diy solar

diy solar

AC coupling my Outback Skybox to a Solaredge inverter

I can tell you the APsystems QS1 4 channel inverters go to zero volts output instantly, as it appears in my system. There is no ramping or bleed off that I have observed.

My house runs on a mostly constant 500 watts so there isn't a large load.
 
I can tell you the APsystems QS1 4 channel inverters go to zero volts output instantly, as it appears in my system. There is no ramping or bleed off that I have observed.
I would imagine the critical timing would be in milliseconds between the time a large load dropped and when a frequency shift would take place which would tell the micros to turn off.
 
I am updating this thread because we have purchased a new home and I will be changing the configuration. I will be selling out current home and leaving the GT solar currently installed. i will be taking the Outback Skybox with me along with the used Sunpower panels installed on the patio cover. I have found a local resource who can help me install a DIY system and apply for a PTO on the new home.
 
I am updating this thread because we have purchased a new home and I will be changing the configuration. I will be selling out current home and leaving the GT solar currently installed. i will be taking the Outback Skybox with me along with the used Sunpower panels installed on the patio cover. I have found a local resource who can help me install a DIY system and apply for a PTO on the new home.
I bet you checked on how good the solar insolation will be before buying the new place. I do not plan on moving but I have thought about if I did. I would probably leave the Enphase system here, but my battery bank and Schneider XW-Pro would go with me. Looking forward to your reports on your new install.
 
Yes, the WAF (wife aceptance factor) was the most important thing, but insolation had to be sufficient. Not ideal with a SouthEast main orientation but there are a couple of smaller SouthWest pitches. There is a shed where I can probably get 8 panels on South West pitch.

The biggest challenge electrically is the 100 Amp Zinsco main panel which has to go. Also it is very close to the natural gas riser. Even though they are both PGE the new regs require 36 inch horizontal distance. That will make the install simpler because I can pull a permit and set the new panel and when inspected call PGE to run a new drop. The new electrical riser will be 36 inches further from the pole so they will have to run a new drop unless they can add a splice. I am giving serious consideration to using a two meter panel because the EV rate on a seoarate meter is so much less expensive than the other EV rate. I will keep track of the costs because all the infrastructure upgrades will be included in my tax credit number.
The other challenge will be getting PG&E to approve the 8 kW of GT solar I want to install. There will be no history and the floor area criteria would suggest only 5 kW will be allowed according to PG&E guidelines. I will emphasize my two EVs and my plans for a HPWH and a new heat pump FAU. I will start a new thread once that begins.
 
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I totally agree, the Zinsco panel has to go. One building I worked at had one, we had a 3,000 watt lamp power supply fail. It only had a 30 amp 3 phase breaker on the 120-208 panel with a 200 amp main. It had shut down on an over temp. I checked the unit when I got there, and nothing was even warm, yet the temp switch was still open, disabling the main contactor. The heat sinks were dirty, so I cleaned it all out and the fan spun free, so I jumped the little temp switch with a clip lead and went to power it up. I heard the contactor pull in, and POP! the entire building went dark. The EM lights come on, I shut down the gear and check the main. Nope, all the breakers in the Zinsco panel were still in the on position, nothing had tripped. It actually tripped a 600 amp fuse on the 480 delta before the main transformer. The distribution panel after the main transformer was also Zinsco, so the 200 amp there didn't trip either. Those breakers were flat out useless. The electrician they brought in said that Zinsco had lost their UL cert back then. I wonder why? It turned out the lamp power supply did have one shorted diode in it. So a short on the secondary of the transformer at about 70 volts pulled enough current to blow a 600 amp fuse on a 480 volt feed.

