Off grid and grid tied inverters vs single hybrid inverter

[Cheap 4-life]

Battery + utility is not a normal operation.
Except in a mobile application, where the shore power available isn't enough to power the loads.
Normally you don't want to be draining the battery when running on utility. Usually when connected to utility. You would want to be charging the battery.

I would want the battery/ inverter output to cover as much of the load as it can and grid takes care of the rest.

 

[Cheap 4-life]

The grid is fine for backup. I just don't have a use for grid-tied. NEM agreements are going downhill fast. And I wouldn't recommend anyone to spend money primarily in that direction.
The grid suppliers have no use for residential production. It's more of a hassle to them. It's available at the wrong place and time to help. If the governments didn't force them, they wouldn't even let it be an option.
In my opinion grid-tied is just throwing money away.
It's a temporary solution, and I prefer to solve things permanently.

I gotta say imo (everyone got one) you are seeing this wrong.. battery grid tie zero export does everything offgrid does but with more benefits and less cost so it’s cheaper, not throwing money away... smaller battery bank and smaller inverter needed which all is less cost and still can cover most of the homes power usage.. As I said before this is how most SolArks are used (for good reasons) untill there’s a power outage. Then offgrid output is used.. No agreements needed..

 

[timselectric]

So you can’t use battery and grid power for the same loads at the same time?

No
But I would never want to.
If I need to be on grid, my battery is depleted.

i thought AC/grid charging was simply disabled when utility was pasdingbthru to the offgrid panel to assist the inverters solar and battery output

It depends on what mode you are in.
In SBU, you can pass the grid through to the loads. And simultaneously charge the battery from grid.
In SUB, you can pass the grid through to the loads.
But not charge from the grid. Because solar power is going through the inverter to the loads.

 

[timselectric]

I would want the battery/ inverter output to cover as much of the load as it can and grid takes care of the rest.

I want to stay off the grid as much as possible.
And only use it when battery is depleted.

 

[timselectric]

I gotta say imo (everyone got one) you are seeing this wrong.. battery grid tie zero export does everything offgrid does but with more benefits and less cost so it’s cheaper, not throwing money away... smaller battery bank and smaller inverter needed which all is less cost and still can cover most of the homes power usage.. As I said before this is how most SolArks are used (for good reasons) untill there’s a power outage. Then offgrid output is used.. No agreements needed..

That's relying to heavily on the grid for me.
But that's why there are so many options available.
Everyone has to decide what they want a system to do.

 

[Cheap 4-life]

If I need to be on grid, my battery is depleted.

yes the grid isn’t needed if you have a large enough inverter to cover all of the infrequent surges and also a large enough battery bank to handle those surges. For most people that don’t need to be fully offgrid due to having a stable grid connection, the much extra added expense of the larger inverter and larger battery bank isn’t necessary. With my setup the battery simply acts as a buffer. Whenever there’s power in the battery it is just used along with grid power if the loads need it.

 

[Cheap 4-life]

No
But I would never want to.
If I need to be on grid, my battery is depleted.

It depends on what mode you are in.
In SBU, you can pass the grid through to the loads. And simultaneously charge the battery from grid.
In SUB, you can pass the grid through to the loads.
But not charge from the grid. Because solar power is going through the inverter to the loads.

i very much like how my system will use battery power at night or when there’s cloud cover and if the loads exceed my inverters max output theninverters simply continue to supply max output and the grid handles anything above the inverters max output. This allows my system to be sized to only cover the max long duration sustained loads of my homes to basically zero out the electric bill. No reason to size my system to cover the infrequent high short duration loads/surges and pay that much higher cost for components.. when I need to be offgrid I will only need to cover a lot less load

 

[Cheap 4-life]

That's relying to heavily on the grid for me.
But that's why there are so many options available.
Everyone has to decide what they want a system to do.

Well no because if the grid isn’t available there’s still offgrid power

 

[TorC]

I can't see any situation in which I'd ever be willing to set up a grid-tie-only system. If I had limited resources, I'd definitely consider setting up a system that relied on the grid for starting large loads or getting through the night with the whole house. I would, however, ensure that it was designed for expansion to cover all from the start - inverters that play nice with expanding, laid out for more batteries, etc..

 

[Cheap 4-life]

I can't see any situation in which I'd ever be willing to set up a grid-tie-only system. If I had limited resources, I'd definitely consider setting up a system that relied on the grid for starting large loads or getting through the night with the whole house. I would, however, ensure that it was designed for expansion to cover all from the start - inverters that play nice with expanding, laid out for more batteries, etc..

