Turning on PV with Sol Ark 15k before net meter install with zero export

[budgetsolarinstall]

I am facing the situation of a very long wait between my inspection and the install of a net meter and subsequent wait till I get permission to grid sell.

In the meantime, I wanted to configure the sol ark 15k preventing grid sell so I can use some solar. This is in Southern NH with Eversource. PV is currently off and will remain off for sure until the town inspection.

I talked to Sol Ark support for quite a bit. Even with all the configuration, it is not possible to fully prevent export to the grid in all conditions.

The safest option seems to be to limit power to load, thereby generating only enough power for the critical load and battery charge.

Even in this mode, if something switches off suddenly that power has to go somewhere and could go to the battery and the house, and if it is still excess will go to the grid.

Disconnecting the grid to prevent grid export could cause over current fault.

Any suggestions as to how I can configure the system so it would not export to the grid?

Right now, the critical loads are kitchen + fridge, two office rooms with networking equipment and computers. Not really a lot of load - would be less than 1kwh for sure. One laptop, one workstation - that’s about it. The only things which could fluctuate are maybe the kitchen appliances and the living room AV which is not really used in the day time.

I plan to keep the battery at 40% discharge so excess power has somewhere to go, if that happens. But note that the charge settings are set to like 40/50 A to get the 10 year warranty on the KiloVault HAB 7.5. So, it may not be able to absorb that much. Also, hoping the remaining home can absorb some of the load.

The current meter supports time of use - had that changed last year. But I called and verified that this one does not support solar production and would need to be replaced. They did tell me not to send power to the grid before the meter replacement.

Any experience of any home owners in this situation would be super useful. Do I really have to keep it shut down?

I even asked sol ark about disconnecting the grid - but they said excess power in that cause when battery is 100% would cause over current fault and not good for the inverter.

Give me your comments, thoughts, feedback.

So far, I think I will just have to keep everything shut down for a month or more until it is all done.

Attached is the usage for yesterday which is typical for a working day, working hours are between 8:30 am - 6:00 pm at the most.

 

[zanydroid]

Did you test your system yet? That is good to do as soon as the installation is done.

How much are you going to save with 1-2 months at this time of year anyway? This feeds into the risk tolerance and risk benefit analysis

If the current meter is analog I don’t think they can possibly detect zero export. Provided you configure zero export correctly. And there is at least one other solar customer downstream of any monitoring they might have at the transformers. Because the other solar customer will sufficiently fuzz that level of data collection.

If you have something like Emporia Vue sensors you can measure how much export actually gets done.

 

[DougfromdaUP]

My utility is ok with a few exported watts as long as you are inspected and UL1741 compliant. It’s free power for them. I would ask your utility.

 

[budgetsolarinstall]

Did you test your system yet? That is good to do as soon as the installation is done.

How much are you going to save with 1-2 months at this time of year anyway? This feeds into the risk tolerance and risk benefit analysis

If the current meter is analog I don’t think they can possibly detect zero export. Provided you configure zero export correctly. And there is at least one other solar customer downstream of any monitoring they might have at the transformers. Because the other solar customer will sufficiently fuzz that level of data collection.

If you have something like Emporia Vue sensors you can measure how much export actually gets done.

Tell me about it! We tested it very briefly during the install. PV has been off since. Drives me crazy as I can’t even keep it running for a few hours to see if it will all work for a longer period of time.

The home does not use much power during the day, but it all adds up with the high rates. So, I would save something - anything would be useful because of the high bill.

The current meter replaced only last year is definitely a smart meter because it can do time of use (peak hours). There are many houses on this street with solar. But there are many transformers too.

The sol ark can measure export. Measuring is not an issue. Preventing export is.

 

[budgetsolarinstall]

My utility is ok with a few exported watts as long as you are inspected and UL1741 compliant. It’s free power for them. I would ask your utility.

Which state is this?

