Usable A/C output question

[oregon_phil]

Since you have racks of computer equipment and have designed your own UPS, you know that the devil is in the details. Before buying any equipment, it would be a good idea to put your entire design on paper to make sure you have everything specified and to see if the design meets your goals. Battery and/or hybrid inverters often cost quite a bit more than standard grid tied inverters.

For me, I have net metering and had to declare my equipment set before my net metering connection was approved. If I change the intent of my original equipment set (like adding another inverter and/or more solar panels, or a battery), I have to go back to the power company for approval with limited exceptions. If you have net metering, you might be in the same situation.

Reading some of your other posts, you have a system that the installer has left you hanging, microinverters that have been obsoleted with virtually no support from Sunpower, do not have installer access to the SunBridge Monitor and possibly have some microinverter failures. I know you bought some microinverter replacements on eBay, but can you install them without installer access to the SunBridge Monitor?

For me, your SunBridge episodes above would drive me crazy. At this point, I would be trying to find out how to salvage as much as I could from my original system and design that into the new and improved battery/hybrid inverter system. You said you didn't have any shade so a string inverter would work fine. If you wanted panel monitoring and/or had some shade, you could put in Tigo TS4-A-O optimizers. I have an SMA string inverter with installer level access that can be used standalone without a continuous internet connection.

Anyway, there are many options out there.

[LeeLewis]

>Since you have racks of computer equipment and have designed your own UPS, you know that the devil is in the details.

It's funny you mentioned that because I'm trying to find the simplest route possible and your point about changing things and needing new approvals is an important one. I can't afford to have to get into complicated or expensive local requirements and permits at the moment.

When the system was working, it basically ran everything most of the time it was generating power and at night, back to grid only. I did calculate how many amp hours I'd need to run the hardware off batteries at night to offset that cost too but don't recall what it was right this moment. The offset made a huge difference.

The plan was to add more battery banks to the UPS's that I have and automatically turn off unneeded hardware at night. I have a 10KW and a couple of 3KW UPS systems. The smaller ones are left over from a server room I shut down so I just need some batteries and a couple of 20 or 30 amp outlets for the AC connectors.

Now that the system isn't working right, it's why I started looking at it a little harder and wanting to learn it and maintain it on my own.
I first need to fix the system, keep it running, even grid tied to take advantage of that extra power again.

>Before buying any equipment, it would be a good idea to put your entire design on paper to make sure you have everything specified and to see if the
>design meets your goals. Battery and/or hybrid inverters often cost quite a bit more than standard grid tied inverters.

Yes and it's why I posted to try and understand what I have first. Initially, I really didn't know what I had yet but now I do.

>For me, I have net metering and had to declare my equipment set before my net metering connection was approved.
>If I change the intent of my original equipment set (like adding another inverter and/or more solar panels, or a battery),
>I have to go back to the power company for approval with limited exceptions. If you have net metering, you might be in the same situation.

I had to go take a closer look and now I see that almost everything out there is power company labelled.

I had mentioned that the solar system outputs to a panel box near the panels, from there, it runs to a breaker box.
The breaker box is unlocked so appears to be mine and not the power company. However, it says to not connect any load to this panel.
The rest all seems to be power company owned.

photo_2022-03-12_14-44-48.jpg


>I know you bought some microinverter replacements on eBay, but can you install them without installer access to the SunBridge Monitor?

Yes, the system is on a canopy, not a roof and I can change parts any time. I have access to the manager but I'm not sure if I'm missing a level or not. I hacked into the operating system so I know how the OS runs. I have admin/admin access which gives a fair amount of access but seems to be missing things like add/remove/edit modules.

>For me, your SunBridge episodes above would drive me crazy.

Yes, I was told by someone that I could slowly replace them with a different brand. Not sure which at the moment.

>At this point, I would be trying to find out how to salvage as much as I could from my original system and design that into the new and improved battery/hybrid inverter system.

It's a big system and I don't have the money right now to make massive changes so have to work with what I have.
I think what's just stopped me in my tracks is that it's more connected to the power company than I thought. I thought I could tap into it without needing all kinds of permissions and permits, etc.

