California Members: NEM3.0 impact on NEM1/2 customers and what to do?

[Ampster]

But that wouldn’t catch any loads served on the EPS side, so it’s not a great idea.

I am not sure I have an EPS on my Skybox and I don't remember seeing one on my old Radian. Is an EPS something specific to the Multiplus? I did not see it here:

Commonly used Forum Acronyms & Abbreviations

Solar is befuddling enough! Why use acronyms? Well, we're lazy typists.... :LOL: xSyP - e.g., 2S2P, shorthand for how many cells in Series (S) and Parallel (P). A - Amperes or amps. A measure of current. See warning. AC - Air Conditioning, sometimes A/C. AC - Alternating Current, a waveform...

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In any case I am glad you understand how difficult it would be for the power company to measure how much batteries are being charged and how to incorporate that into a tarriff.

 

[fafrd]

I am not sure I have an EPS on my Skybox and I don't remember seeing one on my old Radian. Is an EPS something specific to the Multiplus? I did not see it here:

Commonly used Forum Acronyms & Abbreviations

Solar is befuddling enough! Why use acronyms? Well, we're lazy typists.... :LOL: xSyP - e.g., 2S2P, shorthand for how many cells in Series (S) and Parallel (P). A - Amperes or amps. A measure of current. See warning. AC - Air Conditioning, sometimes A/C. AC - Alternating Current, a waveform...

diysolarforum.com

In any case I am glad you understand how difficult it would be for the power company to measure how much batteries are being charged and how to incorporate that into a tarriff.

EPS is the Emergency Power Supply often called the ‘AC Output’ on Hybrid inverters or Grid-Assist Inverters (Inverters that can only accept power in through their AC input and cannot allow power to be output through that AC Input).

And yeah, it’s only a small subset of Hybrids like the Victron or this one coming from Huayu that can be connected in parallel to the grid and can power loads on the grid/AC-Input side: https://m.huayu-solar.com/Content/uploads/2021694206/PDF/AC-Coupled-Quick-Installation-Guide.pdf

That wiring diagram shows the AC-coupled solar on the AC-input of the hybrid inverter, but hybrids like the Multiplus II or any Solark also allow the AC-coupled solar to be connected to the Emergency Power Supply / AC Output (which allows the grid-tied solar power to be activated even when the grid is down).

But you’re correct - since those are the exceptions and it’s more complex, I think they are more likely to use the peak output level from the sum of each array, meaning the lower of (Micro or String) inverter peak output rating or array peak output rating for AC-coupled arrays and the lower of Solar Charge Controller (SCC) peak output rating or array peak output rating for DC-coupled arrays.

 

[Ampster]

EPS is the Emergency Power Supply often called the ‘AC Output’ on Hybrid inverters or Grid-Assist Inverters (Inverters that can only accept power in through their AC input and cannot allow power to be output through that AC Input).

The ports on my Outback Skybox are bidirectional so I don't have that issue. I use the AC output which is the the one connected to the sub panel. When exporting. the power flows from the sub panel where the AC coupled micros are feeding in and the power flows through the inverter and out the Grid port to the main panel and to the grid. I like the simplicity of that connection.

 

[fafrd]

The ports on my Outback Skybox are bidirectional so I don't have that issue. I use the AC output which is the the one connected to the sub panel. When exporting. the power flows from the sub panel where the AC coupled micros are feeding in and the power flows through the inverter and out the Grid port to the main panel and to the grid. I like the simplicity of that connection.

Yeah, that’s the way to do it.

In my case, I’d run my Microinverter array over to a new Critical Loads Subpanel and would also move a very limited number of actual Critical Loads (including fridge, some/all lights, and a few critical outlets, primarily those powering internet and smoke-filtering air fresheners) from the main panel to the Critical Loads panel.

Does the skybox include an Energy Meter or CT sensors allowing it to support zero-export-to-CT?

At $3300 for 5kW, it may be the best performance/price on today’s market (though I’m hoping we’ll eventually see a 24VDC 2kW or 3kW offering for $1 - 2K…).

 

[Ampster]

Does the skybox include an Energy Meter or CT sensors allowing it to support zero-export-to-CT?

Yes it has CTs that measure Load, Grid, Solar and Generator. It also has the ability to use external CTs to place closer to the grid to then measure other loads not on the sub panel. When I eventually set up external CTs I can cover all my loads including EV charging. Long term that is my plan for when I add more solar generating capacity behind the meter without exceeding my export limit in my PTO.

