SDG&E Net Metering bill, interesting observation and solar installation timing

[thejq]

Some quick background. I'm on EV-TOU2 plan with a plugin and an EV. I don't use much during on-peak (at work) and use a lot during super off-peak to charge, run laundry, pool etc. For SDG&E EV-TOU2, in summer months (May-Oct) the on-peak rate is 3x the super off-peak, but in winter (Nov-Apr), it's only 1.2x. I just got my 2nd NEM bill. I started the NEM service 2/3 way through my Sept billing period, so I had a net balance of $50 (but I didn't have to pay until true-up time). For Oct, I had a generation credit of $200 (from on-peak) and used $90 (from off-peak and super off-peak). The huge credit comes from $0.49/KWh retail rate during on-peak. A "true" net metering would use the $200 credit to wipe out both Sept's $50 and Oct's $90 and leave me with about $60 credit for future use. But for SDG&E, it only used $90 credit to wipe out the current Oct's usage and left me with $50 balance from Sept and $110 credit for future use. I'm not sure if the same method is used for other CA utilities. So the following conclusion is YMMV.

So what does it have to do with installation timing? Well if I had installed my solar in the winter, my solar generation would be low to start with and with only 1.2x factor, my usage in $ term would way exceed my generation credit which will leave me with huge balances to pay month after month. Then comes summer, my generation credit would way exceed my usage in $ term which would leave me with huge excess credits. But because the credits cannot be applied retroactively, it will remain credits for future use until true-up which is end of summer. Now at true-up, I would have to pay the accumulated balance and the generation credit would be reset and wasted (because most likely I'm still using more than I generated).

So if SDG&E didn't make a mistake on my bill (by not retroactively applying the generation credit), the best time to install is in May and worst time in Nov. So I, myself, have missed it by 4 months .

This might not be a big problem for the regular solar TOU or tier based rates because the difference in $ term between on-peak and super off-peak is small. But for people with EV-TOU2 who is banking on (or gaming) the 3x factor to offset usage during super off-peak and trying to use more power than generated, solar installation timing seems very important (at least for SDG&E customers). My back-of-the-envelope calculation says one can use almost 1.5 to 1.8 times the amount he/she generates without paying a dime.

This suggestion again is based on the current EV-TOU2 rate (which can change) and assuming usage during on-peak is low and super off-peak, high in SDG&E service area since I don't have data for other regions.

[silversaver]

That's a good question. I did few calculations base on few changes. If your usuage are high during Winter, the TOU might not be a good choice especially with EV. My solar arrays were facing SW245, so my Winter production were low. It is hard to move the consumption during off peak hours (young and growing family). That's why I plan my solar little larger so I can be flexable on usage. My ture up date were in December.... I'm not sure if SCE has the same rule as SDG&E, I'll probably check on that since my 2nd EV will arrives soon. For my understanding, it is always on net balance - net metering. Here is the TOU-EV for SCE:

[J.P.M.]

Some quick background. I'm on EV-TOU2 plan with a plugin and an EV. I don't use much during on-peak (at work) and use a lot during super off-peak to charge, run laundry, pool etc. For SDG&E EV-TOU2, in summer months (May-Oct) the on-peak rate is 3x the super off-peak, but in winter (Nov-Apr), it's only 1.2x. I just got my 2nd NEM bill. I started the NEM service 2/3 way through my Sept billing period, so I had a net balance of $50 (but I didn't have to pay until true-up time). For Oct, I had a generation credit of $200 (from on-peak) and used $90 (from off-peak and super off-peak). The huge credit comes from $0.49/KWh retail rate during on-peak. A "true" net metering would use the $200 credit to wipe out both Sept's $50 and Oct's $90 and leave me with about $60 credit for future use. But for SDG&E, it only used $90 credit to wipe out the current Oct's usage and left me with $50 balance from Sept and $110 credit for future use. I'm not sure if the same method is used for other CA utilities. So the following conclusion is YMMV.

So what does it have to do with installation timing? Well if I had installed my solar in the winter, my solar generation would be low to start with and with only 1.2x factor, my usage in $ term would way exceed my generation credit which will leave me with huge balances to pay month after month. Then comes summer, my generation credit would way exceed my usage in $ term which would leave me with huge excess credits. But because the credits cannot be applied retroactively, it will remain credits for future use until true-up which is end of summer. Now at true-up, I would have to pay the accumulated balance and the generation credit would be reset and wasted (because most likely I'm still using more than I generated).

