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I have a Powerwall. It's price was competitive with a natural gas generator. I was surprised as well (I didn't expect the generator to be that expensive), but w

I have a Powerwall. It's price was competitive with a natural gas generator. I was surprised as well (I didn't expect the generator to be that expensive), but when they came within ballpark, the Powerwall was a no brainer. It does (supposed to have) sustainability assuming it's backed by solar and you have enough sun (as with all solar caveats). The best thing about the Powerwall is that it's not a standby system. It's active everyday. For my house, solar by day, battery by night, recycle, recharge, repeat. This means that when the rare event comes, I don't have to worry (as much) about it not working because I didn't run the thing for 6 months. It can fail anytime, but at least I can, ideally, deal with it while the grid is up, rather than have it fail when it's actually necessary. Also the power switchover is seamless. The Powerwall experience is, indeed, very good.

jacquesm 4y ago
How long do you have it and are you monitoring capacity degradation of the cells?
- whartung 4y ago
  Not long enough to see an impact (only had it a few months, the project took almost 2 years with all of the COVID relate shenanigans). Utilizing the Tesla apps, I honestly am not sure how I would monitor degradation over time. Perhaps were I to download the data, I might glean some insight from that. It's currently not something they highlight.
  - jacquesm 4y ago
    Ok! Slightly jealous with your setup, that sounds like a nice bit of kit you have there.
philwelch 4y ago
With a natural gas generator though, you don't run out of power once the batteries have depleted as long as you still have gas service.
- gopalv 4y ago
  > you don't run out of power once the batteries have depleted That's definitely true if you charge only via grid, but my friends who got a powerwall bought it because they need to off-set the 9 AM to 3 PM solar into a 6 PM to 10 pm usage scenario. Their bet is that in case of an earthquake that doesn't hit their house directly, the solar + powerwall + EVs is a more survivable setup compared to gas pipelines or a propane tank on-site. The other plus side is that they use the device every day, so if it isn't working, they'll know in a day - the previous experience portable generators (though admittedly it is just "burning man" every year) says they need last-minute wrenching if they're idle all year.
  - nnf 4y ago
    This is exactly why I went with Powerwalls. The batteries charge during the day from our solar array and then we use the stored electricity at night. I've only had the Powerwalls for a few months, but we've already had several four- and five-day stretches where our production was high enough and our usage low enough that we didn't buy any power from the utility at all. Contrast this with previous average power bills in the $400/mo range, which are now down to $15/mo. There have also been a couple of brief power outages (5-10 minutes) where the only reason we knew about the outage was that the utility texted us about it before the Tesla app notification appeared on my phone.
  - philwelch 4y ago
    Yeah, powerwall + solar is definitely more sustainable.
ameixaseca 4y ago
I can buy a tri-fuel 10/8kw+ generator for ~$1k, which can run all the standard stuff at home - and some extras, depending on fuel. How's a Powerwall competitive with that? Sure, no seamless transition and a bit of light maintenance. It all depends on how many times per year you need it and for how long. To be honest, I'd love to have a Powerwall - but with the huge cost difference it is unfortunately a no-no.
- theshrike79 4y ago
  Batteries + solar means that you're producing your own electricity every day too. You can't do that with a generator unless you start cooking biodiesel in your garage. For you light maintenance of a 10kW generator might be easy, but for most of us it isn't. It still has a ton of moving parts, each of which can fail and will be hard or impossible to replace in an emergency situation. It's like backups, you really don't have them unless you've restored them once. With a solar+battery setup you're testing the system every hour of every day. With a generator you need to actually schedule a test time every X months and make sure the fuel is still valid.
- whartung 4y ago
  Appreciate that what I got was a bid from a leading generator provider, and the cost included all of the installation, wiring, gas lines, trenching, permits, etc. Also appreciate that when it comes to mechanical things in general, I seem to excel at swinging hammers on to all 10 of my left thumbs. I'm not someone who's going to "do it myself" by any stretch. Just not my gift. I was as surprised as anyone at the overall cost of the project, and how the Powerwall had become competitive to it. I do not think I would have been as happy with the generator as I am with the Powerwall, and the daily utility of the system is just far higher than the occasional backup utility of the generator would have been.
gautamcgoel 4y ago
Don't the batteries wear down after a few years? I thought the batteries were only good for a few thousand charge/discharge cycles.
- pornel 4y ago
  a few thousand cycles * a few days of use per cycle = a decade or two.

