Wall of 10 Tesla Powerwall 2 units

[h2ofun]

I live in Southern California where the utility rates are some of the highest in the country (SDG&E) and since I installed my Solar City (Tesla) panels, the increase in rates the Public Utilities Commission has approved over the last 6 years have erased most of what I had hoped to save when I first installed my unit. San Diego is hopefully soon going to "turn out to pasture" the contract with SDG&E and look elsewhere. NOT SOON ENOUGH!
I wish Tesla were a bit more aggressive with existing households with panels in informing those of us currently trapped by excessive
electricity rates, options such as increasing our existing number of panels and Powerwall pricing and benefits of an install. I continue to wait and hope that the price of the Powerball units will come down in price. Now that production of additional battery facilities within the U.S. and in China, shouldn't pricing become more affordable?

supply vs demand, PW prices easily could go up and up and ...

 

[Big Earl]

We could use such a system for a 100% electric Passive style house with 1 EV (Tesla M3). Our heat is radiant floor with a single 24KW instantaneous water heater which does floor and domestic. We have a couple electric fireplaces for small area extra warmth, and in the summer 1 13000 BTU AC unit cools the entire house easily (2700 sq ft). So on cold days, we use up to about 146kwh of energy for floor heating mostly. So I can easily see this being a good setup for us. Especially the wind component. But alas that was a real big investment, and I doubt we would do it that big.

Being in Massachusetts, I think you would benefit greatly from installing an air-source heat pump in your in-floor radiant heat loop. You could keep the 24 kW electric unit in-line for backup use in sub-freezing weather.

We have a 3700 square foot, all-electric, home in the PNW with 4.5 ton heat pump radiant floor heat, using 20 - 50 kWh/day for heat. That’s supplemented by a propane fireplace (for instant personal comfort) and a high efficiency wood stove (for days below freezing).

Our next upgrade will be a heat pump water heater to replace a standard 40 gallon electric unit in the detached garage and MIL suite.

Our long-term goal is to be grid-independent, if necessary. The location is prone to outages and land slides that could isolate us for an extended period of time. We have a 27 kW propane generator but it’s only on a 500 gallon tank, providing a week or two of power if we rationed our usage. Ideally, we’d like to add some solar, although the site isn’t well-suited to it, a wind generator, although I’m not sure how local code feels about that, and battery storage.

Anyway, this long post is to make the observation that consumption should be minimized before exploring battery back-up options. A heat pump could cut the energy you spend heating in half which, in addition to paying for itself, will reduce the amount of battery storage and solar you need to install.

 

[Zeronet]

why do you need that much? I don't think I could use more than 100kwh in a day even with a 5T ac

This is crazy. Either it is some community of 20 or so residences, or the Tzar's winter pallace. My 2000 sf house never uses more than 25 kWh a day either with peak winter heating or peak summer cooling with a Heat Pump AND Tesla charging.

Spending just a little on insulation and passive heating might be 10 times as cost-effective.

 

[h2ofun]

This is crazy. Either it is some community of 20 or so residences, or the Tzar's winter pallace. My 2000 sf house never uses more than 25 kWh a day either with peak winter heating or peak summer cooling with a Heat Pump AND Tesla charging.

Spending just a little on insulation and passive heating might be 10 times as cost-effective.

You are lucky. I have redid all my stuff in house for insulation. 3300 sf home. Use about 60 to 80 kwh per day, and I have the house at 64, and it is been a very warm winter for us so far in Calif. I guess I will be crazy if I get the number of PW's I am trying for

 

[SMAlset]

We are in Cheyenne, Wyoming and have recently finished installing and bringing online 10 Powerwall 2 units (140 kWh of which 135 kWh is usable). The system is grid tied. We have 4 Skystream 3.7 residential scale wind turbines rated at 2.4 kW each, and just under 8 rated kW of solar PV in trackers with Enphase microinverters. We also have a 22 kW Generac backup generator which is fueled from a 250 gallon propane tank. This system is whole house back up of our all electric home, which has a ground source heat pump for HVAC. We have 3 EVs, a 2012 Signature Edition P85 Tesla Model S we purchased CPO from Tesla in 2016, a 2014 Nissan LEAF SL, and a 2008 Toyota Prius which has been converted to a plug-in hybrid with 17 kWh of salvaged 2013 LEAF batteries. We've been driving electric since 2007. Our previous EVs have been donated to the Historic Electric Vehicle Foundation Museum in Kingman, AZ. Here's a link to an online album of our EVs: Jason Bloomberg's 1993 Eagle Summit Wagon

