Tesla vs. Sol-Ark

[Wzrdmatt]

Just emailed my homegrid rep…

If this helps others, HomeGrid is CPUC approved under their larger umbrella company named Stored Energy Inc. Stored energy was purchased by Lithion Battery. On Dec 1 2022, Lithion sent a request to the CPUC to change the name in the certification.

Solar Equipment List - CA Energy Commission

solarequipment.energy.ca.gov

 

[400bird]

Just emailed my homegrid rep…

If this helps others, HomeGrid is CPUC approved under their larger umbrella company named Stored Energy Inc. Stored energy was purchased by Lithion Battery. On Dec 1 2022, Lithion sent a request to the CPUC to change the name in the certification.

Solar Equipment List - CA Energy Commission

solarequipment.energy.ca.gov

That's super frustrating, for me. Good news for you and Home grid.
Last month I emailed a local vendor and they obviously had no idea next they carry home grid, but didn't offer them as a CPUC approved battery.

 

[Ampster]

Based on the price and OP's desire to not have to deal with the details i would go with Tesla. i have to admit, I am a Tesla Fanboy and have owned three Teslas and love the cars. I gave up a small deposit on two Tesla Powerwalls four years ago in favor of a DIY battery and hybrid inverter installation that I did myself. I am a tinkerer and wanted more battery and did not need all the inverter capacity that two Powerwalls woiuld have given me but I wanted more battery capacity. I frequent the Tesla forums and while there are a few service issues, by and large the user base is happy.

 

[Wzrdmatt]

With Tesla powerwall+ setup… just reviewing the bid notes. The installer is requesting we modify the electric design to split the system into 2x 200amp service connection panels to PGE. It seems, from what Im reading between the lines, these power wall plus can only be 2x powerwall+ per 1x200amp panel?

Can’t imagine this is true. I’ve seen powerwall setups with 8-10 units. Can’t imaging they have 8x200amp panels… anyone has insight?

 

[robby]

I am still trying to wrap my head around the $23,500 price difference.
Something is just not adding up.

 

[400bird]

I am still trying to wrap my head around the $23,500 price difference.
Something is just not adding up.

4x Powerwalls is about $38,000 installed.

2x 28.8kwh Home grid batteries is about $32,000 (I couldn't find anything that added up to 54kwh, 57.6 was close enough for me)
Then you need to add in the two Sol-Ark 15k, cables, bus bars, etc. Where as the Tesla Powerwalls are battery and inverter in one. They just need relatively easy and cheap wiring.
Tesla's Solar price was very competitive when I last checked.

 

[400bird]

With Tesla powerwall+ setup… just reviewing the bid notes. The installer is requesting we modify the electric design to split the system into 2x 200amp service connection panels to PGE. It seems, from what Im reading between the lines, these power wall plus can only be 2x powerwall+ per 1x200amp panel?

Can’t imagine this is true. I’ve seen powerwall setups with 8-10 units. Can’t imaging they have 8x200amp panels… anyone has insight?

I don't think they can back up 400 amps of service. The transfer relays (I think Tesla calls it a Gateway) have a rating, probably 200 amps. I'll bet the installer is going to set you up with a back up loads panel and one that isn't backed up.

Or I wonder if they would install two transfer relay boxes and basically give you two separate systems?

 

[629658]

I am still trying to wrap my head around the $23,500 price difference.
Something is just not adding up.

I agree not what is being reported on these forums. If this guy needs to rewire his utility entrance that’s going to cost some change.

 

[ImAnIdiotPleaseBePatient]

For battery, I can believe that.
For grid-tie PV, I'd be shocked if there were not plenty of installers who could do SMA.
Back 20 years ago when this stuff was just starting, > 50% of all installs in California were SMA (they invented it). Twenty or so other inverter manufacturers shared the other < 50% of all installs.

I could imagine some of the AIO units are a more economical way to do grid tie, PV, batteries. SolArk seems to have a good package with 200A pass-through. They also support AC coupling.

A component system and AC coupled GT PV together with battery probably costs more. It may have greater drive capability, and redundancy. There are several battery inverters which can do this, but of course need to be stackable for your size system. If you find a Schneider installer, their equipment may work well with either DC coupled or AC coupled PV.

