SDG&E TOU Tariffs

[silversaver]

You will find out more about sizing and benefit of little larger solar when you start driving EVs. I start to like Solaredge inverter especially go larger unit with easier expansion feature on mutiple roofs. It seems oversizing the inverter has no affect to the performance unlike other string inverters

If you do driving 15k miles per year, you soon will learn your 3.12kW system is way too small even with TOU....

[thejq]

I agree the RYU should not be the deciding factor unless it is close. I'm not so sure about EV-2 though, the TOU-DR plan will have $0.46/kWH summer peak and $0.13/kWh off-peak, if the baseline credit works the way I hope. I've emailed SDG&E for more info.

I know what you're thinking/hoping, but I think the baseline adjustment credit applies to all three TOU periods. Plus I thought for the solar customers, the only choices are the normal DR, DR-SES and EV-TOU2. Other plans are for non-solar customers. But you should verify.

[J.P.M.]

FWIW on Rates:

1.) T.O.U. is not as easy to analyze as tiered rates (a big no "kidding" on that - applause, etc. - thank you all !).

2.) One way I've found that helps me to make more sense of things is to think of a PV system as a revenue producer and completely delink it from energy use - at least initially.

3.) I put each of the 8,760 hourly rates per a T.O.U. schedule on a spreadsheet. Sounds like a PITA, but not as bad as it seems. For different T.O.U. rate schedules, use additional columns.

4.) For a fixed roof, plug in the hourly output/kW of the chosen equipment from PVWatts, SAM etc. into the spreadsheet.

5.) Multiply each hourly $$ rate (in this case revenue) by each hourly per kW system output for each T.O.U. schedule under consideration. Sum over 8,760 hours.

6.) What you'll have at this point is raw data to see how much revenue each or any T.O.U. plan produces for each installed nameplate kW of system size. In the case of multiple schedules, which schedule produces the most (or least) revenue. That's good, but not complete information.

7.) Depending on how much of your annual load you choose to offset, and assuming the system output is reasonably proportional to system size, divide that annual load by the annual per kW system kWh/yr. output to get a system size. Multiply that system size by the revenue per kW to get annual system revenue. More good info, but still not enough. (An aside: If you have a way to accurately calc. a tiered rate bill for the same usage, that's more nice info, but I'm not sure what use it might be except as an interesting comparison at this point).

8.) Now the fun begins. Fun in the sarcastic sense because perhaps the biggest uncertainty in all this besides, and maybe even more than weather variability, is getting a reasonable guess on hourly use patterns. For simpler T.O.U. rate schedules like T.O.U.- SES, multiply each hourly use by the hourly rate (in this case now a cost) from the T.O.U - SES tariff. Sum over 8,760 hours. This will be your annual bill.

9.) Sticking with the simpler T.O.U.- SES for now, subtract the annual electric bill from the annual system revenue. If a negative #, increase the system size by the appropriate amount. OR, adjust the use pattern (time shift usage) in ways to reduce the cost as possible, as deemed useful or desirable, OR both. If the subtraction results in a positive #, reduce the system size, or splurge on more A/C, EV, etc.

10.) For more complicated T.O.U. schedules that include some consideration(s) of monthly allowances and tiers as will as times of use, a mix of the tiered rate schemes overlaid on T.O.U. pricing is necessary. I'm still working on that one, but something similar to the above with some mod. of the tiered rate schemes will work.

11.) Caveat: All this takes no account of what the results of rate reform will have on rates, or any future rate/tariff changes for that matter.

To sum up: I've found separating system revenue from the electric bill, at least initially, gives me a bit more information and helps me see things a bit more clearly. This is a work in progress.

Take what you want of the above. Scrap the rest.

[sensij]

I agree the RYU should not be the deciding factor unless it is close. I'm not so sure about EV-2 though, the TOU-DR plan will have $0.46/kWH summer peak and $0.13/kWh off-peak, if the baseline credit works the way I hope. I've emailed SDG&E for more info.

[thejq]

Last year we had only a few days of ryu (<5) if I remembered right. So unless in a tie breaker it should not be your main consideration. If you expect lots of excess production in the day and eventually be close to net zero, ev-tou2 should be your best bet, because it's the only plan with the huge factor between day and night.

[J.P.M.]

