Not seeing EV savings

If you are using the EVSE (charging cord) that came with the car plugged into a 120v outlet, then you can use a Kill-a-watt meter to record the actual kWh used for charging your car. I have been doing this since the very first day I purchased my PP 5 years ago. Then if you have the base cost of the electric bill from a month you did not charge at all, you can do the following calculation.

(monthly electric bill with the charge) - (monthly electric bill without the charge) divide this by the total kWh used during the billing period. Or at the least make sure to count the number of full charges (count fractional charge as 50% charge as 1/2 charge, 33% charge as 1/3 charge, and so on). Then you can tally the total charges for the billing period. Divide the increase in the electric bill by the number of charges. That will give you a good estimation of cost/full charge.

The photo is my kill-a-watt meter from yesterday when I finished charging empty to full. As you can see, the full charge takes only ~6.5kWh.

 

What percentage loss formula do incorporate (after using kill a watt metering) once power converts from AC to DC & back to AC again

 

Are you asking me? If so, then I am not using any conversion factor on this number. The kWh at the wall is what I pay. Doesn't matter what the conversion factor is, that is what takes to charge the battery fully. I am interested in recording the cost of EV not the efficiency of conversion. No one knows exactly how much kWh goes into the battery and is used for the traction. A good estimation is ~90% maybe? So, only 5.85kWh goes into the battery from 6.5kWh of AC electricity from the wall. But don't know for sure.

 

My per kwhr rate is about a $1 a kwhr due to fixed fees and taxes combined with low usuage.

The more electricity I use the closer to 10cents a kwhr I get.

As such your “electricity” is only as expensive as its opportunity cost…

I’m going to be paying the same taxes and fees no matter how much electricity I use so including those things in my EV cost is disingenuous ,

AKA If I ditch an EV I’m not going to disconnect from the grid

I would recommend you get the exact cost for each additional KWHR, if it’s 42 cents in reality not including fixed fees you have a good reason to get solar even in your cloudy area

My guess is your under half that in reality since most of the cost stays even if you use no electricity

 

That’s my point the electricity you use for your EV is likely a fraction of the cost as your base usuage so there is no point in tabulating it’s costs over your bill that way

 

Each formula captures its own valid data. Just turns on what you want to conceptualize

 

I have a similar issue with my natural gas meter costs in the summer as @Kebisho1 has with the electic bill.
I have natural gas furnace, water heater, dryer and range. In summer I'm way under the minimum usage and my cost per therm reflects that low usage with total cost per therm up in the $2 per therm range as opposed to around $0.95 (variable average) the other months of the year.

Electric bill is also more expensive per kWh in the summer as compared to winter rates here with our utility.
And it gets cheaper per kWh after going over about 1000 kWh per month. So there are not any real world incentives for actually conserving utility usage here locally either. Still, doesn't stop me from cutting my usage were ever I can find a way to use less water, electric and gas.

On another note, there is a town locally that has a reputation for extremely low electric rates. But no one that lives there ever talks about how much natural gas costs them..

 

I think the situation you are describing with your gas usage and electric is common. We have a hybrid furnace and use gas in the extreme winter for heat. That is our only gas appliance. We use gas December, January, February and March. We use gas for no other months.

Even when we use no gas for the 8 other months we are charged a minimum of around $20 for each month for our natural gas connection even though our only usage occurs during the 4 months mentioned.

In our area connecting to the gas main means a base charge of $20 per month whether you use gas or not. My impression is this is a common billing arrangement for utilities

 

I think there are only two numbers you need to consider when figuring what it costs to drive the PP. First is the number of KWh to fully charge the car as noted by Salamander_King as 6.5. Second is your local rate charged per KWh. Mine is $.096 for the first 600 KWh and $.115 for all above that. The ancillary costs don't figure in as you pay that whether or not you charge your EV. To make it simple I can say that I pay $.11 per KWh or $.72 every time I charge my car. Compare $.72 to 25 miles is the same as comparing $4.00 (cost of a gallon of gas) to 139 miles. (.72/25 = 4.00/xmiles) I know there are more than two numbers here, but I have a math degree.

 

What!? Is that correct, You go over 1000 KWh and they charge you less????? If your on PG&E and you go over the tiered allotment, energy prices almost double, break that allotment (3x average household) it doubles again. The good news is infrastructure cost are fixed. As long as your hooked-up; the utility always gets their piece. So, out here we're encouraged to conserve.

But that doesn't stop the craziness. San Francisco outlawed natural gas in new construction builds last year. I haven't been to school in a while; but I recall heating something with natural gas is much more efficient than with electricity. I guess the natural gas turbine generators for electricity are exempt.......

 

Too broad a brush. Heating with natural gas is typically more fiscally efficient than baseboard resistance heating. That is, until you include the externalized costs.
I don't believe that is the case when compared with modern heat pumps.