I have mixed feelings about the dual meters. If you have grid tie solar on one meter, it will be exporting while the other meter is drawing the power you are making to charge your car. Can you put grid tie solar on the EV Car meter? Since it is a lower rate, you would certainly want that to be a zero export system. With 2 inverters like my Schneider XW-Pro, you could have one on each meter, but have a common battery bank. Have DC solar charge the battery bank, and have AC coupled solar on the house side. All the DC solar charges batteries, and the AC solar back feeds through to grid if you are not using all the power. When you charge your cars, the inverter will see the load and ramp up and invert from the batteries. You could set it for a fixed amount of current, or program it to ramp to hold zero export, or even export some if you wanted. During a power failure, the DC solar still charge the batteries, and the AC solar can charge through the house load inverter to the same battery bank again. That will allow you to still charge the car from stored power as well as anything coming from solar. This should also work on a pair of SkyBoxes. Do they allow multiple units to share the battery? Too bad we don't have many choices on V2X yet. The only one available so far only works with a Nissan Leaf because the unit requires a CHADEMO connector. CCS with DC fast charge should be able to do it, but it is not available yet. And Tesla is working on a system as well.
 
There are several problems here. When on grid, any grid tie inverter on the output side will not limit it's power. The grid is supplying 60 hz, and there is no way to command the grid to change frequency to make the inverter reduce it's output. If it can put out 10.5 KW, at some point of full sun that can happen. The wiring, contacter, and terminals in the outback just can't take it. And you can't assume the essential loads will bleed off some of the power. You don't want something catching fire if a switch is turned off. When it is running off grid, the situation could get even worse. Even with frequency/watt control, it expect no more than 7.6 KW and a certain ramp down. If the current comes on too high, it could get unstable and maybe destroy the inverter in a shower of sparks. Don't risk it. 5K of old school inverter, or up to 7.6K if it does Rule 21 Frequency/Watt. They don't put that in the instructions for no reason.
After a few months of having my IQ7 's up and running, I am ready to go phase 2: attach 36kwh of BYD batteries. I want to be ready for Public Safety Power Shutoffs, be net 0 (cover loads at night), charge my EV (another one coming soon) with solar. And for that I have been contemplating the SolArk 12k: seems to tick a lot of boxes, despite the hefty price.
I agree that attaching the AC to the critical loads panel limits what one can do with it. I can't guarantee to match 6kw of solar production with loads.

Leave Solar at the MSP and have the SolArk consuming with the grid? To take advantage of that solar power during a power cut, I need to add a transfer switch to divert Solar from MSP to the SolArk GEN input. SolArk will turn off ALL IQ7's if the load is lower than production. No throttling available.
During power cuts I could plug in one of the EV's to help max the critical loads to match the solar production. That and I hope SolArk can turn the IQ7's back on, once turned off. Would that be a realistic scenario?
The only clean way to run things I have seen is to convert the solar setup to DC. SolArk's MPPT can throttle Solar DC input. Has anyone found another way?

By the way, for those who have EV's, I found Emporia EV charger (48A capable) can do throttling via an API. I will be adding that charger to my setup: It will be easy to throttle EV charging to match solar production.
 
Leave Solar at the MSP and have the SolArk consuming with the grid? To take advantage of that solar power during a power cut, I need to add a transfer switch to divert Solar from MSP to the SolArk GEN input. SolArk will turn off ALL IQ7's if the load is lower than production. No throttling available.
Every tier 1 grid forming inverter that is capable of AC coupling can do frequency shifting to allow throttling.
If Sol-Ark can't and you already have AC solar, seems like Sol-Ark is a bad choice of you are concerned about power outages.
By the way, for those who have EV's, I found Emporia EV charger (48A capable) can do throttling via an API. I will be adding that charger to my setup: It will be easy to throttle EV charging to match solar production.
Cool, that's good news. Glad to see there is another EVSE that allows some integration.

I've got an openEVSE, I can adjust current and control it via MQTT.
 
