CPUC NEM 3.0 discussion

[YRide]

As my tag line states, I have a generator, solar, and batteries.
Under NEM2, there is no wholesale info. At true up, the cost I get back is in the wholesale
yes, export onto the grid is outflow excess.
Does not matter where the 90kwh comes from, solar, batteries, generator, etc. If the meter sees 90hwh coming from you past meter back to meter to grid, you get 90kwh credit.
Now for the month, there is on the black and white bill, the total month usage from grid, and month how much you sent back. They net this out per month. At 12 months they net it all out and either you pay, or get pennies back on the dollar, like I do.
so if you pulled 100kwh from the grid, and sent back 90kwh, your net would be -10kwh. But its not the amount, it is the cost of energy
at the time you send and pull that is what is the bottom net dollar amount on the bill, positive or negative. I have large negatives on my net monthly bill. This time of the year I use these credits from the summer when pump huge amounts to PG.

Thx a lot! I think I’ve got it now. I get the annual net metering (with time of use $) process I believe.

But it was this monthly export cap I was struggling to understand. As I understand from your last post…PGE can/does measure the outflow only out of your meter, and this is compared against the monthly PVWatts generation limit they have for your based on number of panels, orientation, etc, etc. so on a monthly basis you cannot exceed this amount.

So it’s kinda two things in parallel you have to manage.

It seems like in this case using a ESS with grid charging for TOU arbitrage could help more in the winter months when you don’t have a lot of sun. But that said, you may not even need to do that (in your case it sounds like you have so much summer credits built up that you don’t need to bother with TOU arbitrage).

Btw, do you or anyone else have a redacted (not looking for anyone’s personally identifiable info) version of this “black and white” bill?

 

[swedge]

Still not quite understanding this comment. Are you saying that it’s impossible to exceed your export limit? Or are you saying don’t exceed your export limit?

If you grid charge then export later (effectively TOU arbitrage) is that considered a net zero export? Or does all “export” only count outbound flow, not net flow?

PG&E meters report separately the power drawn from the grid and power exported to the grid. I call these import and export. PG&E can thus make your buy and sell prices different. It also lets them cheat on "Net Energy Metering", which used to mean the we would just run the meter forward and backward and pay only for the "net" difference. NEM3 as it is proposed, is not "Net Metering" at all.

Anyway, if you don't charge from the grid, the only export you can do is of energy which came from solar. So, in that case, you simply can not export more than your solar produces. Since PV Watts does a good job of estimating production, without grid charging, your export won't exceed that limit.

I do not know what rules apply to a battery with no solar. If charged during off peak, and discharged to run the house during peak, one could save some $ and reduce total peak load on the grid, a win-win. But are these systems allowed to export? I don't know. They are not covered by NEM anyway, so a bit off topic.

However there is a second limitation on credit for exports. The point of NEM is to let solar exports be reimported at no net cost. This lets your excess summer production be consumed in the winter, and your mid-day production to be consumed at night. Very clever, NEM, and helped make rooftop solar economically viable. But, what happens if, over the course of the 12 month true-up period, you produce more than you consume? (This is h20Fun's situation.) They call this net surplus generation. This is outside of what NEM is designed for, and so you are paid only wholesale for this excess. So this "net surplus compensation" is a different issue than the export limitation for battery systems.

I hope this clears up your question, but this really is complicated. So much so that the utilities were able to pull the wool over the CPUC's eyes and made them think that killing solar would somehow help poor people, hence NEM3.

I also looked up that posting which explains the true-up for a battery + solar customer: link.

SW

 

[h2ofun]

Thx a lot! I think I’ve got it now. I get the annual net metering (with time of use $) process I believe.

But it was this monthly export cap I was struggling to understand. As I understand from your last post…PGE can/does measure the outflow only out of your meter, and this is compared against the monthly PVWatts generation limit they have for your based on number of panels, orientation, etc, etc. so on a monthly basis you cannot exceed this amount.

So it’s kinda two things in parallel you have to manage.

It seems like in this case using a ESS with grid charging for TOU arbitrage could help more in the winter months when you don’t have a lot of sun. But that said, you may not even need to do that (in your case it sounds like you have so much summer credits built up that you don’t need to bother with TOU arbitrage).

