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Powerwall 2 and Integrated Solar

powerwall.tesla.com

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Re: Powerwall 2 and Integrated Solar

#291

Post by usrusr »

will_hughes wrote: post #210
usrusr wrote: post #169

Earlier quoted context omitted.

Phone batteries get hot, but they have plenty of thermal connection with the environment. This is nowhere close to the magnitude of a heat problem you would have within a massive multicell pack, where the direct environment of one hot cell would be a few other hot cells. Active cooling is not something you add to a pack the size of a Tesla to make it survive a few more cycles, it needs it to survive the first cycle.…

> Does Tesla come with an UI where you can do something along the lines of No, not like that. The charge UI interface has a 'daily' indicated range that you can set, and the top ~10% is marked 'Trip'. Example from a screenshot of the mobile app shows what i mean[1] The advice given to owners is to normally set the charge limit to somewhere in the daily range depending on their expected driving needs the following day…

Actually, that UI is pretty much exactly what I had in mind. All devices that control their own charging should have that "trip" switch. It's a shame that Android does not have an API to customize charge depth like that. I occasionally spend some idle thought on wondering how difficult it would be to overcome this limitation with a bluetooth-controlled charger. Well, I'm not an electrical engineer and "bringing the joys of self-asphyxiation to your phone" maybe would not be the most successful kickstarter ever either.

Re: Powerwall 2 and Integrated Solar

#292

Post by jhayward »

dirtyaura wrote: post #263
tghw wrote: post #258

Earlier quoted context omitted.

A lot of it has to do with geography. Europe is quite a bit further north, and doesn't experience some of the heat that the US does. It always helps me to remember that Rome is further north than New York.

But many parts of Europe need heating instead of AC. I think it has more to do with house sizes. More Europeans live in cities compared to US and thus have on average smaller apartments/houses. Also there might be cultural values in the play, at least central and nordic countries are traditionally quite efficiency oriented.

Electric heating is rarely used; there are many other heat sources available. There are no other energy sources available for cooling (passive cooling design aside), so comparing a heating-dominated climate to a cooling-dominated one will inevitably show more electric consumption in the hot zone. Has nothing to do with efficiency.

Re: Powerwall 2 and Integrated Solar

#293

Post by agumonkey »

antisthenes wrote: post #184
Loic wrote: post #118

Quick question for the people living in the US (Target customers of the Powerwall). What is your yearly power usage? On the website[0] they put for sizing 10kWh/day/BR. Which means 14600kWh/year for a 4 bedroom house. Here in Germany, working from home with a 4BR+office house, we are using 2550kWh/year. So, I suppose the Tesla sizing is to support a "peak day" usage, but still, I am surprised by the calculations. Thi…

The reason their calculations are so high is because in the US, typical houses are made as cheaply as possible, pretty much with paper, plastic and vastly insufficient insulation. That may have changed in the recent years, but holds true for most residential properties built before 1980.

Seems like Western Europe is getting up to speed with standardized insulation. People are monitoring heat leaks in buildings etc.

Two things: 1) I wonder how much energy could be "saved" with proper insulation. Per Country, per planet. 2) Insulation seems like a human sense, by that I mean, whenever I've lived in an old, stone wall house, I enjoyed the delay in temperature. It's still refreshing when the sun hits hard, and still mildly warm when cold settles.

More efficient lifestyle and better quality of life ? I'd sign.

Re: Powerwall 2 and Integrated Solar

#294

Post by semi-extrinsic »

ghaff wrote: post #280
semi-extrinsic wrote: post #161

Earlier quoted context omitted.

If you're concerned about emergencies: for $38 you get a self-contained LED camping lantern that lasts for 30 days on a single charge [1] at the lowest brightness, or 2 days (off at night) on full brightness. For a tiny fraction of the price of a Tesla-based emergency power solution, you could buy two of those for every room, plus an RV cooking gas burner and a big propane tank that covers heating, making food and ho…

The main thing I'd really like to be able to backup is my (oil) furnace in the winter so that it could continue to operate in a power outage. Though,truth be told, I could get a bigger propane tank and either run some backup heat off that or a generator for a couple of my circuits. Pretty much everything else can go out. Obviously food could spoil in an extended outage, but that's a fairly modest cost in the grand sc…

How about installing a wood-burning fireplace? Super cozy also in daily life, probably adds to the resale value of your house, and you can keep firewood indefinitely as long as it's dry.

As for food: stock canned goods for a week. (There's a reason preppers have rooms full of the stuff.) You probably also want to stock bottled water for a week, just in case.

Re: Powerwall 2 and Integrated Solar

#295

Post by ghaff »

semi-extrinsic wrote: post #294
ghaff wrote: post #280

Earlier quoted context omitted.

The main thing I'd really like to be able to backup is my (oil) furnace in the winter so that it could continue to operate in a power outage. Though,truth be told, I could get a bigger propane tank and either run some backup heat off that or a generator for a couple of my circuits. Pretty much everything else can go out. Obviously food could spoil in an extended outage, but that's a fairly modest cost in the grand sc…

How about installing a wood-burning fireplace? Super cozy also in daily life, probably adds to the resale value of your house, and you can keep firewood indefinitely as long as it's dry. As for food: stock canned goods for a week. (There's a reason preppers have rooms full of the stuff.) You probably also want to stock bottled water for a week, just in case.