I am still not sold on the Sol-Ark. Their feature set looks great, and the software looks pretty good, but it just seems a bit finicky. I was truly annoyed at my Schneider when I realized it can't function AC coupled on it's own, but now that I did get the PLC working to run it, I can't be happier. Thanks to Hurricane Kay, we have had spotty to heavy clouds for a few days, even got some rain up here. Solar production was all over the place. My PLC watches the solar input and the house loads and adjusts the battery charge current every 5 seconds. So it ends up looking like this.
Schneider Battery Summary 09-12-22.PNG
The green trace is the charge current, following the extra solar as it changes from the clouds going by, and the loads being used in the house. Since we had really poor solar production last night, I did have it charging at just 11.5 amps all night until 6 am. Then it started to run the house, drawing 11.8 amps before the sun came up. As the sun rose, the battery current dropped until the solar was enough to start charging at 8:40 am. Then it was grabbing all the energy it could. Since it is on the cheap power time, if the solar dropped way low, or the loads get too high, it drops to just 7 amps of charge current, the minimum I can command, but I leave it charge and let the loads use some grid power. It is a little cooler, so the A/C did not run as much today. Looks like it started up before 1 pm and ran almost 2 hours. I see that because of the charge current staying at minimum most of that time, but the solar didn't do great either, could have been clouds too. After 4 pm, I use battery power to eliminate using any grid power. The A/C cam on again at about 3:45. but at 4 pm, I stop charging, and the batteries supplied all the power the solar could not to keep my A/.C running. In the 5 to 6 pm hour, you can see the battery current ramping up as the solar production is falling off. It got to almost 57 amps at the battery before the A/C cycled off again. Solar was still making enough to run the house (with the A/C off) until after 6 pm where you once again see the battery current ramping up to run all my loads.

It looks like I managed to store up enough today to make it well past the 9 pm end of the peak rate time. One of the great features of the XW-Pro is that it powers the output loads, AND will also push additional current back to the main panel, while it is fully grid code compliant. All of my solar is currently AC coupled Enphase installed in the output backup loads panel. The XW-Pro does frequency shifting to reduce solar production while off grid, not just when the batteries are full, but to also limit charge current if needed.

The Schneider software still has limitations and some odd issues, so it is not perfect. It really should not need a PLC to make it do this. But my little PLC only cost about $300, but it did take me a while to figure out the programming, and I still want to add a few features. Until I see something that can do the power time shifting as good as I can now with the PLC, I think this is about as good as it gets. The sad part is you need to be a programmer to do it.

SunPower is now selling their SunVault battery storage system, and they are also using a Schneider XW-Pro, with their own controller to make it act properly with AC coupling. A Pwerwall2 comes close, but no dealer near me would install one with my existing Enphase Solar. And they would not just sell me a unit either. The Panasonic and Generac system look pretty good, but they are pricey.

I have yet to find a decent video testing the Outback Mojave system. I am hoping it can do good energy time shifting.
 
Every tier 1 grid forming inverter that is capable of AC coupling can do frequency shifting to allow throttling.
If Sol-Ark can't and you already have AC solar, seems like Sol-Ark is a bad choice of you are concerned about power outages.

Cool, that's good news. Glad to see there is another EVSE that allows some integration.

I've got an openEVSE, I can adjust current and control it via MQTT.
If it can speak MQTT, I'm sold! Thanks for the tip
 
I am still not sold on the Sol-Ark. Their feature set looks great, and the software looks pretty good, but it just seems a bit finicky. I was truly annoyed at my Schneider when I realized it can't function AC coupled on it's own, but now that I did get the PLC working to run it, I can't be happier. Thanks to Hurricane Kay, we have had spotty to heavy clouds for a few days, even got some rain up here. Solar production was all over the place. My PLC watches the solar input and the house loads and adjusts the battery charge current every 5 seconds. So it ends up looking like this.
View attachment 111631
The green trace is the charge current, following the extra solar as it changes from the clouds going by, and the loads being used in the house. Since we had really poor solar production last night, I did have it charging at just 11.5 amps all night until 6 am. Then it started to run the house, drawing 11.8 amps before the sun came up. As the sun rose, the battery current dropped until the solar was enough to start charging at 8:40 am. Then it was grabbing all the energy it could. Since it is on the cheap power time, if the solar dropped way low, or the loads get too high, it drops to just 7 amps of charge current, the minimum I can command, but I leave it charge and let the loads use some grid power. It is a little cooler, so the A/C did not run as much today. Looks like it started up before 1 pm and ran almost 2 hours. I see that because of the charge current staying at minimum most of that time, but the solar didn't do great either, could have been clouds too. After 4 pm, I use battery power to eliminate using any grid power. The A/C cam on again at about 3:45. but at 4 pm, I stop charging, and the batteries supplied all the power the solar could not to keep my A/.C running. In the 5 to 6 pm hour, you can see the battery current ramping up as the solar production is falling off. It got to almost 57 amps at the battery before the A/C cycled off again. Solar was still making enough to run the house (with the A/C off) until after 6 pm where you once again see the battery current ramping up to run all my loads.

