Solis RHI-S6-EH1P-K-H-US HV Hybrid Inverter

[fafrd]

Most members here are using 48VDC batteries with their hybrid inverters (if not 24VDC or even 12VDC) but Solis just announced a new fully-integrated (no separate Autotransformer) split-phase 240/120VAC hybrid/storage inverter for the US market: https://www.ginlong.com/uploads/file/Solis_datasheet_S6-EH1P(3,8-11,4)K-H-US_USA_V1,2_2023_03.pdf

I’m starting this thread as a placeholder for if/when we get first members using this new offering.

I’m told by Solis that they have no plans to introduce a 48V version of this inverter but see they have a range of 48V Storage Inverters already being offered to the US market, so I’m also interested in whether there are alternative Solis inverters that offer most of this same capability supplied by 48V rather than 120V (or higher) batteries (as well as what gaps there may be).

 

[Solar Guppy]

There are posts already about the S6, which is still just press releases from an end-user view point.

Caution is the word with any newly announced product, if it is anything like the RHI HVES 5G it is intended to replace, your looking at some time before the firmware isn't buggy for an even larger feature set promised, and there are UL9540A batteries ( LG RESU HV, Soluna HV or Pylontech H1 ) available to purchase in the US for this inverter.

Based on previous sales of HV ( 300-400V ) ESS products from all vendors and how many have been discontinued, I don't see any market momentum that would indicate manufactures of having commercial success with the HV choice as all the offerings are proprietary in the battey communications limiting options to one or two high cost per kwh choices.

Look for more offerings, from many players all chasing a yet to be proven market in size for HV ESS.

 

[fafrd]

There are posts already about the S6, which is still just press releases from an end-user view point.

Interesting - thanks.

Caution is the word with any newly announced product, if it is anything like the RHI HVES 5G it is intended to replace, your looking at some time before the firmware isn't buggy for an even larger feature set promised, and there are UL9540A batteries ( LG RESU HV, Soluna HV or Pylontech H1 ) available to purchase in the US for this inverter.

Not in a rush. Architecting now for a build I want to complete in one or even 2 years… (when car conks out and I get an EV).

Based on previous sales of HV ( 300-400V ) ESS products from all vendors and how many have been discontinued, I don't see any market momentum that would indicate manufactures of having commercial success with the HV choice as all the offerings are proprietary in the battey communications limiting options to one or two high cost per kwh choices.

Today, yes. We’ll see how the trend unfolds tomorrow.

First, if Solis follows up with a LV / 48V variant, possibly at lower power levels, an HV battery will no longer be a requirement.

Second, I believe there is a good chance we are going to start seeing more and more HV battery offerings, at smaller sizes, and at more competitive pricing.

The stackable batteries based on 5.1kWh / 48V modules contricted with 100Ah LiFePO4 cells are very appealing but bigger than many honeowners need (at least for offset of overnight consumption, which is the minimum ante for any new solar installs under NEM 3.0).

With the new crop of 50Ah cells hitting the market, including the cylindrical cells, I believe it’s just a matter of time before we see a similar architecture based on 2.6kWh / 48V modules, meaning a minimum 144V 7.7kWh battery composed of 3 modules.

The most compelling feature of HV inverters with very wide battery voltage range such as the S6 is that adding battery capacity is trivial. A new module gets stacked on the battery and all wiring remains unchanged.

Look for more offerings, from many players all chasing a yet to be proven market in size for HV ESS.

I’m guessing that’s the gold rush we’ll be witnessing over the next 5 years and I’m impressed with where Ginlong / Solis has positioned themselves out of the gates.

If I’m going to have to get a specific battery qualified to function with a specific hybrid inverter / ESS, I’m much more agnostic about whether that battery is 48V or HV.

There are enough benefits to higher voltage batteries that once they can be used safely in homes, I think that is where things will be headed.

Ultimately, I think we’re headed to a future where HV Hybrids such as the S6 will have two DC battery inputs - one for the HV House Battery and a second for the V2H connection to the EV (DC output direct from the EV battery).

I was interested to see that Ginlong now sells an EVSE and we’ll see how quickly integrated ESS + EVSE solutions capable of delivering V2H and eventually V2G emerge from them and others…

 

[peufeu]

12-24V only for low power, limits inverter choice to just a few models.

48V is the standard, lots of available stuff, and it's mostly compatible. Pylontech protocol is simple and has been published. In the standard hybrid inverter topology using HV DC bus, you get an isolated transformer-based DC-DC converter between the 48V battery and DC bus. Expect 10% conversion loss, so 80% roundtrip efficiency: it is often not reasonable to charge from grid unless the kWh price varies widely during the day.