>If you wanted panel monitoring and/or had some shade, you could put in Tigo TS4-A-O optimizers.
>I have an SMA string inverter with installer level access that can be used standalone without a continuous internet connection.

Do you mean in terms of replacing the solarbridge manager? I wasn't sure what might work since it would have to be able to read the PLC data right?

[Mike90250]

.....................

So, from what I understand at this point, I have a grid tied system that only generates power when the grid is up. This makes sense now.
It means I have to add some hardware so I can have it continue generating power when the grid is down. It also means I should be able to play with this up to the breaker box that then goes to the power company which is locked..........

Not without changing out your micro inverters, will your solar PV produce power when the grid is off. And it's really tough to fake the grid to get UL listed GT inverters to power up, there are many system tests they go through to rule out "red-neck" engineering.

You would need a Hybrid Inverter and a minimal battery bank to get it to work, and the generator would always run non daylight hours. Or get bigger battery = less generator runtime

[SunEagle]

Not without changing out your micro inverters, will your solar PV produce power when the grid is off. And it's really tough to fake the grid to get UL listed GT inverters to power up, there are many system tests they go through to rule out "red-neck" engineering.

You would need a Hybrid Inverter and a minimal battery bank to get it to work, and the generator would always run non daylight hours. Or get bigger battery = less generator runtime

Why is it so hard for people to understand that there really isn't any Hardware available that allows a large solar pv system to work if the grid is down. I know that SMA allows a small amount using their special inverter hardware but I feel it will be a long time before anyone builds UL rated hardware that will allow complete power generation from a solar pv system when the grid is down.

[LeeLewis]

>Not without changing out your micro inverters, will your solar PV produce power when the grid is off.

Yes, I think this is understood now. These inverters expect grid otherwise they shut down. I of course didn't know that until posting this question as I'm sure, many consumers.

>And it's really tough to fake the grid to get UL listed GT inverters to power up, there are many system tests they go through to rule out
>"red-neck" engineering. You would need a Hybrid Inverter and a minimal battery bank to get it to work, and the generator would always
>run non daylight hours. Or get bigger battery = less generator runtime

Just to try and clarify what I meant... when I used the word 'fake' and in quotes, what I meant is something similar to my generator setup.
The generator has its own transfer switch that it can control, flipping the solenoid and input power source using its battery when it senses that the grid is down.

So what I mean by this is putting another device like some sort of smart transfer switch in between the grid and my solar that can both provide the grid signal that the solar (inverters) needs to continue generating and automatically transfer the output to my own <another device> that would then make use of the solar generated power.

This <another device> is another that I'm not sure what it would be. Since the solar is putting out AC then it's not an inverter that I need but something else? What would that be?

I've read that the main reason behind preventing generation is the usual reason, because power line personnel could be working nearby and get hurt. Makes sense in that respect so I understand that for sure, I would need to transfer output to my own hardware during a loss of grid.

At this point, I'm hoping to find a way to do this without having to change all those micro inverters.

[LeeLewis]

>Why is it so hard for people to understand that there really isn't any Hardware available that allows a large solar pv system to work if the grid is down.
>I know that SMA allows a small amount using their special inverter hardware but I feel it will be a long time before anyone builds UL rated hardware
>that will allow complete power generation from a solar pv system when the grid is down.

Is it that people don't understand or that people always want to find a way to move things forward?
I mean, manufacturers solve needs when they see a market. In my case, and it seems many others who aren't fully licensed installers, some of us want to find a way to use our expensive systems so seek out hardware that would do the job, even if it's not the perfect way, so long as it's safe and legal.

[J.P.M.]

>Why is it so hard for people to understand that there really isn't any Hardware available that allows a large solar pv system to work if the grid is down.
>I know that SMA allows a small amount using their special inverter hardware but I feel it will be a long time before anyone builds UL rated hardware
>that will allow complete power generation from a solar pv system when the grid is down.

Is it that people don't understand or that people always want to find a way to move things forward?
I mean, manufacturers solve needs when they see a market. In my case, and it seems many others who aren't fully licensed installers, some of us want to find a way to use our expensive systems so seek out hardware that would do the job, even if it's not the perfect way, so long as it's safe and legal.