It looks like I managed to store up enough today to make it well past the 9 pm end of the peak rate time. One of the great features of the XW-Pro is that it powers the output loads, AND will also push additional current back to the main panel, while it is fully grid code compliant. All of my solar is currently AC coupled Enphase installed in the output backup loads panel. The XW-Pro does frequency shifting to reduce solar production while off grid, not just when the batteries are full, but to also limit charge current if needed.

The Schneider software still has limitations and some odd issues, so it is not perfect. It really should not need a PLC to make it do this. But my little PLC only cost about $300, but it did take me a while to figure out the programming, and I still want to add a few features. Until I see something that can do the power time shifting as good as I can now with the PLC, I think this is about as good as it gets. The sad part is you need to be a programmer to do it.

SunPower is now selling their SunVault battery storage system, and they are also using a Schneider XW-Pro, with their own controller to make it act properly with AC coupling. A Pwerwall2 comes close, but no dealer near me would install one with my existing Enphase Solar. And they would not just sell me a unit either. The Panasonic and Generac system look pretty good, but they are pricey.

I have yet to find a decent video testing the Outback Mojave system. I am hoping it can do good energy time shifting.
How big is your Schneider XW Pro? Do you have stacking?
I found 6.8kw for a single unit to be on the short side for me. If I don't cover our Heat Pump + electric oven + induction cooking in the critical loads, that wouldn't fly with my Miss. Especially when NorCal power cuts are during heat waves, and we need to prepare dinner while cool.
 
How big is your Schneider XW Pro? Do you have stacking?
I found 6.8kw for a single unit to be on the short side for me. If I don't cover our Heat Pump + electric oven + induction cooking in the critical loads, that wouldn't fly with my Miss. Especially when NorCal power cuts are during heat waves, and we need to prepare dinner while cool.
I have just a single 6,800 watt XW-Pro. But here is the thing. It will crank out 12,000 watts until it gets too hot. While the grid is up, it is certainly not a problem, it will limit out at 6,800 watts, and draw the extra you may need from the grid. And when the sun is up, I can also pull another 3,000 watts from the solar panels. But when off grid, it will try to cover your load until it heats up. So you just need to watch what you turn on at the same time while the grid is down. Since I only have 36 KWHs of battery, I don't have my central A/C compressor running off the XW output. It would supply the current to start it, and keep it running, but I really don't have enough battery bank. And I would then also need more solar panel to charge it back up. But that would be true no matter what inverter you use. It really comes down to the kilowatt hours. If it was crazy stupid hot during a power failure, I might try moving the A/C over to the inverter for an hour or so. And I know I would not try welding while the A/C was running. I have a few fans, and that was enough during our last outage. It did get up to 85F in the house, but it was not a big deal. With the larger stand fan running, it felt nice in the living room. We slept out there on the floor, it was too hot in the bedroom.

I would bet you could run just fine on the 6,800 watts with fairly long surges to near 12,000 watts. The thing is a beast. In real world testing, a single XW 6,800 out performed a Sol-Ark 12K on all kinds of loads. I run my whole house, and was welding with a Hobert MIG 140 and my 3HP air compressor started up. No problem at all, it just kept cranking out 120/240 volt power. The lights didn't even flicker. I heard the hum get a bit louder, looked up and saw 7.4 KW on the power output display. That works out to 145 amps on my battery bank. That was one of the rare times I have ever seen the battery current over 100 amps.

But yes.... Do the math on your loads. If you truly think you need to run all of your electric heating appliances at the same time, then stack a pair. You can actually run up to 4 on a 120/240 volt single phase setup. PVdude on this forum is running a stacked pair now.

