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PG&E NEM 2.0

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@miimura Do you know if adding a Powerwall to existing solar on NEM1 will trigger an NEM2 upgrade? (Technically it adds 5kW of generation, but from what I now I think I understand from many discussions, that is typically not fed back to grid at peak solar production the way they have set it up).
I don't think there is any trigger to bump you out of NEM1 when you add batteries. The NEM1 tariff is clear about how much new solar you can add while remaining on the tariff.
 
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Question: solar generation capacity
I am a newbie , getting my solar installed...
I am curious how does PGE calculate the solar generation capacity.
*Is the the inverter size ? The inverter can be oversized , I am getting a oversized inverter for longer life ...price diff was nothing...
*Is it the max panel capacity ? The problem with this is , you orientation to sun will determine the max capacity ? If you have panels facing different direction and not south , then , obviously they are not working at max capacity ? Your real generation will be lower...

I heard that they allow 10% change later on. How do you calculate what is 10% ? How do you know if the original load approved ( say 5Kwh) was in fact 5Kwh and not 4Kwh due to sun direction ?
 
Question: solar generation capacity
I am a newbie , getting my solar installed...
I am curious how does PGE calculate the solar generation capacity.
*Is the the inverter size ? The inverter can be oversized , I am getting a oversized inverter for longer life ...price diff was nothing...
*Is it the max panel capacity ? The problem with this is , you orientation to sun will determine the max capacity ? If you have panels facing different direction and not south , then , obviously they are not working at max capacity ? Your real generation will be lower...

I heard that they allow 10% change later on. How do you calculate what is 10% ? How do you know if the original load approved ( say 5Kwh) was in fact 5Kwh and not 4Kwh due to sun direction ?

My contractor took care of the paperwork. The final "permission to operate" listed two numbers: nominal for both inverter and panels.

> Total Inverter Nameplate Rating: 3.75 kW
> Total CEC-AC Rating: 4.44 kW​
 
I am curious how does PGE calculate the solar generation capacity.

Your system size can be determined by historical usage, like over a year's worth of power usage. You could also add new, planned EV, like I did to make the system larger. Your installer should be helping you with these numbers. If your system is "getting installed" what was the system size based on? In my case, I had no historical usage for the new home, so I used the SCE recommendation of 2 kWh sq. ft., so my system size is 6.6 kW.

With my Model S, I'm using all the power I generate. Given actual panel output, I can safely add another four panels and be right at the edge at noon facing due south, 180º azimuth. However, you really don't want to oversize your inverter too much. Your installer should know and make the proper recommendation.
 
The limitation to how much you can add later only strictly matters for older systems that are on NEM 1.0. In that case, if you want to stay on NEM 1, you can only add 10% or 1kW, whichever is more. In general, Net Energy Metering is intended for incidental exports only. The system should not be designed to produce more kWh on an annual basis than the customer is forecast to consume.
 
Your system size can be determined by historical usage, like over a year's worth of power usage. You could also add new, planned EV, like I did to make the system larger. Your installer should be helping you with these numbers. If your system is "getting installed" what was the system size based on? In my case, I had no historical usage for the new home, so I used the SCE recommendation of 2 kWh sq. ft., so my system size is 6.6 kW.

With my Model S, I'm using all the power I generate. Given actual panel output, I can safely add another four panels and be right at the edge at noon facing due south, 180º azimuth. However, you really don't want to oversize your inverter too much. Your installer should know and make the proper recommendation.

I have the same case , due to the addition of EV, I oversized. i really do not have a good historical usage or less historical usage...
My system will be approx 4.4KW
I could have got a Solar edge 3800 for compatibility , but opted to to go with Solar edge H5000 , as the cost diff was minimum, and it has larger heat sink as well. It can handle more panels as well if needed
My panels will far from efficient , as i do not have direct south facing . so they will be less than 4.4 KW

The point is, how will PGE know my actual generation ? If they approve me for 4.4 KW , in reality i might be 3.2 KW.
WIll it give me the benefit to add more panels in the future , without more paperwork to make it later to 4.4 +10% ?
 
