The cost of charging

1) It takes 2.5 hours for a full charge, not 3.5 hours.
2) It takes roughly 3 kWh to charge from empty.
3) Look at your electricity bill, and see how what tier / rate you'd be paying with any additional electricity use due to charging. You may be on a time-of-use rate plan (not likely because you don't know), but if you are then obviously charge when it's cheaper when possible.
4) Multiply that rate by 3 to see how much it costs you per charge.

 

i take my total electric bill, the amount i actually pay, and divide it by the number of kWh used. this gives me the real price i'm paying per kWh. here, it's 18 cents. i then multiply it times 3.5 to include all charging losses. so for me, it's about 63 cents per charge. call it 60 and 15 miles per charge in decent weather vs 60 mpg at 2.40 per gallon. pretty much break even right now.

 

Unfortunately the OP didn't state whether their "3 prong" outlet is 120v or 240v. 240v charges more efficiently than 120v. Will they charge once per day? Twice? More? Is the OP billed by SCE? .... or DWP. Also, the OP wants us fellow PC folk to guess whether or not (s)he is on time of use? Can one just presume that by inference when the OP asks about rates for different times of the day? Some people NOT on TOU formulas still think their rates change by time, rather than tiers. In L.A. areas - even TOU rates differ between summer seasons and winter, so the OP simply doesn't give enough info to correctly answer.

 

thats why i subverted his question into my personal experience.

 

I'm in Toronto, and the bill is very confusing to read since none of the listed prices for electricity are representative of the final price, because they add in other costs, some variable, and some fixed.

However, ballpark in offpeak hours (7 pm to 7 am), I'm paying about 12.5¢ per kWh final price, or around 38¢ per charge. That works out to about 30¢ US per charge after the exchange range.

Given that we're paying about $1.05 per litre of gas, that's a significant savings. If in the winter we're using 6 L/100 km, that works out to 17 km per litre, which interestingly is about what the distance the Prius can run on EV.

So roughly, in Toronto in off-peak hours for electricity, gas for the Prius costs us roughly 2.5X - 3X as much as electricity. This doesn't factor in the fact that some workplaces will allow you to charge up your car for free, but they won't provide gasoline for free.

Note though that the costs during peak hours for electricity are almost double off-peak. In the winter, peak hours are from 7-11 am and 5-7 pm.

 

On your bill it is Energy (kWh) charge / Energy used, to get cost per kWh.
You can also check the rates on their website.

Rates are cheap here in Phoenix metro for SRP. I pay 8.03 cents per kWh until May with just the basic plan.
It goes up 10.57-12.31 cents per kWh in May and June depending on how much you use.

I use close to 2 charges a day on average = $14.45 a month.
Late Spring and Summer will go up $20.00-$25.00 a month.

 

Is your electricity provider Southern California Edison? If so, you are likely on Residential Schedule D.
Southern California Edison's standard rates are as follows:
Tier 1 = $0.15/kWh (Up to 100% of your baseline)
Tier 2 = $0.19/kWh (100-130 % of your baseline)
Tier 3 = $0.25/kWh (131-200 % of your baseline)
Tier 4 = $0.31/kWh (Above 200% of your baseline)
The baseline is a kWh per day baseline (one value for winter, one value for summer), so to find out your monthly total baseline multiply that value times the number of days in the billing cycle (and add a $0.93 service fee charge). This will let you estimate your monthly bill within a buck or two. The kWh per day baseline is based off of where you live within the service areas of SCE and can be found on their website.

Take a look at your last bill and see how much you've used. In my case, I usually use up Tier 2 without my car. Therefore, my electricity costs the Tier 3 value (or Tier 4 when I use AC during the summer). This means a "full charge" costs me $0.75. However, what is more useful to me is knowing whether it costs me more or less to charge than use gas. I believe the EPA lists the Prius Plug-in as using 29 kWh/100 miles, so if you want to compare with the price of gas divide that by two. Hence compare the price of 14.5kWh to the price of a gallon of gas (since both let you travel 50 miles). So in the case above, I compare the price of gas to 14.5 kWh * $0.25/kWh = $3.625 cost equivalent of electricity to one gallon of gas.

Time of Use (TOU) rates work differently, but I will not explain them in this post because with a Prius Plug-in's 3kWh battery it's not likely it's worth it to switch to TOU. I recently changed rate schedules because I added a LEAF to my garage.

 

OP- You need a Kill-o-watt meter to monitor how many kWh are used with each charge. The amount shown on the Prius display only shows how much energy the battery is holding, not how much energy was used to charge. Charging is only about 70% efficient.

This is a source of much debate, but I don't find it reasonable to apply any portion of the fixed utility costs when determining the additional cost of charging a car. The reason is that the cost is sunk regardless of whether you plug in or not.

When I state how much it costs to charge my vehicle, I include only the incremental costs for the energy used. This gives me and everyone else an accurate picture of how much my utility bill will increase as a result of plugging in.

That said, my electric rate is a flat $0.08041 per kWh regardless of use or time of day. It takes 3.1 kWh to fully charge my PiP for 12.5 miles of range. That is $0.25 per charge, or $0.02 per mile.

Recently I began L2 charging with a modified Leaf EVSE, so my charging efficiency has increased from about 70% to about 85%.

 

my apologies, our bills are not like that. if we use zero kWh, there is no charge. to get around the utility commission rules here, the electric companies started breaking up the business into generation, transmission, overhead, administration, environmental costs and etc. a kWh is only about half the bill.

 

I don't envy how others are billed. Here is the simple way I am billed each month. Note that water is billed every other month.



Here's the gas bill too.

 

^^^ Wow, cheap! My usage is many, many fold higher than yours, and our prices are higher too.

Part of that though is because I live in a big house with a couple of rooms heated by electricity.

Thus, the Prius Plug-in's cost won't be a huge incremental cost compared to the rest of my house.

 

the easiest way is way to figure out the cost is to get a giant solar array on your roof. That way your cost is free, once the panels amortize their value. For us, our system paid for itself after 6.2 years.

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$0.23 per charge during the 8 coldest months of the year and $0.32 per charge during the warmest 4 months of the year.

 

red, that's a simple bill, i like it. agree with your cost. i wish ours were that simple.

 

+1. I'm estimating an 8 year payback on our array. do not know what constitutes "giant," but we have 24 x275W panels for 6.6kW DC generated, and 6kW AC into the grid.

 

How is it easier to install a giant solar array than to connect a $20 power meter to the EVSE and multiply the kWh displayed by the monthly cost per kWh?

I'm not against solar, but that just isn't an easy way to determine cost. It's also not economical in some regions, mine probably being one of them. With electricity so cheap in the PNW, and the sun so elusive, solar equipment is better utilized in sunnier climes and costlier utility districts.

 

did you include the cost of the gas & oil that you do NOT have to buy? Did you include the Fed & State income tax money you don't have to earn, just to be able to pay for the auto gas & oil ... and the income tax money for the electricity you no longer have to pay for? (my payback formula is very liberal)

I hear ya .... and free isn't necessarily free for 100 % of everybody ... nor does free (think 'freedom' for instance) necessarily mean there isn't an upfront price to pay. Just saying, for many ... it can be free. ymmv
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I'm certainly not against hydroelectric power as an alternative to coal, NG, or oil burning power plants.

Your salmon may disagree.

 

Hill, I take it you're on SCE and not SDGE; if so, when you go to SCE.com and look at prior day's consumption by hour, are you seeing negative consumption on that daily graph?

For us, here's what it looks like for yesterday. I'm assuming those zero hours are generating a lot of power we're currently not credited with (and won't be till the PTO is issued).