These are all "Founders Edition" cases, and getting them was somewhat of a surprise. I bought a "referral premium" from a friend who earned one and lived in an apartment where he couldn't install it. I then purchased 9 more Powerwall 2 units from Tesla, fully expecting to get the regular white ones. Tesla knew we have one Founder's Edition Powerwall 2 and the people I was working with, without my asking for it, sent these so they matched the first one. I have no idea how they were able to do it, but it does make a nice installation which color coordinates well with our Signature Red Model S.

This is the maximal size of an installation with Powerwall 2 units. I haven't seen any others, but would love to see more of them. This is the first Powerwall installation in Cheyenne, and the largest installation in Wyoming.View attachment 627344

I am curious if there is anyone else in this group with 10 Powerwall 2 units in their system and what your experiences with have been?

Wow that looks amazing. Quite the setup and so cool you’ve been an early adopter as well.

When we were waiting for our install date we were contacted by someone at Tesla asking if we would be interested in having the red version ones. We had 3 PWs on order but I had planned out a grey and white garage “look” so we turned down the offer. At the time I suspected that PWs in general were getting in short supply (late spring/summer time) and they had an excess of the red for rewards so were calling people to ask so as to fill as many PW installation orders as they could and get as many people hooked up as they could sooner than later. The fact you had 10 units sure helped deplete that inventory! All red is a definitely a cool look and a mixed color arrangement would have driven me crazy lol.

You were smart to paint that install wall ahead of time. We did the same in our garage and suggest everyone waiting for installation give serious thought to painting at least that one wall. We had all our equipment (inverter and GW2) installed on the same wall as PWs. In our case we didn’t realize our other wall would have 2 load centers installed on it too so that wall didn’t get fresh paint .

 

[Zeronet]

You are lucky. I have redid all my stuff in house for insulation. 3300 sf home. Use about 60 to 80 kwh per day, and I have the house at 64, and it is been a very warm winter for us so far in Calif.

I guess ADDING insolation is not the same as BUILDING insulation. My 5 year-old house has foot-thick insulated concrete form walls and maybe an R100 spray foam ceiling in addition to some passive heating features. Near 5000' in Arizona we have been getting 20 degree lows all month. I keep it at 72 in winter and 75 in summer. Addmittedly, both myself and my builder (NRG, Sedona) are energy fanatics.

I have a friend in Flagstaff with foot-thick flyash block (Flexcrete) walls, 2 4' x 8' Trombe walls facing south and NO heating system other than a little Swedish wood stove. Flagstaff (7000') had a low of 10 and a high of 40 this week.

The Sinagua indians who lived here 800 years ago had 2 foot thick rock walls, while the Spanish later had 2 foot thick adobe walls. The oldest city building in the United States (Palace of the Govenors, Santa Fe, NM) was built in 1610 and has 3 foot thick adobe walls. It is very comfortable inside after over 400 years.

Some day our building codes may catch up to the Sinagua or Spanish.

 

[Ritz]

I live in Southern California where the utility rates are some of the highest in the country (SDG&E) and since I installed my Solar City (Tesla) panels, the increase in rates the Public Utilities Commission has approved over the last 6 years have erased most of what I had hoped to save when I first installed my unit. San Diego is hopefully soon going to "turn out to pasture" the contract with SDG&E and look elsewhere. NOT SOON ENOUGH!
I wish Tesla were a bit more aggressive with existing households with panels in informing those of us currently trapped by excessive
electricity rates, options such as increasing our existing number of panels and Powerwall pricing and benefits of an install. I continue to wait and hope that the price of the Powerball units will come down in price. Now that production of additional battery facilities within the U.S. and in China, shouldn't pricing become more affordable?

