Hybrid inverters with grid tie mode

[Cheap 4-life]

Hybrid inverters that have a grid tie mode. While they are in grid tie mode and the homes loads exceed the max output of the inverter. Will the hybrid inverter continue to supply its max output and simply allow the grid to supply the remaining power the loads need that is above the inverters max output?
If the hybrid inverter is in offgrid mode then of course the inverter will shutoff when loads are above the inverters max possible output. I’m referring to when the hybrid inverter is in grid tied mode not offgrid mode. Also not AC coupled with any other inverter. Just grid tie mode selected in the hybrid inverters settings.

 

[Cheap 4-life]

With a grid tie inverter the excess power the loads need that is above the inverters max output does not go thru the inverter. The loads simply take the extra power needed directly from the utility. This is very useful because I don’t have to have a huge-expensive battery that can cover all of my loads. I use a smaller battery that can cover most of my homes loads. I also then don’t need an inverter that can handle all of my occasional large loads-surges. The grid supplies the surges and occasional large loads. For the rare power outage I wouldn’t be able to power everything in my house because of the inverter not being large enough but that’s would be ok with me.

So I’m still trying to figure out if there’s hybrid inverters that when in grid tie mode act like a true grid tie inverter as I explained

 

[Cheap 4-life]

Load is 7000w. Hybrid inverter max output is 4000w. Inverter supplies it’s 4000w and Grid-utility supplies the remaining 3000w.
Is that how a hybrid inverter works when grid tie mode is selected?

 

[GXMnow]

As much as I am annoyed with Schneider on some software issues, I have to say, my Schneider XW-Pro will do everything you are asking for with no problem at all.

You would want to use a separate solar charge controller to keep the batteries charged. This is the issue I am having, I have only AC coupled solar from Enphase, and the Schneider software will not let me make it go to charge mode on it's own, but if you only use it in invert mode, and have DC coupled solar, it works great. You can set it for the maximum battery current, and set the battery low voltage limit. So while you are on grid, it will grid tie and supply the amount of current you ask for. You will want most of your load to be on the panel after the XW-Pro, so that it can monitor your power consumption. It then has 3 different modes while on grid. There is pass through, where it is basically sitting idle. This mode would be when grid power is cheap. Then there is "grid support" where it will supply power from the battery to the load. You can give it a power limit and it will supply all of your loads up to that limit, and power beyond that will come from the grid. Then there is "Load Shave" that is basically the opposite. This will use grid power for light loads, and only invert and help power loads if the current goes above a certain set current. This is useful if you are in a remote area and your grid feed (or small generator) can only supply say 20 amps. It can add up to another 28 amps from the batteries, so you can run loads up to 48 amps without overloading the grid supply. And if the grid fails, it instantly switches to the inverter and batteries supplying the output up to 28 amps, or your battery current limit setting.

There are other systems with very similar capabilities, and if I was doing my system again, I might have gone with an Outback SkyBox. It is not quite as powerful, but it has better software and everything you need is built into one box. With Schneider, to get all the same function you need the gateway and a solar charge controller.

 

[Cheap 4-life]

Thanks for the explanation. I was hoping that’s how a good hybrid inverter would function. I read over many hybrid manuals but they don’t spit it out right for my brain.
One day (hopefully in the far away future) these grid tie inverters that use 16s batteries will die. Now I know a hybrid inverter will work to replace them.

 

[Cheap 4-life]

As much as I am annoyed with Schneider on some software issues, I have to say, my Schneider XW-Pro will do everything you are asking for with no problem at all.

You would want to use a separate solar charge controller to keep the batteries charged. This is the issue I am having, I have only AC coupled solar from Enphase, and the Schneider software will not let me make it go to charge mode on it's own, but if you only use it in invert mode, and have DC coupled solar, it works great. You can set it for the maximum battery current, and set the battery low voltage limit. So while you are on grid, it will grid tie and supply the amount of current you ask for. You will want most of your load to be on the panel after the XW-Pro, so that it can monitor your power consumption. It then has 3 different modes while on grid. There is pass through, where it is basically sitting idle. This mode would be when grid power is cheap. Then there is "grid support" where it will supply power from the battery to the load. You can give it a power limit and it will supply all of your loads up to that limit, and power beyond that will come from the grid. Then there is "Load Shave" that is basically the opposite. This will use grid power for light loads, and only invert and help power loads if the current goes above a certain set current. This is useful if you are in a remote area and your grid feed (or small generator) can only supply say 20 amps. It can add up to another 28 amps from the batteries, so you can run loads up to 48 amps without overloading the grid supply. And if the grid fails, it instantly switches to the inverter and batteries supplying the output up to 28 amps, or your battery current limit setting.