Imo no reason to design a system to cover all of most homes daily loads. If offgrid Power is needed it’s usually for a short period of time or shit has hit the fan and then I’d be ok with just the essentials being power 24/7 offgrid.. Much easier to manage than big central conditioning units and all the other big loads that are not actually needed

 

[timselectric]

yes the grid isn’t needed if you have a large enough inverter to cover all of the infrequent surges and also a large enough battery bank to handle those surges. For most people that don’t need to be fully offgrid due to having a stable grid connection, the much extra added expense of the larger inverter and larger battery bank isn’t necessary. With my setup the battery simply acts as a buffer. Whenever there’s power in the battery it is just used along with grid power if the loads need it.

And that works fine, until the grid goes down.
Which leaves you relying completely on the grid.
If all that you want is a lower utility bill. This is the way to go.
Because when the grid goes down unexpectedly. That won't increase your bill either.
For me.
The grid is just a backup. One of several.
Just in case my system needs to be down for maintenance.
I'm only keeping the grid available as a backup. Because it's cheaper (at the moment) than my other backup options.

 

[timselectric]

Well no because if the grid isn’t available there’s still offgrid power

Not very much. Or not for very long.
If you have minimal battery capacity.
And if that's acceptable for you, then that's fine.
You know what you want out of your system.

 

[1201]

And that works fine, until the grid goes down.
Which leaves you relying completely on the grid.
If all that you want is a lower utility bill. This is the way to go.
Because when the grid goes down unexpectedly. That won't increase your bill either.
For me.
The grid is just a backup. One of several.
Just in case my system needs to be down for maintenance.
I'm only keeping the grid available as a backup. Because it's cheaper (at the moment) than my other backup options.

How is that so if you have an off grid setup running your critical loads?

 

[timselectric]

How is that so if you have an off grid setup running your critical loads?

How is what so?
My off grid system runs everything. Not just critical loads.

 

[1201]

How is what so?
My off grid system runs everything. Not just critical loads.

Most "off grid" systems don't run all the loads, including yours.

 

[timselectric]

Most "off grid" systems don't run all the loads, including yours.

An off grid system is by design for all loads.
Mine doesn't run all of my loads,............ yet.
Because it isn't finished.
A backup only system is for critical loads only.

 

[Cheap 4-life]

Not very much. Or not for very long.
If you have minimal battery capacity.
And if that's acceptable for you, then that's fine.
You know what you want out of your system.

I can keep the essentials running 24/7 with a battery that is sized appropriately for just the essential. Which also happens to be a large enough battery to make is so I almost need zero power from the grid when the grid is available. Other than short duration surges and many days of clouds in a row. Yes I pay for that from the grid. But that cost is very minimal compared to the amount of solar, battery, inverter needed to cover all those surges and many cloud day in a row for all of my homes loads. And again when the power goes out I don’t need manual transfer switches to turn off large loads. I just have the essentials on the offgrid panel..

 

[Cheap 4-life]

A backup only system is for critical loads only.

I guess my system can be considered a back up offgrid system. But basically all of my homes loads are covered by my grid tie inverters (not the grid) every day and night.
It’s a lot more expense to have a fully offgrid system but if for some reason you want to run all of your homes loads offgrid then more power to ya.. my goal was (and have achieved) to pay basically nothing for electricity and still be able to power my essentials non stop offgrid if needed

 

[timselectric]

That's what it's all about.
Figure out what you want from a system. And design it for that.

 

[GXMnow]

For most people, I don't think it is really practical to provide battery backup power for everything. But I do agree with double the battery you think you need.

I mostly trust my grid here, but when it does go down, I have only a few essential circuits on the battery. My main reason is to make it last as long as possible. If I need to do laundry, I can move it over if needed, and I have enough in the battery.

If we do end up with a long outage, I also have my 5,000 watt generator. I can move my essential loads to the generator and have it put charge into the batteries as well. I have only needed it once since the solar panels went up. My entire first year before I got the battery, we did not have a single grid failure. I doubled the battery bank after that first failure.

And I do totally agree with timselectric... Everyone's needs and expectations are different. There are many different ways to handle this. If I was in one of the areas with the fire safety power shut offs, I would certainly upgrade my system to be able to run more off grid.