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Elon tweets: Solar Roof and solar panels will only be sold integrated with Powerwall

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Nov 28, 2018
10,827
12,560
Riverside Co. CA
I appreciate the notice from @willow_hiller, but am hopeful that in this specific section of TMC, we can avoid the rampant speculation and accusations that tend to happen elsewhere on both this site, and the internet in general.

Translation, it would be nice if we dont just rampantly speculate here, and wait to react until we have some actual information other than cryptic tweets. Note, thats my hope as a regular person, and has nothing to do with moderation. Of course, people can rampantly speculate away if it makes them happy.
 

willow_hiller

Active Member
Apr 3, 2019
3,248
16,458
Maryland
Translation, it would be nice if we dont just rampantly speculate here, and wait to react until we have some actual information other than cryptic tweets.

If Elon is correct about his timing, we won't have to wait long to find out. Hopefully we get an official announcement next week, and we don't need to wait until new orders start getting spec sheets to see what equipment they're receiving.
 

MP3Mike

Well-Known Member
Feb 1, 2016
16,516
38,694
Oregon
I had investigated some DC coupled ESS before I decided to just get an AC coupled Powerwall. The risk of pushing all generation sources through a single inverter seemed too risky due to how often those things fail.

From what I have seen the Powerwall inverters are much more reliable than most of the solar inverters. And I would hope that the new Tesla Solar Inverters would be as, or more, reliable. (Hopefully they use their experience in creating utility/grid level/quality inverters in their residential designs.)
 

wwu123

Member
Apr 11, 2017
425
350
Silicon Valley, CA
Now that I read it again it does appear you’re correct. No more Subpanel for battery to backup only some parts of the house. Now you’re whole house must be backed up with the battery(s) to the main panel. This way you MUST by enough batteries to back up your entire house, thus a way for them to sell more batteries.

It’s the first sentence that is concerning. “Solar feeding exclusively to battery.”
So if I understand, the whole existing panel is a backup panel at that point ...

One person on this subforum is having trouble getting a new 30A water heater circuit to the backup panel after installing Powerwalls, another I believe is having challenges adding a Tesla Wall Connector to their backup panel afterwards. Would this limit the ability to add more loads, or install a Tesla charger, to the existing main panel?
 

charlesj

Active Member
Oct 22, 2019
1,267
294
Monterey, CA
Keep in mind the restrictions on Powerwall feeding the grid directly are caused by the wording of the Solar Federal Tax Credit. And the Biden administration is now working on a separate energy storage tax credit that would eliminate that requirement.

In other countries where Tesla installs Powerwalls, they're free to buy and sell energy from the grid at will.
What I was really after is can the PV energy be sent to the grid when home load is less than production and battery is full? That requires an inverter someplace and a smart control box, Gateway to control power flow.
"Solar exclusively to batter" needs to be clarified for sure.
 
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SMAlset

Well-Known Member
Mar 4, 2017
9,198
10,071
SF Bay Area
Ohhhh...

That makes sense. Since both solar and battery are DC there’s no need for an inverter between the two. This would also reduce energy loss between the panels and and battery too.

after they just came out with their own inverter? Interesting if that's true.

We have a solar panel/PW system using the Solar Edge WaveHD inverter. Whole house back up. What power doesn’t go into our PWs goes back to the grid. Will be very curious to see how these tweets get further explained.

Should possibly make for an interesting earnings call on Monday.
 
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SMAlset

Well-Known Member
Mar 4, 2017
9,198
10,071
SF Bay Area
If the latter is the case, no inverter except in the battery to run the house, no feeding the grid by solar when load is limited and battery is full, solar is shut off, lost generation, and no net energy metering. Just wow.
With heavy restrictions here in California on how many Powerwalls and where and distancing of them, people here simply couldn’t add enough Powerwalls to their house if they wanted to. Heck we charge our two cars now during the day because we are now producing more electricity than we consume. Love it. No A/C need yet so that’s going to be an interesting variable down the road soon for us. I just can’t see anyone paying to toss solar power away (if not stored in PW or sent to grid). Definitely needs clarifying.
 

marty2112

Member
Apr 6, 2015
287
206
Petaluma, CA
Lets see how this all plays out. Assuming he will address next week. I have had PW, subscription panels (installed/removed), and a solar roof added over the past year. The disconnect from each of these groups is amazing/embarrassing. Consolidation would be a fantastic idea. Now, if they are doing it for other reasons (I was quite bummed that I didn't get a Tesla inverter), then shame on them. I'm in Petaluma, so all my Enphase buddies are teasing me even more...
 

