Understanding SDG&E rates

[Merrill]

I do not know how your tou works down south, but in Northern California where we have PG&E we pay 3 times the rate from 12 to 6 pm, so that works well if you can run everything out of theses times. The 3 times rate gets credited back if you have a negative kwh usage during that time. Normally this is also when the solar is generating at its near maximum, so helps with the total monthly billing.

 

[markb1]

I'm not sure if anyone can help because it seems like many of us have the same questions... I have a MS 85KW and a 6.3 KW solar system. Solar produces about 80% of energy used. My pool and MS use the majority of the power unless AC is needed. I just signed up for TOU-2 which starts tomorrow, the new billing cycle. My plan now is to time the charging of the MS and the pool circulation to 12 am - 5 am the super off peak hours. That will be at about $.14/ kw. My question is how much will I be credited for the energy I'm generating and not using during the peak hours during the day? If its some crappy number like $.04/kw, then I should keep the pool running during the middle of the day to offset the power generated by solar. I remember hearing that the power credited in peak hours and used during off peak hours is 2 kw to every 1 we generate. Any thoughts???

John

A couple people were kind enough to share their EV-TOU2 bills with me. I haven't gotten around to posting my analysis, yet, but what it looks like is, basically, you get credited at the full rate. So if you're generating power during the on-peak time, you get credited at around 26 cents per kWh. It's a great deal. 1 kWh generated during peak hours offsets almost 2 kWh during super off-peak hours. But if you generate more electricity than you use during your true-up period, I'm pretty sure you do not get paid 26 cents/kWh for the excess. That is probably where the 4 cent rate comes in.

 

[Lloyd]

A couple people were kind enough to share their EV-TOU2 bills with me. I haven't gotten around to posting my analysis, yet, but what it looks like is, basically, you get credited at the full rate. So if you're generating power during the on-peak time, you get credited at around 26 cents per kWh. It's a great deal. 1 kWh generated during peak hours offsets almost 2 kWh during super off-peak hours. But if you generate more electricity than you use during your true-up period, I'm pretty sure you do not get paid 26 cents/kWh for the excess. That is probably where the 4 cent rate comes in.

This is correct. And if you overproduce they will not send you a check for the .04 /kwh unless you specifically call them and ask for it. If not requested, it goes against the monthly billing for distribution etc. for the following year.

 

[RandyS]

The best strategy for EV owners varies, but for a lot of them with solar it makes sense to go on the EV-TOU2 rate and shift as much load as possible from noon to 8pm to the off-peak or super off-peak timeframe. Things like pool pumps, spa, car charging, etc. Then when your PV system generates during the day, you'll bank up excess generation during that time frame and then you can use/buy much cheaper kWh during the off peak or super off-peak timeframe for your car charging or other high consumption devices. When you move off the DR rate to EV-TOU2, you'll be moving from a tiered billing system (where using more costs more) to a Time of Use billing system (where you have some control over the cost by choosing the time you use the energy). Customers with a PV system and an EV can benefit from this greatly. I work in the Clean Transportation group at the utility, and you are welcome to PM me with more questions.

 

[Merrill]

PG&E does the billing on a monthly basis as far as credits, which gets carried over to the next month. Since I only generate more than I use for 5 months of the year, I do not know what they do at true-up. But you still would need to minimize your usage of on peak electricity as much as you can so your solar system can generate credits during that time.

 

[johnmodels]

Thank you so much for the education!!!! The pieces are starting to come together!!!

 

[johnmodels]

I spoke to 2 people from SDG&E yesterday since I had left a message to have an expert call me back and help me understand my solar/ev/TOU-2 situation. In a nutshell they said that the surplus energy generated mid-day (peak hours) is credited 1:1 with energy/kw used in the evening at off peak hours. There is no dollar relevance on price of energy generated and price of energy used.

BUMMER!!!! Not much advantage.... You loose the $.14 difference of the cost of energy during the day/night. Would have been nice to not have to take it in the shorts. The big guys will always get you in the end....

 

[Lloyd]

That is the exact opposite of what PG&E does, and it may be against California law regarding solar power. You should check and/or call the state regulators.

 

[markb1]

I spoke to 2 people from SDG&E yesterday since I had left a message to have an expert call me back and help me understand my solar/ev/TOU-2 situation. In a nutshell they said that the surplus energy generated mid-day (peak hours) is credited 1:1 with energy/kw used in the evening at off peak hours. There is no dollar relevance on price of energy generated and price of energy used.