So if SDG&E didn't make a mistake on my bill (by not retroactively applying the generation credit), the best time to install is in May and worst time in Nov. So I, myself, have missed it by 4 months .

This might not be a big problem for the regular solar TOU or tier based rates because the difference in $ term between on-peak and super off-peak is small. But for people with EV-TOU2 who is banking on (or gaming) the 3x factor to offset usage during super off-peak and trying to use more power than generated, solar installation timing seems very important (at least for SDG&E customers). My back-of-the-envelope calculation says one can use almost 1.5 to 1.8 times the amount he/she generates without paying a dime.

This suggestion again is based on the current EV-TOU2 rate (which can change) and assuming usage during on-peak is low and super off-peak, high in SDG&E service area since I don't have data for other regions.

I'm pretty sure it trues up at the end of 12 payment periods. I'd call them and confirm that. I've found them to be quite helpful. Also, at true up, if you choose reimbursement rather than rollover for excess generation over the prior 12 months, you will be back to the ~~ $.04-$.05*/kWh for that 12 mo. net excess.

[granders51]

Rollover

I called SDGE a few weeks back...specifically about rollover as I have over 3,000KWH in the bank from my system that went online in Feb 2014...I would prefer to roll over vs. getting $.03 per KWH which is all they pay.

They told me no way to roll over...

Anyone else hear different?

Tracy

[inetdog]

I called SDGE a few weeks back...specifically about rollover as I have over 3,000KWH in the bank from my system that went online in Feb 2014...I would prefer to roll over vs. getting $.03 per KWH which is all they pay.

They told me no way to roll over...

Anyone else hear different?

Tracy

SDGE seems to be playing hardball with its net metering customers. AFAIK PG&E also does not allow rollover but at least allows you to choose the true up anniversary (once!) instead of being forced to follow the install/commissioning date.
Possibly you could take your system out of service for a month (at the appropriate time) and then sign a new agreement to get the date you want?

[granders51]

Rollover

It's so aggravating because 3000KWh at peak of $.39 er KWH is worth ovver $1,200 and they want to give me $90?

That's BS!

TM

[inetdog]

It's so aggravating because 3000KWh at peak of $.39 er KWH is worth ovver $1,200 and they want to give me $90?

That's BS!

TM

And, of course, their perfect response is that it is not their fault that you installed too large a system.
They set out the conditions in advance and you made a decision.

[tracym]

And, of course, their perfect response is that it is not their fault that you installed too large a system.
They set out the conditions in advance and you made a decision.

My system was not oversized. .it was designed for 100% of my existing usage...I went live in Feb so have not been through the winter yet when we should start using up some of these credits...last month we used 200kwh...The first month we didn't generate excess..mainly because it was hot as he'll and we ran the air constant...In the first 9 days of this bill cycle we are negative 168kwh...

[inetdog]

My system was not oversized. .it was designed for 100% of my existing usage...I went live in Feb so have not been through the winter yet when we should start using up some of these credits...last month we used 200kwh...The first month we didn't generate excess..mainly because it was hot as he'll and we ran the air constant...In the first 9 days of this bill cycle we are negative 168kwh...

I am not arguing with that, and I do sympathize with the fact that SDGE will not give you any leeway on the true up anniversary, and also, if what I have heard is correct, will not allow you to use credits for later months to offset billing for earlier months even within the same 1 year cycle. If correct, that is truly despicable IMHO.
If the non-retroactive billing adjustment policy is indeed in place, then a bad anniversary date will hurt you each and every year rather than being just a one time hit the first year.
Up here in PG&E land, if I have a large surplus later in the true up year, it gets counted against the extra power I purchased earlier in the period. So it does not matter at all when the anniversary date is. My monthly bill is only for the connection fee and I get one energy bill every 12 months.

[thejq]

My system was not oversized. .it was designed for 100% of my existing usage...I went live in Feb so have not been through the winter yet when we should start using up some of these credits...last month we used 200kwh...The first month we didn't generate excess..mainly because it was hot as he'll and we ran the air constant...In the first 9 days of this bill cycle we are negative 168kwh...

Well you have until Feb 2015 to use up your reserve. So get a few large electric heaters and use them to heat up your house instead of the gas furnace in the winter. And maybe lease an EV to replace your gas engine car?