There are other systems with very similar capabilities, and if I was doing my system again, I might have gone with an Outback SkyBox. It is not quite as powerful, but it has better software and everything you need is built into one box. With Schneider, to get all the same function you need the gateway and a solar charge controller

If the inverter is in grid support mode. Is there a limit to the amount of power the loads can use from the grid? I’m wanting to set the inverter to supply its max amps and let the grid supply ANY amount over the max the inverter can supply

 

[GXMnow]

The maximum current a single Schneider XW-Pro can handle is 60 amps coming from the terminal block. You could stack two if you need 120 amps max. The inverter will supply up to 28 amps and you can draw the other 32 from the grid. If the inverter shuts down from low battery etc. it can pass the full 60 amps through from the grid input. If it is charging from the grid, the charge current will take away from the 60 amps it can pass because that is also the limit of the input terminal block.

The only time I pull more than 25 amps is when my central A/C kicks on, or I am using my welder or air compressor in the shop. Most of the time, my house runs under 1,000 watts, jumps to 1,800 when the furnace runs in heat mode, and peaks a bit of 3,000 with the microwave and toaster on. The A/C pulls 3,600 watts when running, and a start surge that can hit 105 amps at 240 volts. I only have the A/C connected to my main grid panel. Most of the rest is on the backup loads panel after the XW-Pro.

 

[Cheap 4-life]

The maximum current a single Schneider XW-Pro can handle is 60 amps coming from the terminal block. You could stack two if you need 120 amps max. The inverter will supply up to 28 amps and you can draw the other 32 from the grid. If the inverter shuts down from low battery etc. it can pass the full 60 amps through from the grid input. If it is charging from the grid, the charge current will take away from the 60 amps it can pass because that is also the limit of the input terminal block.

The only time I pull more than 25 amps is when my central A/C kicks on, or I am using my welder or air compressor in the shop. Most of the time, my house runs under 1,000 watts, jumps to 1,800 when the furnace runs in heat mode, and peaks a bit of 3,000 with the microwave and toaster on. The A/C pulls 3,600 watts when running, and a start surge that can hit 105 amps at 240 volts. I only have the A/C connected to my main grid panel. Most of the rest is on the backup loads panel after the XW-Pro.

I’m trying to understand the pass you mention. My cheapo grid tie inverters are connected directly to the main panel. They supply their max output and then the grid supplies the rest of what the loads need. The amount the grid is supplying does not go through the inverter. Can the hybrid inverter you mention do this? Can any of the hybrid “all in ones” do this?

 

[Cheap 4-life]

My plan is to wire a hybrid inverter to my main panel as a GTI to replace the solar-battery powered grid tie inverters I currently use Also want to use a breaker interlock so I can turn off power from the grid to the main panel so I can use the hybrid offgrid when the grids down

 

[GXMnow]

The Schneider XW-Pro has the transfer switch and anti-islanding functions all built in. So it has a grid input, a generator input, and a main output. It can sell power back to the grid input and help run loads in the main panel, but if there is any loss of grid power, it will disconnect from that input. The output will continue to output power from the battery bank if the grid fails. The LED lights in my home barely even flicker when it switches to grid forming backup power mode. But this output panel with a single inverter is only capable of 60 amps. The is the limit of the internal contactor and the terminal blocks.

When I first put my XW-Pro in service, I only had it connected on the grid side. I programmed it to sell 5 amps of current back to the grid from 4 pm to 9 pm when my grid rat doubles for "peak rate time". In the morning, I would manually trigger it to charge the battery bank again. In this setup, it had no way of knowing how much power I was actually using. So I had to watch my power meter, and dial it in so I was not pushing too much back to the utility. You can add a box called a "Watt Node" that you can then dial in and it will adjust the sell to grid current to get the amount you desire to go back out to the grid. This can be set to zero, and it will only use enough battery power to run everything in your home and no export out. Or you could have it export a little more or less, and set time limits for when it can sell.