At $3300 for 5kW, it may be the best performance/price on today’s market (though I’m hoping we’ll eventually see a 24VDC 2kW or 3kW offering for $1 - 2K…).

There are some rumors that the Skybox and the Radian are going to be replaced by a new hybrid called the Mojave, which is due for release in 2022. It looks to be a larger capacity unit and might come in around the price point of the SolArk. I actually bought my Skybox when they first came out at a price point of $6,000 and six months later they dropped the price.

 

[fafrd]

Yes it has CTs that measure Load, Grid, Solar and Generator. It also has the ability to use external CTs to place closer to the grid to then measure other loads not on the sub panel.

I should have been more clear. When I referred to ‘CT sensor’ I should have said ‘external CT sensor’ (such as the ones pictured in that Huayu wiring diagram).

The CT sensors integrated into the hybrid inverters themselves are a given (or an inline shunt if they prefer to measure current that way) but fin’t provide the functionality I’m seeking.

I want to offset load on the grid/AC-input side and that can only be done by using an external CT sensor (or external inline current sensor) between the grid and the first loads.

When I eventually set up external CTs I can cover all my loads including EV charging. Long term that is my plan for when I add more solar generating capacity behind the meter without exceeding my export limit in my PTO.

Well please let me know when you’ve got the functionality working with your Skybox. That is precisely the functionality I’ve got working now with my 2 little 1kW GTIL inverters (but no backup capability)…

There are some rumors that the Skybox and the Radian are going to be replaced by a new hybrid called the Mojave, which is due for release in 2022. It looks to be a larger capacity unit and might come in around the price point of the SolArk. I actually bought my Skybox when they first came out at a price point of $6,000 and six months later they dropped the price.

I was going to add a full (permitted) Magnum PAE solution but came to the conclusion I could not justify spending that much (especially when rewiring costs are factored in).

So I just want to find a listed / permit-able hybrid solution delivering ~2-3 kW costing no more than 2-3 times the $550 total I paid for my two 1kW GTILs…

This new thread could be relevant for us NEM1.0 and 2.0 customers looking to figure out how to add batteries to our grid-tied solar systems: https://diysolarforum.com/threads/no-more-inverter-needed-in-future.32908/#post-403266

It’s only 230VAC/50Hz for now but since it inherently integrates two independent 115V sine wave generators, it fundamentally already ‘split-phase’ and a 240/120VAC 60Hz version for the US market should be straightforward offer they have overcome their initial ramp challanges.

Since their largest investor is San Francisco-based Walden International, I believe it’s only a matter of when and not if they are going to enter the US 240/120VAC split/phase market…

 

[Ampster]

It would have been better for us if they had elected to use panel rating coupled to a lower tax rate.

Again it depends on the DC to AC ratio. I know a guy in rural Illinois that has a DC to AC ratio of 2 to 1. His panels are various orientations such that he gets very little clipping. In my case my hybrid DC to AC ratio is less than 1 to 1 because my hybrid is mostly there to invert the battery capacity and manage the AC coupled micros. The DC coupled solar is really an afterthought but some reports suggest that having some DC solar panels makes the Skybox function better than just using batteries and AC coupled solar.

 

[fafrd]

Again it depends on the DC to AC ratio. I know a guy in rural Illinois that has a DC to AC ratio of 2 to 1. His panels are various orientations such that he gets very little clipping. In my case my hybrid DC to AC ratio is less than 1 to 1 because my hybrid is mostly there to invert the battery capacity and manage the AC coupled micros. The DC coupled solar is really an afterthought but some reports suggest that having some DC solar panels makes the Skybox function better than just using batteries and AC coupled solar.

I used a DC array to charge my battery because it is much straightforward to throttle-back output power when the battery is full using DC-coupling rather than AC-coupling.

And the ~13% higher efficiency of DC-coupled charging versus AC-coupled charging was a bonus:

AC-coupled: 95.5% x 90% = ~86%
DC-coupled: 97% (+13%)

That new AC-coupled battery charger technology I linked to claims it delivers 99% efficiency when powering loads and it is possible that it delivers similar efficiency when charging from AC.

If that is true, it would change the math enormously…

But the bigger advantage of an AC-coupled battery such as that may be that it could literally be plugged into any 20A outlet…

 

[Hedges]

I am not sure what limitation you are referring to? There are some practical limits when AC coupling that do relate to battery size and AC coupled solar. My guess is it has to do with the need for a buffer when off grid and the latency in shutting down AC coupling when loads drop suddenly. As far as I know that is not as big an issue when the grid is up because the grid provides that buffer. I will read the rest of the thread to see if it is clarified.

