Generator or Inverter for residential use?

[Neuk_]

Maybe this?

Transformer vs Transformerless Inverters

Hi Forum would someone be able to explain and or point me to some good literature about the difference between an inverter that works with a transformer vs a switching transformer. are there any pros and cons? I realise that this might be a slightly controversial topic, but in the interest of lea...

powerforum.co.za

Interesting reading, thanks for sharing.

 

[Speedster]

Yes, sure, but as a novice myself, and I would personally prefer it to be a thread on the powerforum.

Edit: I think that it would be better for him Solis to get someone knowledgeable of the Solis design architecture to assist him in answering these type of questions. Peer review is good, and the best peer review for this type of question (that I know of) would be the powerforum. Too often these debates devolve into a kind of religious discussion, like the example which you posted (which draws parallels with the debate on valve vs tranny amps). If you want your questions ansswered honestly with no bullschit, take them to a forum with respected peers. And even then, do your own filtering.

I'm re-reading the convo yesterday and not quite sure which questions you feel weren't answered properly? I'd like to post these to him as I am seriously considering this inverter and want to make sure I ask all the right questions before I do so. I also hear you about the powerforum, my experience there hasn't always been as positive nor the community as supportive as here.

 

[RonSwanson]

I'm re-reading the convo yesterday and not quite sure which questions you feel weren't answered properly? I'd like to post these to him as I am seriously considering this inverter and want to make sure I ask all the right questions before I do so. I also hear you about the powerforum, my experience there hasn't always been as positive nor the community as supportive as here.

OK, so let's take your first question -- actually two questions: a) Does it "blend", and b) you give a very specific example / scenario of what you mean by "blend" when drawing current / load from the inverter and using multiple sources (Battery and Grid). Your question is well articulated, this is fundamental to any ESS system. His response is "Yes", but instead of elaborating on the specific example and perhaps giving more examples, he fudges and starts talking about transformer vs transformer less designs, IMHO this is irrelevant. He then moves onto battery charging. also irrelevant, because you are talking about servicing a load from a blend of sources. It does not answer your question and the very specific example which you gave IMHO.

The answer to your second question seems to suggest that he hasn't taken a look at the datasheet either, otherwise he would have corrected you with facts. Your question was basically 25A X 48V = 1200 W so how does this make 8000 watts (assuming of course one battery at 48v). He refers to I=V/R formula but no facts or specific examples. Then he talks about charging again, when you are talking about load. I do not know the SOLIS, and haven't seen the datasheet myself, but there is an absence of a factual answer that specifically addresses your question.

Maybe I'm too fussy though?

 

[TheChamp]

The answers do fall short of being satisfactory, especially the most important first one.

On your second question, doesn't the inverter come with a built in battery? What does the "Solis energy storage inverter" mean?

 

[vassen]

I managed to track down the Solis engineering guy. See his answers (in bold) to my Q's below.

1. Is the inverter able to blend PV/battery and grid? i.e. if I draw more than the PV / battery can provide does the inverter supplement this with grid power, or does it switch over to only using grid power? Yes this is the advantage of this version (or topology) of inverter over say your transformer-based Victron inverter which creates the grid for you. This acts as a PV inverter with batteries and is constantly measuring the grid power. When the grid power goes positive (export) it charges the batteries (reducing this export) and when it sees import (you paying), it discharges the batteries.
2. The datasheet on the ginlong website says that the max battery draw is 25A for all models. Is this correct? How would that work for a 8kW or 10kW inverter? Yes the battery conversion stage of each model is not the same as the maximum PV on that inverter. It almost requires two numbers to name it… Anyway the datasheet for each should specify the maximum charge/discharge power. Remember if it is in current multiple it by the battery voltage to get the power. Also please note, most battery charge at a 0.5C rate (which means takes 2 hours to charge them), a 14kWh battery bank only needs a 7kW charger. Discharge is much better though but effects efficiencies.
3. Does the inverter have an aux or secondary output? This would typically be used for something like a pool pump or electric geyser if the batteries are full and there is excess PV generation. It has an aux port but not for that purpose, it is for your critical circuits. In other words when the grid is connected to the inverter, it just puts the grid power onto the critical circuits. However if the grid is ever lost (due to load shedding like you might experience every so often in SA) the inverter will use the batteries to create its own grid and runs those critical circuits off the PV and the batteries. This transfer is taken care of automatically inside of the inverter at a really high speed (<40ms) which keeps your desktop PCs up (like a UPS). I installed a system like this for my family in Cape Town and they love me for it, they don’t even know about load shedding

So with the first answer, it doesn’t really say much. It would be better to check international sites for some reviews.

Regarding the second answer, this inverter is not a 48V inverter. Meaning you cannot use your standard pylontech batteries. The battery voltage is between 160V to 600V. That’s how they can get the 8kw with only 25A. This also means you do t have a large option of batteries to choose from.

