Leveraging "Time of Use" Rates

[Musterion]

Hi folks, in particular @kev1n , @miimura , @RE Insider :

I have a 60 panel solar generator in Bay Area and am on EV-A after doing some cost comparisons. After comparing last couple years to the other choices, it seems that was the best choice, although it wasn't obvious at the time compared to the time-shifted alternates, which are no longer available. In previous posts I've thanked @miimura for incredibly useful spreadsheet calculators, predating what PG&E has only done recently (without details) on their website for EV and TOU rate comparisons. Thank you again! Like @kev1n, I looked earlier at the powerwall and it didn't make sense even in optimal conditions (charging at night and discharging at peak) based on cost. At that time, I would only do it for backup generation during power failure, but Tesla changed their options and the best battery for daily use is incompatible for deep discharge, i.e. generator usage. @miimura, do you think this cost calculus has changed with SGIP rebates? Then there is Keith (@RE Insider) -- I noticed clicking on your link gives a special referral page to Swell energy -- so what is your financial connection and benefit to the advice you are giving here? Are you a vendor, and/or getting remuneration for referrals? It would be best to disclose your financial interests if you are soliciting on this site. Your advice about when to charge and the cap on different PG&E rates is well known to those of us who already did the math. What is up for debate is the financials of battery storage and all that I would require is some real numbers on cost, max kWh charge/discharge per day (cycle count) and ability or non-ability to use as back-up generator (or limitations therein if infrequent) and I could do my own calculation, and the others on the thread I'm sure will appreciate your full disclosure.

 

[miimura]

SGIP is a mess and always has been. In prior years it was gamed by vendors robo-reserving all the funds for commercial use. I was hoping that the revamped program would be better this year. Now it appears that the utilities are only processing a couple residential applications per day from the stack they were given by the SGIP administrators.

My personal opinion is that the Step 1 rebate level is too high for PowerWall because it could make the battery completely free, leaving you to pay only for installation. However, you still have to pay 40% of the total installed cost, so there is motivation for the installers to rip you off in order to maximize the incentive.

Regarding the financials - if you have enough solar that your annual energy cost is zeroed out, you cannot save any more money with a PowerWall. I have a small solar system that doesn't cover my EV charging usage, so I can pay off my Powerwall with reduced PG&E bills. Between that and the up-front money I was going to spend on a backup generator, it's pretty clear to me that it will eventually pay for itself. The biggest problem is that I still don't know what my final out-of-pocket cost will be. My install cost from Swell Energy and SGIP status is still unknown.

 

[RE Insider]

Hi folks, in particular @kev1n , @miimura , @RE Insider :

I have a 60 panel solar generator in Bay Area and am on EV-A after doing some cost comparisons. After comparing last couple years to the other choices, it seems that was the best choice, although it wasn't obvious at the time compared to the time-shifted alternates, which are no longer available. In previous posts I've thanked @miimura for incredibly useful spreadsheet calculators, predating what PG&E has only done recently (without details) on their website for EV and TOU rate comparisons. Thank you again! Like @kev1n, I looked earlier at the powerwall and it didn't make sense even in optimal conditions (charging at night and discharging at peak) based on cost. At that time, I would only do it for backup generation during power failure, but Tesla changed their options and the best battery for daily use is incompatible for deep discharge, i.e. generator usage. @miimura, do you think this cost calculus has changed with SGIP rebates? Then there is Keith (@RE Insider) -- I noticed clicking on your link gives a special referral page to Swell energy -- so what is your financial connection and benefit to the advice you are giving here? Are you a vendor, and/or getting remuneration for referrals? It would be best to disclose your financial interests if you are soliciting on this site. Your advice about when to charge and the cap on different PG&E rates is well known to those of us who already did the math. What is up for debate is the financials of battery storage and all that I would require is some real numbers on cost, max kWh charge/discharge per day (cycle count) and ability or non-ability to use as back-up generator (or limitations therein if infrequent) and I could do my own calculation, and the others on the thread I'm sure will appreciate your full disclosure.

There’s a lot of confusion in the market regarding the TOU rates and that is why I posed the question to the forum. To your question, I own a solar consulting firm and not a contractor. I get asked daily about TOU rates here in California and have subscription based software that provides me real-time rates structures for most of the state which allows me to help homeowners and business owners better understand which utility rate structure is best for them. In the post, I offered members of this forum a free rate analysis. I’ve enjoyed the interaction and in some cases, have confirmed with some folks that they are indeed on the best rate structure and have advised others to switch plans based on their unique usage patterns.