I never liked cooking on an electric stove, though, I have only tried resistive ones, not an induction stove. Electric ovens work well, but gas is just so much cheaper to run. I am looking into adding a mini split heat pump for two zones because my central air does not cool the upstairs area well. If I get that, it will also be able to do heating.

My stove, oven, furnace, water heater, and clothes dryer are all natural gas. So the 6,800 watts for me is more than enough. Now if we do have a major earthquake, and the gas lines fail, I will lose those appliances. But I could still cook with the microwave and my propane grill. In the dead of winter, I might need a small space heater her to stay warm, but here in So Cal, the "dead of winter" rarely even goes down to freezing. Taking a cold shower would suck. I have thought about getting a small secondary electric hot water heater. That is the one thing that would be a pain in a long term gas main failure. I do like the idea of the heat pump water heater, but they are so expensive. I just can't picture the energy savings paying off in my lifetime. A gas water heater is just plain cheap to operate. I wonder if I could plumb my natural gas water heater to run off the grill propane tanks? How far off would the mixture be? And let's be real here... If we lost the gas lines in an earthquake, what are the odds we would still have flowing water mains?

So far, my home has only been subject to one "public safety power outage" when they were worried about high winds and dry conditions sparking a fire. And that one only lasted 12 hours. And a fire started anyways, about 10 miles from here.

I am not a prepper. My solar conversion is to save money and be more comfortable if there is a grid outage. We have had 3, and it was fun being the only lit up house for several blocks. I ran out 2 extension cords and my neighbors ran their refrigerators off of my XW for half a day. The grid power came back up at 4 am. My neighbors A/C unit firing up woke me.
 
Thanks for the insight! This is definitively very helpful.

I am seeing now how much expensive and limited the SolArk's are.

I'm not a prepper but would love to be net 0 in electricity (use grid as backup).

The Schneider is definitively a nice piece. I watched that video comparing 2 Schneider XW-Pros with a SolArk 12k: awesome!
I may start with one unit and expand later if needed. I have not lived a winter with my solar setup, so I don't know how it will handle it but so far, I have never used more than 5.5k (well, except when I am charging EV, but EV charging will be out of the critical loads).

I am planning to have the solar connected to the main service panel (MSP), so that I can EV charge with solar power during the day. Where do you have your solar connected? In case of grid down, a transfer switch would allow me to switch from the MSP to somewhere in the inverter, so I can start the micro-grid and use it.

Are you happy with the Schneider interface?
Do you know if this unit can throttle the IQ7+ microinverters to adjust production to loads? This is in case of a grid failure.
 
I've got a single XW pro
My AC is in the backup loads panel and the XW will start and run it just fine.
AC coupled PV goes in the back up loads panel to allow it to function when off grid or when the grid is down. It does frequency shift my Solar Edge grid tie inverter. I've heard it does the same with Enphase micros.

The EVSE is in the main panel and still charges from solar. No need to have them in the same panel.

The biggest issue with the XW is just getting your battery charged when AC coupled and grid connected
 
I've got a single XW pro
My AC is in the backup loads panel and the XW will start and run it just fine.
AC coupled PV goes in the back up loads panel to allow it to function when off grid or when the grid is down. It does frequency shift my Solar Edge grid tie inverter. I've heard it does the same with Enphase micros.

The EVSE is in the main panel and still charges from solar. No need to have them in the same panel.

The biggest issue with the XW is just getting your battery charged when AC coupled and grid connected
hmmm, interesting. That's a simpler setup than the one I have been thinking...

How does your EVSE get solar from the backup loads if it's connected to the MSP?

I was planning to have my solar and inverter grid in connected to at the MSP. In normal use, the inverter would see only source which has grid+solar together. My EVSE is also connected there, but I will be able to throttle how much power it uses, to match the solar production.

In case of a grid failure, I was contemplating a transfer switch to divert the solar from the MSP directly the inverter (without knowing exactly where... In the case of the SolArk I would have connected to the GEN breaker).

But now that you mentioned, maybe I can connect it to the backup/critical loads panel.
 
hmmm, interesting. That's a simpler setup than the one I have been thinking...

How does your EVSE get solar from the backup loads if it's connected to the MSP?
Wires? I guess I don't understand the question.

