TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here: paypal.me/SupportTMC

SCE rate plans

Discussion in 'Model S: Battery & Charging' started by AZbba, Sep 4, 2014.

  1. AZbba

    AZbba Member

    Joined:
    Sep 4, 2014
    Messages:
    58
    Location:
    Temecula
    So, I've done some research and heard a few things but I'm still having some trouble with the decision of what plan to go on.

    I have solar (roughly 5KW system), and have produced a slight excess over the year.

    Right now I am on the normal non-tou tiers.

    I have heard that if you have solar you want TOU, but I live in a hot area and do tend to run the AC most of the day during the summer, so it is scary signing up for something that is 49c/kwh for 10am-6pm.

    But I'm assuming we will automatically be on Tier 2 due to using so much for the Tesla. And if I made an excess last year even with AC, I would assume that excess production during 10am-6pm would be credited at 49c/kwh (during summer). So, logically going on TOU would give me more "free" energy for the tesla, since most of the energy produced was during peak times, and only some of the energy used was. I could save even more by starting laundry/dishwashing after midnight as well.

    Am I missing anything?
     
  2. astrotoy

    astrotoy Member

    Joined:
    Jan 24, 2013
    Messages:
    266
    Location:
    SF Bay Area
    I am in NorCal with PGE on their TOU EV rate, with solar. My situation is similar to your projected scenario. although our rates are a little different - not quite so high at the high rate. I produce all of my solar during the peak times, so I get credited at the highest cost rate. However, much of my consumption (including all of the Tesla charging) is during the night rate, which in our case is a little less than 30% of the peak rate. So I sell high and buy low in a pretty predictable way. Works for me. Apparently it works for PGE also since they don't have so much need for peak power generation which is much more costly for them, including the capital cost of extra power plants just to meet peak demand.
     
  3. Timothy

    Timothy Driving on Sunshine

    Joined:
    May 4, 2011
    Messages:
    283
    Location:
    Santa Barbara, CA
    We have had a solar system for 5 years and the Tesla for 3 years. We have SCE also and had a TOU plan--but not for EVs --for the first four years. We barely had a negative bill each year.

    A year ago we also purchased a FIAT 500e in addition to the Roadster and switched to a TOU EV rate. 49c/kWh at peak--but only 9c/kWh midnight to 6am. We just finished our first year and have $900 to our credit! (SCE won't pay us that, but that is another story.) We charge both cars at night plus program the clothes washer and dishwasher to run at night and it turns out we use 30% or our electricity in the super off peak range. We don't have an air conditioner in Santa Barbara (only hits 90 degrees 2 days a year!) so our situation is slightly different.

    You might consider switching incandescent bulbs to LEDs to help the electrical bill. You might also call your solar installer and also SCE and see if they can do a detailed analysis of your use and generation of electricity to see which plan is better for you. My bet is that the TOU EV plan will be best. You are only committed for a year if you change the plan, however, so you can always switch back in a year if you are unhappy.
     
  4. jstepy

    jstepy Member

    Joined:
    Jun 6, 2014
    Messages:
    133
    Location:
    Orange County CA
    We are in Huntington Beach and SCE's antics like Timothy is dealing with above with his large surplus is the main reason I started entertaining the idea of getting a Tesla.

    We were originally on the standard tier system but quickly made the change to TOU as mentioned above... Buy Cheap Sell High. It was the best decision we made as we had generated over our 12 month relative period $320 bucks. BUT... for our $320 buck credit we got a whopping $38.50 from Edison. I was so mad that I decided we were just going to run the AC and pool pump like crazy the last months of our relative period just to eat through our credit and screw SCE... why should I make free electricity that they turn around and sell to my neighbor at peak rate?

    So after I calmed down a little I realized that wasting electricity just to waste it wasn't the greatest thing in the world... so why not fuel a Tesla with it?

    While I wait for the Tesla to be delivered any time this month we are still on the TOU that is ON Peak from 12-6pm... I have been researching the the EV TOU as it adds the super off peak rate from 12am to 6am. Like Timothy I will probably sign up for that and run pool pump those hours, dishwasher and washing machine etc. taking advantage of the super off-peak rate.

    AZbba I too was concerned about making the switch at first. I thought about the summer time when kids are home in the pool and AC is running all during those peak hours but it still worked out way better being on TOU then the standard Tier System.
     