If you feel that I’m soliciting on this site, please private message your concerns – my offer was a free rate analysis.

My tread was not about the Tesla Powerwall (PW) and I don’t claim to be an expert on this topic, but I share with you my understanding on the topic. The Powerwall is more attractive for folks that have Solar PV. The SGIP incentives require 52 full discharges a year for a period of five years and also requires that the PW is charged by PV and not the grid – same applies to the 30% Federal tax credit.

The PW is not for everyone, but there are some clear benefits. Benefits like keeping your Solar PV energized during a grid failure, 30 amps of battery backup, potential arbitrage (charging during non-peak periods, and discharging to offset loads during peak periods) and then there is the “cool factor”.

Let’s talk pricing and incentives – depending on your utility, the SGIP incentive with vary. It’s my understanding that the SGIP level 2 for SDG&E is fully exhausted – SCE & PG&E (step 2) will be dropping in a week or so. If your able to leverage both the 30% Federal Tax Credit & SGIP (step 2) your net installed costs could be less than $4,000 depending on your site conditions.

I’ll upload the PW datasheet just in case there are members that have not seen it. I was told that the PW software will allow the user to set charge and discharge cycles which is pretty cool, unless you don’t meet the minimum SGIP requirements. If anyone know what the charge & discharge “efficiency” is, please share it with the group.

 

[caltrader]

Anyone confused on which (SDG&E/SCE/PG&E) rate structure will benefit you the most? There is a lot of confusion out there. If you own a Tesla AND a Solar PV system, you should be leveraging your electric companies “time of use” rates to your advantage – if you aren’t, you’re paying to much. Having been in the renewable energy consulting business for seven years, I’d be more than happy to identify which rate structure will benefit you the most at no charge…View attachment 236513

Anyone confused on which (SDG&E/SCE/PG&E) rate structure will benefit you the most? There is a lot of confusion out there. If you own a Tesla AND a Solar PV system, you should be leveraging your electric companies “time of use” rates to your advantage – if you aren’t, you’re paying to much. Having been in the renewable energy consulting business for seven years, I’d be more than happy to identify which rate structure will benefit you the most at no charge…View attachment 236513

I 'opted out' of the digital meters many years ago, and now own my analog meter. There was an issue in San Diego where the new digital meters ordered from Itron were programmed to 'run backwards' at 1/2 rate. Solar customers were outraged, hired attorneys, and required San Diego Power to reprogram the digital meters for 1:1 ratio. Did the power company think solar customers wouldn't notice?

3 Years ago I installed my 10.7kW solar system and have received checks from SCE at the end of my relevant periods.
I've been charging my MS for 6 months now and it looks like I will break even or perhaps owe a little.

Does SCE still offer TOU metering, and would I benefit giving up my analog meter?

 

[RE Insider]

I 'opted out' of the digital meters many years ago, and now own my analog meter. There was an issue in San Diego where the new digital meters ordered from Itron were programmed to 'run backwards' at 1/2 rate. Solar customers were outraged, hired attorneys, and required San Diego Power to reprogram the digital meters for 1:1 ratio. Did the power company think solar customers wouldn't notice?

3 Years ago I installed my 10.7kW solar system and have received checks from SCE at the end of my relevant periods.
I've been charging my MS for 6 months now and it looks like I will break even or perhaps owe a little.

Does SCE still offer TOU metering, and would I benefit giving up my analog meter?

Hello CalTrader - Thanks for your question. I had not heard about SDG&E "rigging" the digital meters - sounds like a big "mis-step" on thier part. TOU rates and very advantangous for folks that have both Solar PV & EV's. This is a no-brainer - have SCE install the bi-directional digital meter so you can start earning "dollar" credits for over-production and charge at a cheaper rate during super off-peak periods. The TOU rates act like a "turbo-charger" for your car. You should see a 5-15% "boost" net effect on your annual bill. I'd also like to suggest that you "roll-over" your credits and the end of the year rather than "cashing" them out. When you roll over the credits you get full "retail" credit compared to "wholesale" credit (3-4 cents kWh). I suggest TOU-D-A for 90% of my clients.

Good Luck!

 

[caltrader]

Hello CalTrader - Thanks for your question. I had not heard about SDG&E "rigging" the digital meters - sounds like a big "mis-step" on thier part. TOU rates and very advantangous for folks that have both Solar PV & EV's. This is a no-brainer - have SCE install the bi-directional digital meter so you can start earning "dollar" credits for over-production and charge at a cheaper rate during super off-peak periods. The TOU rates act like a "turbo-charger" for your car. You should see a 5-15% "boost" net effect on your annual bill. I'd also like to suggest that you "roll-over" your credits and the end of the year rather than "cashing" them out. When you roll over the credits you get full "retail" credit compared to "wholesale" credit (3-4 cents kWh). I suggest TOU-D-A for 90% of my clients.

