Cost of electricity in CA for Prius plug in

Californians seem to be paying a lot for electricity.

If you have any space for PV panels, that will probably drop your cost per mile significantly. PV installations are running about $0.15 per kWh here in Maine, and should therefore be much cheaper in CA (both more sunny days, and more sun per day).

 

Its interesting they don't include the E-6 Time-of-use rate which is similar to E9-A and will continue to be available. The one-calculation-fits-all assumptions of the calculator will get you started on determining your potential costs but you need to look at your PG&E electricity statements to figure out what your costs will be. Its complicated.

Billing is based on tiers of usage. The baseline kWh depend on where you live and are different for winter/summer. Cost per kWh is modest for usage less than base line and the second tier which is 100% to 130% of baseline. Third tier and above are much more expensive. If you are already on the third tier most months the kWh to charge the car will be at that high rate and will most likely cost about as much as gas per mile hence little or no advantage for the PiP. In my case installing solar panels to reduce my usage, including the PiP, to within the baseline creates a reasonable savings. Without the solar panels I would have no $ advantage with the PiP.

 

To clarify a bit for non-PG&E readers, the E6 rate option is only an option for people with solar panels. It has tiers and Time Of Use pricing. The old E9 rate for EV owners was similar. The new EV rate is Time Of Use but has no tiers and so it is not as great for customers who keep their usage near the baseline amount but it can be better for people who had been in tier 4 under another rate system.

 

Oh... I didn't realize the new EV rate has no tiers. The Off-Peak rate of $0.10/kWh would definitely be cheaper than using gas.

I don't believe the E-6 rate requires solar panels. The rate sheet says "APPLICABILITY: This voluntary schedule is available to customers for whom Schedule E-1 applies. " It is the basic TOU schedule for those who wish to modulate their usage based on time of day.

 

You appear to be correct about E-6. I had always seen it talked about in the context of solar installations and wrongly assumed it was only for customers with solar.

 

I ran PG&E's rate calculator for my current tiered E-9 vs. the new non-tiered EV rate. My rates would be significantly higher under the EV rate, since I barely get into Tier-3, let alone Tier-4. At some point, they are going to kick people out of the E-9 plan (or so they said last year when the new EV rate was announced). Maybe I should look at E-6 at that point.

 

I wouldn't trust that nice calculator very much. I put in my actual kWh for the last 12 months which were all under the baseline for E6. My averages were 180 kWh/month winter and 143 kWh/month summer using the advanced calculator. I used 20 miles per day driving. The calculator said adding a PEV would create an average increase of $33/month plus gas for anything over 14 miles/day. At the low baseline rates (about 10 cents/kWh) that would be 330 kWh for charging the battery or 11 kWh/day. That is equivalent to 3 plus full charges per day, not a good estimate. I charge about 3.3 kWh/day or about 1.2 full charges/day.

OK I already have a PiP and solar panels keep the kWh below the baseline so the calculation is for adding another PiP with low overall houshold usage. In that case I would expect the average cost to increase about $10 per month not $33. When the calculation gets into higher tiers it gets more complicated but for an "average" house it gave a $47/month increase which makes me believe they are using too high a daily charge for a Prius, more like what you would expect with a Volt or recharging the Prius 2 or more times a day to go all EV.

 

I just figured out that we are talking about two different calculators. The one I used just took my historical usage as recorded by my smart meter and computed what my bill would have been under various rate plans. They were trying to get me to convert to EV, but the numbers that came out emphatically told me to stay put in E-9.

 

They do. You have to select it from the pull-down menu. It turns out that I'm on the E-8 rate, which is cheapest for me.

 

Go to Pacific Gas and Electric Company . It uses your actual electric bill data for the last 12 months and compares various rate options for you. You have to log in.

 

I'm not sure where you are getting the $.10/kWh from. The calculator is comparing E-1 rates (Tiered) to EV rates (Time of Use). Apples to oranges. You can select E-6 from the pull-down, which might give you a more accurate comparison to your current situation.

 

Does SCE have any rate comparisons like this? I glanced over their EV TOU rates and it seemed it wasn't worth it for the PiP.

 

The idea is you are charging during off-peak times, that is, before dawn. My example is for total monthly kWh that is less than baseline. Therefore the charging is at the off-peak rate, let's call it $0.11/kWh as shown in the Total Rates table for E6. I used the Advanced Options and I did chose rate E-6 and entered my usage kWh. The results show average E6 costs at $42/month and average E6 costs With PEV at $75/month, hence they are saying it costs $33/month to charge the car. At off-peak rates that is about 10 kWh/day, well maybe 9 kWh/day which is 3 full charges.

Total Energy Rates $ per kWh)
Summer
Baseline Usage PEAK PART-PEAK OFF-PEAK
$0.28719 ( ) $0.17528 ( ) $0.10074 ( )

Winter
Baseline Usage PART-PEAK OFF-PEAK
$0.12129 ( ) $0.10495 ( )

Note: the $42/month is actually about 25% more than I paid for the previous 12 months which says my actual peak, partial, off usage is somewhat different than what they assumed.

The E-6 rate table is here http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_E-6.pdf

 

The SCE EV calculator is useless for the PiP as it assumes a 20 mile EV range for a Plug-in Hybrid, which causes a major error in its results. (As in overestimating the cost effect of EV on Rate D, and probably overestimating savings on the EV-TOU and EV Rates.)

 

I don't know how accurate the calculator is. Earlier in the thread though, it says that it takes 4.5 kWh to charge the battery. You say 3.3. The calculations are probably using the higher number. On the other hand, the calculator says the PIP goes 14.5 miles on battery, which is overly optimistic.

I know I will be in Tier 3 under my E-8 plan if I charge a PIP under my normal rate schedule. However my last power bill had 2 different rates for Tier 3 during the billing period. So I think that Tier 3 $/kWh change throughout the year. Too confusing to me to run a hand calculation to check the model PG&E is using for their calculator.

I agree though, there seems to be something wrong with the PG&E calculator for the PIP. Seems too high. The Chevy Volt numbers come out a lot better compared to the Prius liftback than the PIP does. They should also put more PVs in the calculator too.

 

I was just using approximations for a full charge. The actual numbers are 2.8 kWh to about 3.1 kWh depending on temperature and other factors. I don't know where 4.5 kWh came from. The battery is rated at 4.4 kWh and operation is between 20% State-of-charge and 85% SOC.

In any case the PG&E calculator may to lead folks to incorrect (negative?) conclusions about the PiP. PG&E rate calculations are so complex its a wonder they even attempted to design the calculator. In fact the disclaimer when you first access the page does a pretty good job of warning about accuracy of the results.

 

I am still a bit confused about the PG&E calculator tool people are talking about. The one I used did not require me to enter anything. I clicked on a rate plan and it calculated what my bill would have been under that rate plan, using the daily usage data they had for me. What people are talking about here seems to involve some kind of "what-if", like adding a particular kind of plug-in car.

 

It's the one here: PEV Calculator

 

You put in your zip code, miles per day, type of car and time of day to charge. If you click on Advanced Options you can put in more information. It doesn't ask who you are.


Here are some sample results using the Advanced Options. Unfortunately the results are very misleading as to the electricity cost for a PiP.

 

I found the calculator fairly accurate prior to my PiP purchase. Today, however, it is something else. If you type in 11 miles, then it gives a more accurate estimate.

I'm quite upset that they readily admit the new EV plans cost more than the old E9 plans (for anything less battery capacity than a Volt). It looks like I may need to go to E6 or E7 once they force migrate me.


iPhone ?