  5. Getinring

    Getinring Member

    Joined:
    Jul 22, 2014
    Messages:
    32
    Location:
    Los Angeles
    I've had my Tesla for about a month and recently we also purchased a Fiat 500e for my wife's short commute to take advantage of the white Hov sticker. Our last year edison usage was close 12000 kwh so have been getting quotes from various solar companies. To make a long story short, we can only create a system that matches our last year usage without compromising they aesthetics of the house.
    T other
    My basic dilemma with tou plan is although I'm gone most of day during weekday, I am home starting about 4 with 2 kids under age of 5. So that means I do need run AC when it's 100 degrees out amongst other energy consumption. I'm assuming that the tesla avg roughly 5000kwh per year and the fiat maybe 2500 to 3000.

    now I understand charging after midnight for both will benefit from the 9cents per kwh and I can shift our things to off peak time. Th hard part I have trouble understanding is that given my production will never match usage with 2 electric vehicles, how dose edison calculate the little energy I use during peak and non peak time vs what I generate. I.e. This whole notion of buying low and selling high is maybe what I'm having trouble understanding. If I come home at 4 pm and start blasting AC, how is my bill monthly calculated exactly.
     
  6. Timothy

    Timothy Driving on Sunshine

    Joined:
    May 4, 2011
    Messages:
    283
    Location:
    Santa Barbara, CA
    As I understand it, they charge you the peak rates from 10-6 weekdays, off peak 6am-10am and 6pm-midnight and all weekends, and super off peak midnight-6 am. So the net metering bill is a balance of the cost of electricity at the time you use it and you get credit for what you generate at the time you generate it. Obviously, you generate zip in the super off peak hours--but try to shift as much of your use to then as possible! In our case (no air conditioning) we use 30% of our electricity in the super off peak periods.

    In your case, you are using the air conditioner at peak 4-6 pm but then it drops off in cost after 6 pm so the numbers may not be as bleak as it seems. SCE and your solar contractor should be able to analyze your bill so you can see what the cost/benefit is.

    I went to a friends house and he installed solar 10 years ago. His panels were standard ones for the time at 150 watts per panel. I put my system in 5 years ago with standard panels of 200 watts. Now standard panels are 250 watts--and all are the same size panel so the technology is improving. If you have limited space for panels, you might consider the current high watt panels which I think are now up to 325 watts per panel. (You will have to check on that number.) These panels cost more, of course.

    When we put our system in 5 years ago the cost was $7.14/watt. In Santa Barbara now the Community Environment Council puts together a couple dozen buyers at a time to go to the solar companies together so they can get better rates--now at $3.50/watt. Hopefully, such an outfit exits in LA.

    Between my Roadster and my wife's FIAT 500e we figure we save between $1500 and $2000 in gasoline costs per year, so you need to put those figures in your calculations.

    I hope you can make it work!
     
  7. Getinring

    Getinring Member

    Joined:
    Jul 22, 2014
    Messages:
    32
    Location:
    Los Angeles
    Thanks Timothy for the advice. So since you're almost in same situation with 2 EV and solar I think I see what you're saying.
    with time of use plan, let's say during day time 10 to 6, SCE would charge based on whatever my net meter is and multiple that by the rate. And likewise for the off peak and super off peak midnight to 6am.

    Since my solar production is during the peak hours and I would consume very little except for the hours of 4pm to 6pm, how does Edison credit that amount assuming I have excess production. Obviously 6pm on I have no solar production so the meter will always spin forward albeit at a reduced rate.
     
  8. Timothy

    Timothy Driving on Sunshine

    Joined:
    May 4, 2011
    Messages:
    283
    Location:
    Santa Barbara, CA
    So from 10-6 you would probably be generating more than you use and you would get credit at the high rate for your excess generation.
     
  9. jstepy

    jstepy Member

    Joined:
    Jun 6, 2014
    Messages:
    133
    Location:
    Orange County CA
    Timothy -

    You need to just break your usage out in 3 sections (In my example I assume staying in Tier 1 Rate of Summer)

    From 6 am to 10 am & 6 pm to 12 am you multiply your Net Usage kWh by $0.15 - Your meter will be doing very little turning backwards during this period. On my system I get a little bit of going backwards from 8:30 to 10:00 am.

    From 10 am to 6 pm you multiply your net usage kWh by $0.32 which is greater then double the Off-Peak Rate - This will be your bulk of production and credit at the higher rate. Even if the AC turns on from 4-6 you will still have a credit... once 6 pm rolls along it will be cheaper to run the AC.

    From 12 am to 6 am you multiply net usage kWH by $0.09 (charge Tesla, Run Pool Filter, Run dishwasher, Put a load in dryer etc.-using Time Delay Feature)

    I was concerned this last month as my wife is no longer working and spending more time at home running the AC occasionally during the day rather then being at work all day during peak production. It has not effected my credits that much at all.

    During these last few weeks of higher heat we actually have been running the AC mostly from 12 am to 6 am as well... we get the house super cold (quite chilly when we wake up) and it actually lasts till about 6 pm.

    But the biggest help in our SCE credit has been getting ON-PEAK credit from 10 am to 12 pm. Before we were on the standard TOU rate that was 12 to 6 pm ON-PEAK only... but switching to TOU EV rate we get those two extra hours which are quite good in production terms at that high rate. So I earned 2 hours of high rate production and opened up the door to late night super cheap usage.