BUMMER!!!! Not much advantage.... You loose the $.14 difference of the cost of energy during the day/night. Would have been nice to not have to take it in the shorts. The big guys will always get you in the end....

I don't believe this is correct. I will post some of the sample bills that have been shared with me (after I remove personal information). I tried very hard to get answers from SDG&E when I was researching this, and I got the feeling that not even SDG&E's employees understand the rate structure. Mostly, SDG&E gave me ambiguous information, but they also gave me information that flat out contradicted what other SDG&E employees had told me. And I was talking to the department that supposedly specializes in the solar and EV rate plans.

 

[johnmodels]

I too have received many different responses and all have come with little confidence behind the voice. I guess it is what it is. I will get my first bill a little over a month from now with the TOU-2/ solar. I also check my solar production and sag&e every day. It is hard to see from the SDG&E site what times energy is generated and used.
john

 

[markb1]

Ok, here are some pages from one EV-TOU2 bill that DRM was kind enough to share:

 

[FalconNinetyD]

We just completed our first month on ToU2 rates (Time of Use when you have solar/EV, 1 electric meter) with SDG&E. Damn their bills are confusing to read! I still don't understand how they determine the credit for the electricity that we generate. Like the bill that Mark posted above, I see no detail on their calculation, just a "Applied Generation Credit": -$50.71 on -290 kWh. This translates to about $0.175 per kWh, but the statement that Mark posted above shows a credit of $450.29 on generation of 447 kWh?

A few notes:

I've set my wife's Volt and my Model S to charge during super off-peak (12A-5A), though there were a few days where we each charged outside of Super off-peak rates (mainly because the Tesla didn't have 4.3 firmware for the entire month).

We have a 7.6 KW system, which produced approximately 1,043 kWh of electricity during our last billing period. According to SDG&E, our household used a net of 257 kWh for a cost of $30.40 ($0.118 per kWh). In comparison, last months non-ToU bill was for 645 kWh (days are getting longer, sun is in a better position), with a cost of $121.88, or $0.189 per kWh. So it seems like the price per kWh dropped significantly, it's just that SDG&E isn't very clear with their calculations.

 

[markb1]

We just completed our first month on ToU2 rates (Time of Use when you have solar/EV, 1 electric meter) with SDG&E. Damn their bills are confusing to read! I still don't understand how they determine the credit for the electricity that we generate. Like the bill that Mark posted above, I see no detail on their calculation, just a "Applied Generation Credit": -$50.71 on -290 kWh. This translates to about $0.175 per kWh, but the statement that Mark posted above shows a credit of $450.29 on generation of 447 kWh?

$450.29 is the cumulative credit. If you look at the summary on the last page I posted, you can see that builds up over the true-up period. This is the last bill of the true-up period, so the entire credit gets applied, even though it's more than the NEM charges. (I'm not sure what happens to the excess, but it doesn't carry over into the next true-up period.)

- - - Updated - - -

In your case, you had -290 kWh on-peak, 157 off-peak, and 390 super off-peak. The total rates right now are $0.17431, $0.16688, and $0.14082 (from the link in the first post of this thread).

If you take just the negative amount, -290 kWh on-peak, multiplied by the rate, you get $50.55. That's pretty close to your generation credit. (In my experience, my calculation always come out close to SDG&E's, but are never exactly the same!) You apparently don't have any other credits carried forward from the previous bill.

Taking the positive amounts, 157 * 0.16688 + 390 * 0.14082 = $81.12. Subtract the generation credit calculated above, you get $30.57. SDG&E only overcharged you by 17 cents. I wish they could explain how they actually calculate it. (It's probably insanely and inexplicably complicated.)

 

[RandyS]

Hi Guys,
Sorry that the bills are confusing to read...We're always looking to make things better....

Having said that, I went to the Manager of our billing department and wanted to verify that my understanding was correct (and he verified that it is).

If you are on the EV-TOU2 rate with a PV system, you are credited for your generation produced during the TOU period that it is generated. And if you have a large load like an EV or a pool pump, hopefully those can be timed to run during the super off-peak time (midnight to 5am). If that usage occurs then, you will be billed at the appropriate super off peak rate for that consumption.

One of the only times when it may not make sense to be on the EV-TOU2 rate is if you consume a lot of energy during the on-peak time. But there aren't many residential customers who fall into that category, so most customers will benefit by switching to the EV-TOU2 rate and respecting the TOU time periods with their heavier loads...

There is a CPUC rate proceeding statewide that is underway to look at all of the various issues and subsidies associated with residential rates to determine how to go forward in the future...Maybe something will come out of that later this year...

