Inverter with off grid capabilities WITHOUT battery

[timselectric]

Moonlight, can actually produce power.
Just not much, compared to daylight.

 

[Ampster]

Sunny Boy does that, 2000W 120V available when grid is down but sun is up from "Secure Power" feature of newer models.

Yes that is a great feature. Of course it still doesn't work at night. Also if you have to meet Rapid Shut Down requirements it has to be disabled.

 

[Hedges]

Yes that is a great feature. Of course it still doesn't work at night. Also if you have to meet Rapid Shut Down requirements it has to be disabled.

One of their papers said the voltage from a PV string in RSD is too low to reenable, but they have a way with a couple 9V batteries to work around it. I had understood they get Secure Power to work despite RSD, apparently that's how.

I Kludge you not!

TECHNICAL NOTE: Sunny Boy US-41: Secure Power Supply Operation with TS4-R-O

PURPOSE This notice provides instructions for installing the Secure Power Supply for a Sunny Boy PV system outfitted with SMA TS4-R-O devices. APPLICABLE PRODUCTS Sunny Boy 3.0 / 3.8 / 5.0 / 6.0 / 7.0 / 7.7-US-41 Type designation: SBx.x-1SP-US-41 Firmware software package version: 3.01.06.R or...

www.stellavolta.com

 

[12VoltInstalls]

Maybe but that would mean adding yet another feature to look for for my inverter, which is that it should be able to accept any battery.

By “inverter” I think you are referring to an AIO- All In One- unit which usually contains a solar charge controller, a ‘utility’ charger, and an inverter at a minimum.
The inverter merely takes battery power and turns it into 120VAC (or 240V or whatever it is made for) to output for use. Inverters are generally designed for a specific battery voltage: 12V, 24V, 48V DC

The solar charge controller- SCC- is what charges the battery/batteries. Within its designed voltage, any good AIO or standalone SCC will be setable/programmable for whatever battery type/chemistry you use.

the 2 models of hybrid inverter my provider showed me both use only proprietary batteries

I’d shop further. There’s plenty of decent equipment that let you choose your own batteries; some available that will integrate with their own brand battery will also accept other batteries but just not feature the battery status/reporting integration capabilities.

 

[12VoltInstalls]

We laugh but sometimes my charge controller does say it’s charging with 40w at night when the moons bright. Probably just a false positive

I haven’t ever seen a charging wattage, but a couple times under bright moon when I was using the AN30, the display indicated the sun was out. An actual 40W would be pretty cool!

 

[Hedges]

One of my Sunny Boys did show 10W or 20W at night.
I did the math for illumination from yard light, decided that wasn't sufficient to be the source.
Its electronics and display are powered by PV, not by AC and it doesn't have a battery. The power was coming from SOMEWHERE.
My best theory was that some coupling on AC side was being rectified to DC and providing a bit of power.

 

[timselectric]

Or aliens were trying to communicate with us. And you just ignored them. lol

 

[efficientPV]

I run my washing machine from solar panels with a $20 inverter and no battery. A cloud passes and it will stop. I just press start after it is gone and the machine remembers where it was. No need for expensive technology.

 

[Fardenco]

Just need to do much much more research, before you spend any money.
There's many ways to skin a cat.
This stuff can be done very cost savvy.

Yes, I know, in fact I'm not planning on making my installation next week, I'm thinking maybe 6 months to one year from now
The price I have for now is around 5500 to 6000€ for a 6.5kWc kit. I'll install the panels myself.

By “inverter” I think you are referring to an AIO- All In One- unit which usually contains a solar charge controller, a ‘utility’ charger, and an inverter at a minimum.
The inverter merely takes battery power and turns it into 120VAC (or 240V or whatever it is made for) to output for use. Inverters are generally designed for a specific battery voltage: 12V, 24V, 48V DC

The solar charge controller- SCC- is what charges the battery/batteries. Within its designed voltage, any good AIO or standalone SCC will be setable/programmable for whatever battery type/chemistry you use.

I’d shop further. There’s plenty of decent equipment that let you choose your own batteries; some available that will integrate with their own brand battery will also accept other batteries but just not feature the battery status/reporting integration capabilities.

Yeah that's what I'm referring to.
Ok I understand. And is there any better option between AIO and standalone SCC ?

I run my washing machine from solar panels with a $20 inverter and no battery. A cloud passes and it will stop. I just press start after it is gone and the machine remembers where it was. No need for expensive technology.

Yeah but your system was totally off grid, right ? What I'm looking for is a grid tied system that can also power my house by solar energy only in the event of an outage

 

[timselectric]

The fact that you want to send excess power to the grid. Puts you in a smaller, more expensive options list.

 

[Hedges]

Sunny Boy with Secure Power could fit the grid-tie plus occasional backup requirement pretty well.

 

[Fardenco]

Sunny Boy with Secure Power could fit the grid-tie plus occasional backup requirement pretty well.