HV offers better efficiency and performance in theory, lower conversion loss, lower current for the same power, etc. Problem with HV is 1) cost, 2) they're all closed black-box systems, inverters are often married to their battery brands. So for long-term support you need both inverter and battery companies to stay alive and willing during the full lifetime of both products. If one breaks down before the other will you find a replacement that is compatible or need to change both battery and inverter? For "all in one big box" stuff like LG RESU, if it breaks down you have to send the whole battery in for repair ; with modular systems you can send in the faulty module and keep the others.

Also with HV the DC-DC converter is usually not isolated, it's just a buck-boost. That's nice because it gives higher efficiency, however it introduces the user (and installer) to a rich vibrant new universe of red tape. 48V is relatively safe, but a 150-300V battery is very dangerous. On a 48V system if there is a short to Earth on the battery side, nothing happens because the DC-DC converter in the inverter is isolated. However on a HV battery it is usually not isolated so faults can result in very high DC (or worse DC modulated into HF by the inverter) ground fault currents. So here (France) you get a little surprise in the regulation fine print, in the form of a 600€ mandatory "Type B" residual current device that can actually handle this type of fault... or maybe you need two, I don't remember.

 

[fafrd]

12-24V only for low power, limits inverter choice to just a few models.

48V is the standard, lots of available stuff, and it's mostly compatible. Pylontech protocol is simple and has been published. In the standard hybrid inverter topology using HV DC bus, you get an isolated transformer-based DC-DC converter between the 48V battery and DC bus. Expect 10% conversion loss, so 80% roundtrip efficiency: it is often not reasonable to charge from grid unless the kWh price varies widely during the day.

HV offers better efficiency and performance in theory, lower conversion loss, lower current for the same power, etc. Problem with HV is 1) cost, 2) they're all closed black-box systems, inverters are often married to their battery brands. So for long-term support you need both inverter and battery companies to stay alive and willing during the full lifetime of both products. If one breaks down before the other will you find a replacement that is compatible or need to change both battery and inverter? For "all in one big box" stuff like LG RESU, if it breaks down you have to send the whole battery in for repair ; with modular systems you can send in the faulty module and keep the others.

Also with HV the DC-DC converter is usually not isolated, it's just a buck-boost. That's nice because it gives higher efficiency, however it introduces the user (and installer) to a rich vibrant new universe of red tape. 48V is relatively safe, but a 150-300V battery is very dangerous. On a 48V system if there is a short to Earth on the battery side, nothing happens because the DC-DC converter in the inverter is isolated. However on a HV battery it is usually not isolated so faults can result in very high DC (or worse DC modulated into HF by the inverter) ground fault currents. So here (France) you get a little surprise in the regulation fine print, in the form of a 600€ mandatory "Type B" residual current device that can actually handle this type of fault... or maybe you need two, I don't remember.

Agree with everything you have written. Here in the US, and especially in California which leads the market and the standards, ‘black box’ is the trend.

I’m not competent to comment on the ultimate safety of HV systems with sufficient guidance / regulation, but I see a few facts:

HV for DC-coupled solar arrays is pretty much a solved problem now (safe). Certainly versus where I was 30 years ago.

HV is also the standard for EVs, so a future where EVs directly powering high did inverters fro their batteries in DC will require HV DC power.

If HV ESS is fundamentally less safe than 48V ESS, despite efforts put into standards and testing, the market will move to 48V as the residential standard.

HV offers greater flexibility and scalability than 48V, not to mention compatibility with EVs, so if safety concerns can be addressed through design and regulation, it will become the residential standard.

In any case, hopefully we agree being prepared for both possible futures is the wisest / safest from what we can glean today…

 

[peufeu]

Yes, HV is better on all technical criteria (efficiency, power density, EV compatibility, etc) but worse on cost, openness of standards, legal fine print, etc.
There is no hard technical reason for all these drawbacks, only greed, corporate bullshit and red tape, so let's hope they get ironed out.

 

[fafrd]

Yes, HV is better on all technical criteria (efficiency, power density, EV compatibility, etc)

Yes, and perhaps most importantly scalability. The new of HV hybrids such as the Solis allow you to start with a 3-48V stack = 144VDC or even a 5-24V stack = 120VDC and then increase a module at a time as high as 10-48V modules or 20-24V modules for 480VDC without changing any wiring. Try increasing storage capacity like that using a 48V battery…

but worse on cost, openness of standards, legal fine print, etc.

Wasn’t it once the same with PV strings? The biggest negative I see is increased risk and less widespread knowledge of how to handle HVDC wiring (even by AHJs). It takes time for knowledge and code to come up to the level that an average electrician and an average AHJ can assure a safe installation without issue.

