Which Inverter(s)?

Zodiacal Light

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Hi,

I'm seeking advice as towhich inverter or inverters I shouldpurchase for my system. I have 27 Jinko JKM405M-72HL-V (405W) panels. That's a theoretical maximum of10,935 watts; obviously in practice it'll averagesignificantly less. I've grid power available, buta net metering agreement definitelyisn't going to happen.

Right now, my motivation for doing solaris entirely financial, thereforeI'm not interested in a fully off-grid system with batteries. My goal is a grid-tiedsystem thatfully accommodates all of the panels' real maximum output while always avoidingbackfeeding anyexcess energyinto the grid. And, needless to say perhaps,I'd prefer to keep the equipment costs as low as is realistically possible.

I've seen the ECO-WORTHY GTIL inverters. Unfortunately they're only twokWmaximum, so I think I'd need at least four. It's also unclear to me whether my panels, which have a Vmp of 42V and a Voc of 50.1V, will work at all with these inverters due to their 45 to 90 volt DC input range.
 
Buy a proper grid-tie inverter. Its cheaper than GTIL and its legal in most places. You should get one with HVDC so you can serie the panels instead. Thats my tip

You can get those inverters today for nothing 2nd hand.
 
ZodiacalLight said:
I've seen the ECO-WORTHY GTIL inverters. Unfortunately they're only twokWmaximum, so I think I'd need at least four. It's also unclear to me whether my panels, which have a Vmp of 42V and a Voc of 50.1V, will work at all with these inverters due to their 45 to 90 volt DC input range.
These inverters typically run off a 48v (nominal) battery bankrather thansolar panels directly. Sounds like you are skipping over Charge Controllers and Battery Bank?
 
daromer said:
Buy a proper grid-tie inverter.

That of course was my original intention. But, circumstances prevent me from obtaining a net metering agreement with the poco, and I have a smart meter. Won't the GTI inevitably inject any excess energy into the grid, consequently either greatly increasing my electric bill or loudly announcing the presence of an "illicit" solar system? What if I simply ensure I'm always consuming at least the power output of the panels at any given time?
 
It can do that but its not legal in most places. Note that its not +-0... its more like +-many watts... So if you start a consumer it will start pushing into the grid... Guess whats happen when you stop that consumer :D The inverter will push back to the grid untill it have managed to sense that change.
We talk about fraction of a second but overall this is noticeable if you have a newer meter.

So if you ask me its not very good solution.

If you want to stay on the legal side you either need to make sure to get the agreement or you should go with an off grid system and then use ATS to switch between grid and battery/solar power.
 
OffGridInTheCity said:
Sounds like you are skipping over Charge Controllers and Battery Bank?

I didn't realize they weren't intended to be directly connected. Given that, what advantage do they have over hybrid inverters? I really don't want to have to purchase batteries as that would seriously drive up my cost per watt.
 
ZodiacalLight said:
OffGridInTheCity said:
Sounds like you are skipping over Charge Controllers and Battery Bank?

I didn't realize they weren't intended to be directly connected. Given that, what advantage do they have over hybrid inverters? I really don't want to have to purchase batteries as that would seriously drive up my cost per watt.
I get that you don't want batteries due the cost - and perfectly reasonable choice. But by definition, a battery-less system is 'grid-tie' or 'hybrid with no battery'- which is a category of equipment suited for grid-tie... and will have PV type input specs and grid specific interconnect features. Associated is an expectation ofpermits / power company approved equipment.

The ECO WORTHY was designed as atake-off of a battery banktoconsume PV power directed to a battery bank...which is why you don't see PV voltage range specs on the input. Its more of an alternative to consume off-grid power - and I deployed one for a few months in the early days myself. However iI've come to view it asrisky for several reasons -as one could accidentally send power out to the grid and they are not ETL/UL listed (equipment safety concern).

Technically(voltage wise) you can try powering from panels directly.. but panel voltage can swing wildly thru the day and seasons... which gets us back to proper grid-tie equipment that has PV input specs and internals to manage the PV input :)
 
Zodiacal Light said:
Hi,

I'm seeking advice as towhich inverter or inverters I shouldpurchase for my system. I have 27 Jinko JKM405M-72HL-V (405W) panels. That's a theoretical maximum of10,935 watts; obviously in practice it'll averagesignificantly less. I've grid power available, buta net metering agreement definitelyisn't going to happen.