What would be a good Smart Meter Net energy monitoring solution ?
I just know one below. Should i buy . is it useful with NEM 2. Perhaps to setup my car charge directly with the sun .
Any ideas ?
Rainforest EMU-2 Energy Monitoring Unit
Many Thanks for suggestion. Excited to do Solar...
 
The point is, how will PGE know my actual generation ?

It's been a few years now. I don't ever recall seeing an Edison person visit the residence, but I'm sure they did while the contractor was at the house. The city required permits, so the contractor had to submit all the information to the city engineering dept. Perhaps the city worked with Edison? Don't recall. I am sure Edison also came out to inspect the tie in to their residential demarc, so the system wouldn't damage their equipment or grid. The city also came out three times during the build to check trenching depths (my system is ground mounted) and electric panel tie in. In the end, the size of installation was never questioned.

My permit to self-install my 40 amp EV receptacle also required a permit and one inspection. The permit was $150 and the parts required to self-install the receptacle were $50. Go figure.
 
I am not in PG&E land, so the following may not apply ...

My utility approves net metering for residential PV if anticipated generation based on PVwatts is less than 120% of historical use. I was initially not allowed, but I showed the utility that my usage had spiked in the last couple of months before the PV was started, and I mentioned my intent to increase consumption further a few months later with an additional EV. That was enough to gain approval.

Note:
PVwatts takes panel orientation into account
At least in my case, someone was willing to accept a reasonable argument about my future use.

Opinion: I *think* the utility motivation for restricting generation to personal use stems from the desire to not pay the same amount for electricity that they charge the consumer. If that is true and understood by both sides then an honest appraisal by the to-be PV owner of future consumption should help.

Put another way: Buy and use the EV for a month or two, then apply.
 
What would be a good Smart Meter Net energy monitoring solution ?
I just know one below. Should i buy . is it useful with NEM 2. Perhaps to setup my car charge directly with the sun .
Any ideas ?
Rainforest EMU-2 Energy Monitoring Unit
Many Thanks for suggestion. Excited to do Solar...
Why do you think you need more than your utility meter and the monitoring system provided by the solar vendor? The only reason I can think of is if you want to keep track of other important circuits like your EV charging equipment. If your car will be home during the day, it is possible to have your car charge within the output of your solar system. However, I've not seen a turnkey system to do this in the US. These advanced EVSE are more available in Europe where electrical service is smaller and they are needed so that you don't pop the main breaker while charging and using other high drain devices in the house at the same time.
 
I *think* the utility motivation for restricting generation to personal use stems from the desire to not pay the same amount for electricity that they charge the consumer. If that is true and understood by both sides then an honest appraisal by the to-be PV owner of future consumption should help.

That is very true. Before the EV, I was getting peanuts from SCE at the end of my 12-month period that amounted to 3.5 cents/kWh compared to the four-tier billing rates they had at the time that ranged from 15 cents to 35 cents/kWh. You really don't want to put in more panels than you will need.
 
That is very true. Before the EV, I was getting peanuts from SCE at the end of my 12-month period that amounted to 3.5 cents/kWh compared to the four-tier billing rates they had at the time that ranged from 15 cents to 35 cents/kWh. You really don't want to put in more panels than you will need.
Well, if there is an arrangement for the utility to only pay wholesale rates for excess generation then I don't see why the utility cares. This may be a case of legalisms, where the utility has to contract with the PV owner as a business.
 
I am not in PG&E land, so the following may not apply ...

My utility approves net metering for residential PV if anticipated generation based on PVwatts is less than 120% of historical use. I was initially not allowed, but I showed the utility that my usage had spiked in the last couple of months before the PV was started, and I mentioned my intent to increase consumption further a few months later with an additional EV. That was enough to gain approval.

Note:
PVwatts takes panel orientation into account
At least in my case, someone was willing to accept a reasonable argument about my future use.

Opinion: I *think* the utility motivation for restricting generation to personal use stems from the desire to not pay the same amount for electricity that they charge the consumer. If that is true and understood by both sides then an honest appraisal by the to-be PV owner of future consumption should help.