And people wonder why there was a net loss of 135,600 folks from California last year. There are PLENTY of other places to live that don't require a 2nd mortgage to pay your electric bill. For reference, here are the states that are in the top 10 and bottom 10 in terms of cost per kwh.

Electricity Rates by State (January 2021) | ChooseEnergy.com®

With the "new normal" of working from home, perhaps it's time to explore alternatives.

Of course, if you can lay your hands on panels, the payback period should be significantly reduced when you consider what you're paying your local utility.

Best,

 

[Ritz]

You are lucky. I have redid all my stuff in house for insulation. 3300 sf home. Use about 60 to 80 kwh per day, and I have the house at 64, and it is been a very warm winter for us so far in Calif. I guess I will be crazy if I get the number of PW's I am trying for

That's quite a bit of power. We normally use about 1000kwh per month which is about half of what you're using. That's in a 5500sq/ft house (about 15 years old) and 8 tons of heat pump HVAC draw and a family of 4 (5 if you include the Tesla 3...heh). The only real effort I've made to curtail consumption has been to replace both heat pumps last year and I've switched all the lighting to LED. And I was complaining about my bill when we're only paying 11 cents per kwh.

Best,

 

[TMThree]

Excellent question. We lived with off grid renewable energy since the 1980s at our previous home. Ideally, to function as an off grid home, one should have sufficient batteries to meet load for 3 - 7 under zero to low gain (power generation) days, and be able to sustain that during the heaviest loads of the year (if you don't want to rely on a back up generator).

I think for most people a NG generator would be far more cost effective. The number of days you need that much capacity are small. A NG generator would be the cost of maybe 2 powerwalls.

No matter how many powerwalls you get, there can always be a week of clouds, a forest fire, etc. that hampers the sky. Best you can do is plan for the most likely situation and a backup plan if that fails.

 

[jboy210]

I think for most people a NG generator would be far more cost effective. The number of days you need that much capacity are small. A NG generator would be the cost of maybe 2 powerwalls.

No matter how many powerwalls you get, there can always be a week of clouds, a forest fire, etc. that hampers the sky. Best you can do is plan for the most likely situation and a backup plan if that fails.

It can depend on your situation. In addition to backup, for us, the Powerwalls help reduce our power bill by letting us not need grid power during the high rate times every weekday evening and in the summer for days. This is a pretty big cost savings.

 

[miimura]

I think for most people a NG generator would be far more cost effective. The number of days you need that much capacity are small. A NG generator would be the cost of maybe 2 powerwalls.

No matter how many powerwalls you get, there can always be a week of clouds, a forest fire, etc. that hampers the sky. Best you can do is plan for the most likely situation and a backup plan if that fails.

A lot of people, especially ones like the OP, don't have NG supply anywhere nearby. Their only alternative is delivered propane which is much more expensive per unit of energy.

 

[TMThree]

A lot of people, especially ones like the OP, don't have NG supply anywhere nearby. Their only alternative is delivered propane which is much more expensive per unit of energy.

yeah, and time of use can make powerwalls have ROI. In my area, we get no writeoffs, no TOU, so the powerwalls end up being a cost and hard to justify. Especially if you think the new cheaper battery cells might make it into the next generation.

 

[CrazyRabbit]

I wish I had in floor radiant heat so I could use my slab as a thermal battery and only heat it when the my solar was producing. Solar is cheap, and more versatile then solar (not PV) loop, well if you had a pool to heat in the summer maybe another story.

 

[Jason Bloomberg]

Cool, if you need more trackers I have two Zomeworks that I never installed I will let go at a good price. I see from a previous comment you have a really high load to supply. Mine is probably below 50kwhr. I have been investigating going off grid as well. A lot of people look at EVs and solar independently but I personally see the most benefit comes from being off grid and full electric on transportation. The best benefit I see from new energy is cutting umbilical cord from corporations that want you dependent on their supply for survival. I am surprised you came to the conclusion of up to 7 days with zero power from your solar/wind. The area you are in should be relatively cloud free and lots of wind. Have you based that on actual occurrences? What was the lowest power output/longest time frame you have experienced so far? Do you think that would be reduced with more solar? What is output of solar on cloudies days as a percentage of normal? My current gut level estimate here in Alabama is 3 days would cover high 90 percent of situations, but I may be underestimating. By the way, I have recently been researching mini split heat pump systems and it turns out they come very close to gains from ground source by eliminating duct losses etc.

