My new solar and Powerwall installation

[ohmman]

Ohmman, you do the grid better service if you can dump your battery to the grid during peak demand periods of appx 6pm-9pm in CA. That also is net metered out at the higher rate. Then charge your EV off the grid overnight and recharge the powerwalls in the morning hours of 8am to noon so you can use only renewable energy to charge the batteries. That then makes the powerwall system eligible for the 30% ITC.

Thanks. I have to admit, I haven't looked into the ITC at all. I'll do that.

I am in the same situation as you, I have a dollar credit but a positive kWhr usage. I am not sure I understand how PG&E will be $1000 poorer?
Also with the new rates approved by CPUC I now pay a minimum $10 a month to SCE. Has that not rolled out to PG & E?

PG&E will be ~$1000 poorer because currently they take that excess generation and sell it to the neighbors at peak rates. Granted, their rate plans may be different so the numbers don't necessarily line up exactly that way. But the point is that they're selling my excess generation during peak hours and aren't paying (me or anyone) for it.

And yes, we have the MDC of about $10/month ($0.32854/day).

 

[miimura]

PG&E has applied the minimum daily per-meter charge across all residential rate plans whether you have solar or net metering or not.

 

[JSkrehot]

This is good advice but I have a clarification. It's more about "if your system produces enough power to net your costs during an entire year." The last two years, I was a net consumer of 1+MWh over the course of the true-up cycle but still ran a $1000 credit with PG&E. This is due to my consumption being shifted to the off-peak period, and my production occurring during peak. Therefore, the economics don't necessarily favor matching production and consumption.

A second note - I have to forfeit that $1000 credit each year. They won't pay me for being a net user of electricity during the true-up period. My two Powerwalls will allow me to store some of my excess peak PV production and use it overnight to avoid the "dirtier grid". So in my case, there's a small economic argument for the Powerwalls, assuming I can manage my usage over the true-up. I won't be $1000 richer each year - but PG&E will be $1000 poorer. And, more importantly, I'll offset some of that evening grid usage.

The real reason for me is to cover us in the case of power outages. Most of the year, a two or three Powerwall setup should cover all of our needs at the house during extended outages. Since we're on well, it will also allow us to have water.

I am not sure what $1,000 dollar credit you are referring to, this I am assuming was an early adopter incentive for converting to solar and is no longer part of any current PG&E offer. Also, when you say you are a consumer of 1+MWh over the course of a true up cycle, does that mean that after your production for a year, you consume an additional >1 MWh from the grid? Am I correct to assume that your solar system does not produce an equal or greater amount of MWh that you use in a calendar year? If you get a lot of power outages, I can see the argument to do the Powerwalls. I am not understanding how you could ever shift enough energy usage to pay for them. You did state above it is mainly for power outages, I can't remember the last time we had one that was not scheduled for some kind of work being done and was not even 30 min long. If someone wants to be green, more power to them. However, I was only stating that if your system produces an equal amount or greater MWh's in a calendar year, having Powerwalls does not make any financial sense with Net Metering. I am only 4 months into fully understanding this stuff after doing a self install of my system, but am always open to learning.

 

[Ampster]

I am not understanding how you could ever shift enough energy usage to pay for them.

With Solar and TOU rates the difference between super off peak at $0.11 and peak at $0.47 in summer amounts to $0.36 per kiloWatt. In my case, running my critical loads off the batteries means most if not all of my solar production gets credited at the full rate and I charge the batteries at the lowest rate. Even at 20% efficiency loss there is an economic benefit. The payback may be as long as 20 years, but as the California grid evolves a Powerwall could give an owner a hedge against changes of the peak rate to times that are not as beneficial to solar generation.

 

[ohmman]

I am not sure what $1,000 dollar credit you are referring to, this I am assuming was an early adopter incentive for converting to solar and is no longer part of any current PG&E offer. Also, when you say you are a consumer of 1+MWh over the course of a true up cycle, does that mean that after your production for a year, you consume an additional >1 MWh from the grid? Am I correct to assume that your solar system does not produce an equal or greater amount of MWh that you use in a calendar year?