When the grid is up, the transfer relays in the XW have the back up loads panel connected to the grid and main panel.
Any solar production not used in the backup loads panel (or used to charge the battery) flows out to the main panel. Anything not used in the main panel flows to the grid.
I was planning to have my solar and inverter grid in connected to at the MSP. In normal use, the inverter would see only source which has grid+solar together. My EVSE is also connected there, but I will be able to throttle how much power it uses, to match the solar production.

In case of a grid failure, I was contemplating a transfer switch to divert the solar from the MSP directly the inverter (without knowing exactly where... In the case of the SolArk I would have connected to the GEN breaker).

But now that you mentioned, maybe I can connect it to the backup/critical loads panel.
Using a transfer switch for your AC coupled solar would work, but unless it exceeds the 60 amp rating of the XW's transfer relays it seems redundant. As the PV could just as easily be disconnected from the grid by the XW.
 
I should also say that putting your AC coupled PV in the backup loads panel is the way Schneider recommends if you read their documentation.
 
How does your EVSE get solar from the backup loads if it's connected to the MSP?
I know @400bird answered the question but I thought I would add additional information from the perspective of a different inverter but the same configuration. The only way to have AC coupling work when the grid is down is to have the GT inveter(s) wired to the critical loads panel. That way the GT inverter(s) see the grid which the hybrid inverter is forming. When the grid is up, any excess production that does not serve the loads or charge the batteries is exported through the pass through port on the hybrid and goes through the MSP but powers the EVSE before being exported. I do not have the ability with that configuration to charge the EVs when the grid is down but I do have an alternate method if that is ever an issue during a prolonged power outage. With the way rates and rate periods have evolved, I have concluded it is optimal for me to charge from excess solar during the day than use the off peak rate of over $0.20 per kWh plus accumulate Non Bypassable Charges.

The only issue worth noting is that I have to manually adjust the current on the EV charger if I only want to use solar production. I pick a current that corresonds to the amount of solar that is being produced after loads and that is tricky if there is variable weather and/or clouds. To solve that issue, I am considering investing in another EVSE manufactured by Emporia Energy which will communicate with my existing Emporia Energy monitor and adjust the charging rate to only use available solar production.
 
Wires? I guess I don't understand the question.

When the grid is up, the transfer relays in the XW have the back up loads panel connected to the grid and main panel.
Any solar production not used in the backup loads panel (or used to charge the battery) flows out to the main panel. Anything not used in the main panel flows to the grid.

Using a transfer switch for your AC coupled solar would work, but unless it exceeds the 60 amp rating of the XW's transfer relays it seems redundant. As the PV could just as easily be disconnected from the grid by the XW.
I guess
I know @400bird answered the question but I thought I would add additional information from the perspective of a different inverter but the same configuration. The only way to have AC coupling work when the grid is down is to have the GT inveter(s) wired to the critical loads panel. That way the GT inverter(s) see the grid which the hybrid inverter is forming. When the grid is up, any excess production that does not serve the loads or charge the batteries is exported through the pass through port on the hybrid and goes through the MSP but powers the EVSE before being exported. I do not have the ability with that configuration to charge the EVs when the grid is down but I do have an alternate method if that is ever an issue during a prolonged power outage. With the way rates and rate periods have evolved, I have concluded it is optimal for me to charge from excess solar during the day than use the off peak rate of over $0.20 per kWh plus accumulate Non Bypassable Charges.

The only issue worth noting is that I have to manually adjust the current on the EV charger if I only want to use solar production. I pick a current that corresonds to the amount of solar that is being produced after loads and that is tricky if there is variable weather and/or clouds. To solve that issue, I am considering investing in another EVSE manufactured by Emporia Energy which will communicate with my existing Emporia Energy monitor and adjust the charging rate to only use available solar production.
Oh, I didn't know this was possible!: "When the grid is up, any excess production that does not serve the loads or charge the batteries is exported through the pass through port on the hybrid and goes through the MSP". This pass-through seems like a functionality that simplifies a lot the design I had in mind.
I need to read more about this. I assume this is a feature of both Schneider and Outback?
Thank you both for chiming in
 
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