Since you seem to be asking for opinions, and if that's a real set of questions and not rhetorical, lots of people simply do not understand how their electrical system works or interacts with the grid much less how a grid tied PV system interfaces with the grid. Not saying they should be as informed as much as a lineman working for the POCO, but they're simply and generally ignorant in those matters.

Been my experience to find that lots of folks don't want to move forward (if that's how progress is defined) as much as they want things to be as cheap, simple and non intrusive into their modes of existence as possible.

Also, the POCOs and other parties with a vested interest in keeping the grid functioning (and making money providing a product) have a large interest in not letting every yahoo that thinks they know something about electricity get loose and do something to the grid that screws it up more than it already is.

[Mike90250]

>
Is it that people don't understand or that people always want to find a way to move things forward?
I mean, manufacturers solve needs when they see a market. In my case, and it seems many others who aren't fully licensed installers, some of us want to find a way to use our expensive systems so seek out hardware that would do the job, even if it's not the perfect way, so long as it's safe and legal.

There ARE battery based systems that can do Load Shave at the peak hours, Zero export if that's what your PowCo demands. But it all has to be UL listed/certified to not fry the lineman trying to fix the power pole down the street.. And it's not interchangeable with the gear you already have. You have to pull the panels to get the micros off, and may as well replace with new panels which may need new racking, and you may need to re-roof while you are in the middle of it.

My inverter has two, 240VAC inputs, one for the Grid that it can export power on, and the other for the backup generator if the grid is down and clouds limit solar harvest. But you aren't getting a 6kw hybrid inverter for $2k from china w/6mo warranty

[SunEagle]

>Why is it so hard for people to understand that there really isn't any Hardware available that allows a large solar pv system to work if the grid is down.
>I know that SMA allows a small amount using their special inverter hardware but I feel it will be a long time before anyone builds UL rated hardware
>that will allow complete power generation from a solar pv system when the grid is down.

Is it that people don't understand or that people always want to find a way to move things forward?
I mean, manufacturers solve needs when they see a market. In my case, and it seems many others who aren't fully licensed installers, some of us want to find a way to use our expensive systems so seek out hardware that would do the job, even if it's not the perfect way, so long as it's safe and legal.

Again there is current hardware on the market like the Secure Power option in the SMA inverters. They have an internal transfer switch and the ability to provide about 15 amps of power through a dedicated outlet. The problem I have heard is that the "transfer" is all manual which makes it a little hard for people if they are not there to make the system work.

As much as I would like to see an inverter that would continue to work if the grid is down I still think that there will need to be an automatic transfer that can isolate the pv system from backfeeding the grid and still provide AC power to the home. Some people have already built these but they have not gotten the UL listing needed to sell it legally in the US market. Maybe sometime in the future a manufacturer will determine that they can make a profit from this hardware but I think we are going to need many more homeowners to install solar so the customer base is bigger.

[oregon_phil]

Again there is current hardware on the market like the Secure Power option in the SMA inverters. They have an internal transfer switch and the ability to provide about 15 amps of power through a dedicated outlet. The problem I have heard is that the "transfer" is all manual which makes it a little hard for people if they are not there to make the system work.

As much as I would like to see an inverter that would continue to work if the grid is down I still think that there will need to be an automatic transfer that can isolate the pv system from backfeeding the grid and still provide AC power to the home. Some people have already built these but they have not gotten the UL listing needed to sell it legally in the US market. Maybe sometime in the future a manufacturer will determine that they can make a profit from this hardware but I think we are going to need many more homeowners to install solar so the customer base is bigger.

I have the SMA secure power installed and you do have to flip a manual switch to activate it. It does provide power, but SMA keeps saying don't plug anything into it if you need stable power. You do have to remember to flip the secure power off (disable) after the emergency. Also, just because SMA has secure power, doesn't mean it will work in your specific application. Ideally, SMA would like to use secure power where rapid shutdown devices are not needed. Rapid shutdown devices complicates things and there are SMA disclaimers all over that secure power may or may not work. There's are too many rapid shutdown solutions out there and SMA would have to verify each and every device to create a list of SMA secure power approved rapid shutdown devices. And what if devices revise firmware; more approval headaches.