    Hope that all made sense.
     
  10. Getinring

    Getinring Member

    Joined:
    Jul 22, 2014
    Messages:
    32
    Location:
    Los Angeles
    After thinking about it and with your comments, it makes more sense now. So is it fair to say that when building your solar system, it may be good to just cover or offset what you use in the peak hours given so cheap in off peak and super off peak time after midnight? The solar systems keep proposing systems that offset close 100 percent of my energy usage from last year not counting charging the electric cars of course. I have limited roof which won't allow for more than that anyways. It just seems like producing a system that offsets 100 percent will just produce more credits for the peak hours. As you know the bigger the system, he higher the costs of all the panels and modules. Currently we used about 11600 kWh last year and if you look hourly it is lower during 10 to 6pm but fairly consistent 24/7 esp in summer.
     
  11. miimura

    miimura Active Member

    Joined:
    Aug 21, 2013
    Messages:
    1,241
    Location:
    Los Altos, CA
    #11 miimura, Sep 12, 2014
    Last edited: Sep 12, 2014
    A good solar installer that has your best interest in mind (and not his own) will size your solar system to zero your annual bill, not zero your annual net usage. PG&E and SDGE have a gap between zero billable dollars and zero net usage where your annual negative dollar balance is thrown away. If you are a true net generator, they pay a very meager amount. PG&E pays about 4 cents/kWh for surplus production. I'm sure SCE is the same in this regard. Clearly, if you are interested in your system paying for itself faster, you should not size the system such that it over-produces your calculated bill. A good solar installer will take your prior year usage from SmartMeter data, add your projected EV overnight charging and come up with a system size that will get close to zero utility billable dollars at the end of the year. However, most of the time, they take your month-by-month kWh or even $ billed from the past year and approximate your usage profile based on the area's norms. If you have sizable EV charging and they use gross kWh or prior billed dollars, you will end up with an over-sized system that will needlessly result in a negative annual true-up that gets discarded.

    This is a typical day in May with some 40A EV charging overnight. My solar is 4.32kW DC and the bars in the chart are net kWh in 15 minute intervals.

    PGEUsageDayView_zps6aac3289.jpg
     
  12. Getinring

    Getinring Member

    Joined:
    Jul 22, 2014
    Messages:
    32
    Location:
    Los Angeles
    Miimura thanks for summarizing what I'm starting to realize or for putting it in precise terms. I keep hearing buy low sell high which is a good principle but at the same time both my solar companies emphasize how SCE pays 4 cents kwh for any excess. So as you put it, net usage per time period during the day if you're on time of use plan gives a truer picture what your bill will be like. Both companies I got estimates from went with the month by month edison bill from last year and came up with a system which will produce or offset that amount consumed. When you look at the hour by hour analysis daily I have fairly steady usage throughout he day except from 6pm on when there's probably at least 1 kwh or more per hour.

    So I now have 2 electrical vehicles and I'm estimating conservatively 8000kwh per year which charging after midnight at 9 cents kwh comes out to $720 per yr which I'm thrilled with considering the cost of gas. So now important question is what size system do I get to zero out my bill or at least get it as close as possible. They keep insisting that I'll be fine but that's not great reassurance when investing in a 26 to 30k system as they're proposing. I have 2 proposals for 6.8 and 7.7 kW system so have put more thought into this.

    - - - Updated - - -

    I also forgot to mention that they proposed systems to cover my annual usage without electric vehicles because I don't have any more available roof space. However they both try to tell me that the system will match my output and then I just worry about the 8000 kwh for the EVs. Now I calculate that to be 666 kwh per month. Sce tier 1 and 2 only go up to about 500kwh month. Under standard residential plan I would be probably pay a pretty penny. Now if I switch time of use the 9 cents kwh midnight to 6 is doable and I could shift a lot my usage to that time as well. Just as you say if the solar system proposed matches my annual consumption last year, sounds great but all that production really applies to my usage during peak hours 10am to 6pm. Am I correct? It almost seems in my situation I should just build a system that covers my annual usage 10am to 6 pm then calculate roughly how much energy I use in the other times multiplied by Sce time of use rates to get a truer picture of my bill. Then assess how long it would take me to pay off system vs just continuing my current usage with the electric vehicles as well
     
  13. miimura

    miimura Active Member

    Joined:
    Aug 21, 2013
    Messages:
    1,241
    Location:
    Los Altos, CA
    Almost all of your solar generation will be between 10am and 6pm. There may be a little between 8am and 10am, but the percentage will be low, less than 10% unless you have panels facing significantly to the east. That makes it a lot easier to figure out. In PG&E territory it's harder to figure because we have peak rates that start at 1pm or 2pm.

