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PG&E E9 Timing (California)

PG&E has a special rate schedule for owners of electric vehicles - E9. If you are using this schedule, there are 2 to 3 periods during the day where the rate changes. The cheapest rate is typically from Midnight to 6am. The schedule is a bit messy, likely due to a bug in the billing software with daylights savings time. They do document the timing, but it ends up making it more complex than it should be. Anyway, I built this visual spreadsheet to cover 2013 and 2014 timings in an easy to see format. The E9 tariff is experimental, and is planned to go away at the end of 2014.

http://teslatap.com/_outside/PG&E%20E9%20Timing.xls

Nice visual spreadsheet. I'm not in the PG&E area, but that really helps illustrate the various rates.

Thanks on this. I looked into this in CT and as far as I can tell the "cheap" night rate on the two rate plan was higher than the fixed third party 24/7 rate I have. It was also a floating rate subject to summer spikes with two months notice needed to switch (so by the time you realize it spiked it's too late). I think I also needed a new expensive meter. What savings are people seeing for night rates vs lowest available primary/third party lock/other rates and what is the upfront cost to be able to use the night rate?

Great spreadsheet and very helpful .... Thanks!

@TeslaTap

Your chart seems to show peak hours during summer weekends. From the E-9 pdf on the PG&E website, it would seem that Saturdays and Sundays are off peak except for 5 PM to 9PM that are partial peak. Do you have more recent information?

PG&E now has a "Green Button" on the PG&E My Energy web site that will allow you to download your energy use - both gas and electricity. Combined with the PG&E smartmeter this will give you a graph of your electricity use in 15 minute intervals. By reviewing this data, it is possible to calculate which tariff program makes most sense for each individual.

Now we just need someone to write a program that will allow you to plug in your usage history and it will tell you which rate program is most economical.

Yes. a program would be nice. I spent hours on a spreadsheet formula which proved my suspicion. That suspicion was that the flat rate would be cheaper because we use enough energy in the peak time that the insane rates under TOU more than outweigh the benefit of charging at night to the tune of about $70/mo. My recommendation, if you expect the charging to increase your consumption by 40% or LESS, you are likely to be better off with a flat rate (or at least you should definitely do the math).

The best deal if installation cost is manage-able is a second meter just for the charger which is on TOU (E-9b rate schedule for those with PG&E).

Don't let the provider talk you into a TOU rate. If you are concerned just do the math. Yes it's a pain until someone writes a program, for sure.

PG&E will be offering new EV rate schedules around June 1st. These will eliminate the tiers and baseline quantity and allow for unlimited off peak charging just under $0.10 per kwh. I personally cannot wait because I am usually in the highest tier due to EV charging and that's about $0.30 per kwh on the E-6 TOU schedule. The baseline is only 11.7 kwh per day, which is completely used up with a little over one hour of charging at 40A. I have solar and generate about 17 kwh a day average, but even with a TOU schedule I am often in the highest off peak tier due to EV charging. I plan to install a separate meter and get the EV-B schedule on that meter.

Any program to calculate which plan is better would be very complicated. I looked at this for my setup: I've had solar for several years, and am on the E6 rate plan.
I looked at the E9-B plan, but decided against it for a couple of reasons: 1- the extra cost for installation, and 2- the credits for our solar system wouldn't apply to the second meter (EV) charges.
When looking at switching to the E9-A plan, I had to do a lot of guessing. Our smart meter was just installed last Nov, so I only have hourly consumption information from then. I do have our solar generation information, and the E6 TOU records, so I made some educated guesses about the differences in our TOU between E6 and E9. Then adding in our estimated EV usage (my wife just got a Volt, and I'm waiting on my Model S). For me, it looks like E9-A comes out better than E6. But this depends on several factors:
- When and how much do you use your electricity (hour by hour)?
- If you generate, when and how much do you generate?
- What rate tier do you get into?
- Hour much electricity do you need for your EV?

For me, it looks like I'll lose an hour of peak generation and eat 2 more hours of peak usage. I used to generate more electricity in the summer than I used, but hit tier 4 in the winter (but now with the EV's, I'll be using more in the summer, though in Off Peak).
Yet another factor to consider- the cost in the lower tiers of E9-A Partial Peak is lower than E6 Off Peak, though that changes in the upper tiers.