[solardreamer]

>

Just to try and clarify what I meant... when I used the word 'fake' and in quotes, what I meant is something similar to my generator setup.
The generator has its own transfer switch that it can control, flipping the solenoid and input power source using its battery when it senses that the grid is down.

So what I mean by this is putting another device like some sort of smart transfer switch in between the grid and my solar that can both provide the grid signal that the solar (inverters) needs to continue generating and automatically transfer the output to my own <another device> that would then make use of the solar generated power.

This <another device> is another that I'm not sure what it would be. Since the solar is putting out AC then it's not an inverter that I need but something else? What would that be?

Your micros (and other grid-tied inverters) are grid-following power sources. So, what you need beyond a typical transfer switch to isolate from the grid is mainly a grid-forming power source and an island grid controller system to manage excess solar power and maintain stability in real-time. This is commonly done in microgrid systems and you can google to learn more. The word 'fake' is misleading because it often makes people think grid-following power sources are not designed to work in island grids and/or not with generators. So, I suggest using 'emulate' instead. Remember, the utility grid itself is mainly powered by generators so microgrids can certainly work with an appropriate generator as the grid-forming power source.

>
At this point, I'm hoping to find a way to do this without having to change all those micro inverters.

No need to change micros. There are many home battery/hybrid inverters (e.g. Tesla, SMA, Schneider, Outback, Magnum, Victron, etc.) that can work directly (AC coupling) with micros. These are the conventional solution but they are not inexpensive. Otherwise, you can check out other alternatives discussed in the other forum threads I referenced earlier.

[oregon_phil]

>

I had to go take a closer look and now I see that almost everything out there is power company labelled.

I had mentioned that the solar system outputs to a panel box near the panels, from there, it runs to a breaker box.
The breaker box is unlocked so appears to be mine and not the power company. However, it says to not connect any load to this panel.
The rest all seems to be power company owned.

photo_2022-03-12_14-44-48.jpg

>I know you bought some microinverter replacements on eBay, but can you install them without installer access to the SolarBridge Monitor?

Yes, the system is on a canopy, not a roof and I can change parts any time. I have access to the manager but I'm not sure if I'm missing a level or not. I hacked into the operating system so I know how the OS runs. I have admin/admin access which gives a fair amount of access but seems to be missing things like add/remove/edit modules.

Yes, I was told by someone that I could slowly replace them with a different brand. Not sure which at the moment.

I found the installation manual for both your SolarBridge Power Monitor and SolarBridge solar panels with microinverters, p250lv-208/240. Your installation looks like the attached picture taken from the manual. I did add the AC shutoff in the diagram to show your setup. If I am not mistaken, you should own everything (see red box) on your side of the electric meter.

Other searches on Google shows the SolarBridge Power Monitor to occasionally have a corrupted internal SD Card. SD Cards do go bad. It's anybody's guess what was on the SD card. How this affects you situation, I don't know.

A couple years ago, there was a thread on this forum where somebody wanted access local panel data from the SolarBridge Power Monitor. They were not successful. You have spare microinverters, but can't access the Power Monitor to add/remove/edit modules. Most everything about your setup is proprietary except the solar panel and MC4 connectors. I question whether or not you'll be able to hack into the controller more than you have already.

A typical SolarBridge solar panel installation shows it to be daisy chain connecting the AC from one panel to the next. If you try to replace the SolarBridge microinverters with another brand of microinverter, then you have to recreate the AC wiring underneath the solar panels since you can't use any of the AC circuit from SolarBridge.

[LeeLewis]

Since you seem to be asking for opinions, and if that's a real set of questions and not rhetorical, lots of people simply do not understand how their electrical system works or interacts with the grid much less how a grid tied PV system interfaces with the grid. Not saying they should be as informed as much as a lineman working for the POCO, but they're simply and generally ignorant in those matters.

Been my experience to find that lots of folks don't want to move forward (if that's how progress is defined) as much as they want things to be as cheap, simple and non intrusive into their modes of existence as possible.