As for electric vs gas, this varies greatly from region to region and program to program.
In our case, we locked in our electrical prices for 35 years some 6 years ago. After rebates and incentives are included, our cost to drive 50 miles is about $0.25.
This is an extreme case, but the existence of people paying less for electricity shows you how the average cost, can indeed, be as low as it is. Just as the existence of people paying high rates in CA, etc. raise the average.

 

No, EV driving will be more expensive for Prius Prime with 42¢/kWh electricity. However, I doubt anyone's monthly consumption can be only 48 kWh. Don't you even have a refrigerator? Check your bill again.

 

we used to get notified monthly by our power co that we were using more electrons than our neighbors,
along with a report of everyones usage by address, and ways to cut back.

then they got bought out, and now we get a thank you with our bill.

 

Do the math as if you used 500 kwh of energy. You would find the fixed costs to be relatively small. With your usage you need to get a small amount of solar and use net metering. Your driving and actual electricity cost would go to zero. You just need to stay there for seven to ten years for the economics to work.

 

That is one of the best conservation methods. We still have a neighborhood comparison of the average neighbor. Our utility found that making this info available cut electrical use by about 3%.

 

I'm charging daily, on a set schedule, and TOU with my utility company - I'm being billed 166 KWh for last month's charging only. My electricity usage almost doubled, when I got the Prime. I'm not going to mix utility fees into the calculations (fixed infrastructure charge), since I need to pay it anyways for my house power. A conservative estimate is a minimum $50/month savings over the PriusC I was running - this includes adding in the additional electricity cost. If your Prime is replacing a 30mpg gasoline only car (PriusC was averaging 49 mpg), the savings should be much larger, assuming your not paying $0.42/KWh.

If your electricity cost is actually that high; buying a standard Prius or Corolla hybrid would've saved you a lot of money.

 

@BiomedO1 anyone that has electric heat in this area knows the difference in their utility bill ! And it's a rare occurrence in this area to move into a house or apartment that uses electric baseboard heating. That is except that one town / community with extremely low electric rates, mentioned above in my post #31.
Typical Electric baseboard heating or what have you for electric heat such as a water heater, dryer, dishwasher, range etc. , nearly doubles the cost of the fuel to heat the same amount of space or water or oven and stovetop pans using our electric and gas rates from the local utility. I'm not sure about the heat pump thing yet, my suspicion is it's more an adverting gimmick than an actual year round fuel saver. I'll site ads for home auto and life insurance, medicare supplemental insurance commercials, new high efficiency gas furnaces with above 95% efficiency ratings advertised to save the owner near a thousand $ a year on the gas bill when the efficiency rating is mostly about the carbon that leaves the stack or pipe from un-burned fuel.
Same with geothermal construction that doesn't have a natural geothermal source to tap at the site. Don't forget about steam (hot water pex radiant, etc ) heat either. It can be very efficient when setup correctly, even more so that forced hot air.

Of course in an area like San Fran the threat of a quake rupturing gas lines is significant, and San Frans always been a leading city for electrical things that most other cities are just recently starting to introduce. Thinking of the subway in LA or the Bart in San Fran, I'm pretty sure I wouldn't want to be in there if and when a quake hits the area and moves enough stuff around.

 

I'm not sure in @Kebisho1 case, but in this area, there is a minimum set of charges added to each of the utilities customers bill. If the usage is so low that the minimum service and delivery fees on the bill are not met by sufficient usage it can raise the rate per kWh a lot. For instance in my case the service and delivery fees for gas service require 30 to 35 therms used per month before the fees become balanced. In summer I use 10 to 20 therms a month and my rate per therm is almost double of what the rate per therm is when I use 30 or more therms per month. In winter I can use around 400 therms a month. And it's pretty hard to use less than that when it's significantly below freezing outside in our 100 year old house.

I've only gone over 1000 kWh a month once in 20 years, so I don't have as much data for the high electric usage as I do for the low gas usage, but it was eye opening to see the electric charges that month. My lowest monthly electric was around 300 kWh, but I was scrimping in every way I could think of that month.

 

Here we pay a little over 10 cents per kwh charging 2 Primes with a little over a 12 mile commute 1 way. Prime does the job. You know Boston has a harbor. Unfortunately it seems that it is only going to get worse for cost of operating an electric vehicle. Shame because it is so unnecessary. Diversity is not just limited to you know what. It applies to energy as well and keeping energy more in balance and upgrades to battery technology rather than push and shove authoritarian crapola. We could benefit while also keeping environment, cost, and improvements in technology. I love an electric vehicle and not just because it for me is cheaper to drive. I love it because I out grew the need to hear my vehicle rumble down the street and opted for a quiet and smooth ride.