I did much better than the advertised deal, after a week of shopping. 2LT trim w/ DC Fast Charger, true $0 at signing, $134.55 / mo for 36 mo, 15k mi annually. I will also get $2500 rebate back from the state, and $500 discount on a level 2 charger, getting me a 30 A charger for ~$110, or a 16 A charger for free. This car can only charge at 3.3 kW (about 14 A), but the higher power should be useful on EV's in the future, so I'll probably go that way.

The dealership will honor the deal through end of the month tomorrow, until their inventory is gone. Less mileage would probably be $15-$30 / mo cheaper. I can PM the sales person's name and number, for anyone interested.

Thank you.

[gvl]

No free charging for the Spark. There are several of the NRG SAE combo chargers around town, but they aren't cheap. More of an emergency situation than an everyday plan. Good news is that it is advertised as 20 min to 80% charge, so you can get 65 mi of range pretty quick. Bad news is that with the more common 240 V level 2, it is 7 hours to charge... not especially helpful unless it is set up like at sea world and the car is just going to sit anyway.

NRG subscription plan isn't too bad if you charge more than 3 times a month. As for L2 taking long time, you'll find that unlike filing the tank at a gas station you only need enough charge to get too the next charging station which is typically your home, so you'll rarely need to spend 7 hours plugged in at a public location, not to mention you don't typically start charging from empty.

[sensij]

My Mercedes B Class deal is $229 per month tax + maintance included. 36 months 12k miles per year. $0 down, about $800 driver off (1st month + license). Yes, still can apply state clean vehicle rebate of $2500 which received. $2500/36 months = $69.44 saving per month. For about $160 per months included tacx + service, it is a no brainer. MSRP $47k.

B class internal charging speed is 10kWh, my charger can only feed at 240v X32A @ 7.6kWh

Yeah, that price is about double the Spark's for same miles, which is consistent with their sell price. You get a lot more car, which is great if you need it.

[sensij]

Congrats! Sounds like a good deal, I like Spark EV but it is a bit small for my needs. Good SAE Combo plug QC infrastructure is growing thanks to NRG. Do they give you a free 2 year charging card too?

No free charging for the Spark. There are several of the NRG SAE combo chargers around town, but they aren't cheap. More of an emergency situation than an everyday plan. Good news is that it is advertised as 20 min to 80% charge, so you can get 65 mi of range pretty quick. Bad news is that with the more common 240 V level 2, it is 7 hours to charge... not especially helpful unless it is set up like at sea world and the car is just going to sit anyway.

[silversaver]

Sounds like you got yourself a killer deal. Too bad the B-Class doesn't support DCQC, for me it is a deal breaker.

It should not be a real problem because non of the resident home can do that yet. I'm not plan on driving around and find a DC charger and wait 1 to 2 hours and drive home. what are the chance you find a quick dc charger?

with 10kWh charging speed, 3 hours charging time is not too bad. all you need is get a true 40A charger.

[gvl]

My Mercedes B Class deal is $229 per month tax + maintance included. 36 months 12k miles per year. $0 down, about $800 driver off (1st month + license). Yes, still can apply state clean vehicle rebate of $2500 which received. 2500/36 months = $69.44 saving per month. For about $160 per months included tacx + service, it is a no brainer. MSRP $47k.

Sounds like you got yourself a killer deal. Too bad the B-Class doesn't support DCQC, for me it is a deal breaker.

[gvl]

Congrats! Sounds like a good deal, I like Spark EV but it is a bit small for my needs. Good SAE Combo plug QC infrastructure is growing thanks to NRG. Do they give you a free 2 year charging card too?

[silversaver]

My Mercedes B Class deal is $229 per month tax + maintance included. 36 months 12k miles per year. $0 down, about $800 driver off (1st month + license). Yes, still can apply state clean vehicle rebate of $2500 which received. $2500/36 months = $69.44 saving per month. For about $160 per months included tacx + service, it is a no brainer. MSRP $47k.

B class internal charging speed is 10kWh, my charger can only feed at 240v X32A @ 7.6kWh

[russ]

That may be true. In the world I live in, the government *is* throwing money at it, and I am not such a purist that I won't position myself to receive some if it.

Even Sunking grabbed on to a golf cart when the opportunity came by. No reason not to take the opportunity - you will get to help pay for others anyway.

[sensij]

Without the government throwing money at them to pacify greens there is no market.

That may be true. In the world I live in, the government *is* throwing money at it, and I am not such a purist that I won't position myself to receive some of it.