I have IQ 7a's with CT I wasn't aware there was an option to turn off grid export thanks for the tip I'll investigate how to set that up and see that dresses my issue.
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Sol-Ark 15K All in One Inverter Released.
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Ampster
Renewable Energy Hobbyist
Unless you are off grid the non export control has to come from the micro side of things with CTs or a setting in the micros. I don't have a SolArk but the issue is a general AC coupling issue, I have the same issue with my Skybox. but I have an export arrangement with my utility so only the amount of export is the issue. When I say amount, I mean that I do not want to exceed the 7.6kW max that they expect my system to export base on the size of system that I have in my NEM agreement. I add more capacity behind the meter that serves loads and charges batteries my total kWh NET export will be below what that size system could produce. My net consumption will also be less and I do not think they have data analysis tools sophisticated enough to figure out that I have added more capacity. Therefor my strategy is to add more DC solar capacity that the Skybox can control. Let me know if I need to provide more detail. My whole strategy is to keep adding capacity behind the meter to continue to serve my loads and import less and less from my utility. Over the next years I plan on expanding my minisplit, adding a HPWH and trying to charge my EVs more from solar and less often overnight.
Ampster
Renewable Energy Hobbyist
It is not something I have pursued and I am apparently grandfathered into a type of Enphase account that gives me Administrator rights so I can only able to offer encouragement but no specific advice. I seem to recall reading that it was possible with a simple Envoy, which is where the CTs are connected and provide input.
Ampster.. Thanks for your replies.. It sounds like our solar strategy is similar.. and the biggest reason I bought the 15K Solark is to enable me to expand in future using less expensive DC only solar panels. I spent about 20 hours on Enphase University and have completed the "Solar install" courses, and confirmed that I am a certified installer in Enphase speak, and was able to fully commission my array last Sunday, and not have any fear of losing my warranty. So I will be investigating using the IQ7a inverters to limit grid export (for now) to as close to zero as possible.
I will be getting my local inspection request in this week, and hope that goes well, then the last paperwork is to submit phase 2 of my "interconnect agreement" with my local supplier. My understanding is they will purchase as much as I send back to the grid, but the $/Kwh is only about 4.5 cents as that is what the Enphase Installer App found when it searched and updated my install parameters this past Sunday.
I will update this thread if I discover a graceful way to use the Enphase tools to limit my grid input. Can you confirm that your 7.6 Kw max is a per second limit , not per minute/per hour or per day? Why does your local grid supplier care if you exceed that, my guess is they aren't paying you much per KW exported.
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Ampster
Renewable Energy Hobbyist
I believe PG&E uses 15 minute windows for their calculations. They do not have an explicit export limit. I derive that from the limitation of system size in my NEM Agreement. I assumed that the only way they had to determine that I had increased capacity was to look at my export power in kWs not my kWh production. They actually pay full retail until True Up when any annual excess is only paid at about $0.05 per kWh. During the winter my Net consumption increases and I offset that with summer Net generation. I can only guess that the loss of revenue is why they care. When I applied for my PTO I had to justify the size of my system based on theoretical consumption of two EVs and converting to an electric dryer. Their square footage metric would only have allows a 4 or 5 kW system.
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Ampster.. Wow.. Sounds like big brother is really in charge where you live. Quote: "I had to justify".....crazy. Here in south eastern PA, I just have to pay a larger fee if I install a larger system. My 12Kw array after downgrade for typical losses fee was $100, and I believe next size up is $300. I did find that there is a profile I could install on my inverters for "no export" so you are 100% correct. Issue with this approach is my Combiner box is 200 feet behind my home because I wanted to avoid potential issues with extra wire expense , and possible powerline communications issues I read about. So my Generation CT is in that box, and reports a very accurate PV generation. The second CT designed to monitor the grid power is now just double checking the solar generation, and I didn't see any way to bury the small CT wires in my trench and then try to install them up at the house on the grid feed. Having both of those monitors is a requirement for the zero export monitor, so I am out of luck on that option. Oh well.. will just wait until I get all approvals and run the array only when I have loads that use up all the power, and continue with some experiments using the Sol-ark features to limit power sent to grid. See image attached.