The $1000 is the amount of surplus revenue that is "owed" to me at my true-up, despite consuming an additional > 1MWh from the grid. That's because, as @Ampster duly noted, I sell at well over $0.40/kWh and buy at $0.11/kWh. TOU is the differentiator, and I'm not sure you're accounting for that in your statements.

 

[K-MTG]

The $1000 is the amount of surplus revenue that is "owed" to me at my true-up, despite consuming an additional < 1MWh from the grid. That's because, as @Ampster duly noted, I sell at well over $0.40/kWh and buy at $0.11/kWh. TOU is the differentiator, and I'm not sure you're accounting for that in your statements.

What is your typical energy cost? Mine is roughly $100 lower currently compared to the summer:
My electric bill from the utility (SCE) is: ~$220
Solar City $0.15 per kw (4 kWh system) is : ~$80

I use roughly 70 kilowatts on average per day

 

[JSkrehot]

The $1000 is the amount of surplus revenue that is "owed" to me at my true-up, despite consuming an additional > 1MWh from the grid. That's because, as @Ampster duly noted, I sell at well over $0.40/kWh and buy at $0.11/kWh. TOU is the differentiator, and I'm not sure you're accounting for that in your statements.

PG&E states they buy surplus energy at $.035/kWh, how are you selling at well over $0.40/kWh?

 

[ohmman]

PG&E states they buy surplus energy at $.035/kWh, how are you selling at well over $0.40/kWh?

Rate plans matter. EV plan currently pays $0.44976/kWh during the summer peak.

http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_EV.pdf

 

[K-MTG]

Rate plans matter. EV plan currently pays $0.44976/kWh during the summer peak.

http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_EV.pdf

I think SCE just credits the net usage even though I am on the TOU plan. So if I put back 1 kilowatt into the grid during peak hours they will store a credit of 1 kilowatt that can be used anytime (off peak/super off peak). Thus I am rewarded the same regardless of when I give them my power. Kind of unfair.

PGE seems to be more fair.

 

[RandyS]

PG&E states they buy surplus energy at $.035/kWh, how are you selling at well over $0.40/kWh?

Here's my explanation of the situation (I work for the utility in San Diego)...
* The solar NEM customer's bill gets trued up once per year (on the anniversary date when solar is installed)
* If you are an undergenerator for the year, you get the retail pricing credit per kWh for your excess solar production that is exported to the grid (which is 49 cents in the summer during the on-peak period for the EV TOU rates)
* However, once your annual generation exceeds your annual consumption, you are paid essentially a wholesale price FOR THE EXCESS over and above your consumption (which would be the 3 or 4 cents quoted per kWh).
* Therefore, it isn't as economically viable to be a large overgenerator for the year, but you can rack up some good credits as an undergenerator
* One of the best situations on the EV TOU rate is generating excess power during the on-peak period and getting 49 cents credit, and then charging your car at midnight, which costs 19 cents per kWh...

I hope that helps...

 

[ecarfan]

Randy, thanks for your very clear explanation.

My system started operating under the NEM agreement in late September 2016, so I haven't reached my true-up date yet. I anticipate that my annual generation will exceed my annual consumption. That was my intent when designing my system. I am on the EV rate plan with PG&E. I recognize that my system is not optimal from an economic point of view, but that was not my priority.

 

[Ampster]

PGE seems to be more fair.

I am on SCE TOU-D-A and I believe all NEM customers are treated the same. The rates may be slightly different between utilities and there is a difference between early adoptors (NEM 1.0) and more recent adoptors (NEM 2.0)
If you are on TOU, you will see six rows on your bill regarding your consumption and generation in kWhrs. The first three will be amounts of consumption for on peak, off peak and super off peak. The next three will be Net Generation for the same periods. If you see Tiers you are not on a TOU rate. If you never have net generation then you may only see three rows for consumption.
The monthly carry over is shown on a sidebar as a cumulative number. As of my second relevant period I have a cumulative $200 owing but as solar generation picks
up in the Spring it will go negative.

