HN ↗
sandworm101 · · focus · HN ↗
<a href="https://offgridsolarguide.com/lead-acid-battery-brands-for-off-grid/#Flooded_Lead-Acid_Batteries" rel="nofollow">https://offgridsolarguide.com/lead-acid-battery-brands-for-o...
chrismorgan · · focus · HN ↗
I haven’t known any Lithium-ion batteries yet, so I have no personal figures on them. But what I’ve heard is generally more like “they said 8–10 years but it’s still fine after 12”.
bluGill · · focus · HN ↗
You can get decades our of a proper lead-acid battery, but only if you correctly account for all those factors. Start with batteries that you add water regularly (I'm not sure if this is monthly or yearly). Then make sure you have more than enough so that even in the worst case power outage they finish at 30% charge (meaning most don't get close to 50% discharge - the 30% an educated guess but needs more research for your conditions since this needs to be a rare event, the more often you get the worst case outage the more charge needs to remain after). Finally make sure you have a good chargers - modern "battery tender" (a brand name - there are others) makes a big difference.
Lead-acid has been used in major large installation and have a long history of lasting for 20 years when treated properly.
Lithium batteries are still new enough that we don't have a history. We have educated guesses, but those guesses tend to be conservative. Maybe they will turn out to last just as long or even longer. Only time will tell if they are as good or not. However we also know you can abuse lithium batteries and get much worse life. (the Nissan Leaf is famous for significantly worse capacity at 8 years)
chrismorgan · · focus · HN ↗