Also, the POCOs and other parties with a vested interest in keeping the grid functioning (and making money providing a product) have a large interest in not letting every yahoo that thinks they know something about electricity get loose and do something to the grid that screws it up more than it already is.

I'm not wanting to appear to be rhetorical, I'm trying to put a plan together, hence the questions. I'm not a licensed electrician, I've done a lot of electrical work over the years but I am not a pro and certainly don't know the lingo well enough to sound like a pro .

I will hire a pro any time I can afford it but the past two years have hurt a lot and I hate seeing this huge investment going to waste so wanted to try and do something about it. While I can put some money into it and not trying to cheap out, I simply don't have a ton of funds to put into it so need to find a way to do this myself, on the 'cheap' for now.

Totally understand the power companies point of view but I'm just a consumer trying to figure out how to put this thing to better use than it is now.

I appreciate your input as it's an interesting psychological point of view of things.

[LeeLewis]

Thank you very much for so much input.
First, the system is installed on a canopy, not the roof so I have relatively easy access to the inverters and all of the wiring.
Ok, from now on, I'll call it 'simulate', not 'fake' .
I have to re-read everything shared because there's a lot of info but there is something I should add which I think is important.

A manual transfer method is fine with me. Once I fix the system, I'm perfectly fine with using it as a grid tied system. I can use the extra generated power to charge some additional battery banks for my UPS's for example. I could upgrade those UPS batteries to more modern, long lasting, all kinds of things which are UL rated and legal.

What I'm really wanting to do and I know realize I didn't clarify is to look at this as a rare event. What if something really bad happens and the grid goes down for a month.
I'm looking at my solar system as a potentially usage asset in some situation where the grid is down for a long period of time. I'm not really thinking off-grid or hybrid, I'm thinking in some big emergency where everything goes to hell, if I could use this system, it could have substantial value.

So basically, I just want to have a plan, have the hardware ready for such an event. I'm not a preper but there's so much going on in the world that things could change and I'd like to feel I did what I could to prepare as I'm sure many wonder about these days. I feel stupid having such a big system that I know I could not even use if infrastructure went down for a while.

Even if I don't hook it all up right now, just having it ready and knowing how it will work is what I'm looking for.
For short term grid outages like hours to days which has already happened, my generator is perfect but for something longer term, where maybe even gas gets cut off, I'd like to have my 10KW system as a usable asset.

I hope this better explains what I'm wanting to achieve.

[LeeLewis]

Trying to respond / edit my previous comment but the site won't let me, telling me the message is unapproved.
Hopefully, moderator can remove my previous post and I'll re-enter it here trying to be careful of what ever caused it to be not approved.


Thank you very much for so much input.
First, the system is installed on a canopy, not the roof so I have relatively easy access to the inverters and all of the wiring.
Ok, from now on, I'll call it 'simulate', not 'fake' .
I have to re-read everything shared because there's a lot of info but there is something I should add which I think is important.

A manual transfer method is fine with me. Once I fix the system, I'm perfectly fine with using it as a grid tied system. I can use the extra generated power to charge some additional battery banks for my UPS's for example. I could upgrade those UPS batteries to more modern, long lasting, all kinds of things which are UL rated and legal.

What I'm really wanting to do and I now realize I didn't clarify enough, is to look at this as a rare event. What if something really bad happens and the grid goes down for a month. I'm looking at my solar system as a potential usage asset in some situation where the grid is down for a long period of time. I'm not really thinking off-grid or hybrid, I'm thinking in some big emergency where normal services are interrupted for a sustained period.

So basically, I just want to have a plan, have the hardware ready for such an event. There's so much going on in the world that things could change and I'd like to feel I did what I could to prepare as I'm sure many wonder about these days. I feel stupid having such a big system that I know I could not even use if infrastructure went down for a while.

Even if I don't hook it all up right now, just having it ready and knowing how it will work is what I'm looking for.
For short term grid outages like hours to days which has already happened, my generator is perfect but for something longer term, where maybe even gas gets cut off, I'd like to have my 10KW system as a usable asset.

I hope this better explains what I'm wanting to achieve.