SMA does have a lot off off-grid battery installations based on Sunny Island, maybe mostly elsewhere in the world. And then they have commercial MW scale systems. I would imagine that gets more of their attention.

Here's the installer finder page for SMA: https://www.sma-america.com/powerup/homeowner-business-owner

For Schneider: https://solar.se.com/us/en/find-a-preferred-installer/

SolArk has a following, but is not the same class of company or product as those two.

fwiw i watched a youtube vid that said that recent sma inverters had been having a lot of problems so he stopped installing them, and he knew of others with similar issues. not sure if true or not, but i see almost no installs using sma in america anymore. All enphase, solaredge, and then the rest.

 

[Hedges]

Can you give a link to that?

I read a comment from long ago (older models) that their arc-fault had so many false trips as to be unusable.
If something is going on now with current model SB7.7-1SP-US-41 I need to know about that.
I've put in NEM reservation with PG&E for that model.


"The company sold inverters with a cumulative output of 13.6GW in 2021"

SMA Solar’s 2021 inverter sales fall due to chip shortage

SMA Solar Technology’s sales for 2021 came in below prior expectations for the year as the inverter supplier was impacted by a shortage of electronic chips – a headwind it expects to persist in the coming months.

www.pv-tech.org

I don't know the breakdown between residential units in the 5kW +/- range, and the 4MW units.
I could imagine chasing code changes and maintaining popularity with installers is a challenge.

Enphase and SolarEdge, you say? Enphase of course because not string constraints, and no RSD required. SolarEdge, the things I've seen would indicate installers are running away from them.

I could certainly imagine SMA is slow to keep up with changes.

 

[ImAnIdiotPleaseBePatient]

Can you give a link to that?

I read a comment from long ago (older models) that their arc-fault had so many false trips as to be unusable.
If something is going on now with current model SB7.7-1SP-US-41 I need to know about that.
I've put in NEM reservation with PG&E for that model.


"The company sold inverters with a cumulative output of 13.6GW in 2021"

SMA Solar’s 2021 inverter sales fall due to chip shortage

SMA Solar Technology’s sales for 2021 came in below prior expectations for the year as the inverter supplier was impacted by a shortage of electronic chips – a headwind it expects to persist in the coming months.

www.pv-tech.org

I don't know the breakdown between residential units in the 5kW +/- range, and the 4MW units.
I could imagine chasing code changes and maintaining popularity with installers is a challenge.

Enphase and SolarEdge, you say? Enphase of course because not string constraints, and no RSD required. SolarEdge, the things I've seen would indicate installers are running away from them.

I could certainly imagine SMA is slow to keep up with changes.

I Will see if I can find it. About to board a plane. I remember it was a video of a guy reviewing solar panels (an installer) but I will try to dig it up.

 

[DieselArt]

Hi Everyone,

First time poster, I'm looking for some advice and from lurking for months, ya'll seem really helpful. Definitely not a DIY guy for this job, too big...

We're in the process of building a new home, located in California (PG&E). The house is large, and will be 99% electric (3x Heat Pump HVAC units, 2x ERVs, 2x HPWH, well pump, and all the other stuff that goes along with a home). Long story short, we've had an energy model (inc. Manual J) performed, and the models show the home is requiring around 36MW/year to run everything comfortably.

Our energy modeler recommended we target a 25kw solar array on the roof, and a minimum of 38kw for batteries. The system will be grid tied, and we expect to be on NEM2.

With that general project background, here is the current situation I need help with. I have two bids for two very different systems.

• Installer 1: 25KW (62x 400W panels), with 4x Tesla Powerwall+ units (54kw total battery storage)
• Installer 2: 25KW (52x 480W panels), with 2x Sol-Ark 15k and 2x HomeGrid Stack'd (54kw total batter storage)
• Installer 3: Enphase system was rejected, as the company providing the quote withdrew due to load requirements (I don't have any additional details).

I've read the bad stories on Tesla's products, poor customer support, and also read some really good stories too. I've read a lot of favorable posts on Sol-Ark, but also seen the bad stories too (mainly around unbalanced loads on the 12k, and China based servers). Needless to say, I'm conflicted about the best path forward.