 

[markb1]

Sorry that the bills are confusing to read...We're always looking to make things better....

It's not just that the bill is confusing. I couldn't get an adequate explanation of the rate structure, even after talking to the department that is supposed to know this stuff. And I still can't precisely reproduce the calculations that go into my bill, so I really have no way to verify that I'm being billed correctly.

 

[Teriyaki88]

Thanks for the clarification! My EV-TOU2 starts tomorrow. I think my first bill will be killer but looking forward to this billing program.

Hi Guys,
Sorry that the bills are confusing to read...We're always looking to make things better....

Having said that, I went to the Manager of our billing department and wanted to verify that my understanding was correct (and he verified that it is).

If you are on the EV-TOU2 rate with a PV system, you are credited for your generation produced during the TOU period that it is generated. And if you have a large load like an EV or a pool pump, hopefully those can be timed to run during the super off-peak time (midnight to 5am). If that usage occurs then, you will be billed at the appropriate super off peak rate for that consumption.

One of the only times when it may not make sense to be on the EV-TOU2 rate is if you consume a lot of energy during the on-peak time. But there aren't many residential customers who fall into that category, so most customers will benefit by switching to the EV-TOU2 rate and respecting the TOU time periods with their heavier loads...

There is a CPUC rate proceeding statewide that is underway to look at all of the various issues and subsidies associated with residential rates to determine how to go forward in the future...Maybe something will come out of that later this year...

 

[earlyretirement]

Great information so thanks so much for sharing. I'm in San Diego with SDGE. Have any of you gone with a dedicated TOU meter that will be dedicated to charging your EV? From what I gather, SDGE will supply the meter but you must hire an electrician to do this.

Have any of you done this here in San Diego? How much did you pay for setting this dedicated TOU meter up for your EV? I don't have solar and don't plan to install it if that makes any difference.

Thanks in advance.

 

[Bobrrr]

It looks like SDGE just rolled out new rates including what they call tou-dr and tou-dr-p. It's really confusing. It appears that there is a credit for kWh used up to 130% of baseline. The peak period structure is way different than the old ev tou structure. SDGE is projecting that you-dr-p will save me about 15% per year over my present ev tou plan. There's also a guarantee that they'll charge me at the old rate plan if it doesn't save me money during the first year. You need to stick to the plan for at least 12 months.

I'm tempted to switch to avoid the egregious tou 2 rates for peak usage when I want to run AC from noon to 6:00 pm when the weather here has been approaching 90 degrees every day.

Any advice from SDGE customers on this? Thanks!

 

[Gremlin]

Update:

Total Residential Electric Rates | San Diego Gas Electric (now includes 7/1/12 rate change)

Latest "commodity cost", which corresponds the "generation" section of the bill: http://regarchive.sdge.com/tm2/pdf/ELEC_ELEC-SCHEDS_EECC.pdf

Original post:

Can anyone help me understand SDG&E's rates?

EV-TOU: http://sdge.com/tm2/pdf/ELEC_ELEC-SCHEDS_EV-TOU.pdf
EV-TOU-2: http://sdge.com/tm2/pdf/ELEC_ELEC-SCHEDS_EV-TOU-2.pdf

And the normal residential rates for reference: http://sdge.com/tm2/pdf/ELEC_ELEC-SCHEDS_DR.pdf

I believe the "UDC Total" column corresponds to delivery on the bill. What it's a total of is unclear, as it is certainly not the sum of the other columns.

Now looking at the TOU rates, I see there is barely any difference for the "UDC Total" between different times of day, which is weird. I can only assume that the generation costs must be where the variance is, but where do I look those up?

SDG&E also has this page with a little table to show EV-TOU rates: EV Rates | San Diego Gas Electric

I can't figure out what those rates include (delivery? generation? taxes?), or whether those are up to date. Does anyone understand this stuff?

Live in VA charge my car at 1 AM in the morning when Dominion charges 4 cent a Kilowatt hour : ). Im on the EV + home plan. EV + Home Pricing Plan

 

[Bobrrr]

Live in VA charge my car at 1 AM in the morning when Dominion charges 4 cent a Kilowatt hour : ). Im on the EV + home plan. EV + Home Pricing Plan

Four cents is a great rate. Here in the land of the shuttered nuclear power station, we pay 16-18 cents per kWh from midnight to 5am for the tou ev rate. In exchange for that, we pay 46 cents per kWh during the peak hours from noon to 6pm. Running the AC on a 90 degree day costs about $1.35 per hour in the afternoon. Ouch !