 

[JSkrehot]

Here's my explanation of the situation (I work for the utility in San Diego)...
* The solar NEM customer's bill gets trued up once per year (on the anniversary date when solar is installed)
* If you are an undergenerator for the year, you get the retail pricing credit per kWh for your excess solar production that is exported to the grid (which is 49 cents in the summer during the on-peak period for the EV TOU rates)
* However, once your annual generation exceeds your annual consumption, you are paid essentially a wholesale price FOR THE EXCESS over and above your consumption (which would be the 3 or 4 cents quoted per kWh).
* Therefore, it isn't as economically viable to be a large overgenerator for the year, but you can rack up some good credits as an undergenerator
* One of the best situations on the EV TOU rate is generating excess power during the on-peak period and getting 49 cents credit, and then charging your car at midnight, which costs 19 cents per kWh...

I hope that helps...

Are you grandfathered in to an older agreement? I can not find anywhere in my NEM Agreement, nor on the PG&E website that states if you under produce for a calendar year that you will be paid the retail rate for any excess production during summer months. I definitely will not under produce for the year now, however, that can change once I get the Model 3, however, I have free charging at work, so I am hoping to add very little to my yearly usage. I am on TOU-A and not yet on the EV-TOU, as I am still waiting on Model 3 to be available. Is there a difference in in what you get paid for overproduction on the EV-TOU? Awesome if you get it, which it sounds like you do. Just trying to figure out if there is a way to get paid retail rate for any excess as well. Jealous of your profile picture too.

 

[ohmman]

Are you grandfathered in to an older agreement? I can not find anywhere in my NEM Agreement, nor on the PG&E website that states if you under produce for a calendar year that you will be paid the retail rate for any excess production during summer months. I definitely will not under produce for the year now, however, that can change once I get the Model 3, however, I have free charging at work, so I am hoping to add very little to my yearly usage. I am on TOU-A and not yet on the EV-TOU, as I am still waiting on Model 3 to be available. Is there a difference in in what you get paid for overproduction on the EV-TOU? Awesome if you get it, which it sounds like you do. Just trying to figure out if there is a way to get paid retail rate for any excess as well. Jealous of your profile picture too.

Net Surplus Compensation (NSC) is based on your 12-month true-up and only applies to excess generation over that period. In my case, as I mentioned above, I am a net consumer from the grid, but a net exporter of more valuable "peak" energy. Therefore, I run a dollar credit on my true-up, but do not receive anything in return since there is no net surplus.

Wholesale rates apply to NSC and range from $0.03 - $0.04/kWh, as you mentioned earlier in the thread.

 

[Ampster]

I am on TOU-A and not yet on the EV-TOU, as I am still waiting on Model 3 to be available. Is there a difference in in what you get paid for overproduction on the EV-TOU?

The difference between TOU-D-A and EV-TOU (TOU-TEV) is for solar customers we get a higher rate for what we generate. Last time I looked we paid $0.01/kWhr more for super off peak and for me That was not enough savings to give up the higher rate.
Have you completed a 12 month relevant period yet? If you track your bills during that period it will be easier to understand how it works.

 

[miimura]

Are you grandfathered in to an older agreement? I can not find anywhere in my NEM Agreement, nor on the PG&E website that states if you under produce for a calendar year that you will be paid the retail rate for any excess production during summer months. I definitely will not under produce for the year now, however, that can change once I get the Model 3, however, I have free charging at work, so I am hoping to add very little to my yearly usage. I am on TOU-A and not yet on the EV-TOU, as I am still waiting on Model 3 to be available. Is there a difference in in what you get paid for overproduction on the EV-TOU? Awesome if you get it, which it sounds like you do. Just trying to figure out if there is a way to get paid retail rate for any excess as well. Jealous of your profile picture too.

