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Powerwall 2 and Integrated Solar

powerwall.tesla.com

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Re: Powerwall 2 and Integrated Solar

#281

Post by binoct »

ghaff wrote: post #234
antisthenes wrote: post #184

Earlier quoted context omitted.

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.

What a sweeping generalization. Furthermore, unless you're in an area of the country that requires the use of a lot of AC--or you have electric baseboard heat--insulation doesn't even play that much into electricity usage.

I can see why one would bristle at the term 'cheap', but where energy efficiency is concerned there is a big difference between the EU and US. Energy costs are higher, regulations tend to be stricter, and usage lower in the EU.

On insulation, I'm assuming you mean in areas where AC isn't heavily used insulation doesn't help electricity bills if heat is provided by gas/oil?

Re: Powerwall 2 and Integrated Solar

#282

Post by swissoak »

manav wrote: post #75

I haven't looked into it yet, but I'm curious about using utilizing my Teslas in case of emergency for power. With 75kwh+ each (leased so no concern about cycles) I don't think I'd need a powerwall at home.

Your better bet would be buying a $1000 2000W generator. 4 gallons of gas will give you 24 hours of peak output. About 2 gallons for less than peak output for 24 hours. They're pretty quiet, too, and smaller than a carry-on suit case.

Re: Powerwall 2 and Integrated Solar

#283

Post by rsync »

beambot wrote: post #153
rsync wrote: post #97

Earlier quoted context omitted.

"The thing is cloud-connected, remote-controlled by Tesla. " If your use-case is backup power in case of utility failure, how does that work ? If utilities fail, the network connection to the battery may also fail, right ?

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.

Re: Powerwall 2 and Integrated Solar

#284

Post by JoeAltmaier »

mikeash wrote: post #269
JoeAltmaier wrote: post #242

Earlier quoted context omitted.

Good points. But for me, I live on 80 acres and it happens that the county natural gas pipeline runs under it. The easement (signed in the 60's) included the right to connect to the pipeline at will. When we built the house, we exercised that right. So even though I am rural, I don't have to buy liquid propane to heat my house. I'm tapped into a 100,000 home supply line. Its been depressurized maybe twice for mainten…

Nice setup! How much did connecting to the pipeline cost? Making an individual connection to something so large sounds expensive, but obviously I have no actual clue.

Fortunately there was a hairpin(?) connection across the road, so I agreed to connect there. That means they didn't have to depressurize just for me. Cost nothing (easement terms). However they charged me for the pipe to run the 200' from there to the house! I could have negotiated that better.

Re: Powerwall 2 and Integrated Solar

#285

Post by ghaff »

binoct wrote: post #281
ghaff wrote: post #234

Earlier quoted context omitted.

What a sweeping generalization. Furthermore, unless you're in an area of the country that requires the use of a lot of AC--or you have electric baseboard heat--insulation doesn't even play that much into electricity usage.

I can see why one would bristle at the term 'cheap', but where energy efficiency is concerned there is a big difference between the EU and US. Energy costs are higher, regulations tend to be stricter, and usage lower in the EU. On insulation, I'm assuming you mean in areas where AC isn't heavily used insulation doesn't help electricity bills if heat is provided by gas/oil?

>On insulation, I'm assuming you mean in areas where AC isn't heavily used insulation doesn't help electricity bills if heat is provided by gas/oil?

Correct. Heavy use of electric heat is fairly uncommon as it's relatively expensive. (In the Northeast, it would be considered a serious negative if a house had only electric heat.) Of course, insulation helps with overall energy usage if there's either a lot of heating, a lot of cooling, or both--however it's provided. I'm also sure the US tends to have larger houses, more large electric appliances, and other home features that increase electricity use.