Btw, do you or anyone else have a redacted (not looking for anyone’s personally identifiable info) version of this “black and white” bill?

yep

Thx a lot! I think I’ve got it now. I get the annual net metering (with time of use $) process I believe.

But it was this monthly export cap I was struggling to understand. As I understand from your last post…PGE can/does measure the outflow only out of your meter, and this is compared against the monthly PVWatts generation limit they have for your based on number of panels, orientation, etc, etc. so on a monthly basis you cannot exceed this amount.

So it’s kinda two things in parallel you have to manage.

It seems like in this case using a ESS with grid charging for TOU arbitrage could help more in the winter months when you don’t have a lot of sun. But that said, you may not even need to do that (in your case it sounds like you have so much summer credits built up that you don’t need to bother with TOU arbitrage).

Btw, do you or anyone else have a redacted (not looking for anyone’s personally identifiable info) version of this “black and white” bill?

 

[h2ofun]

PG&E meters report separately the power drawn from the grid and power exported to the grid. I call these import and export. PG&E can thus make your buy and sell prices different. It also lets them cheat on "Net Energy Metering", which used to mean the we would just run the meter forward and backward and pay only for the "net" difference. NEM3 as it is proposed, is not "Net Metering" at all.

Anyway, if you don't charge from the grid, the only export you can do is of energy which came from solar. So, in that case, you simply can not export more than your solar produces. Since PV Watts does a good job of estimating production, without grid charging, your export won't exceed that limit.

I do not know what rules apply to a battery with no solar. If charged during off peak, and discharged to run the house during peak, one could save some $ and reduce total peak load on the grid, a win-win. But are these systems allowed to export? I don't know. They are not covered by NEM anyway, so a bit off topic.

However there is a second limitation on credit for exports. The point of NEM is to let solar exports be reimported at no net cost. This lets your excess summer production be consumed in the winter, and your mid-day production to be consumed at night. Very clever, NEM, and helped make rooftop solar economically viable. But, what happens if, over the course of the 12 month true-up period, you produce more than you consume? (This is h20Fun's situation.) They call this net surplus generation. This is outside of what NEM is designed for, and so you are paid only wholesale for this excess. So this "net surplus compensation" is a different issue than the export limitation for battery systems.

I hope this clears up your question, but this really is complicated. So much so that the utilities were able to pull the wool over the CPUC's eyes and made them think that killing solar would somehow help poor people, hence NEM3.

I also looked up that posting which explains the true-up for a battery + solar customer: link.

SW

This is why in the past solar could only be sized to 100% of proveable use in the last 12 months. They do not want folks doing what I have done.

 

[YRide]

Thx. And thanks to @swedge too for the link to t

This is why in the past solar could only be sized to 100% of proveable use in the last 12 months. They do not want folks doing what I have done.

i think that went up to 150% going forward in NEM3/NB, right?

Is it possible to get your allowable/max export amounts per month from PGE ahead of time? Or will you only know them all after the each month (and thus the first year)?

Also, does PGE adjust the allowable export annually? I believe PVWatts has calculations for panel degradation, dust, etc…

 

[h2ofun]

Thx. And thanks to @swedge too for the link to t

i think that went up to 150% going forward in NEM3/NB, right?

Is it possible to get your allowable/max export amounts per month from PGE ahead of time? Or will you only know them all after the each month (and thus the first year)?

Also, does PGE adjust the allowable export annually? I believe PVWatts has calculations for panel degradation, dust, etc…

Yep but NEM3 kills any value to have solar, IMO. So who cares the percentage, IMO.
I never could get ahead of time, but, once I had one, I could put my system in PVwatts and basically figure out it. This was usefull since I was able to call PGE and tell them, with this data, they had not updated my account to give me credit for my additional 15KW of solar they gave me a PTO on. So, not that hard to do.

 

[STS-134]

Yep but NEM3 kills any value to have solar, IMO. So who cares the percentage, IMO.

I don't think it kills the value of solar. It certainly does elevate the value of having storage, and if you generate (via solar) all of the energy you use, you still don't have to pay PG&E, at least not until they implement a flat grid support fee that's independent of energy consumed or exported.