jacquesm 4y ago

How long do you have it and are you monitoring capacity degradation of the cells?

whartung 4y ago
Not long enough to see an impact (only had it a few months, the project took almost 2 years with all of the COVID relate shenanigans). Utilizing the Tesla apps, I honestly am not sure how I would monitor degradation over time. Perhaps were I to download the data, I might glean some insight from that. It's currently not something they highlight.
- jacquesm 4y ago
  Ok! Slightly jealous with your setup, that sounds like a nice bit of kit you have there.

philwelch 4y ago

With a natural gas generator though, you don't run out of power once the batteries have depleted as long as you still have gas service.

gopalv 4y ago
> you don't run out of power once the batteries have depleted That's definitely true if you charge only via grid, but my friends who got a powerwall bought it because they need to off-set the 9 AM to 3 PM solar into a 6 PM to 10 pm usage scenario. Their bet is that in case of an earthquake that doesn't hit their house directly, the solar + powerwall + EVs is a more survivable setup compared to gas pipelines or a propane tank on-site. The other plus side is that they use the device every day, so if it isn't working, they'll know in a day - the previous experience portable generators (though admittedly it is just "burning man" every year) says they need last-minute wrenching if they're idle all year.
- nnf 4y ago
  This is exactly why I went with Powerwalls. The batteries charge during the day from our solar array and then we use the stored electricity at night. I've only had the Powerwalls for a few months, but we've already had several four- and five-day stretches where our production was high enough and our usage low enough that we didn't buy any power from the utility at all. Contrast this with previous average power bills in the $400/mo range, which are now down to $15/mo. There have also been a couple of brief power outages (5-10 minutes) where the only reason we knew about the outage was that the utility texted us about it before the Tesla app notification appeared on my phone.
- philwelch 4y ago
  Yeah, powerwall + solar is definitely more sustainable.

ameixaseca 4y ago

I can buy a tri-fuel 10/8kw+ generator for ~$1k, which can run all the standard stuff at home - and some extras, depending on fuel. How's a Powerwall competitive with that? Sure, no seamless transition and a bit of light maintenance. It all depends on how many times per year you need it and for how long. To be honest, I'd love to have a Powerwall - but with the huge cost difference it is unfortunately a no-no.

theshrike79 4y ago
Batteries + solar means that you're producing your own electricity every day too. You can't do that with a generator unless you start cooking biodiesel in your garage. For you light maintenance of a 10kW generator might be easy, but for most of us it isn't. It still has a ton of moving parts, each of which can fail and will be hard or impossible to replace in an emergency situation. It's like backups, you really don't have them unless you've restored them once. With a solar+battery setup you're testing the system every hour of every day. With a generator you need to actually schedule a test time every X months and make sure the fuel is still valid.
whartung 4y ago
Appreciate that what I got was a bid from a leading generator provider, and the cost included all of the installation, wiring, gas lines, trenching, permits, etc. Also appreciate that when it comes to mechanical things in general, I seem to excel at swinging hammers on to all 10 of my left thumbs. I'm not someone who's going to "do it myself" by any stretch. Just not my gift. I was as surprised as anyone at the overall cost of the project, and how the Powerwall had become competitive to it. I do not think I would have been as happy with the generator as I am with the Powerwall, and the daily utility of the system is just far higher than the occasional backup utility of the generator would have been.

gautamcgoel 4y ago

Don't the batteries wear down after a few years? I thought the batteries were only good for a few thousand charge/discharge cycles.

pornel 4y ago
a few thousand cycles * a few days of use per cycle = a decade or two.