There are a lot of variables here. My experience of having sufficient battery to las 3 - 7 zero to low days comes from over 20 years with living with off-grid solar PV and wind. That was in Chadron, NE in a different house, with different equipment, and a different location than where we are now. We will see how this system performs with what initially appears to be 1-2 days of worst case scenario reserves. We have had here 3-4 days of very low gain days during the year. Alabama isn't Wyoming, so you can't project what works for you, including sunshine, with what happens here. I'm basing my estimates of our needs on over 2 years of monitoring with SENSE. We installed our ground source heat pump in 2014. At that time, mini-splits were not as efficient as they are now, but still are not as efficient as ground source heat pumps. Where you are, they may be sufficient. Here we can get weeks of sub-zero weather, and mini splits will resort to supplemental heating elements if they are air - exchange, rather than ground exchange units. We also like having the centralized HVAC so we can filter, and UV treat the air, as well as it is quieter throughout the house than mini splits.

 

[Jason Bloomberg]

I live in Southern California where the utility rates are some of the highest in the country (SDG&E) and since I installed my Solar City (Tesla) panels, the increase in rates the Public Utilities Commission has approved over the last 6 years have erased most of what I had hoped to save when I first installed my unit. San Diego is hopefully soon going to "turn out to pasture" the contract with SDG&E and look elsewhere. NOT SOON ENOUGH!
I wish Tesla were a bit more aggressive with existing households with panels in informing those of us currently trapped by excessive
electricity rates, options such as increasing our existing number of panels and Powerwall pricing and benefits of an install. I continue to wait and hope that the price of the Powerball units will come down in price. Now that production of additional battery facilities within the U.S. and in China, shouldn't pricing become more affordable?

Powerwall units have increased $500 per unit in late 2020. Ours were ordered and paid for prior to that increase. I don't see them coming down in price any time soon.

 

[petit_bateau]

@Jason Bloomberg : can I ask how you are getting along with the Skystreams ? When did they get installed ? What hub height ? What wind resource ? (nice set up by the way)

 

[navguy12]

@Jason Bloomberg: may I ask a few novice questions (awesome setup by the way)?

1. Can you provide the dimensions as depicted:

2. Can these batteries actually be installed out doors in a climate where winter temps descend below -25C?

3. If these batteries are installed outdoors, is there some sort of software "anti theft" protocols built in (such as operation tied to a specific GPS location for example)?

My third question is simply a concern I would have that these items could be a portable commodity if there are no built in safeties preventing unauthorized removal. Cheers. Thanks.

 

[h2ofun]

@Jason Bloomberg: may I ask a few novice questions (awesome setup by the way)?

1. Can you provide the dimensions as depicted:

View attachment 628379

2. Can these batteries actually be installed out doors in a climate where winter temps descend below -25C?

3. If these batteries are installed outdoors, is there some sort of software "anti theft" protocols built in (such as operation tied to a specific GPS location for example)?

My third question is simply a concern I would have that these items could be a portable commodity if there are no built in safeties preventing unauthorized removal. Cheers. Thanks.

If I get some, mine will be outside. If someone wants to steal, they can go for it. Would not be easy

 

[Barrygold]

Powerwall units have increased $500 per unit in late 2020. Ours were ordered and paid for prior to that increase. I don't see them coming down in price any time soon.

And another $500 today
Tesla increases the price of Powerwall again - Electrek

 

[Ampster]

If I get some, mine will be outside. If someone wants to steal, they can go for it. Would not be easy

I agree. Even if they did, what would they do with them? Can they actually run without a long term connection to the mothership? They have to have some identifying serial number or Mac address so if they were connected to the cloud Tesla could disable the firmware. It is not the same concern about turning off a Tesla going 70 mph down the freeway.