While volumes are low / specialized, HV batteries are certain to carry a cost premium, but as they become more widespread, I suspect that will eventually vanish. I could build an HV LiFePO4 battery today at costs approaching what is cost me to build a 48V LiFePO4 battery 2 years ago…

There is no hard technical reason for all these drawbacks, only greed, corporate bullshit and red tape, so let's hope they get ironed out.

The safety issue is real and a very valid reason to take a prudent and slow approach to defining safety guidelines and code (again, as was the case for DC-coupled solar strings several decades ago).

Anyone with an automobile knows how to handle a 12V battery, and stretching that understanding / knowledge to 24V or even 48V is a far safer leap than talking about 300VDC or even 600VDC.

Had no qualms building my 24VDC LiFePO4 battery and putting together my ~40VDC 1S3P DC-coupled backup power system.

The technology is now available for me to follow the same path with a 144VDC LiFePO4 battery and a 180VDC 6S1P DC-coupled PV string, but I’m not comfortable given my understanding of the safety concerns and the guidelines available.

There is always an early adopter’s tax in pretty much any field, so I see the current situation and the evolution I’m expecting over the next ~3-5 years to be more normal and natural than you do…

As an example, I was an early adopter of OLED TV, getting one of the first 65” OLED TV models for over $5000 in 2015. A new 65” OLED TV with performance vastly superior to my 2015 model can be bought for well under $2000 today…

 

[fafrd]

Since I just found the manual, though I would share;

https://www.ginlong.com/uploads/file/User_Manual_Solis_S6-EH1P(3,8-11,4)K-H-US_V,3,1_02,07,23.pdf

Note that there is no transformer - this appears to be a dual-HF configuration…

The wiring diagrams starting on page 50 appear to be quite comprehensive.

 

[daklein]

At some point I might be interested in one of these inverters, or similar split phase 240v for US hybrid inverters with HV battery.

Most EV batteries, especially for the DIY inclined, _should_ work with these new Solis inverters, by pretending to be a BYD battery controller. https://github.com/dalathegreat/BYD-Battery-Emulator-For-Gen24

 

[daklein]

 

[glandpuck]

I am in the process of completing configuration for the Solis S6 inverter with high voltage batteries. I have read this thread. The difference between a stack of low voltage batteries and high voltage batteries lies only in the BMS. The battery packs themselves are 48 volts wired in series by a BMS that supports serial configuration and even then parallel connection of the stacks. The "high voltage" batteries meet UL9540A and are paired with the Solis which meets UL9540. The battery choices are limited due to the inverter and battery needing to be preconfigured to work together when connected by CAN RS485 protocol. This provides ease of installation and maintenance and limits the error potential in an "open, agnostic system". The inverter is high frequency, but because it is a new model, it supports induction loads of larger capacities for longer periods of time with low failure. Besides, my 5 ton AC condenser is highly efficient with an LRA of 16 amps. As for 48 volt batteries being the standard in the USA, that is not anything but a wish not written in stone anywhere. All AC coupled batteries are already high voltage. Think of those. Also, high voltage DC allows for much better efficiency for PV capture, battery charging and use (especially when it comes to DC charging an EV at high voltage rather than conversion to 240V AC.

I have done a fairly comprehensive search of California compliant inverters and batteries. Simply put, my research has shown that the Solis model has the most complete feature set of any hybrid inverter in the high voltage class. And it is affordable as compared to other options. Only time will tell if the hardware and batteries are durable and reliable 24x7. I have been very pleased with my current Outback system and SMA systems. They are set and forget. But I am modernizing my systems due to time of use rates and the need for a new battery bank. These companies do not offer the flexibility nor capacity for power output that my site requires.

As for installation of the system, I am shooting for a late October/November completion date. Product is just beginning to reach US distributors. So hopefully in the next few months there will be many more posts from consumers on their experiences.

 

[glandpuck]

At some point I might be interested in one of these inverters, or similar split phase 240v for US hybrid inverters with HV battery.

Most EV batteries, especially for the DIY inclined, _should_ work with these new Solis inverters, by pretending to be a BYD battery controller. https://github.com/dalathegreat/BYD-Battery-Emulator-For-Gen24

The Solis is a closed system and will not work unless connected to approved batteries that have the firmware to talk via the RS485 can bus protocol. there is no means to manually configure charging. Its like an Apple lightening or USB plug n play connection. And I do not have any knowledge that the BYD BMS would work with a Solis inverter. BYD is not an approved battery at this time.

 

[Solar Guppy]

I do not have any knowledge that the BYD BMS would work with a Solis inverter. BYD is not an approved battery at this time.