Sol-Ark was my front runner, as it's modular and doesn't tie me to Tesla's ecosystem. I like the concept I can upgrade the homegrid (or another vendor) batteries easily, and like the idea of fully redundant inverters to power the home. Sol-Ark easily hooks into a backup generator, which we will be installing at some point. It seems like a clear winner, until I saw the price delta for the Tesla system today.

After tax credits, the Tesla system will be approx. $23.5k cheeper.

While I'd love to save the money, I also acknowledge sometimes you need to spend more to get quality. Primary, I'm more worried more about a reliable electric system I don't need to fiddle with; I don't want my wife calling me, while I'm out of town, asking how to turn the inverters back on... that said, cost comes in a very, very close second, especially when it's 23.5K.

So that's my story. I would really appreciate any advice you have to help in the decision making process.

Thank you
Matt

Here’s my 2 cents. If you’re driving a tesla and use the Tesla app already you’re probably going to go with the powerwalls. My own brother has a Tesla system with 3 power walls and he loves it. However he needs help programming his DVR so having a system that is hands off is perfect for him. Recently he got to see a few of the SolArk systems I’ve done and he liked the versatility that is possible. Personally until powerwall changes the battery chemistry to lithium iron phosphate I wouldn’t use them. I would suggest locking in a contract ASAP with a system as others have said. Even if its just solar grid-tied for now then add batteries later. One thing Sol-Ark has going for it is they are battery agnostic. You can use any battery brand or technology enabling you to build a large capacity system to back up your whole house for several days, costing less than a third of the high priced name brand
batteries that corporate solar providers steer you toward. I like Tesla as a company but I dont like how they force you to stay with their ecosystem by not allowing communication with most other brand inverters. Just my opinion. Tesla does seem to have the best warranty when you have a problem but I know people have had concerns dealing with the customer service end of things.

 

[ImAnIdiotPleaseBePatient]

> Sol-Ark was my front runner, as it's modular

tfw proprietary ecosystems are so dominant that an AIO is modular ?

 

[629658]

4x Powerwalls is about $38,000 installed.

2x 28.8kwh Home grid batteries is about $32,000 (I couldn't find anything that added up to 54kwh, 57.6 was close enough for me)
Then you need to add in the two Sol-Ark 15k, cables, bus bars, etc. Where as the Tesla Powerwalls are battery and inverter in one. They just need relatively easy and cheap wiring.
Tesla's Solar price was very competitive when I last checked.

You would only need one 15k you can attach a massive amount of ESS to one Sol Ark.

 

[400bird]

You would only need one 15k you can attach a massive amount of ESS to one Sol Ark.

Well, you dug up an older thread and the OP has not responded in quite a while, they may have made a decision already.

My post that you were quoting is just based on the OP's original specs/requirements.

Yes, you can attach unlimited storage to one inverter.

But, the inverter is limited on AC output and PV input. In this case it looks like the OP is over on both counts. Hence, 2 inverters in parallel is likely needed, his quotes were probably correct on that matter.

 

[629658]

Well, you dug up an older thread and the OP has not responded in quite a while, they may have made a decision already.

My post that you were quoting is just based on the OP's original specs/requirements.

Yes, you can attach unlimited storage to one inverter.

But, the inverter is limited on AC output and PV input. In this case it looks like the OP is over on both counts. Hence, 2 inverters in parallel is likely needed, his quotes were probably correct on that matter.

Just wanted to make sure he was comparing apples to apples. Our utility treats each powerwall as if it’s a completely separate system. Meaning if you install 2 you will need 2 separate interconnect agreements.

 

[Ampster]

You would only need one 15k you can attach a massive amount of ESS to one Sol Ark.

That is the difference between a Powerwall system and a SolArk or other hybrid inverter system. With Powerwalls, each increment of storage gets you more inverter capacity. With a hybrid inverter system you can had massive amounts of storage without having to have more than one SolArk or other hybrid inverter system.

 

[Hedges]

Sunny Boy Storage, part way in between in terms of modularity.
Inverter is 6kW
You can connect up to three batteries.
One model battery, stack up to four series-connected modules for 400V and 10kWh, connect three to SBS.
Another model battery is 32kWh. It has higher current output, possibly only one can connect (I'm not sure.)

$2500 for inverter ($2500 more for auto-transformer and transfer switch.)
$6500 for 10kWh, $18k for 32kWh from BYD.