When your loads are in the backup panel on the inverter main output, then it knows how much power you are using. It will self adjust to supply all of your loads in the backup panel. In my case, I also have my Enphase grid tie solar going into the backup loads panel. So at 4 pm, when I have it switch to run on battery power, it will monitor the power going out the grid terminals. I have it set to export just 2 amps now, because most of my load is in my backup panel. At 4 mp, on most days, my solar is still making more power than my house needs. So the inverter is in "grid support" mode, but it is actually not putting out any power. In fact, my solar is running everything in the backup loads panel, and is pushing 3 to 5 amps back to my main panel, and 1,000 watts are still going out to the grid. So at that point, my batteries are just waiting. Today, it took until after 6 pm for the solar to fall off to where the battery bank needed to start supplying power. The XW-Pro just ramps up as the solar falls off, and keeps supplying all of my backup panel loads, and another 2 amps going out the grid side to my main panel. Here is the battery summary for yesterday.

You can see that it charged at constant current from just after 9 am until about 3:10 pm. There was a short, maybe 15 minute constant voltage absorb charge that ended about 3:20 pm. At 4 pm, nothing happens because the solar is going strong. You see the current ramp down into discharge after 6 pm. The big spikes at 7 pm 9:30, and 10:15 are the microwave oven. The base current drops in half after 9 pm. That is because I have it stop grid selling at 9, but it will still power everything in the backup loads panel. It typically has enough battery to run all of my backup loads well into the next day. On this day, it was still running off the battery all the way to 3 am. At 51 volts, it turns off the grid support and has to wait until the battery charges again. And there is my big software complaint with Schneider. It has no way of starting the charge mode by itself. So someone at my house has to log in and click on force bulk charge every morning about 9 am. To be fair, this is an issue because I am using someone else's grid tie solar power system. It has no way of knowing there is solar power coming in. I could probably also start it via internet on the remote app, but I don't have that configured. The Schneider fix is to have DC solar charge controllers handle the battery charging. And I am on the fence. I have sized up a system and may be adding 6, 8, or 9 panels, depending on what size I get for a good deal, and a Schneider MPPT 60-150 charge controller to my system. Nine 300 watt panels will produce a solid 12 KWH or more and have no problem topping up the battery bank every day to run my loads every night. And it will free up my grid tie panels to run my A/C during the summer. Right now, I am only using 7.9 KWH's from the battery each day. My current battery bank could cycle over 15 KWH's if I wanted to push it, but I am saving some incase of a power failure over night. I have made a deal to buy more cells so I can double my battery capacity. Once I do that, and add the extra solar panels, I should be able to fully run even my A/C on all solar power, and only use a few watt hours for starting surges. I only need about 8 more KWH's to be producing more than I use 24 hours a day and running on either live solar or stored solar in the battery bank.

 

[Cheap 4-life]

Thanks for your help. Sounds like a good setup.
Can the main panels loads still use ANY remaining amount of power they need (above what the hybrid is supplying thru grid input-output) directly from the electric companies power supply?

I do need to do zero export. You say with the Schneider I need that node thing to do that? I wonder how accurate the zero export is. Like if it always allows the grid to supply a small amount so feeding past the meter isn’t happening

 

[Cheap 4-life]

In grid support mode, when the hybrid is supplying power to loads through the grid input-output that’s connected to the main panel, what happens when the main panel loads exceed what the hybrid can handle? I’m thinking it doesn’t matter how much power the loads in the main panel use. They will use whatever they need directly from the grid-main panel.
In grid support mode, If the homes load is 18000w I’d assume the inverter would produce up to 28amps and the remaining power the loads need is used directly from the electric companies power supply. Is this correct?

 

[GXMnow]

Yes and Yes.