 

[h2ofun]

I don't think it kills the value of solar. It certainly does elevate the value of having storage, and if you generate (via solar) all of the energy you use, you still don't have to pay PG&E, at least not until they implement a flat grid support fee that's independent of energy consumed or exported.

Just cheaper to buy a generator. We shall see what happens in a few months, maybe you are right. Again, I have yet to lose power. And most folks do not stay in their houses long enough to payback, IMO.

 

[STS-134]

Just cheaper to buy a generator.

If you want to survive an extended outage, you have to buy a generator and a large propane tank. This is completely separate from solar and storage and fulfills a different role.

We shall see what happens in a few months, maybe you are right. Again, I have yet to lose power. And most folks do not stay in their houses long enough to payback, IMO.

I was talking to a guy who was trying to sell me on solar and he insisted that he's heard stories of tenants being willing to pay more in rent because a house has solar to offset electrical usage. Exactly how true that is, I'm not sure, but I'm pretty sure that if I ever did rent out this house, I'd get something for having solar if I decided to ever install it. Whether it is enough to match the investment that I put in is entirely another matter though, and it probably also depends on how competitive the rental market is at any given point in time.

 

[YRide]

If you want to survive an extended outage, you have to buy a generator and a large propane tank. This is completely separate from solar and storage and fulfills a different role.

I was talking to a guy who was trying to sell me on solar and he insisted that he's heard stories of tenants being willing to pay more in rent because a house has solar to offset electrical usage. Exactly how true that is, I'm not sure, but I'm pretty sure that if I ever did rent out this house, I'd get something for having solar if I decided to ever install it. Whether it is enough to match the investment that I put in is entirely another matter though, and it probably also depends on how competitive the rental market is at any given point in time.

NEM2 grandfather (20yrs from PTO I think) is transferable in a home sale, so something to consider when pricing out…some cost recovery. That said, you’ll likely be buying into NEM3

 

[STS-134]

NEM2 grandfather (20yrs from PTO I think) is transferable in a home sale, so something to consider when pricing out…some cost recovery. That said, you’ll likely be buying into NEM3

I could probably do NEM2 if I rushed things. The guy trying to sell me solar said I could add storage later on and still be grandfathered into NEM2. The problem is, I'm not sure when my roof will need replacing. Apparently there's a 30% rebate on solar/roof installs and if my roof goes any time in the next 10 years, I'd be able to get a discount on it, so I think it's worth waiting for that, even if that pushes me into NEM3. I'm sure that the cost of storage will likely come down.

 

[swedge]

yep

View attachment 890895View attachment 890896

Am I reading this correctly? In the month you exported only 17 kWh? Heat pumps running on afterburner? A month long personal solar eclipse. Snow blanketing your solar arrays?

Perhaps today is not the day to mention your lack of power outages. We had a brief outage early this morning, but fortunately the PW had grid-charged to 80% starting at midnight, the most aggressive charge I've seen it do. It does seem to anticipate cloudy days, much to my surprise. Pleasant surprise this morning.

SW

 

[h2ofun]

Am I reading this correctly? In the month you exported only 17 kWh? Heat pumps running on afterburner? A month long personal solar eclipse. Snow blanketing your solar arrays?

Perhaps today is not the day to mention your lack of power outages. We had a brief outage early this morning, but fortunately the PW had grid-charged to 80% starting at midnight, the most aggressive charge I've seen it do. It does seem to anticipate cloudy days, much to my surprise. Pleasant surprise this morning.

SW

Yep, you read correctly. I am using like 60 to 80 kwh per day for my house. So basically everything I produced went to either run the house, or attempt to charge the batteries. I now put my batteries on 100% even though storm watch is now on. I only product 1.9kwh the entire day yesterday because of the thick rain clouds. Today I produced a huge 3.8kwh.

So yep, even with tons of solar, this time of the year, and big storms we have having now, so glad I bank TONS during the summer months!
I love having my house at 70 degrees now, and my house is not small. Happy wife though since costing us nothing, I just paid it
all upfront.

 

[swedge]

I was talking to a guy who was trying to sell me on solar and he insisted that he's heard stories of tenants being willing to pay more in rent because a house has solar to offset electrical usage.

