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Can growatt be configured to backfeed to grid when power is on?

Takagati

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May 9, 2021
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Planning out a new system. We are grid tied. I'm liking the growatt systems.
However, everything i read says im not able to run my meter backwards off my solar once my batteries are full?

Is it not able or am I missing something?

Thanks
 
This is the same as the little green 2.4kw MPP unit. I traded out an old SMA for two of these in parallel and they have been feeding the grid for over a year now as well as supplying the house via solar and battery. Setting 23 will get you there.

Yep i have them too, also over a year feeding utilities, battery and home:) ..... but if your state requires UL1741 (I think all U.S. requires...) you wont be able to do net metering or any contract with utilities. You aren't supposed to connect inverters without the UL to the grid.

Not sure if there is any MPP's Solar or Growats that can back feed and have the UL.
 
Yep i have them too, also over a year feeding utilities, battery and home:) ..... but if your state requires UL1741 (I think all U.S. requires...) you wont be able to do net metering or any contract with utilities. You aren't supposed to connect inverters without the UL to the grid.

Not sure if there is any MPP's Solar or Growats that can back feed and have the UL.
The important part is the islanding ability and the frequency limiting between 59.3hz and 60.5hz
 
Yeah they are safe, but as far as i know you wont sell electricity if you dont have the UL in US, not legal..
Depends on if you are replacing an old grid tied inverter or not. If you are going for a new Net Metering agreement then its a big NO
 
Do be aware that according to the National Electric Code EVERY hard wired in device in your electric system MUST BE UL listed by UL or listed by any NRTL (nationally recognized testing laboratory) to UL standards for the PURPOSE INTENDED (that is the purpose stated in the UL or NRTL application category). A building inspector can and will red tag a building for this violation of the building and electric code. Additionally if you should have an electrical fire your insurance company has an automatic out. Your insurance policy will have in clear writing that all revenant building, fire and electric codes must be met, if not they have no obligation to settle with you as you are in violation of the code. Chinese hardware in no way will pass UL, or any NRTL . CE certification is worthless in the USA, it’s not a standard here. CE certification is valid in other countries but not in the USA.

All of my equipment is certified by UL (Underwriters Laboratory) or ETL (Electrical Testing Laboratory) I know I’m safe!

The exact reason that Growatt etc. is a no-no for grid tie grid feed in is that does require a building permit and no building inspector will sign off on non-UL devices. Some off shore manufacturers do get UL/ETL certification to sell their products in the USA, Samlex has a whole line of inverters that are UL listed and will pass code, I have installed Samlex N+1 inverter systems for government agencies, in law enforcement networks.....they have all the bucks they need to do it right, pay very good too! AFAIK Samlex does not do grid tie but their N+1 system is one of the best, along with Exeltech they own the field (mission critical network). Samlex , Taiwan design, China built, USA UL listed
 
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Some Chinese inverters are UL certified but they few and far between IMHO. The Deye inverters are a good example of ones that are though. It's one of the reasons we sell them.
 

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  • DEYE INVERTER - UL[3539].pdf
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Little offtopic, but how expensive the certification process could be?, or maybe its too hard too meet?, US its a huge market so not sure why the Chinese brands would lose on that.
 
According to boB at MidNite Solar millions can be spent trying to meet UL or NRTL even for little things like lightning arrestors. The testing agency will draw it out for months, and that is for every variant of every model......it’s a nightmare.
 
Do be aware that according to the National Electric Code EVERY hard wired in device in your electric system MUST BE UL listed by UL or listed by any NRTL (nationally recognized testing laboratory) to UL standards for the PURPOSE INTENDED (that is the purpose stated in the UL or NRTL application category). A building inspector can and will red tag a building for this violation of the building and electric code. Additionally if you should have an electrical fire your insurance company has an automatic out. Your insurance policy will have in clear writing that all revenant building, fire and electric codes must be met, if not they have no obligation to settle with you as you are in violation of the code. Chinese hardware in no way will pass UL, or any NRTL . CE certification is worthless in the USA, it’s not a standard here. CE certification is valid in other countries but not in the USA.

All of my equipment is certified by UL (Underwriters Laboratory) or ETL (Electrical Testing Laboratory) I know I’m safe!

The exact reason that Growatt etc. is a no-no for grid tie grid feed in is that does require a building permit and no building inspector will sign off on non-UL devices. Some off shore manufacturers do get UL/ETL certification to sell their products in the USA, Samlex has a whole line of inverters that are UL listed and will pass code, I have installed Samlex N+1 inverter systems for government agencies, in law enforcement networks.....they have all the bucks they need to do it right, pay very good too! AFAIK Samlex does not do grid tie but their N+1 system is one of the best, along with Exeltech they own the field (mission critical network). Samlex , Taiwan design, China built, USA UL listed
It's the type of UL (ETL) listing that is important for grid tie. While Samlex and a few others such as Aims and Gaiandel, etc. possess a UL certification, those certifications were intended for mobile applications and are not the same as the UL1741, Rule 21 or Heco. To drill down on this a bit more, the grid tie compliance extends to the batteries as well. Any Net metering system here in California that is set up as a hybrid must use compliant batteries. There are only a few of those as well when you look at the utility approved vendors. Simpli-Phi, Discover, Darfon and possibly Fortress now.
The statements about Growatt not having certifications is incorrect. They have introduced a line of hybrids for the US that is fully certified for every state including California and Hawaii. Here is a link https://www.growatt-america.com/show-9-634.html . The downside is that for these models they have opted for high voltage batteries like Tesla or Pica(Generac).