    Maybe the easier way to understand it is to see how it's calculated. Below is a snapshot of my spreadsheet that I created to calculate PG&E bills on the various rate plans. The data is from my SmartMeter in July 2013. My solar system is 4.32kW DC and I charge one EV, a RAV4 EV, exclusively charged at home overnight.

    PGE Solar EV Bill Calc Sample.jpg

    So, you can see that my solar generated 45.68kWh excess during Peak hours and generated a $14.20 bill credit and my EV charging and other minor household overnight loads consumed 429.72kWh and only cost me $16.57. The solar also generated a 64.2kWh surplus during Part-Peak hours which gave ma a further $6.53 bill credit leaving $4.16 of credit for the month to be added to my annual true-up. That was with 319.84kWh net energy taken from the grid. My system is not sized to even zero my bill. In 2013, I paid PG&E about $700 for the year, including 8 months of EV charging. Obviously your rates are different than mine, and this particular rate plan had a crazy low Tier 1 Off-Peak rate of below 4 cents/kWh. However, it should give you a pretty good idea that you don't have to be anywhere near zero net usage to have a negative bill.
     
  14. simplesolar

    simplesolar Member

    Joined:
    Jun 30, 2013
    Messages:
    250
    Location:
    SoCal
    I've done probably 20+ systems for tesla owners including my own on TOU EV. First step I would do is figure out how much your peak power usage is during the daytime is and size a system accordingly rather than sizing the system base on your total consumption. If you want to post a daily usage charge I can analyze it for you and let you know what a good size system to zero out your bill can be. For example I use roughly 1500kwh a month, but I can zero out my bill using a 3kw system because of the TOU rates. Installers with no TOU EV charging experience will try and sell me a 10kw system rather than a 3kw which has a big price difference. My case if pretty extreme, but I've sized a couple 5kw systems that can eliminate bills in the 1000-1100 kWh/ month range. Also keep in mind that TOU rates is different from summer and winter. I typically calculate any excess energy generated during the day at a 1 to 3 ratio for charging at night to be safer instead of the summer time average 5:1.


    - - - Updated - - -

    Here is a real life example.

    The client's net usage for the month is 256 kWh net, but because of his TOU EV rate, he actually had a $-151.36 bill!!!!
    SCE Bill copy.jpg SCE Bill copy 1.jpg
     
  15. Getinring

    Getinring Member

    Joined:
    Jul 22, 2014
    Messages:
    32
    Location:
    Los Angeles
    Thanks for all the help guys. The more I press the solar companies about the EV use, I just get reassurances that I will be fine without really showing me how it will work. When you have almost a 40 percent increase in usage due to 2 electric vehicles, you need more than just reassurance from solar company. Simplesolar, I sent you a email 3 weeks ago, did you get it and if not maybe I can send it again?

    Living here in inland empire where temps can be 104 like year and with 2 toddlers, I need have the AC so really can't cut or shift usage more than maybe just running washer dishwasher later once on a time of use. My last year usage consisted of avg of 1400 kwh for the 5 months may to sept. And roughly 650 kwh the other 7 months. From about 4 pm to midnight, almost 3 to 4 kwh per hour. The other hours closer to 1. From 10 am to 6 pm I used almost 17kwh yest. Simple solar can I send you via email a hourly usage profile from edison or other info so you can give me advice based on your experience. Right now I'm dealing with real solar group and LA solar, real solar proposes 6.8kw system with 25 270w panels and la solar 7.7w with 26 300w panels. My last yar usage was 11600 kwh but keep in mind I estimate additional 8000kwh for the cars this next year.
     
  16. simplesolar

    simplesolar Member

    Joined:
    Jun 30, 2013
    Messages:
    250
    Location:
    SoCal
    weird, never got it. I just sent you a PM with my personal email. I haven't seen your roof so I can't comment on how much panel can fit. But based on your usage, if you are using 17kwh during the peak hour, it is best not to go TOU since you would need a 20kw-22kw system to generate any excess. In this case it might be worth it to get a 2nd meter or else your bill might actually be higher than before. But also curious, what are you using that is using up 17kwh a hour, which is quite a bit!

     
  17. Getinring

    Getinring Member

    Joined:
    Jul 22, 2014
    Messages:
    32
    Location:
    Los Angeles
    Simplesolar
    Thanks so much for all the advice and detailed analysis of my electrical usage. I wasn't really expecting you would take my hourly energy data for winter and summer and give me a spreadsheet analysis for my yearly costs with the time of use and 2nd meter electrical plans from Edison. Too bad I didn't get in touch earlier otherwise I probably would have gone with you. Anyways thanks for showing me that a 2nd meter could potentially save me $500 yr charging 2 cars with solar covering my household usage which is pretty heavy. It's nice to know that instead of $500 summer monthly electrical bills now I could save so much more with solar.
     

Share This Page