It looks like you don't understand the fundamentals yet. Net Metering is exactly that - the number of kWh you have consumed during each time period is totaled up and multiplied by the $/kWh rate for that period. It doesn't matter if the total kWh is positive or negative. Everything it totaled up to dollars for each billing period. The dollars are totaled up for the year. If your total dollars are positive, they go month by month and deduct any amount you have already paid in Minimum Charges on your normal bill. Then they will add your remaining True-Up energy charges to your normal bill. If your total True-Up dollars are negative for the year, but your kWh were positive for the year, the dollar credit balance is wiped out. If your dollars and kWh are both negative, then they take the negative kWh and multiply by ~$0.035/kWh and pay out your Net Surplus Compensation.

Here is an example of how the monthly calculation works. Sorry this table is overly complicated, but it is generalized for all rate plans. Schedule EV is simpler because it has no tiers. This is actually June/July 2013 usage data even though the rate calculation is the current Jan/Feb 2017 rates.

So, you can see (in the yellow shaded cells) that for the Summer-Peak period I generated 61.66kWh more than I used, in the Part-Peak period I generated 79.02kWh more than I used, but in the Off-Peak period I used 525.72kWh more than I generated. So, the dollar totals are in the lower right corner -$27.73 Peak, -$19.42 Part-Peak and +$62.10 for Off-Peak. Net $14.95 for a net of 385.04kWh which comes to $0.0388/kWh

This is for NEM 1.0. There would be additional "Non-Bypassable Charges" for NEM 2.0 customers. I don't have an example of a NBC calculation yet.

Here is the same usage data on E-TOU-A. E-TOU-B is $101.81. Please change your rate plan as soon as you start charging an EV during overnight hours.

 

[K-MTG]

I am on SCE TOU-D-A and I believe all NEM customers are treated the same. The rates may be slightly different between utilities and there is a difference between early adoptors (NEM 1.0) and more recent adoptors (NEM 2.0)
If you are on TOU, you will see six rows on your bill regarding your consumption and generation in kWhrs. The first three will be amounts of consumption for on peak, off peak and super off peak. The next three will be Net Generation for the same periods. If you see Tiers you are not on a TOU rate. If you never have net generation then you may only see three rows for consumption.
The monthly carry over is shown on a sidebar as a cumulative number. As of my second relevant period I have a cumulative $200 owing but as solar generation picks
up in the Spring it will go negative.

You must have a large system, I am on the TOU-D-B plan as I use roughly 1500-2000 kw in a month

 

[JSkrehot]

Net Surplus Compensation (NSC) is based on your 12-month true-up and only applies to excess generation over that period. In my case, as I mentioned above, I am a net consumer from the grid, but a net exporter of more valuable "peak" energy. Therefore, I run a dollar credit on my true-up, but do not receive anything in return since there is no net surplus.

Wholesale rates apply to NSC and range from $0.03 - $0.04/kWh, as you mentioned earlier in the thread.

I got you now, thanks for the explanation, just making sure I was not missing out on something.

 

[Ampster]

You must have a large system, I am on the TOU-D-B plan as I use roughly 1500-2000 kw in a month

]
No my PV system is only 4kW and last year my net usage at true up was 5,300 kWhrs. about 4,000 of that was at the super off peak rate. I had a bill at the end of $39 plus I paid approximately $120 in monthly minimums so my cost for that 5 mWhrs was about $0.03 /kWhr. The benefit to me is I get a baseline credit the makes a big difference. I am in an all electric home and have my heat pump water heater programmed to run at super off peak hours as well as my car charging.

 

[nativewolf]

]
No my PV system is only 4kW and last year my net usage at true up was 5,300 kWhrs. about 4,000 of that was at the super off peak rate. I had a bill at the end of $39 plus I paid approximately $120 in monthly minimums so my cost for that 5 mWhrs was about $0.03 /kWhr. The benefit to me is I get a baseline credit the makes a big difference. I am in an all electric home and have my heat pump water heater programmed to run at super off peak hours as well as my car charging.

And to be fair Hermosa beach has a pretty temperate clime and that has to help on the cooling/heating. A very nice place to visit.