The BYD HVL is on the approved list provided by Solis for UL9540 and with the ongoing delays with Ginlong all options listed should be ready when products actually show up for retail sales. Of the choices offered, Pylontech would be the lowest risk and cost as it is the same battery support by the 5G HVES the S6 is replacing. The pylontech H1 will be available from the powerstore in a couple of weeks and the BYD HVL has been out for over a year according to my contacts.

 

[cordycep]

The BYD HVL is on the approved list provided by Solis for UL9540 and with the ongoing delays with Ginlong all options listed should be ready when products actually show up for retail sales. Of the choices offered, Pylontech would be the lowest risk and cost as it is the same battery support by the 5G HVES the S6 is replacing. The pylontech H1 will be available from the powerstore in a couple of weeks and the BYD HVL has been out for over a year according to my contacts.


View attachment 165483

HI: I was thinking about buying 16KW BYD HVL, but that cost $9200 . Pylontech is about $2k cheaper so thinkign of dropping BYD. Which one did you get? So I leaning toward Pylontech, even though I have a permit for BYD HVL. The BYD can discharge 50A, Pylontech discharge at 37A.

 

[Solar Guppy]

I haven't bought either but the S6 is finally shipping in stock, actual just got the call on Friday.

For UL9540 options the lower cost is Pylon and by ~3.3K compared to the BYD HVL for 24Kw option as a comparison.

I'm not sure what way I'll end up going, My 5G's are running well, so not highly motivated to spend the $$ to upgrade but the higher power is very attractive of the S6.

 

[AntronX]

Wow. HV is the future.

Run it with 72x LF280K 240Vdc battery. 64kWh and a lot of amps to run tankless water heater, range, dryer heater and inverter HVAC direct on DC leaving this inverter to interface with grid, solar panels and to run remaining AC appliances.

 

[Solar Guppy]

The Solis S6 does not support user batteries, it is a closed communications and with approved batteries is UL9540 listed.

Feature wise it has everything the EG4 / Deye / Solar-Ark has, much lower cost but then there is the batteries, and it is convection cooled, no noisy fans!

 

[mciholas]

The Solis S6-EH1P11.4K-H-US looks awesome. No fans, has a built in AC bypass switch (very handy for my use case), good certs, high efficiency, slim packaging, light weight, low cost ($2400!).

It has only major failing: it requires HV batteries. Technically, HV batteries are better. Less losses (which is why they can go fanless), lighter wires, etc. But the reality is cost per KWH, the HV batteries are significantly more expensive. There is nothing that rivals the Ruixu Lithi-2 at $3K for 16 KWH in HV batteries, for example, that's $188/ KWH.

So, sadly, it doesn't make my list for contenders.

Now if someone knows where to get HV batteries for $200 per KWH, I'm all ears. The availability of cost effective HV batteries would change the inverter marketplace.

The design parameters make it look like a version of the Growatt MIN11400TL-XH-US. Specs aren't the same exactly, but it is clear there is a connection.

Mike C.

 

[ImAnIdiotPleaseBePatient]

The Solis S6-EH1P11.4K-H-US looks awesome. No fans, has a built in AC bypass switch (very handy for my use case), good certs, high efficiency, slim packaging, light weight, low cost ($2400!).

It has only major failing: it requires HV batteries. Technically, HV batteries are better. Less losses (which is why they can go fanless), lighter wires, etc. But the reality is cost per KWH, the HV batteries are significantly more expensive. There is nothing that rivals the Ruixu Lithi-2 at $3K for 16 KWH in HV batteries, for example, that's $188/ KWH.

So, sadly, it doesn't make my list for contenders.

Now if someone knows where to get HV batteries for $200 per KWH, I'm all ears. The availability of cost effective HV batteries would change the inverter marketplace.

The design parameters make it look like a version of the Growatt MIN11400TL-XH-US. Specs aren't the same exactly, but it is clear there is a connection.

Mike C.

Pylontech Force H1 Rechargeable Li-ion Battery - ShopSolar.com

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shopsolarkits.com

Pylontech HV battery is $187/KWh

 

[mciholas]

Pylontech Force H1 Rechargeable Li-ion Battery - ShopSolar.com

Pylontech Force H1 Rechargeable Li-ion Battery | Lifetime Customer Support (Email, Live Chat, Phone) | Shop Now

shopsolarkits.com

Pylontech HV battery is $187/KWh

Price listed is $1333.

Capacity is 3.552 KWH.

Doing the math... $375/KWH. That's double the cost of Ruixu.



The system requires a minimum of two units which is where the 7 KWH number comes from, but that's not the module capacity.

Mike C.