It would be nice if CPUC created a NEM billing scheme to bill the home consumption and the solar separately. That way the renter pays regular price and the landlord gets the NEM credits. This would enable landlords to install solar, which otherwise is economically infeasible. Of course the utilities would lobby that out of the conversation, as they have just done with NEM. Sigh.

btw, I watched STS-31 from the causeway. An unforgettable experience! I was next to some folks from Perkin-Elmer, and I quipped (a line borrowed from an old Bill Cosby record), "I sure hope the mirror don't crack." I was trying to break the tension, but they did not appreciate the effort. Sadly it turned out to be oddly prophetic.

 

[STS-134]

It would be nice if CPUC created a NEM billing scheme to bill the home consumption and the solar separately. That way the renter pays regular price and the landlord gets the NEM credits.

You could effectively do the same as a landlord just by creating a contract that states that the tenant pays the landlord at the PG&E retail rate and the landlord's costs vary based on NEM credits and actual consumption. Would be a royal pain to calculate this and bill the tenant every month but there's nothing I'm aware of that would prevent such a contract from being drawn up as a condition of the lease.

This would enable landlords to install solar, which otherwise is economically infeasible. Of course the utilities would lobby that out of the conversation, as they have just done with NEM. Sigh.

Or you just increase the rent and roll the cost of the solar credits into the cost of the rent.

btw, I watched STS-31 from the causeway. An unforgettable experience! I was next to some folks from Perkin-Elmer, and I quipped (a line borrowed from an old Bill Cosby record), "I sure hope the mirror don't crack." I was trying to break the tension, but they did not appreciate the effort. Sadly it turned out to be oddly prophetic.

I watched STS-134 from the causeway. Only got to see it for about 20-25 seconds though before it disappeared into the clouds.

 

[sunwarriors]

I don't think it kills the value of solar. It certainly does elevate the value of having storage, and if you generate (via solar) all of the energy you use, you still don't have to pay PG&E, at least not until they implement a flat grid support fee that's independent of energy consumed or exported.

Run the math without batteries, it looks really bad from my rough calcs. Of course, in San Diego, we're looking at credit of only like 13% or something for export vs. 25% under other IOUs I think.

I don't think solar will work well for most folks not getting batteries. Batteries were already a hard sell before, but people will now have to pay near double for installs on NEM3.0 to get batteries and batteries can mostly only zero out your bill at best. You'll never get much credit for export when it's only worth 25% or 13% when during winter months, you're stuck with little/no solar.

We'll really see in a few months/years, but I think it'll be pretty painful for the industry.

 

[STS-134]

Run the math without batteries, it looks really bad from my rough calcs. Of course, in San Diego, we're looking at credit of only like 13% or something for export vs. 25% under other IOUs I think.

I don't think solar will work well for most folks not getting batteries. Batteries were already a hard sell before, but people will now have to pay near double for installs on NEM3.0 to get batteries and batteries can mostly only zero out your bill at best. You'll never get much credit for export when it's only worth 25% or 13% when during winter months, you're stuck with little/no solar.

We'll really see in a few months/years, but I think it'll be pretty painful for the industry.

Batteries are way overpriced right now. Think about how much a Powerwall costs and take 75-100 kWn worth of Powerwalls and price that out, and ask yourself why you're paying as much or more for that as you are for an entire car with the same amount of battery capacity in it. With these changes, battery manufacturers will be forced to lower prices.

 

[sunwarriors]

Batteries are way overpriced right now. Think about how much a Powerwall costs and take 75-100 kWn worth of Powerwalls and price that out, and ask yourself why you're paying as much or more for that as you are for an entire car with the same amount of battery capacity in it. With these changes, battery manufacturers will be forced to lower prices.

I have doubts that they will lower prices much honestly in the short term (5 year time frame or less). They haven't gone down recently (they've gone UP), but we'll see how it plays out. I don't know if you have solar/storage yourself, but there is something always around the corner and I see people delaying and saying prices have to go down (sorta like with housing prices), and keep saying it for years on end.

Housing prices only went down recently, when interest rates doubled and for many people, housing prices are still up tons. This sorta applies to getting an EV too. It's a great feeling never having to get gas and have $0 power bills (I'm still using credits, I think I will have a bill next month though due to gas usage for heat).