The third answer is also not very clear. Doesn’t answer whether it is similar to the sunsynk where it cuts off before the critical loads

Lastly it may be a really good unit, but the question you have to ask is what happens if it doesn’t work. How do you get support. Goodwe units are highly rated but others have complained a lot about the support to the point of regretting buying it. I would rather get something that has a good local support structure in place.

BTW, the sunsynk 3 phase is expected in country around Q2 this year.

 

[RonSwanson]

So with the first answer, it doesn’t really say much. It would be better to check international sites for some reviews.

Regarding the second answer, this inverter is not a 48V inverter. Meaning you cannot use your standard pylontech batteries. The battery voltage is between 160V to 600V. That’s how they can get the 8kw with only 25A. This also means you do t have a large option of batteries to choose from.

The third answer is also not very clear. Doesn’t answer whether it is similar to the sunsynk where it cuts off before the critical loads

Lastly it may be a really good unit, but the question you have to ask is what happens if it doesn’t work. How do you get support. Goodwe units are highly rated but others have complained a lot about the support to the point of regretting buying it. I would rather get something that has a good local support structure in place.

BTW, the sunsynk 3 phase is expected in country around Q2 this year.

Interesting facts on the battery voltages, I might now just bother to read the SOLIS datasheet
Thinking of between 3 - 10 Pylontechs in series, maybe cut down on cable costs...
Let me study it first...

 

[vassen]

Thinking of between 3 - 10 Pylontechs in series, maybe cut down on cable costs...

Nope. You can’t connect the pylons in series, or at least the us3000 or 200s. The bms won’t work correctly. You do get another high voltage type but they are not very common.

 

[vassen]

My first day of breaking 30kwh. Hit 32kwh. Could have probably got more if I managed my loads a bit better and avoided those dips.

 

[RonSwanson]

Nope. You can’t connect the pylons in series, or at least the us3000 or 200s. The bms won’t work correctly. You do get another high voltage type but they are not very common.

That's interesting, they list some Pylontech batteries the Pylontech US2000 and US3000 as compatible batteries for the RHI-3P(5-10)K-HVES-5G

https://www.ginlong.com/Uploads/file/Compatible_Battery_List_en.pdf

Edit: the .pdf is quite deceptive, I see that they list the Pylontech H48074 and H48050 as compatible batteries. Pylontech Powercube series. They seem to be 2.4KWh 48V units, but minimum of 3 need to be deployed with no a separate BMS. Also fairly pricey.

https://www.sustainable.co.za/pylontech-h48050-2-40kwh-48v-hv-li-ion-solar-battery.html

http://www.frankensolar.eu/download.php?file_uid=3474bd32-50c8-5144-a148-971cc3d88f45

 

[vassen]

Problem is they are not too common. I have seen some at gc solar. Slightly more expensive than the us3000

BATTERIES – GC Solar online Shop

onlineshop.gcsolar.co.za

 

[Speedster]

Another development, found out yesterday the place I'm moving to is loadshedding exempt. Suddenly a non-hybrid is an option. Hmmmm

 

[RonSwanson]

Another development, found out yesterday the place I'm moving to is loadshedding exempt. Suddenly a non-hybrid is an option. Hmmmm

Hospital block?
It seems that you aren't exploring the single phase conversion option, or is it still on the table?

 

[Speedster]

Hospital block?
It seems that you aren't exploring the single phase conversion option, or is it still on the table?

That's very much still on the table too, although I'll only be able to get clarity on that once I have access to the house and can investigate the circuits. If these Solis are up to the task then R40k for a 8k three-phase hybrid might be the best option, although I'm looking at single-phase hybrid (Sunsynk 8k @ R30k plus single-phase conversion @R?) and three-phase grid-tie (Solis 8k @ R20k) too. Although the more I think about grid-tie the less optimistic about grid-tie I become as not being able to time-shift the energy seems pretty useless.

 

[Lupus]

Hospital block?
It seems that you aren't exploring the single phase conversion option, or is it still on the table?

Hospitals get shed as well, there are very few areas that are exempt.

 

[Speedster]

Hospitals get shed as well, there are very few areas that are exempt.

Hospital block?
It seems that you aren't exploring the single phase conversion option, or is it still on the table?

Apparently it's due to the embassies in the block.

 

[Mr Scratch]

Yip only embassies are really except

 

[Speedster]

Yip only embassies are really except

And, apparently, my soon-to-be new house

 

[Mr Scratch]

And, apparently, my soon-to-be new house

Very lucky!!!

 

[wingnut771]

Yip only embassies are really except

So the ANC does get embarrassed.

 

[AchmatK]

Not ideal pv generation conditions today in Cape Town and have two load shedding slots overnight. Will not use batteries and leave them at 100% for load shedding.