Thanks again for your suggestion, just sad, I cannot make use of this Enphase option.
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Hedges
I See Electromagnetic Fields!
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I'd think you'd want some data wires anyway. I installed PVC conduit and have Lan and sprinkler wires in it. Plan to pull another for load-control relays.
When I put my PV in almost 20 years ago, there was CEC rebate 50%, and hardware cost me $8/watt. We were allowed up to 200% of present usage. I have a pool. I made sure usage was high on one month's bill. Smaller limit allowed today. Most homes need 5kW so that much doesn't require documentation.
If I find a way to control production by protocol I might do that to have excess panels and inverter capacity without exceeding my connection agreement. Now that rates are highest 4:00 to 9:00 PM, supplying most of my power then could mean system able to exceed 10kW middle of the day. In my case inverters are near utility connection and loads are further.
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I'd think you'd want some data wires anyway. I installed PVC conduit and have Lan and sprinkler wires in it. Plan to pull another for load-control relays.
When I put my PV in almost 20 years ago, there was CEC rebate 50%, and hardware cost me $8/watt. We were allowed up to 200% of present usage. I have a pool. I made sure usage was high on one month's bill. Smaller limit allowed today. Most homes need 5kW so that much doesn't require documentation.
If I find a way to control production by protocol I might do that to have excess panels and inverter capacity without exceeding my connection agreement. Now that rates are highest 4:00 to 9:00 PM, supplying most of my power then could mean system able to exceed 10kW middle of the day. In my case inverters are near utility connection and loads are further.
My understanding is that when grid tied if there is more AC power than is being used, it must go back to the grid as there is nowhere else for it to go. In a grid down/off grid situation, they can frequency shift to turn off all AC inverters, but not portions of them.
Well.. I had a pretty disappointing day with my 15K Solark.. I moved the Solar Array wires from the main panel to the Gen connection, and went into the smart load settings, and turned on the AC coupled feature, and the unit never read 240V on the Gen input connection, so my AC coupled Solar Array never turned on.
240V was coming into from grid, 240V is going out to my main panel, and my entire house is running via the Solark power feed. But main panel on front says OFF, and there is not V feed to the generator pins so the AC coupled PV never sees grid and does not turn on.
Called Sol-ark tech support, and they found nothing wrong with my unit, but informed me that unless you have a DC power source connected to the Sol-Ark (Batteries, or DC Panels.). the AC coupling feature does not work.
So until I install some DC panels, or hook up my batteries, I have a very expensive paper weight hanging on my wall.
Crazy
240V was coming into from grid, 240V is going out to my main panel, and my entire house is running via the Solark power feed. But main panel on front says OFF, and there is not V feed to the generator pins so the AC coupled PV never sees grid and does not turn on.
Called Sol-ark tech support, and they found nothing wrong with my unit, but informed me that unless you have a DC power source connected to the Sol-Ark (Batteries, or DC Panels.). the AC coupling feature does not work.
So until I install some DC panels, or hook up my batteries, I have a very expensive paper weight hanging on my wall.
Crazy
Ampster
Renewable Energy Hobbyist
Modern GT inverters built to UL1741SA can modulate power. In the case of micros, I don't know the specifics about whether only some turn off or all modulate based on frequency shift of the inverter providing the signal for AC coupling
Ampster
Renewable Energy Hobbyist
Not crazy, that is how AC coupling works with any inverter capable of AC coupling. As we discussed earlier, a battery source is required. DC panels help it work better because they can react to load drops faster giving a cushion of time for the grid forming inverter to change frequency.
Unless I mis understood your post and you were connected to the grid. In that case the grid should have passed through to the micros. There may be a setting to enable the gen port on the SolArk. I don't know those details. In my case my micros connect to the AC output which is bidirectional and always has power when grid is up. When the grid drops the batteries power the inverter which provides the signal.