It was something in PG&E's rules about adding battery storage so you could store PV generated power during off-peak, then backfeed the grid on-peak. And, you could only store power obtained from PV to later backfeed, not "help" PG&E shift its production capacity to when needed by storing from grid off-peak.

Here we go. Only applies to systems that aren't "small". Small systems under 30kW PV can have 10kW battery inverter. I suppose that means my 2.5kW PV inverter could be paired with 10kW battery inverter. (Wonder it the Sun Tax would be $20/month or $100/month?)

https://www.pge.com/pge_global/common/pdfs/solar-and-vehicles/net-energy-metering/net-energy-metering-overview/nem-multiple-tariff/NEM-Paired-Storage-Frequently-Asked-Questions.pdf

 

[Hedges]

And DC charging of EVs is also an intriguing idea, though a dedicated array only used to charge an EV sounds wasteful.

If you work nights and park at home all day (or charge from PV at work during the day), could feed 100% of PV production into EV battery, then top off with grid power after sun sets.

The only benefit I see in continuing to run under ST for a year or two while the dust settles is that you leave your options open about formally making changes only after how the rules are being applied has been made clear.

Yeah, wait and see might work.
Hopefully, someone will see the light and not mandate that all rooftop PV exports to be the grid go to PG&E with $zero reimbursement.

My minimal 2500W inverter would probably export most of its power with just refrigeration cycling. But maybe I can set up my pool pump VFD to implement zero export, consume surplus based on current transformers.

 

[GXMnow]

I missed a few days, and we have a lot of posts here now.

I am still trying to read and understand all the new rules in the NEM 3.0 document. It's quite obvious they are upset that they will be selling less electricity and they want to make as much or more money from people NOT using their electricity. It really is a scam.

If they decide to mess around with the rate structure and give everyone a fixed few for having the grid available to cover maintenance cost, but then charge LESS per KWH, I guess that would be fair. But what they are trying to do is give all of us Solar users higher rates, AND charge us fixed fees when we don't use power from them. That just seems wrong. If we do go to "Zero Export" we should be charged the same as a non solar customer for the power we do end up using. Don't pay me anything for export, but then don't jack my rates to have power either. I was quite annoyed by the loss of my tiered billing. When my lowest tier was just $0.12 per KWH, and now my cheapest TOU rate is $0.22 During most of the year, I would have been able to stay totally in Tier 1 with my solar install, but thanks to forced TOU, I am paying about 50% of what I did before, while using just 25% of their power. So my cost per KWH from So Cal Edison is essentially double now. And that is just NEM 2.0

With the proposals for NEM 3.0, it looks like my bill could be as high as it was pre solar. If I "Decommission" half of my Enphase array, and change that to DC to charge my batteries. I might be in a much better position. Then my system will only be 1,920 watts of grid tied solar inverters.

The whole issue of wanting us to add batteries makes the issue get very strange. I read the rule as how much solar panel, not inverter capacity. And I am 25% over paneled on my micros. So that does make a difference. When set to "Zero Export" a battery inverter should not add to any "grid benefit charges". And the amount of solar we have should not mean squat to them if we are not exporting. I can see their point when we push power out, they do need to deal with that power, but it is becoming plainly obvious that they want to just make Solar no longer cost effective so people just buy the power from them and don't bother with solar panels.

Clearly, I need to read over the rules a bit closer to figure out how to work the system. I also may end up writing a few letters. California as well as the federal government has been pushing us to go solar, and now they want to penalize us because it worked and people did it. That is just plain wrong. It is like when they pushed us to reduce water consumption here. Everyone put in the low flow crap, and then the water company jacked the rates to make our bills the same while we use 30% less water.

 

[BurningDaylight]

Can anybody tell me if the grandfathered 15 year period of NEM 2.0 transfers with a house sale to the new owner?

 

[fafrd]

Can anybody tell me if the grandfathered 15 year period of NEM 2.0 transfers with a house sale to the new owner?

Yes. 15 years from original activation date with the remainder transferring to new owner with sale of the house.

 

[Ampster]

Throughout this thread there has been speculation about how one could cancel their NEM agreement. I just read mine and it appears all I have to do is give PG&E 30 days notice. I don't know if that will allow me to escape that $8 per kW assessment but I have 14 years to figure that out.

Yes. 15 years from original activation date with the remainder transferring to new owner with sale of the house.