I have both a wood stove and a wood burning fireplace. The backup was part of my justification for getting the stove. I don't know if it would be sufficient if I lost power for an extended period of time in really cold weather to keep pipes from freezing but you can't guard against every eventuality. (I also worry about what can happen when I'm not around.)

As for the food, I'm close enough to civilization that I'm not too worried. Worst case I get snowed in for a couple of days. I won't starve.

Re: Powerwall 2 and Integrated Solar

#296

Post by illumin8 »

usrusr wrote: post #291
will_hughes wrote: post #210

Earlier quoted context omitted.

> Does Tesla come with an UI where you can do something along the lines of No, not like that. The charge UI interface has a 'daily' indicated range that you can set, and the top ~10% is marked 'Trip'. Example from a screenshot of the mobile app shows what i mean[1] The advice given to owners is to normally set the charge limit to somewhere in the daily range depending on their expected driving needs the following day…

Actually, that UI is pretty much exactly what I had in mind. All devices that control their own charging should have that "trip" switch. It's a shame that Android does not have an API to customize charge depth like that. I occasionally spend some idle thought on wondering how difficult it would be to overcome this limitation with a bluetooth-controlled charger. Well, I'm not an electrical engineer and "bringing the j…

Most decent smartphones are already doing battery management and avoiding extreme draining or charging of the cells.

Think about it this way: If your phone has 8 hours of use, chances are the battery could really give you 9 or 10 hours if it was fully charged, but the manufacturer is software limiting it to prolong the life of the battery.

Re: Powerwall 2 and Integrated Solar

#297

Post by Spooky23 »

swerling wrote: post #267
vollmond wrote: post #212

Earlier quoted context omitted.

Just to add more anecdata: * 150-year-old rowhome in central Pennsylvania, USA. * 2 adults, 2 small children, dog/cat. * Window unit air conditioners (2 running most of the time in summer, with a 3rd in the attic office running a lot less since I don't use it much). Hoping to install mini-split system eventually, but it's low priority * Gas steam heat * Gas stove/oven * Gas water heater (I think) * Electric baseboard…

I've got an 80-year-old row house in Queens, NY. Family of 4, no pets. Our electricity usage is well below yours. We don't make a huge effort to conserve, and I don't believe our house is particularly well insulated. We have no special energy tech, unless you count the LED lights. We have a lot of electronic gizmos sipping away at any given time. Winter: we don't have the baseboard heaters, but I work from home most…

The GP had electric baseboard heat. That's a black hole for electricity usage purposes.

Re: Powerwall 2 and Integrated Solar

#298

Post by pault »

Keyframe wrote: post #219
j1vms wrote: post #165

Earlier quoted context omitted.

> The big difference is because of air conditioning and baseboard heating (...) Which makes you wonder why there is not as much high-profile attention on A/C (and to a lesser extent electrical heating) as being a problem worthy of rethinking by Silicon Valley (perhaps even ahead of solar, in North America).

It might be (it is) anecdotal, but as someone from Europe it struck me odd how much Americans love their A/C. Too much, in fact. Almost everywhere I went it was too cold. Somewhat like in SE Asia. That might be the answer to high energy use.

Another anecdote: I live in Belize and my girlfriend runs a hostel, and we can always tell which rooms have guests from the southern US because the AC will be set to 18C (~64F). For some reason northerners don't tend to do this, I assume because they don't use AC as often at home. The Texans I know are the worst. They make their apartments so cold I need a blanket if I'm going to stay for a movie, and they sleep under massive down comforters. In the tropics! It's so maddeningly wasteful. I rarely use my AC and sleep under a single top sheet with no discomfort.

Re: Powerwall 2 and Integrated Solar

#299

Post by Keyframe »

pault wrote: post #298
Keyframe wrote: post #219

Earlier quoted context omitted.

It might be (it is) anecdotal, but as someone from Europe it struck me odd how much Americans love their A/C. Too much, in fact. Almost everywhere I went it was too cold. Somewhat like in SE Asia. That might be the answer to high energy use.

Another anecdote: I live in Belize and my girlfriend runs a hostel, and we can always tell which rooms have guests from the southern US because the AC will be set to 18C (~64F). For some reason northerners don't tend to do this, I assume because they don't use AC as often at home. The Texans I know are the worst. They make their apartments so cold I need a blanket if I'm going to stay for a movie, and they sleep unde…

I live where it tends to get hot and humid (not tropics humid though), but turn on A/C only if it's really unbearable at night. Even then, at most 5C difference. Usually, single top sheet, as you've said, a cool drink and maybe a fan is enough. I understand that humidity is tough though, but one can get dehumidifying alone from A/C or a standalone dehumidifier.

Re: Powerwall 2 and Integrated Solar

#300

Post by greglindahl »

rsync wrote: post #283
beambot wrote: post #153

Earlier quoted context omitted.

It's not hard to imagine the solution: fall back to sane defaults like every other system not connected to the cloud.

"It's not hard to imagine the solution: fall back to sane defaults like every other system not connected to the cloud." Almost nothing behaves like this - even if it claims to. A good example is the sonos music system. They claim that it will work properly (with your local music source) without Internet access. That is false.

One example is Tesla cars. They work fine when not connected to the cloud, although you'll want to occasionally connect to install new firmware.

This whole thread is based on speculation -- the details are not yet known.

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