Good Luck!

I've changed my preferred method of excess production to roll-over for this years relevant period. You're correct, I don't need a stinking wholesale credit.

 

[caltrader]

Hello CalTrader - Thanks for your question. I had not heard about SDG&E "rigging" the digital meters - sounds like a big "mis-step" on thier part. TOU rates and very advantangous for folks that have both Solar PV & EV's. This is a no-brainer - have SCE install the bi-directional digital meter so you can start earning "dollar" credits for over-production and charge at a cheaper rate during super off-peak periods. The TOU rates act like a "turbo-charger" for your car. You should see a 5-15% "boost" net effect on your annual bill. I'd also like to suggest that you "roll-over" your credits and the end of the year rather than "cashing" them out. When you roll over the credits you get full "retail" credit compared to "wholesale" credit (3-4 cents kWh). I suggest TOU-D-A for 90% of my clients.

Good Luck!

Ok...I'll look into a digital meter and TOU-D-A. However, we're retired, run our dual zone 8 ton total A/C fixed at 76 degrees all day and 73 at night. Out of courtesy to SCE, I only charge my MS in the early morning hours. Also, in 3 years I've never owed anything at the end of my relevant period. Got a check for $135 last year.
Given that info...why would I want to give up my owned analog meter and chance the Cal PUC allowing utilities to throttle net metering to less than 1:1. It's already proven they can do that.

Another question please...if I get a couple PowerWalls...can I in fact go off grid? I've been told legally that's not possible due to safety reasons. Thanks

 

[smilepak]

Interesting Thread and I want to take it a bit further in the thought process. At the moment for Southern California Edison, the TOU for me is split into 3 rates. You have the Peak, Off Peak, and Super Off Peak. The Super Off Peak is after 10:00 PM - 7:00 AM @ 0.12 per Kw. (Flux +/- up to 0.02 each season).

I've always up to this point have set my charging to start at 12:00 AM and giving my daily driving habits, I complete by 2:00 AM approx.

Now to take this a bit further, I also have Solar Panel with SunPower that each panel produces 327w. I have enough panel that during most days (minus charging Tesla), i am about -3 to +5 at the end of the day.

For solar, during the day, each hour of good sun production, I am at -2 or -3 kw per hour that goes back into the grid to be consume later.

So is it better to charge the Tesla during the day where I can take advantage of the over production and NOT having it go back to grid or let it go back to grid to be use at night where the cost per kw is cheaper to begin with?

 

[Ampster]

I am curious in California if some one is going to be able to avoid being on TOU rates after 2018. Haven't the regulators dictated that?

 

[miimura]

For solar, during the day, each hour of good sun production, I am at -2 or -3 kw per hour that goes back into the grid to be consume later.

So is it better to charge the Tesla during the day where I can take advantage of the over production and NOT having it go back to grid or let it go back to grid to be use at night where the cost per kw is cheaper to begin with?

Why would you want to forego the Peak period credit under NEM when you can charge so cheaply at night? Self consumption of solar makes the most sense when you don't have Net Metering. For example, in some places you are only credited 5 to 10 cents per kWh for what you feed into the grid. In that case, you want to use as much of your own solar as possible to avoid paying 15 to 20 cents for grid consumption. In California, even on NEM 2.0, you're better off charging at night at the lowest possible rate and letting the solar earn you credits.

 

[cpa]

I am curious in California if some one is going to be able to avoid being on TOU rates after 2018. Haven't the regulators dictated that?

As I understand it, we can opt out of TOU rates--at least with Pacific Graft and Extortion-- which we plan to do.

 

[miimura]

As I understand it, we can opt out of TOU rates--at least with Pacific Graft and Extortion-- which we plan to do.

His point was that the ability to opt-out of TOU may come to an end. My A-1 commercial account was forced to TOU and Peak Day Pricing in 2016. The SVCE CCA transition has at least got us out of PDP. However, the A-1 TOU is not a big deal. It's like $0.20 vs. $0.22/kWh Off-Peak vs. Peak.