Right now, my motivation for doing solaris entirely financial, thereforeI'm not interested in a fully off-grid system with batteries. My goal is a grid-tiedsystem thatfully accommodates all of the panels' real maximum output while always avoidingbackfeeding anyexcess energyinto the grid. And, needless to say perhaps,I'd prefer to keep the equipment costs as low as is realistically possible.

I've seen the ECO-WORTHY GTIL inverters. Unfortunately they're only twokWmaximum, so I think I'd need at least four. It's also unclear to me whether my panels, which have a Vmp of 42V and a Voc of 50.1V, will work at all with these inverters due to their 45 to 90 volt DC input range.

The GTIL is awesome. I use 2 of them. You can use four or as many as you want. I could not get net metering either so I went with these and couldnt be happier. These are one of the cheapest GTI. I use a 60v nominal battery for the 45-90v operating range. A 48v nominal battery will not allow the inverter to operate properly. A 48v battery should be used for the 22-65v inverter.


When a load stops the inverter will backfeed for split second before it can respond. This backfeed is not noticeable by the electric company so no worries. This would happen with any inverter that is trying to limit the amount it supplies to make the grid supply very little.
These inverters barely use any power when they are sitting idle. They will limit the amount the grid supplies to 0-35w


These inverters run very well off of just panels. You would need ti put two of those panels in series for the 2kw 45-90v GTIL2. Just the volts from one of those panels will be good for the 22-65v 1kw inverter. Its more expensive to use the 1kw because you would have to buy more of them. 1kw can also supply 240v like the 2kw inverter.
 
Cheap4-life said:
The GTIL is awesome. I use 2 of them. You can use four or as many as you want. I could not get net metering either so I went with these and couldnt be happier.

Nowthis is what I wantedto hear!:D

These inverters run very well off of just panels. You would need ti put two of those panels in series for the 2kw 45-90v GTIL2. Just the volts from one of those panels will be good for the 22-65v 1kw inverter. Its more expensive to use the 1kw because you would have to buy more of them. 1kw can also supply 240v like the 2kw inverter.

That's excellent.My primaryconcern was that 90Vmight bethe absolute maximum tolerable input voltage for the GTIL2. Am I to understandthat it's actually the maximum continuous operating voltage? Because I think that givena Voc of 50.1V, the output of two of those panels in series couldoccasionally exceed 90V.

Do you by chanceknow anything about data acquisition abilities of theGTIL?


OffGridInTheCity said:
Associated is an expectation ofpermits / power company approved equipment.

Here at least, that process for DIY solar systems is, to put it mildly, cost prohibitive. I mean, I fully understand that the poco requires some authority over grid-tied inverters, but when even the bloody panel mounting rails need to be certified, that seems to shout "artificial barrier to entry." Maybe I should have just purchased a much lower wattage turnkey system that would have been eligible for approval without significant scrutiny, but I've made my bed and now I have to lie in it.

The ECO WORTHY was designed as atake-off of a battery banktoconsume PV power directed to a battery bank

FWIW, there appearto bemore than a few peopleout thereat least interested in using it in grid-tied systems that aren't authorized to backfeed. Strangely, one wascomplainingonAmazon that the export limiting feature didn't work, andthe poco was summoned. They supposedly thentold him he would need a net metering agreement if he wanted tobackfeed,and proceededtoreplace his smart meter with an electromechanical one. Why do you suppose they would go and do a thing likethat? Wouldn't that only enable him to go on breaking their rules?
 
My mistake. I missed where you said the voc of your panels. If one panels voc is over 45v then 2 of them in series would be over 90 volt. I know of a few people that fried these inverters because their panels voc was above 90v there is also a member that had 2 panels in series with a 95voc and he has never overvolted his inverter. Its hot where he lives so maybe thats dropping the volts. I personally would stay away from the 90voc. When I wasnt using batteries I had 2 panels in series that had a voc of 80v. And it worked well.