Also. on my first reading of my current NEM agreement. it appears that the sale of a property means the new owner does not get any benefit of the grandfathering but I do not know the mechanism for them to be in any form of NEM agreement or if the old agreement had the same wording. I sold two home with NEM agreements, One with a PTO of 2014 in SCE and another with a PTO of 2018 in PG&E. I will let those buyers worry about that when their day comes.

 

[fafrd]

Throughout this thread there has been speculation about how one could cancel their NEM agreement. I just read mine and it appears all I have to do is give PG&E 30 days notice. I don't know if that will allow me to escape that $8 per kW assessment but I have 14 years to figure that out.

That's good to know. So the two follow-on questions are:

1/ can a property that has already been on NEM1 or NEM2 and decomissioned start a new solar application under the Successor Tariff and be eligible for the year-one discount on Grid Access Fees and/or qualify for the battery incentives?

2/ if you disconnect from NEM but leave your solar array producing in a zero-export setup (without informing your utility), can they figure that out from your consumption pattern and what is the penalty for operating a zero-export solar array without PTO from the utility?

Also. on my first reading of my current NEM agreement. it appears that the sale of a property means the new owner does not get any benefit of the grandfathering but I do not know the mechanism for them to be in any form of NEM agreement or if the old agreement had the same wording. I sold two home with NEM agreements, One with a PTO of 2014 in SCE and another with a PTO of 2018 in PG&E. I will let those buyers worry about that when their day comes.

I believe there is language in the Preliminary Decision of the Successor Tariff addressing precisely that, so it is possible they have added new transferring of grandfathering benefits that were not in the original NEM1 or NEM2 agreements...

 

[Ampster]

what is the penalty for operating a zero-export solar array without PTO from the utility?

Penalty? What law would give them any right to tell you what you can do behind the meter? You are not exporting, correct? There is more risk that a building department would figure it out if it is visable from the street. PG&E can't even keep their powerlines clear enough to prevent fires. How would they even be able to analyze the usage of millions of customers usage and write an algorithm that would identify reduced consumption?

 

[fafrd]

Penalty? What law would give them any right to tell you what you can do behind the meter?

There are laws governing wiring and circuits connected to the grid. I’ve posted an article on that subject a few posts back…

You are not exporting, correct? There is more risk that a building department would figure it out if it is visable from the street.

If you ‘decommission’ a permitted solar array with your utility but then continue to use it to power a zero-export hybrid inverter, there is nothing for an inspector to see from the street - you already have a permitted solar system…

PG&E can't even keep their powerlines clear enough to prevent fires. How would they even be able to analyze the usage of [/u]millions of customers usage[/u] and write an algorithm that would identify reduced consumption?

We talking about those NEM1 or NEM2 customers who decommission, so it’s likely to be a tiny fraction of the ~1million existing NEM customes (unless it becomes a ‘thing’).

 

[Ampster]

There are laws governing wiring and circuits connected to the grid. I’ve posted an article on that subject a few posts back…

I think is is important to separate building code laws that govern what goes on behind the meter and the regulations that the IOUs would like you to think regulate what goes on behind the meter. In reality the IOU regulations only apply to us if our inverters export to the grid and/or we have a contract with them in which we agree to their rules. Years ago I read an academic treatise that influenced my thinking about our right to generate power behind the meter. Here is a link:

https://www.google.com/url?sa=t&source=web&rct=j&url=https://escholarship.org/content/qt3643z0qx/qt3643z0qx.pdf&ved=2ahUKEwjtx5C2wfv0AhUSQ80KHcnzAZ8QFnoECD4QAQ&usg=AOvVaw0fTYdr38GRQUMX02iUmrTS

I think the article is even more relevant today given the erosion of NEM benefits. I would love to see the concept tested in a significant court case but I am not willing to be the guinea pig for such a case.

 

[time2roll]

Some day we all may just have a battery charger connected to the grid and mostly be autonomous. Our own inverter can power the main panel.

I don't like the electric company reaching over and charging fixed fees for the solar I have behind the meter. I would be willing to give up the permit to generate.

 

[GXMnow]

I may write a letter to SCE from a new email account, asking about moving to their service area.

Something along the lines of...
I have a solar power system that is zero export. I would like to use it when I move into your service area. I would like to have a grid power connection for the times when my solar does not produce enough power to run my home, so I don't need to run the generator. Again, it will only draw some power from the grid when production does not meet the power demands, and no power will ever export out to the grid. Consumption from the grid will range from zero to maybe 100 KWH's a month for a small home with a family of 3. Do I need to file any paperwork with you to use my system? What kind of rate plan do you offer for low power use customers?

It would be interesting to see how they answer that.