Then there's the new EV rate plans coming, which eliminates the tiers, but adds a Peak time in the winter. I haven't really looked at these yet, but they look like they might be better if you are in the higher usage tiers.

@shs "Your chart seems to show peak hours during summer weekends."

Yep, it was screwed up. The wording in the PG&E tariff could be better. For those that want to look at the E9 tariff document:

http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_E-9.pdf

I've corrected the image and the spreadsheet as there are no peak hours on weekends, and the off-peak is larger than I had shown previously.

great spreadsheet, thank you!!!

Thanks.

Have you looked at the usage and cost charts available under pge.com/myusage? They don't seem to properly account for the Daylight Savings Time adjustment described in this paragraph from the referenced PG&E document:

"DAYLIGHT SAVING TIME ADJUSTMENT: The time periods shown above will
begin and end one hour later for the period between the second Sunday in March and the first Sunday in April, and for the period between the last Sunday in October and the first Sunday in November."

I haven't compared my actual bill to the "myusage" numbers, but I now suspect that they don't agree 100% because of this oversight in PG&E's charts.

In the myusage charts, I'm seeing only "off-peak" rates plotted from midnight to 7 am, for every single date in all bills, despite the indication that I should have been charged partial peak rates from 1 am to 8 am, weekdays, from 10 Mar through 6 Apr, as shown in the spreadsheet.

Schedule EV will eliminate the 4 tiers, which is good, but it bumps up the off-peak charging rate from $.03-04/kWh to $0.10-11/kWh, and other rates even more, which is bad.

I downloaded three months of usage data into a spreadsheet and tried to calculate what I would have paid under the proposed EV rates vs. E-9A for the same usage (ignoring DST adjustment). The cost savings for me (only 10K miles/year) was a measly $10/month in favor of Schedule EV.

PG&E documents describe the new proposed schedule EV rates as "revenue neutral," which is hard to understand since they get about double the revenue from EV owners compared to non-EV owners, with no change to infrastructure.

Since pge started reporting daily usage up to previous day in an excel format, I checked my rates on the E9 plan.

Strange thing I noticed: I pay just 6c a kwh if I charge between 12am and 1 am ( my commute is only 30 miles rt)

I switched to charge from 1 am 4 days ago. When I recalculated, I saw that the rate went UP to 15c per wh.

Naturally I reset back to charge at 12 am.

Don't know why this us the case. I live in Fremont.

@RedShift, I'm in Fremont and on E9a plan. I charge my car at 1:00 AM and see the rate of 6c/Kwh. I'm viewing my daily usage on their website not downloading to excel. Can check what rate does it display on their site?

I will check tonight, from home.

@RedShift You may have exceeded your baseline.

I've been on E-9 since February 1st but the bills still reflect the old baseline rates. PG&E says they will be correcting this in my next bill. I am looking forward to a noticeable refund. I'll keep you posted.

@RedShift, increase in usage beyond baseline might trigger the increase to Tier 3 which is at approx. 16c/Kwh. Probably that's what's happening in your case.

@RedShift:
The increase in hourly rate could be tied to the change from Tier 1 to Tier 2 or Tier 2 to Tier 3.

Within a billing period, we are allowed a "baseline". In my case (E-9 rate plan), my baseline is 351kWh. During baseline, I pay 4.82 cents/kWh (winter off-peak which is between 12M and 7am not taking account for DST). After I burn through baseline I move the Tier 2, which I pay 6.69 cents/kWh during off-peak. At Tier 3, I pay 16.056 cents/kWh.

The switch from one tier to the next could occur on an hourly basis (which I've confirmed by looking at my historical data on the PG&E website).

In that it does not take too much charging to blow through the baseline amount, the new EV-A and EV-B plans that have a flat rate, for a given time of use, but no baseline, might well be the better deal.

@all who advised about baseline: thanks! That certainly seems plausible.

Next month I should get my permit to charge free at work, so I might start staying within my baseline from next month. We will see.

Am I misunderstanding?

I thought E9 was a TOU (time of use) plan. Is there also a baseline?