 

[DougfromdaUP]

Michigan

 

[budgetsolarinstall]

Michigan

Lucky you! I called them today, my utility says not to export power before the meter is replaced for sure.

What happens when the meter does not support export, and export happens?

 

[Shimmy]

Do you have batteries? If so it becomes trivial to just go off-grid during the day and connect back after sundown.

 

[budgetsolarinstall]

Do you have batteries? If so it becomes trivial to just go off-grid during the day and connect back after sundown.

So disconnect from the grid, then?

 

[zanydroid]

Huh?

Off grid during the day is of course fine.

But if you connect grid after sundown you will parallel the inverter to grid. You have to shutdown the inverter. You will have momentary parallel operation which is technically a no no on the interconnect rules of at least two POCO that I’ve looked at.

Or have a power down few seconds in the house.

Now it depends on what the definition of no export is. I bet most customer service will not give you a precise definition, though perhaps it’s safest for them to say “don’t turn it on”. It then is up to you whether you want to define it yourself in lieu of looking up the interconnect rules so you can claim ignorance

 

[zanydroid]

And regarding the question of what happens if you turn it on with existing smart meter. Probably nothing will explode. Not clear whether they have mechanisms in place to detect export. They will certainly see that your consumption has gone way down. Maybe they’ll take action and ask for a signed declaration of what happened. Who what level legal force it has.

EDIT: ie, you could tell them you operated it in pure off grid mode even though you didn’t (and it’s quite likely your permit and SLD will indicate that would have been hard for you to do what you claimed). Figuring that out would require them to dedicate a EE or electrician to analyze your claims and Perry Mason you into a corner. Plausible? Might not be worth their effort on their part

 

[budgetsolarinstall]

But if you connect grid after sundown you will parallel the inverter to grid. You have to shutdown the inverter. You will have momentary parallel operation which is technically a no no on the interconnect rules of at least two POCO that I’ve looked at.

What exactly does parallel mean? I don’t understand. Do you mean battery may feed for a moment into the grid? The panels are not producing after sundown.

 

[zanydroid]

Parallel in the electrical sense. Inverter output active and connected to grid. And the AC input in a hybrid like SolArk is bidirectional so connecting AC input and many operating modes where the grid relay is closed would be parallel.

Your battery in self consumption mode can send to grid in some configurations because in those configs it uses zero export CTs to offset all house loads while on grid.

 

[timselectric]

Did you install a bypass transfer switch?
If so, just run off grid during the day. And bypass through the night.

 

[zanydroid]

Another way they can Perry Mason you is to ask for an EE to stamp any claim you make about why your bill went down in a contractually compliant way ?

I guess they can do that anyway if you did things properly and operated off grid. That would be a bit unfair.

 

[Shimmy]

So disconnect from the grid, then?

During the day you can happily charge your batteries from PV while supporting your daytime loads. At night you program the inverter to not export. Without solar this should be reliable.

As for disconnecting from the grid, you can just open the breaker for the inverter input during the day, and re-close it before the batteries are depleted.

 

[2TrevorJ]

I just opened the main breaker and ran my house off grid for like 10 days while waiting on the PTO.

If it was that important to control every watt I think with a smaller setup I would just set zero export power at the household idle current vs the 20W default. You can go as high as 500W. Should definitely keep you from exporting providing you don't have any big loads cycling (even with full batteries).

 

[niktak11]

My meter is digital and no one has ever complained about a few cycles of export after operating like this for 15 months now.

 

[budgetsolarinstall]

My meter is digital and no one has ever complained about a few cycles of export after operating like this for 15 months now.

Which state?

 

[Oldphile]

I'm in NH and Eversource is my utility. I operated mine for a few days prior to PTO. I did see a few bursts of 100 watts of export, but no response from Eversource. I didn't have batteries. If you're feeling defiant (I was) go to the "Other" tab in the "Limiter" settings and change Zero Power Export to 200W or more. The inverter will always draw this amount from the grid first, creating a buffer for when loads drop off or clouds suddenly evaporate.