Re: Powerwall 2 and Integrated Solar

#286

Post by jackrh »

pjc50 wrote: post #192
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…

I have a solar installation which makes it slightly harder to work out what I've actually used - I know what I've generated, and what I've paid for, but since the metering isn't net that doesn't quite let me work out actual usage. I have however got a very nifty graph of my solar generation (3.8kW roof system, 56N Scotland): https://flatline.org.uk/daystats.html What I think you can see if you poke about the graph is…

I don't know if this is available in the UK but in the US we can get devices like the one I got that allows us to monitor our usage and calculate usage vs generation. https://rainforestautomation.com/rfa-z109-eagle/

http://pvoutput.org/list.jsp?userid=41746 This web site collates all the data from your solar system (again, if it supports that like my enphase system) and the power company. $10 per year donation.

https://itunes.apple.com/us/app/pvoutput-pro/id994297624?mt=... And this little app adds a beautiful way to explore the data. $2 to get all the features.

This is all a bit involved to setup but the end product, that iOS app, is just brilliant. It just takes the data from pvoutput and massages it into an addicitive portable display. 1.5 years later and if the monitoring system is down for more than 12 hours my wife yells at me.

I am ignoring the powerwall because we have a sweetheart deal with net energy metering in southern california and the power delivery has been rock solid. So it would just be a minor insurance policy in case of a catastrophic event.

Re: Powerwall 2 and Integrated Solar

#287

Post by ghaff »

vollmond wrote: post #212
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…

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…

That's quite similar to me with a 4BR in Massachusetts.

I'm in the 550-600 kWH range for most of the year. Goes up a little bit in the summer if I'm running my 1-2 window unit ACs on occasion. In the summer, I do run several fans more or less continuously.

I do have an electric oven, dishwasher, washer, dryer, and several refrigerators. I also still have a fair number of halogen or other incandescent lights although I'm slowly swapping in LEDs. On the other hand, it's mostly just me and I do a fair bit of traveling so appliances and lighting probably don't add as much as they could.

I have a little bit of baseboard heat but I rarely use either that or my space heaters. (Forced hot water heat and water heater.)

My electric company says my use is about average in the area for the size of my house (albeit their figure is a few hundred square feet too low).

Re: Powerwall 2 and Integrated Solar

#288

Post by beambot »

JustSomeNobody wrote: post #163
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.

Except that doesn't always happen. Plenty of companies don't have the foresight to think about sane defaults. There was some IoT dog feeder that didn't have sane defaults posted here a while back. I know I know "but Tesla". Sure, maybe they'd be different. Or maybe not.

So let's just assume the worst, right?

Re: Powerwall 2 and Integrated Solar

#289

Post by RandomOpinion »

celticninja wrote: post #231
mrfusion wrote: post #220

Earlier quoted context omitted.

If you use a laptop a ups can power your router and modem for quite a long time. Or you can buy a huge ups for a lot less than 3000 and power a desktop machine too.

What's the running cost of a huge ups?

>What's the running cost of a huge ups?

A UPS will require a battery replacement every 10 years or so, regardless of whether you ever have to go on battery power or not. The UPS should automatically sense the status of the battery and warn you when a replacement is needed.

Pick a model from one of the major manufacturers and look up the replacement battery costs to get an idea of what it will cost.

Re: Powerwall 2 and Integrated Solar

#290

Post by ghaff »

mhenr18 wrote: post #259
Brakenshire wrote: post #190

Earlier quoted context omitted.

To convert that to kWh, assuming a 10-15c/kWh rate, that would equate to 40,000-60,000 kWh per year in the SW and 6,400-9,600 kWh in the NE. My figure for a 4 bed house in the UK is about 4,800 kWh per year.

I'm unsure about the US but I know that where I live a solid third or so of my power bills are a fixed rate that you pay to access the grid (so pretty much line rental). It doesn't feel to me like that's a particularly unique situation. So it's worth keeping in mind that the actual power usage figure may be a fair amount lower, and that your SW calcs are a bit of a worst case estimate.

That's not the case on my bill in the Northeast. There's a $4/month customer charge but everything else is kWh based (whether from the supplier or the distributor).
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