Put another way: Buy and use the EV for a month or two, then apply.

OK Thanks. I get it.
There are just two many variables to estimate , and no one can be very definitive , until they have historical data.
If the utility can be flexible to understand that , i guess that makes sense.

Generation side variables: solar Orientation, trees etc
Consumption side variables : I am able to charge my EV at work now, but that can change in future...
Bill side variables : Time of use pricing with Electric cooking and seasonal factors... , Spouse acceptance to TOU behaviour...
Even though my usage may be higher than my systems of say 4 KWH , but the goal would be to balance the bill with TOU pricing Currently i am on flate rate , will shift to TOU.
The night time rate of 13 cents also does not pinch me..
 
Why do you think you need more than your utility meter and the monitoring system provided by the solar vendor? The only reason I can think of is if you want to keep track of other important circuits like your EV charging equipment. If your car will be home during the day, it is possible to have your car charge within the output of your solar system. However, I've not seen a turnkey system to do this in the US. These advanced EVSE are more available in Europe where electrical service is smaller and they are needed so that you don't pop the main breaker while charging and using other high drain devices in the house at the same time.
Thanks.
When you say 'utility meter' , you mean to physically goto the ,meter to check the usage in real time ? or is their any other way to get this data ? I guess it takes 24 hours for this data to be posted on the PGE portal and then i can see some charts . Is that what you are referring to ?
In my case, part of it is just interest and excitement to monitor these things and also ultimately to charge my EV directly.
I mean why should i spend so much money to buy a power pack , when i have much bigger battery already at home , which needs to be charged . On weekends , uptill 2 PM the TOU rates are same as night time.
 
Thanks.
When you say 'utility meter' , you mean to physically goto the ,meter to check the usage in real time ? or is their any other way to get this data ? I guess it takes 24 hours for this data to be posted on the PGE portal and then i can see some charts . Is that what you are referring to ?
In my case, part of it is just interest and excitement to monitor these things and also ultimately to charge my EV directly.
I mean why should i spend so much money to buy a power pack , when i have much bigger battery already at home , which needs to be charged . On weekends , uptill 2 PM the TOU rates are same as night time.

Can someone suggest a link , how does Powerwall logic work. How does it decide, when to charge ?
As i understand, the best way would be to connect to the smart meter zigbee and get Net Metering data if its +/-
If i decide to charge my EV on solar , it would be similar logic as well.
 
So PG&E (maybe others) only care about peak value and not overall production? So could I conceivably sneak in 1kw in more easterly panels and another 1kw in westerly panels and stay off the radar?

Has anyone been visited by the solar panel police yet?
 
So PG&E (maybe others) only care about peak value and not overall production? So could I conceivably sneak in 1kw in more easterly panels and another 1kw in westerly panels and stay off the radar?

Has anyone been visited by the solar panel police yet?

Good question and good question.
If the limit is for peak , which i think is the case .....it should be peak.
I like the world 'solar panel police' , but they need to define the policies very clearly , before the police can execute its crimes.....
 
I hope I do not get reported to the authorities. We are on PG&E NEM 1.

We installed our original PV system six years ago. It was sized properly with a string inverter for the 14x185w panels. I felt like we could use a few more at the time, but my wife nixed it. Regardless, our annual true-up was $150-$200 per year. We remained on the tiered rate structure because TOU made no sense during our blistering summers.

We purchased our Model S in May 2014, and in June had another contractor install 7x270w panels with micro inverters so as not to run through the string inverter. Clearly our addition exceeded the 1kW/10% threshold mentioned above. We were either ignorant of this rule, or we had forgotten the rule after the initial set-up.

Our annual true-ups after the addition have remained about the same; perhaps slightly less. We have not been visited upon by the solar police.

I really do not know how PG&E audits their customers who have rooftop solar. Perhaps they just have some sort of filter to be on the lookout for wild reductions in deliveries and do not look at generation and receipt. Since the Tesla is offsetting most, if not all, of our second installation, we have slid through their internal review process, if they even have one.