 

[RE Insider]

Ok...I'll look into a digital meter and TOU-D-A. However, we're retired, run our dual zone 8 ton total A/C fixed at 76 degrees all day and 73 at night. Out of courtesy to SCE, I only charge my MS in the early morning hours. Also, in 3 years I've never owed anything at the end of my relevant period. Got a check for $135 last year.
Given that info...why would I want to give up my owned analog meter and chance the Cal PUC allowing utilities to throttle net metering to less than 1:1. It's already proven they can do that.

Another question please...if I get a couple PowerWalls...can I in fact go off grid? I've been told legally that's not possible due to safety reasons. Thanks

Hello CalTrader - You would need a garge full of PowerWalls if you want to continue using your A/C day & night. OffGrid is possible, but not cost effective for 99.9% of the homes in California.

 

[RE Insider]

As I understand it, we can opt out of TOU rates--at least with Pacific Graft and Extortion-- which we plan to do.

CPUC Decision 15-07-001 (7/13/2015) mandates the "Big 3" (SDG&E, PG&E & SCE) to begin transitioning all ratepayers to TOU as of January1, 2018 - http://docs.cpuc.ca.gov/PublishedDocs/Published/G000/M153/K110/153110321.PDF This will no doubt will strengthen the case for Solar and/or conservation.

 

[RE Insider]

Why would you want to forego the Peak period credit under NEM when you can charge so cheaply at night? Self consumption of solar makes the most sense when you don't have Net Metering. For example, in some places you are only credited 5 to 10 cents per kWh for what you feed into the grid. In that case, you want to use as much of your own solar as possible to avoid paying 15 to 20 cents for grid consumption. In California, even on NEM 2.0, you're better off charging at night at the lowest possible rate and letting the solar earn you credits.

I agree @miimura

 

[RE Insider]

Hello Members - I just wanted to circle around and share with you that I've been able to help nearly a dozen TMC members by analyzing their current electrical rate structure and either confirm that they are on the most advantageous rate structure or suggest a better one. I've uploaded the results from my largest savings analysis to date ($1,550 annual savings) and all he had to do was to make a quick call to his electric company and ask for a specific rate structure. Now $1,550 is not common, but I'm able to save most TMC members money if they have not yet switched to time of use. And again, I do this at no charge for TMC members. If you want me to analyze your rate structure, just click here - Authorize Access to Utility Data (powered by UtilityAPI)

 

[Bigtanuki]

I've changed my preferred method of excess production to roll-over for this years relevant period. You're correct, I don't need a stinking wholesale credit.

how did your excess production option changed? I am with PG&E.

 

[RE Insider]

how did your excess production option changed? I am with PG&E.

Hello Bigtanuki - Simply put at the end of your 12 month relevant period (or your trueup period), once you go Solar you have the option to "roll-over" any overproduction and cash out at 2-4 cents kWh. I always suggest to roll any credits over as they become more valuable over time.

 

[UCIBtheG]

The Powerwall is more attractive for folks that have Solar PV. The SGIP incentives require 52 full discharges a year for a period of five years and also requires that the PW is charged by PV and not the grid – same applies to the 30% Federal tax credit.

Hi RE Insider, can you please provide a source to back up the SGIP incentive requirement of charging by PV and not the grid? I'm currently in limbo waiting for my SGIP step 2 approval to proceed with PowerWall 2 installation. I do not currently have a PV system, though I may get one down the road. I thought I had researched this fairly thoroughly for "gotchas" in advance and definitely don't remember any PV requirement. Once I get the PowerWall, I plan to change to the TOU plan (SMUD customer here, we only have one TOU plan) to charge the PW, then use that to power the home throughout the day.

 

[RE Insider]

Hi RE Insider, can you please provide a source to back up the SGIP incentive requirement of charging by PV and not the grid? I'm currently in limbo waiting for my SGIP step 2 approval to proceed with PowerWall 2 installation. I do not currently have a PV system, though I may get one down the road. I thought I had researched this fairly thoroughly for "gotchas" in advance and definitely don't remember any PV requirement. Once I get the PowerWall, I plan to change to the TOU plan (SMUD customer here, we only have one TOU plan) to charge the PW, then use that to power the home throughout the day.

Hello I've uploaded the SGIP Handbook. It's a tough read. I beleive section 5 provided the guidelines. I exchanged several emails with Swell Energy pertaining to this topic (see attached). I encourage you to call the company that you purchased the PowerWall to address your questions.

Once you recieve your SGIP authorization, you have twelve months to install the PowerWall. You may want to consider going solar sooner than later or delay your installation accordingly.

Please feel free to email me at [email protected] if you want some "pointers" on selecting or sizing a solar (PV) system.

Hope that helps!