Yes it's the kind of feature I want but my problem with it is that from what I understand, it's limited to 2kW

Edit : Thinking about it 2kW would already be great, but after looking for it, it seems like the SMA inverters that have this "SPS" feature are not available in France...

 

[Britguy]

Yeah but your system was totally off grid, right ? What I'm looking for is a grid tied system that can also power my house by solar energy only in the event of an outage

You're making a mistake in your thinking ........ off grid is the way to go.
Why do you want to provide power to the grid?
1. The grid doesn't want your power.
2. The grid won't pay much for your excess power.
3. Grid tie costs a lot more money in installation, inverter and permissions.
4. When TEOTWAWKI happens, and the grid ends forever, you'll still have no power.

Best to use a cheap off grid inverter with no battery.
1. Most will use solar, then top up any needs from the grid.
2. You can add a battery later.
3. You'll still have power after TSHTF.

 

[timselectric]

You're making a mistake in your thinking ........ off grid is the way to go.
Why do you want to provide power to the grid?
1. The grid doesn't want your power.
2. The grid won't pay much for your excess power.
3. Grid tie costs a lot more money in installation, inverter and permissions.
4. When TEOTWAWKI happens, and the grid ends forever, you'll still have no power.

Best to use a cheap off grid inverter with no battery.
1. Most will use solar, then top up any needs from the grid.
2. You can add a battery later.
3. You'll still have power after TSHTF.

I'm with you on this. I don't want anything to do with the grid. Other than to use it if I need to do any maintenance or upgrades. And then, kick it back to the curb, where it belongs. lol

 

[pollenface]

You can do it with a step down converter to change the voltage to 13-14v. Wouldn't recommend doing it without a solar panel that exceeds your needs.

 

[Jim Lee]

Havnt seen an inverter yet that can do that. But if the array is over sized then it can power some loads when cloudy

I have 11.8Kw of solar panels and I get between 1 and 2 Kw per hour production on cloudy days. As long as it is light you will get some production.

 

[Rho]

Delta H6 hybrid inverter will supply 6kw as a grid tie inverter and will also supply 6kw to offgrid love ads without using a battery. I have one I’d be willing to get rid off. I used it for one month before I realized my electric company wasn’t 100% honest about their solar program.

Yes the electric companies are that way.

 

[Cheap 4-life]

I have 11.8Kw of solar panels and I get between 1 and 2 Kw per hour production on cloudy days. As long as it is light you will get some production.

Indeed

 

[Cheap 4-life]

Yes the electric companies are that way.

I didn’t sign any kind of agreement so I shouldn’t have expected much

 

[Fardenco]

You're making a mistake in your thinking ........ off grid is the way to go.
Why do you want to provide power to the grid?
1. The grid doesn't want your power.
2. The grid won't pay much for your excess power.
3. Grid tie costs a lot more money in installation, inverter and permissions.
4. When TEOTWAWKI happens, and the grid ends forever, you'll still have no power.

Best to use a cheap off grid inverter with no battery.
1. Most will use solar, then top up any needs from the grid.
2. You can add a battery later.
3. You'll still have power after TSHTF.

Well it's true they don't pay much but that's still enough to be worth it as long as I do the installation myself
For 6.5kW of solar panels + supports to mount them + the inverter, the electrical box, cables and everything, I'm at about 5500€
I should be able to sell unused energy for about 0.06€ per kWh, or maybe 0.1€ if I manage to find an electrician who would agree to help me
There is this stupid thing in France, for the main electricity provider to buy your energy, your installation must be done by a certified electrician. You can't do it yourself and then pay someone to verify it. Then your only option is to sell the energy to other providers for cheaper. To be honest I think the 0.1€/kWh is in part paid by the government as some kind of aid, but still. Paying someone to make my installation would cost me easily 3 times as much so that's not worth it
Anyway, selling my surplus is a way for me to justify a bigger installation, more powerful, in the long term it will be more profitable and in the mean time I'll have more panels to work with in the event of a power shortage

 

[timselectric]

Well it's true they don't pay much but that's still enough to be worth it as long as I do the installation myself
For 6.5kW of solar panels + supports to mount them + the inverter, the electrical box, cables and everything, I'm at about 5500€
I should be able to sell unused energy for about 0.06€ per kWh, or maybe 0.1€ if I manage to find an electrician who would agree to help me
There is this stupid thing in France, for the main electricity provider to buy your energy, your installation must be done by a certified electrician. You can't do it yourself and then pay someone to verify it. Then your only option is to sell the energy to other providers for cheaper. To be honest I think the 0.1€/kWh is in part paid by the government as some kind of aid, but still. Paying someone to make my installation would cost me easily 3 times as much so that's not worth it
Anyway, selling my surplus is a way for me to justify a bigger installation, more powerful, in the long term it will be more profitable and in the mean time I'll have more panels to work with in the event of a power shortage

If you choose grid tied without battery backup.
When the grid goes down, so do you.