If you have a bypass switch to power the critical loads panel you can test if the micros are connected correctly and power up when they sense AC. Do you have a critical loads panel?
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Hi Yes I'm connected to the grid and fully expected the software to support ac coupled solar with grid up. And yes I was changing the smart grid tab to ac couple on the gen input port. I have a manager contact at sol-ark who sent me updated firmware and was discussing my ac coupled install and no battery. I pinged him to clarify. But the tech support person insisted that other techs confirmed the statement no DC available no AC coupled solar. Will update here but I fully agree if all my inverters need to see is 240v to turn on and the solark has 240v grid up and running and attached it should work for AC coupled solar input. We shall see. I have a large battery to build but didn't think it was critical path.
Ampster
Renewable Energy Hobbyist
It may be unique to the SolArk because of the way they use the Gen port instead of the AC out. If that is the case I would agree with your assessment, that it is crazy. After you quoted my post, I asked the question if you are using a critical loads panel on the AC out port of the SolArk? If so was there any load on the critical loads panel?
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629658
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I know Generac doesn’t use 2 wire start but there is a workaround available. Engineer 775 on YouTube has done some Generac installs with the Sol Ark. One of his videos he completely eliminated the ATS and brought it in on the Gen leg. I have a Kohler 18k generator attached to my Sol Ark through an ATS on the grid leg.
In this configuration, I had a complete misunderstanding on how the Sol Ark works with the Generator and ATS. So the generator is completely isolated behind the ATS normally. Even if running it cannot pass power. The ATS is monitoring grid in an outage, the ATS will throw the contactor and now the gen is attached to the Sol Ark electrically. The Sol Ark will not immediately start the generator it will use solar and battery until they are exhausted to our setting of 30% SOC. At that time the Sol Ark will start the generator and charge the batteries and then shut down. About 1-1.5 hours for us. This cycle will repeat until power is restored and the ATS then reconnects to grid.
The point is the generator is going to be used in small increments to keep your batteries charged. It is not used primarily to power your loads as you are used to. This provides a significant reduction in fuel usage. During daylight, your solar will perform this so the generator will primarily be used at night when your batteries drop below 30% SOC.
It works well and saves us a lot of fuel usage instead of running 24/7 during a grid outage.
In this setup the Sol Ark uses a CT to monitor the grid leg and it can tell if the power coming down the grid leg is generator or utility power. When grid is restored the Sol Ark will see it and act accordingly.
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629658
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Batteries are necessary in off grid situations. PV can run your home but it doesn’t have the surge capacity to start motors. The batteries kick in momentarily to start motors.
Ampster
Renewable Energy Hobbyist
Do you have a SolArk AC coupled to Enphase inverters?
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629658
Guest
No I am dc coupled. My generator is on my grid leg and my Gen leg is open so in a future expansion I’m planning on adding 4-5 micro inverted panels on the Gen leg at a later date.
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629658
Guest
No you do not. There is a checkbox in the menu “gen on grid” which then tells the Sol Ark to look for gen on the grid leg. A CT limiter is installed on this leg too so the inverter will not attempt to back feed or “sell” power to the generator.
Hedges
I See Electromagnetic Fields!
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OK, in that case perhaps it will just disconnect microinverters (generator port) when it discovers generator on grid is in use (backfeed through generator CT?) Or maybe let them operate for a while, so long as loads and battery consume the power.
Sunny Island documentation suggests generator's RPM and frequency response under load may let GT PV also supply (frequency drops within spec when loaded). It is told explicitly when generator is the source, so once it detects backfeed it would open relay.
Obviously with more DC than AC coupled, SolArk can manage PV more gracefully than having AC coupled alone.
Sunny Island documentation suggests generator's RPM and frequency response under load may let GT PV also supply (frequency drops within spec when loaded). It is told explicitly when generator is the source, so once it detects backfeed it would open relay.
Obviously with more DC than AC coupled, SolArk can manage PV more gracefully than having AC coupled alone.