Yes, as far as I know, all of the TOU plans have a baseline, except the proposed EV-A and B rates that should become available on June 1. The problem is that if I understand it correctly, your total usage for a month goes over baseline, then you are charged the higher rates (higher tiers) for usage in all of your tiers. Not sure how they calculate that. Probably will find out soon as my usage is up thanks to all the miles we are putting on the car. It is easy to be seduced by the very low tier 1 rates, but since a few hours of charging blow away your baseline....

I think the E9-A makes little sense to average users, if they don't have free employer( in my case, client) provided charging at work.

My usage is roughly 10-15 kwh per day, and I reached my baseline within 2 weeks. I am only getting permission to charge at my client location from next month, and will exclusively charge there. However come summer, I will reach the baseline again, I fear.
Adding to the confusion is the higher rates in summer and TOU shifting around, it's not a very good plan for many people.

When will the EV rate be available and is it advantageous?

"Am I misunderstanding?

I thought E9 was a TOU (time of use) plan. Is there also a baseline?"

Absolutely. I get totally hosed by E9a and tiers, so I'm sure.

My billing cycle starts April 9, and I'm charging my Model S at midnight for about 6 cents a KWh, but climbs very quickly as I go through the tiers. Bear in mind, I had a $420 electric bill before I got a Tesla (work from home with staff) so there's other consumption.

https://plus.google.com/photos/107761297884639198094/albums/587132019936...

You can see how, by April 23, I'm paying 20 cents an hour. And I'm paying 34 cents for my daytime consumption. It'll get worse in summer when peak pricing kicks in.

I still think this is better than the conventional non TOU I had before, because I was able to switch my THREE big consumers to midnight: Tesla, spa, & pool. But the math is bloody complicated when you overlap TOU with Tiers, seasonal rates, etc.

I'm looking forward to the new EV rates, and also will put in a big solar plant later this year.

As I mentioned above, the PG&E EV-A and EV-Brates should be available on June 1. With the current EV E-9A rate schedule, the baseline rate summer off peak is ~4 cents a kWh. Trouble is if you use twice the baseline, the rate goes to ~20 cents a kWh. With the non-tiered EV-A rate schedule all off peak use will be billed at ~10 cents a kWh. So if you can stay within baseline or not above twice baseline, the E-9 rate is probably better (or E6). Keep in mind that a bit more than an hour charging a day on average will use up your baseline. In my case, since my heat is electric and I do plan to drive enough to blow through the baseline, I think I'll be better off with the proposed EV-A rate. The good news is that with solar the higher rates in the summer during the day are not all bad as you will build credits in higher cents/kWh during most of that time.

Solar is a must if you switch to a TOU plan for most people. We installed solar last fall. I switched us from E-6 which is the TOU most solar customers are on to E-9 to get those really low off peak rates. Our electric bill this month was only $14. With the solar panels offsetting usage we came in under the baseline so I got all my MS charging in at 0.0482/kwh.

As others have posted else where, switching from E-6 to E-9 for solar panel/electric car families is not a slam dunk. The periods of the day that are defined as peak/partial peak/off peak are different between the E-6 and E-9 rate schedules.

For example, the summer peak for E-9 is extended to 9pm versus 7pm for E-6. That will take a bite out of the savings we are getting with that super low off peak rate of E-9 because we produce very little solar energy after 7pm and none after the sun goes down.

Unfortunately, the proposed Schedule EV-A will not save us much compared to the current Schedule E-9A. With schedule E-9A you get very cheap rates ($0.04 - $0.05/kWh) off-peak, but only for a limited time at the beginning of your billing period, before you use up your baseline. This takes only a few days to two weeks, depending on your daily driving needs. With the proposed schedule EV-A, there are no baseline usages, and no tiers, but you will never pay less than $0.09-0.10 kWh, no matter when you charge the car.

Based on my usage (driving only about 40 miles / day, charging only off peak), my average cost per kWh will only drop about one penny per kWh when I switch from Schedule E-9A to Schedule EV-A.

Before switching from E-6 to E-9A I ran PG&E's PEV Calculator, but I don't think it accounted for the our tiered rates, because it vastly underestimated what my electricity cost would be (click the Advanced Options button, bottom right corner, for available options).

Based on this California Public Utilities Commission document, it seems that Schedule EV won't really go into effect until December 31st, 2014 (!), but I may be reading it wrong.

Can anyone add a reference to a document that says Schedule EV will actually go into effect June 1, 2013?


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