As for the Amazon review. My units definitely do not backfeed. I purchased an iotawatt to insure it wasnt. I have heard of people having backfeeding issues when using a 120v supply from the 1kw inverter. I believe that the fella on Amazon was using the 120v supply. Our utility meter does not have neutral in it. Trying to zero out that meter with 120v inverter supplies that use neutral would cause problems imo. Utility meter reads our power usage with one ct (most of the time) and at 240v.
Are you saying that they then gave him a meter that can run power usage backwards? That would be great! I would think they would (after he was caught backfeeding) have put in a meter that is used for grid tie systems and started charging him for it. They still would see the backfeed and also charge him for that.


https://www.facebook.com/groups/1455824754596738/
Thats a forum for splitphase users. Im RjJess on there.
 
Cheap4-life said:
My mistake. I missed where you said the voc of your panels. If one panels voc is over 45v then 2 of them in series would be over 90 volt. I know of a few people that fried these inverters because their panels voc was above 90v there is also a member that had 2 panels in series with a 95voc and he has never overvolted his inverter. Its hot where he lives so maybe thats dropping the volts. I personally would stay away from the 90voc. When I wasnt using batteries I had 2 panels in series that had a voc of 80v.

Well, I've already purchased the panels, so, it is what it is. :-/But, Voc is "open circuit" voltage. The voltage should drop quite a bit when an actual load is present, yes? For example, the voltage at maximum power, Vmp, is 42V. If the GTIL1 can't reliablyrefrain from exporting, do I have another choice besides taking the risk with the GTIL2?

Are you saying that they then gave him a meter that can run power usage backwards? That would be great! I would think they would (after he was caught backfeeding) have put in a meter that is used for grid tie systems and started charging him for it. They still would see the backfeed and also charge him for that.

That's what I'd expect also, but he clearly saidthey replaced his smart meter with an electromechanical one. Are there electromechanical meters that treatbackfeed as energy consumed?
 
Safest bet for you (with those panels) is to get the 1kw models that have a voltage range of 22-65v


They would be perfect for the voltage of those panels.
The standard meter put in homes nowadays will treat backfeed as if its power you are using therefore charging us for it.

You could get a more expensive GTI that operates on a much higher panel voltage. They are called string inverters. I dont know of any that will limit to not backfeed. Outback sells an inverter that can also limit like you want.
 
Cheap4-life said:
Safest bet for you (with those panels) is to get the 1kw models that have a voltage range of 22-65v

They're fairly inexpensive. It won't hurt too badly to buy a couple to test regardless of the results. I think that's what I'll do.

The standard meter put in homes nowadays will treat backfeed as if its power you are using therefore charging us for it.

I don't know, maybe things are different elsewhere in the US, but in northern Illinois, where I live, the standard meters put in homes these days are smart meters. I'd have thought they'd be configurable to do the same thing. But then, who knows?

Outback sells an inverter that can also limit like you want.

You don't by chance have a link, or a model number?
 
https://www.facebook.com/groups/1455824754596738/
Thats a link for using the GTIL2 inverters when you have splitphase


No I dont have a link for the outback. Its the outback radian. I had started a thread looking for other inverters to replace the functionality of GTIL2 but daromer closed the thread. The name of the thread is other inverter options
 
I've seen some of the MPP Solar units advertise batteryless operations. This is one way to guarantee that power never returns to the grid. This of course requires you to rewire your critical loads to a separate panel and have the MPP Solar power them directly, with the grid as a backup. Not sure how well this really works so can't validate on it. Seen some users on youtube post their success in running it without battery but they seem to be doing it as a test and just disconnecting their battery. Not sure how it works in the long term. I assume when the sun goes down, it kicks back to line mode and kick into solar mode when the power is there.
 
Batteryless cant run loads reliable. They are basically a version where you can remove the battery for maintenance. We have seen some People having issues trying to run Them in load Said and they cant handle it. They work ok as grid tie unit but why buy a unit that is made for battery and not use it ;)

Normal grid tie system is most likely better that can do 0offset from the start
 
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