Regarding my original topic. I did call SDGE about retroactively applying the credit. Just like J.P.M. said, they will re-balance the credit against usage at the true-up time. But they also said watt-for-watt which is not TOU or EV-TOU is supposed to work. Anyway, I guess I will find out in a year.

[inetdog]

Well you have until Feb 2015 to use up your reserve. So get a few large electric heaters and use them to heat up your house instead of the gas furnace in the winter. And maybe lease an EV to replace your gas engine car?

Regarding my original topic. I did call SDGE about retroactively applying the credit. Just like J.P.M. said, they will re-balance the credit against usage at the true-up time. But they also said watt-for-watt which is not TOU or EV-TOU is supposed to work. Anyway, I guess I will find out in a year.

I have heard a totally unverified but disturbing assertion that they will only balance peak hours kW surplus against peak hours consumption, potentially leaving you with a huge surplus in peak hours but a moderate bill for off-peak that cannot be balanced away.
I would love to see an authoritative analysis based on an actual yearly bill rather than an interpretation of the published tariff.

[thejq]

I have heard a totally unverified but disturbing assertion that they will only balance peak hours kW surplus against peak hours consumption, potentially leaving you with a huge surplus in peak hours but a moderate bill for off-peak that cannot be balanced away.
I would love to see an authoritative analysis based on an actual yearly bill rather than an interpretation of the published tariff.

For some reason, I don't think every CSR knows all the details of NEM, solar generation and the implication with EV-TOU plans. From the last two bills, I'm sure they balance the on-peak, off-peak and super-off peak in $ terms (not wattage). I'm just not sure if the credit can be applied retroactively. Since J.P.M. has had his anniversary already, and he's sure it will. I think the answer is most likely yes, which means the installation date is not important.

[J.P.M.]

For some reason, I don't think every CSR knows all the details of NEM, solar generation and the implication with EV-TOU plans. From the last two bills, I'm sure they balance the on-peak, off-peak and super-off peak in $ terms (not wattage). I'm just not sure if the credit can be applied retroactively. Since J.P.M. has had his anniversary already, and he's sure it will. I think the answer is most likely yes, which means the installation date is not important.

I'm on tiered rates w/ some excess gen. until an EV comes along I can make economic sense out of to buy. My info on excess gen. payments came from the horse's mouth at SDG & E; that is, any excess generation left over at true up is either carried forward or paid to the user at wholesale rate, tiered cust. or T.O.U. cust. BTW: you need to ask for the check. Otherwise, the excess is carried over. Maybe I got it wrong. Give them a call. FWIW, it took me about 7 min. I'd also caution that CA POCO's do seem to handle some things differently within PUC mandates, one to the other and this may be one of them.

[thejq]

I'm on tiered rates w/ some excess gen. until an EV comes along I can make economic sense out of to buy. My info on excess gen. payments came from the horse's mouth at SDG & E; that is, any excess generation left over at true up is either carried forward or paid to the user at wholesale rate, tiered cust. or T.O.U. cust. BTW: you need to ask for the check. Otherwise, the excess is carried over. Maybe I got it wrong. Give them a call. FWIW, it took me about 7 min. I'd also caution that CA POCO's do seem to handle some things differently within PUC mandates, one to the other and this may be one of them.

I've given up on calling SDG&E. Every time I call, I get a different answer, and everyone thinks he/she is the expert, and the previous guy was wrong. I will wait until the true-up. If I think there's a problem I will call and argue then.

[wwu123]

I've given up on calling SDG&E. Every time I call, I get a different answer, and everyone thinks he/she is the expert, and the previous guy was wrong. I will wait until the true-up. If I think there's a problem I will call and argue then.

Looks like you're ready to just wait til next year to figure out for sure, but just wondering about that $50 charge for Sept, was that only for the 1/3 of the bill under NEMS, or also inluding the 2/3 of month under TOU but not NEMS? Because you had huge NEMS surplus for October, should have been a surplus for the last 1/3 or Sept as well by any logic. So sounds a bit like the $50 charge included the pre-NEMS first part of the month to not have a surplus.

Maybe there's just some reason they can't/won't offset that because is was before NEMS, even though they're letting you wait a year before paying it. PG&E closes out the pre-NEMS with a partial-month statement that you have to pay in full, and then the first NEMS statement was also a partial month, but I don't have to pay until true-up.

Just throwing up some speculative ideas that maybe it has nothing to do with offsetting prior NEMS usage, but can't really tell without getting a closer look at the bills.