fiatlux

Member
Jul 28, 2018
17
31
Palo Alto, CA
Spot-on SMAIset! We're in California and the expense + waste + physical-layout & extra boxes required are a major turn-off. I've waffled back and forth for months wanting to place an order for 8kw + 3PW, as we really want full house backup (200amp main panel). However the thought of 3PW + gateway + inverter + mandated cut-off switches everywhere ==> ~10 boxes on the side of the house spanning 15 feet of wall is a rube-goldberg deal breaker. Also, as packaged, the 3PW are needed for full-house backup (amps), but would have a capacity far higher than what we could produce + consume daily.

Here's what I'm hoping and guessing Tesla might be up to:
  • Larger amp-capacity Powerwalls, lowering the number of powerwalls for typical homes to one or two (one ideal!). I suspect the inverter is the bottleneck here and not the battery cells. In fact, eliminating the inverter (per PW) should reduce cost significantly.
  • Larger kWh-capacity Powerwalls, i.e. going from 13kWh to ~25kWh. Like many, we basically want to cover overnight usage and have some basic grid-outage-backup ability. We're ok to lower our consumption during rare outages (seriously, over 10 years we had an 8h outage and a few 2-3h outages). High usage is typically during the day when the sun is shining, and most don't use much overnight etc... 25kW would give us ~2/3 of a full day's use, and plenty to go overnight.
  • Just like the tweet said: solar-dc -> powerwall with charge/flow-through controller -> inverter w/integrated gateway.
  • I suspect this setup will also allow power to flow back into the grid, just that they will want to emphasize how cool this all is and maximize that margin. Also, many areas are lowering NEM rates, so there is a growing benefit to local storage.

Now in theory we're down to two beautiful Tesla branded boxes on the side of the house, with far less mounting and far less conduit/cabling/termination. We've also reduced the number of physical shells, controllers/monitoring, and most importantly inverters from 4x to 1x.

This all would (a) motivate us to immediately place an order, (b) raise Tesla Solar's margin from ~0 to > 20%, (c) yes as others mentioned, lower demand for those wanting the cheapest option, (d) hopefully allow the business to raise the quality of support, given the margin, further encouraging fence-sitters like us.
 
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aswami

Member
Feb 12, 2021
82
75
Phoenix
Keep in mind the restrictions on Powerwall feeding the grid directly are caused by the wording of the Solar Federal Tax Credit. And the Biden administration is now working on a separate energy storage tax credit that would eliminate that requirement.

In other countries where Tesla installs Powerwalls, they're free to buy and sell energy from the grid at will.

I believe that you are absolutely right. Even I see this as a positive to both Tesla and their customers. Please note the following:

1. While it's true that the option of "cheap" Tesla solar is gone. People get solar + battery backup from Tesla at about the same cost as solar only from others.

2. You are not longer in a situation where there is a power outage on a bright sunny day, your solar panels are producing a lot of power, and your home is still powerless. This is the current issue with no-battery solar installs.

3. The option to sell excess generation back to the grid will continue to exist. Nowhere does Elon say that this will go away.

4. With power being sold from Powerwalls, there is a lot more flexibility and control as to when and how much power will be sold back to the grid. This opens up a whole slew of opportunities to maximize profits for both Tesla and the customers. The two places (Massachusetts and UK) where Tesla is running pilot projects to sell power from the Powerwall to the grid, customers are being paid BIG bucks because Tesla sells the power during peak demand periods when it gets the most money.

Only question / hope I have: For those of us who have installed Powerwalls in the old design, I hope there won't be any issue in participating in any special Powerwall energy sale program that Tesla introduces! Does anyone know if the current Powerwall + solar install design allows for energy to be sold from Powerwall to teh grid?
 