There used to be a PW shortage and there is demand from EVs and home storage now. I think NEM3.0 will force storage or don't bother with solar, at least from my quick calcs so I don't think prices will go down as fast as some folks seem to spout off.

I've stated here before that home batteries don't really have an ROI and I'd say don't bother if that's someone's only concern. I think most folks do it for a lot of other reasons. Control/power outage support/flexibility/climate/lower concerns with whatever the IOU chooses to do with rates come to mind for me. When the IOUs know only 5-20% (what is the #?) has home batteries vs. only solar, they will do things to take advantage I feel. IOUs can adjust peak rates when there is no solar and make up any $$ needed, but if you have batteries, you can deflect all of that.

My bigger hope long term is Enphase figures out V2G and one can use their EV for those long cloudy dry spells (like this week).

 

[fresnoboy]

If you want to survive an extended outage, you have to buy a generator and a large propane tank. This is completely separate from solar and storage and fulfills a different role.

I was talking to a guy who was trying to sell me on solar and he insisted that he's heard stories of tenants being willing to pay more in rent because a house has solar to offset electrical usage. Exactly how true that is, I'm not sure, but I'm pretty sure that if I ever did rent out this house, I'd get something for having solar if I decided to ever install it. Whether it is enough to match the investment that I put in is entirely another matter though, and it probably also depends on how competitive the rental market is at any given point in time.

This is a key thing for folks to understand. batteries are not a viable substitute for a generator. And if you buy a generator and have the backup functionality paid for, then acquiring powerwalls just for peak demand load shifting doesn't make any financial sense, even in PG&E land's rapacious peak hour rates. As long as people are buying powerwalls even if the numbers don't work, Tesla has zero interest in cutting prices on them.

I don't understand why PW's are in such demand. NEM3 may incent battery storage, but the overall economics for solar + storage went down, not up, at least at current battery prices. Now, with EV's with large inexpensive battery capacities starting to be sold, they may have a chance to make the load shifting financials pay out. The problem is integrating these things with useful control systems is painful now, though maybe that will get better.

 

[STS-134]

This is a key thing for folks to understand. batteries are not a viable substitute for a generator.

I had this discussion with a friend who was arguing that PWs would make it where he didn't need a generator. I had to ask, what happens if the outage occurs on a cloudy winter day? What happens if it's smoky and hot, and you're running the HVAC to keep the house cool, and the panels just aren't generating?

Then you get people who argue that a generator connected to natural gas is a viable substitute for an on-site fuel source. They're going to be sorry when an earthquake takes out the natural gas service and they're stuck without electricity for days, and the generator isn't doing anything in the very scenario they bought it for.

And if you buy a generator and have the backup functionality paid for, then acquiring powerwalls just for peak demand load shifting doesn't make any financial sense, even in PG&E land's rapacious peak hour rates. As long as people are buying powerwalls even if the numbers don't work, Tesla has zero interest in cutting prices on them.

I don't understand why PW's are in such demand. NEM3 may incent battery storage, but the overall economics for solar + storage went down, not up, at least at current battery prices.

The only thing I can think of is that there appears to be a very large percentage of people whose goal is to make it where they don't have to pay anything to PG&E (or at least pay very minimal bills), return on investment be damned. Back when E-1 was the dominant plan and NEM1 was the norm, you'd see people buying enough solar to offset all of their usage, and that never made sense to me. Back then, the best ROI on solar was to get enough of it to knock yourself out of Tier 3 and Tier 4, since you could effectively get electricity from the solar at Tier 3 or Tier 4 rates and decrease the payback time dramatically. Putting enough solar to offset Tier 2 and Tier 1 usage never really made sense. And the economics get even worse when you consider that a lot of people do the calculations such that they figure out how long it would take for the solar/storage to offset an equal amount of PG&E bills, neglecting the fact that had you not gotten solar/storage, you could have invested that money in something else and it would be making money in the meantime.

If you do the calculation for a PW, and look at its capacity and warranty (# of cycles), you'd find that you're paying over 20¢/kWh just to time shift electricity usage, and that doesn't even account for the fact that you don't get 100% of the electricity out of a battery that you put into it. I'm not sure in what world it ever makes sense to pay 20¢/kWh to avoid paying peak rates, even at PG&E prices.