You can either have the XW-Pro only supply power to it's output side, or command it to "sell to grid" out the input side. If it is selling to grid, you would need to add the "Watt-Node" unit to measure the grid power. I am still running without a Watt-Node. In this mode, I can tell it how much power to push back out the grid input side. I just estimate how much the house needs, and when loads turn on and off, it varies how much may go out to the grid from my home, or draw some in if needed. This is okay for me as I have a net energy metering agreement that allows me to push out up to 16 amps, or 900 KHW's per month. When you add the watt node, you get another control page. You can set it for how much you want to allow it to export. The watt node will adjust the inverter power to maintain your desired current. It could be from always taking in a little current to pushing out current. If you need true zero export, then yes, you will need the watt node.

When the grid is up, you can always take any power needed from the grid. Your main panel is fed by the grid, and if there is no inverter, it all works just fine. What happens with the inverter is that is will supply power as well as the grid. In the case of the USA version of the XW-Pro, it can be set to supply up to 6,800 watts, about 28 amps on bother legs of the 120/240 split phase output. It will even supply up to 40 amps on one leg under a large imbalance. There are models for 230 volt single phase as well, and 3 can be grouped to make 3 phase. If you have it set for grid sell with the watt node programmed for zero export, the inverter will take battery power and convert as much as is needed to zero out the grid power. If the demand in the house exceeds the power limit, 6,800 watts in my case, then any current above that will come from the grid. If the battery runs down, the inverter may shut down, and then all of the power will just come from the grid.

What do you plan to use to charge the battery bank? You still need to get the power from somewhere. To get the most out of the Schneider system, you should have DC coupled solar to charge the battery bank. The XW-Pro can chare from the grid, but you have to manually trigger it to start a charge cycle. With the DC solar, it just gets charge current whenever sun is hitting the panels.

 

[Cheap 4-life]

Cool, sounds like Schneider hybrid will work like I want it to. Now I gotta figure out which other hybrids can do the same so I can be cheap ?
Right now I use an outback fm80 for the chargecontroller. Id Like to not have to use a separate charge controller. Hybrids are supposed to have a built in DC to DC charge controller. I gotta reread what you said about why I’d need a separate charge controller.

 

[GXMnow]

Schneider does it with separate boxes so you can choose what you want. They have 3 or 4 different charge controllers. You could just keep your Outback FM80. That is a good unit and it will work fine. The only issue is you won’t be able to monitor it on the same page. You will see the batter voltage climb, but won’t see the amount of current. Not a big deal. You could add the battery monitor to get charging status. Their system is all building blocks. So far I only have the XW-Pro and the Gateway. You do need to gateway to configure and monitor the XW-Pro. I may be adding an MPPT 60-150 and nine More 300 watt solar panels just for battery charging.

 

[Cheap 4-life]

Will this inverter do what I have been talking about?
https://www.invertersupply.com/index.php?main_page=product_info&products_id=4488
What else would I need. I couldn’t find the watts node

 

[GXMnow]

the inverter you linked it the Schneider SW. it is a solid unit. I think 4,400 watts max, and only a 30 amp pass through relay. It does a lot of what the XW-Pro can just at lower power, but it can’t push any power back out the grid input side. It will only power the backup load panel on the output side. I almost went with the SW but then I realized it would not be able to push battery power to help run my central A/C that is back in the main panel. It also is just a little too small to deal with all of my AC coupled solar power

Here it is the wattnode box.

WattNode Wide-Range Modbus - Buy - Continental Control Systems, LLC

Universal Modbus power meter for any electrical service from 100 to 600 Vac, wye, delta, single-phase or three-phase.Revenue grade class 0.5 accuracy. Correct wiring errors remotely and SunSpec certified.

ctlsys.com

There are not very many hybrid battery inverters that can sell to grid. The few cheap ones do not have UL listing and would not be legal to install here in California. If safety certification is not important to you, you may be able to use a GroWatt or the similar clones on Ali Express. I did look into that route, but once you figure in what you spen on the batteries, is it worth cutting corners on the heart of the system?

Going to sleep here, need to be up in 5 hours. Goodnight.

 

[Cheap 4-life]

Is there a growatt or clone that can feed the grid and has zero export and can use up to at least 64v battery? And allow the loads to use power from the grid at the same time as pv-battery if the amount of load exceeds inverters max output?
4000w Outback Radian looks like a good option for me. It’s $2k

 

[Dsiee]

What about the Growatt Hybrid SPH series?

 

[Cheap 4-life]

I don’t think that inverter can use the battery to supply grid loads