 

[Cheap 4-life]

You're making a mistake in your thinking ........ off grid is the way to go.
Why do you want to provide power to the grid?
1. The grid doesn't want your power.
2. The grid won't pay much for your excess power.
3. Grid tie costs a lot more money in installation, inverter and permissions.
4. When TEOTWAWKI happens, and the grid ends forever, you'll still have no power.

Best to use a cheap off grid inverter with no battery.
1. Most will use solar, then top up any needs from the grid.
2. You can add a battery later.
3. You'll still have power after TSHTF.

Grid tie using batteries is the way to go if grid power is connected to the house.
1.2. It doesn’t matter if the grid wants your power. There’s limiters on many grid tie inverters that stop power from going into the grid.
3. Using grid tie inverters with limiters does not cost more, in fact a lot less. The inverter and batteries can be sized to only cover the maximum constant loads. Offgrid the inverter and battery needs to be a lot bigger to handle all of the loads.
4. I small offgrid inverter wired to a small critical loads panel is all that needed for the essentials.

Advantages of Grid tie inverter Connected to battery over off-grid inverter for places where grid is available and for people who are experimenting on Lithium batteries to save money at night.

1. No overload.
In case the load exceeds the Grid tie inverters capacity, the Gti will just keep on running at full load. The power shortage will be supplied by the Grid, hence no power failure. Unlike the off grid inverter, The off grid inverter will shutdown in case of overload, hence you have power interruption in your house. Based on my experiences, this is problematic if it happened at night and when I am far away from home. Overload is one of the major cause of off grid inverter failure.

2. High surge current of big inductive loads like aircon and pump is supplied by the grid Because Gti with limiter is slower to react to changes in load current.. While off grid inverter will solely absorb the brunt of surge power, which is also one common cause of inverter failure.

You can use electric drill, grinders and any power tools without stressing your Gti and battery. I had several experiences where welding job was done in the house and the GTI and battery are not stressed out or battery voltage will not drop to a very low level. Off grid inverter , in case of high load starting current, the battery voltage may drop down to a very low level, causing it to shift to grid power prematurely.

3. Most GTI have a low no load loss of about 3-5w. Off grid inverter has about 15-60w no load loss depending on the size of inverter.

4. Off grid inverter max efficiency is about 85%. Grid tie inverters usually have a much higher max efficiency 95%+. When using batteries, this cost a lot of money.

5. To prolong life of inverter, it is a practice not to operate the inverter at max power for a long period of time. This is very hard to do when using off grid inverter, because you don’t have control of how people in your house will use electricity. For GTI, you can easily adjust the max power you want for your GTI

6. When using Off grid inverters for motors and compressor, you have to size it based on surge power . Common to see 3x surge power for off grid inverter. Surge power normally runs for a few milliseconds. So you will be force to buy a large capacity inverter to serve your surge power. While GTI is sized based on your regular load.
Meaning you have to buy off grid inverter atleast twice the power of GTI.

7. In case of inverter breakdown when using off grid inverter, you lost power in your house.
While using a gti no power interruption in your house.

8. Prolonging life of battery-
a. In my personal experiences, high battery temperature is one of
major reason why batteries fail prematurely. Never operate batteries at more than 40degC. Less is better. And you can easily control battery temperature by controlling the discharge current or power. For GTI, this is easy to do because you can easily adjust the current or power discharge by your battery.. Its very hard to control this when using off grid inverter.

During summer months, where ambient temperature can go very high even at night, you can easily adjust battery temperature by reducing further the current or power discharge by your battery.

b. Manufacturer has recommended discharge current rate of batteries to meet the required lifespan specified in their datasheet. For example, If the manufacturer recommended max 10A, then you can easily do this when using GTI consistently. While its very hard to do consistently using off grid inverter.

Bottomline is, use only off grid inverter for emergency or power failure. Power supplies will eventually fail. Make them ready for emergencies. Not for everyday use when grid is available. Use GTI with or without limiters instead which has far more advantages.

No I didn’t come up with all that but I agree with all of it

 

[Fardenco]

If you choose grid tied without battery backup.
When the grid goes down, so do you.

Only if there is no sun or if the inverter does not support it (and most of them don't)
But some grid tied inverters are able to provide power from the panels to the house in the event of an outage even without battery, this is precisely what I'm looking for

 

[timselectric]

Only if there is no sun or if the inverter does not support it (and most of them don't)
But some grid tied inverters are able to provide power from the panels to the house in the event of an outage even without battery, this is precisely what I'm looking for

True, but that's going to cost you more.
It all depends on how much you want to spend.

 

[Britguy]

No I didn’t come up with all that but I agree with all of it

Sadly all nonsense.
My off hybrid inverter tops up from the grid if more power is required and switches to bypass in overload conditions. Grid tie requires much paperwork and extra expense to comply with the electric company and state rules. Most electric companies require installation by a specialist, no DIY, so that's at least $3000 extra from the get go.