JeremyWhaling

Member
Jul 25, 2019
114
87
So. Cal.
After reading these tweets I feel dread. Hopefully my second small solar order currently in permitting to do our east roof doesn’t magically double in cost like those solar roofs. I’d love a power wall but we really don’t need one (power too reliable I guess).
 

wwu123

Member
Apr 11, 2017
425
350
Silicon Valley, CA
Also how would this work for those of us who currently have the main panel type where the left half of the panel is where the power company plugs their meter in, and the right side is where all the breakers are? How would Tesla be able to insert in between those two?
 

vicpw

Member
Sep 23, 2019
10
3
vic aus
I'm assuming the bundling is also to solve the problem of Tesla looking bad after it costs a small fortune to get it all installed and then the utility company decides if you can use it. Hours after Elon's reply was when the announcement was from now on it's bundled

Screenshot 2021-04-22 164101.png
 

aswami

Member
Feb 12, 2021
82
75
Phoenix
I'm assuming the bundling is also to solve the problem of Tesla looking bad after it costs a small fortune to get it all installed and then the utility company decides if you can use it. Hours after Elon's reply was when the announcement was from now on it's bundled

View attachment 655920

"Utility permission is still needed for when Powerwall is full & can stabilize the grid."
= Powerwall used to sell power at high prices to the utility during times of high demand
= Profit for Tesla and the customer!
 

bob_p

Active Member
Apr 5, 2012
3,727
2,922
What's likely driving this is limitations in how many batteries can be provided for PowerWall manufacturing. Production of Semi and CyberTruck have also been affected because Tesla can't produce enough batteries to ramp up production for those vehicles. So it's not surprising Tesla is putting limits on PowerWall configurations - since they can't produce enough PowerWalls to meet their internal and external demand.

Based on Musk/Tesla's track record - would not be surprised to see this policy change again. Tesla is structured to make rapid (and sometimes frequent) changes to strategy, products and pricing - so if they are able to get more batteries for PowerWall production, this policy could change again.

Though for now, they are creating an opening for solar competitors to take some of the energy storage and solar business away.
 
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willow_hiller

Active Member
Apr 3, 2019
3,248
16,458
Maryland
A small flurry of tweets from Elon last night about Tesla Energy. I think this one about the 7.6 kW Tesla Inverter in particular might be relevant to this discussion:
"Newest units can probably do as much as 10kW continuous & double that in peak power at 30C ambient temp. In house power vernacular, this translates to ~80LRA (soft start of 3.5 ton HVAC). Two Powerwalls would double this, three would triple, etc."

Sounds like Elon is saying the solar inverter would feed 10 kW into the home grid, and adding two Powerwalls (5 kW each) would allow a homeowner to run a device up to 20 kW. Are current Powerwall installations able to deliver power in parallel with solar in this manner? I figured if you had two Powerwalls, you'd only ever be able to run 10 kW continuous, not 20 kW on a sunny day.
 

h2ofun

Active Member
Aug 11, 2020
3,038
659
auburn, ca
Smart move. This while splitting of loads is just too much effort. This is why my generator is wired for whole house, and my batteries. He is smart, let others have the real technical stuff. There is plenty of low hanging fruit for him. Like what income levels buys teslas. Same can be said for solar roofs, and to some extent, batteries.
 

wjgjr

Active Member
May 11, 2020
1,331
1,051
Silver Spring, MD
Some very interesting news, and hopefully it does overall make for a smoother install process for future customers. And it does seem to be in line with Tesla tending to try to have fewer options and more efficient installs to keep costs down.

That this should give competitors some more customers (those whom dont see the value in powerwalls).

I also find it interesting that they (Tesla) will currently not sell powerwalls to people with existing solar, who dont want to add on another PV install.

In a nutshell, Tesla is likely trying to say something like "our price with a powerwall is the same price as So and So without one, and you can get it sooner with ours".

This seems like one of those things that they might change their mind on, though, as there are plenty of people who want solar without powerwalls, and now those people will be pushed elsewhere.
We saw with the whole solar roof pricing debacle that Tesla was offering a free PW in some cases to try and entice some customers to accept the new contract. With that and these announcements, it suggests PWs are priced to make a decent profit for Tesla. So I wonder if the bundling of panels + PW, in addition to making the installs easier/cheaper, is also intended to improve overall profit margins where current solar panel installs may not be (sufficiently) profitable.

Keep in mind the restrictions on Powerwall feeding the grid directly are caused by the wording of the Solar Federal Tax Credit. And the Biden administration is now working on a separate energy storage tax credit that would eliminate that requirement.

In other countries where Tesla installs Powerwalls, they're free to buy and sell energy from the grid at will.
There is an independent issue (which I know was addressed in another tweet) about utility rules. Even if the tax credit changes come to pass, I think that there may still be a lot of utilities resistant to allowing full freedom to charge/discharge at will. And I am not convinced that having the solar flowing through the battery will actually be enough to make non-exportable power suddenly exportable, but it will depend on the language of the interconnection agreements.
 

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