The Colorist has listed here about Deye inverters. I have installed and use one of those and can attest to its compliance. The 7.6 or 8kw is virtually the same as the Sol-Ark. Not a knock off, the same engineers designed it and it's sold for a lot less. The downside is that there is no stateside tech support.

The way around Using some of the better built overseas inverters such as Growatt, MPP and others that only carry the CE certification is to make the setup portable, or plug in. If a permit is acquired for a critical load panel that has a standard 30 to 50 amp gen plug then the entire inverter system can be plugged in or unplugged making it a portable system. I normally use a Square D 100 amp or 200 amp outdoor rated sub panel with one of their interlock devices to shift from grid to inverter.
In our county here in California off grid PV panel installations are fairly easy if you keep them ground mount and under 7' high. There is not a consideration as to what they are connected to because they plug in as well.

The utility company (PGE) here wants us to be completely tied to them with any system. But there are many legal ways around that. I run a two acre property that is grid tied with one system. The only purpose of that system is to feed power to the grid and the only purpose of the grid is to supply charging when needed.
The home and shop are run off of the other system with an emergency grid backup charger and generator should the sun not shine for extended periods. That system is hardwired however because the Deye has the UL approval that the Colorist was talking about.
 
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Oh so I am quite well aware of exactly what the codes are,.....My experience was not to feed the grid , that is of no consequence in a ”mission critical power system” the point is to always have the power you need to make the systems run. I did professional communications networks as systems engineer and used any power source available. Solar was invented by the communications industry to power our communications network. ATT pioneered it with the first patent on the modern monocrystalline cell to power their communications network. 1955. The only inverters that we used were N+1 Nets
 
Oh so I am quite well aware of exactly what the codes are,.....My experience was not to feed the grid , that is of no consequence in a ”mission critical power system” the point is to always have the power you need to make the systems run. I did professional communications networks as systems engineer and used any power source available. Solar was invented by the communications industry to power our communications network. ATT pioneered it with the first patent on the modern monocrystalline cell to power their communications network. 1955. The only inverters that we used were N+1 Nets
Agreed. When the grid is down I just make sure I don't do things like run the clothes dryer. My batteries can't handle that for too long.
 
I have long since retired from the communications industry, I’m only interested in off grid totally stand alone systems. I’ve been doing it for quite a while now, I have not had a LVCO or system shutdown in 20 years, yes there is systems maintenance to do in any power system. I did it for a career and I do it now. My systems are 100% redundant nothing can fail and leave me with no power for more than a few moments. I have two MidNite Classic’s, a Exeltech UL listed hardwire inverter, a MagnaSine 120/240 UL listed hardwire inverter...it’s not a PAE Pretty darn good American gear....I do not need to depend on any POCO to supply me with power.....and I don’t need to sell it to them
 
Planning out a new system. We are grid tied. I'm liking the growatt systems.
However, everything i read says im not able to run my meter backwards off my solar once my batteries are full?

Is it not able or am I missing something?

Thanks
I'd find a dump load such as hot water generation for hot water or heating purposes before I would consider grid tie. If you consider the extra expense of purchasing UL listed equipment, the permitting process and other costs, it isn't worth it. Power companies will begin reducing the net metering banked Kwh, just watch. My brother has a wind tower, the costs involved with hookup to grid were expensive, then his utility required an insurance policy on top of everything else. He was getting paid originally $0.10 per Kwh for the first few years, then the utility merged with another and those contracts were thrown out and they put in net metering. He locks his tower now when he hits the monthly limit. He would be giving the power away for free if he didn't, meanwhile his equipment would be wearing out and maintenance would be more often.

Load reduction or island power production is the answer. If you have excess generation, then expand your system to include a variable dump load. This is why you buy equipment that is not grid tie.
 
I'd find a dump load such as hot water generation for hot water or heating purposes before I would consider grid tie. If you consider the extra expense of purchasing UL listed equipment, the permitting process and other costs, it isn't worth it. Power companies will begin reducing the net metering banked Kwh, just watch. My brother has a wind tower, the costs involved with hookup to grid were expensive, then his utility required an insurance policy on top of everything else. He was getting paid originally $0.10 per Kwh for the first few years, then the utility merged with another and those contracts were thrown out and they put in net metering. He locks his tower now when he hits the monthly limit. He would be giving the power away for free if he didn't, meanwhile his equipment would be wearing out and maintenance would be more often.

Load reduction or island power production is the answer. If you have excess generation, then expand your system to include a variable dump load. This is why you buy equipment that is not grid tie.
Load dumps are a good alternative. I currently have a mini split heat pump on my system but I can see where if I dumped the full excess power of my PV into heating water in the afternoons I could extract enough heat back to take showers and possibly do some space heating. If I connected it through my existing Takagi tankless WH the Takagi would only come on when the temp was too low thereby saving propane as well.
 
Dump loads are real on battery based off grid systems as well, I use Trace C-40 PWM controllers set up as diversion control to dump excess 24 volts from the battery charge cycle, 2 separate solar systems, 2 diversion controllers, 2 double element heaters divert about 2600 watts max to a single tank, p.v. hot water as a byproduct of pv electric system.
 
Have you looked at the MIN Series of Growatt Inverters? I think they may be UL Listed?
 

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  • UL 1741SA certificate.pdf
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