Electricity cost more than gasoline these days.

I have done this with the PiP. It takes 3 kWh to charge from "empty", and I go about 13 miles on the charge. At my $0.08 / kWh, the total cost to charge is $0.24. $0.24 / 13 miles = $0.02 per mile. My cost per mile is about $0.04 / mile on gasoline at current prices.

Now that I'm using a 240v L2 charger, I don't have the equipment to measure energy consumption, but as Hill pointed out, it's about 15% more efficient. Finishing the charge 1hr sooner means the cooling fans don't have to run as long.

 

Not only that, it's worth noting that the Prius two Eco gets better MPG then the prime. That of course assumes that you're not taking very short trips all the time, if that's the case then you might be better off with the prime if the energy price levels flip, but I drive on the highway four hours per week, the prime just doesn't make sense for me.

week

 

EPA rated, and without any electricity used in the Prime.

You'd have to be paying more than $0.15 per kWh for electricity for the Prime to lose in cost per mile at today's gas prices in your area.

 

How does one account for less ICE wear ...
.

 

That could have been factored in by longer oil change intervals, but Toyota uses a flat miles driven regardless of mode and engine conditions.

 

Considering the ICE is highly likely to out-last the battery, I don't consider this an advantage of the Prime.

 

Does the car record how much electricity is used to charge it? Or do I have to break out the Kill A Watt for that?

 

Folks handy and comfortable with electricity can even put together their own KWH meter for 240V.

I've done this for my water heater, ductless heat pump, and electric dryer, using standard old but refurbished electric meters previously used by utilities for ordinary home billing. These are available cheap from some RV supply houses.

The water heater and heatpump are hardwired, so I added meter bases in their branch circuits, and just plugged the meters in. Because this goes into the house wiring, it legally requires a permit and an inspection. I was doing my own electrical work when moving the water heater from kitchen to garage, and when installing solar PV, so simply included the sub-meter projects in with those permits and inspections. This will not be a friendly or inexpensive route as a stand-alone project.

But the electric dryer is plug-in, so no hardwiring or electrical permits are needed. Just take another meter, a meter base, a separate dryer pigtail to plug in to the wall, and a new socket on a pigtail. Voila, a 240V 'kill-a-watt', or at least the KWH function of it.

Don't attempt this sort of project if you are not already comfortable working with electricity. The potential dangers are considerable.

 

The attached pic - for DIY'ers is about as simple as it gets - splicing one of these bad boys in line.
But like fuzzy says, don't do it if you aren't knowledgeable about electricity
.

 

The car shows how much charge it accepted in the battery, but doesn't show how much was wasted as heat, or in running the charge controller, fans, etc. This is how you calculate the charge efficiency. Take the kWh the car shows in the battery, and divide by the kWh from the wall as measured by a Kill-a-watt. This is how we know 240v charging is more efficient than 120v.

If I recall, that device is about $150 on Amazon. The disappointing thing is that you can pick up a 120v Kill-a-watt for $15, but there isn't anything even remotely as cheap for 240v, even though the principle and construction is the same.

 

Ingredients for my 240V watt-hour meter for my clothes dryer:

Refurbished meter: $16.50 at Hialeah Meter Co.
Meter base: $11
Dryer pigtail: $9 at a big box hardware store
Dryer outlet (surface mount): $7
Wire: leftovers
Wire strain relief/clamps: leftovers

 

I think we picked up ours for about $90 on Amazon. I used it to see the accuracy of our inverters' meter.
.

 

You can also just get an EVSE that has the kW meter built in.

 

Is that accurate? I thought they recently removed the quota on stickers. My neighbor has an Audi Etron and he just got his green sticker a week ago...

 

you're quoting from july. they have since extended the stickers.

 

According to this study in 2013
https://www.veic.org/docs/Transportation/20130320-EVT-NRA-Final-Report.pdf

"A more granular analysis of the data revealed Level 2 charging to be considerably more efficient than Level 1 charging in “low-energy” charge events—when less than 2 kWh drawn from the grid. Level 2 charging was observed to be 12.8% more efficient on average than Level 1 charging in these instances. In “high-energy” charge events—when greater than 2kWh was drawn from the grid—Level 2 was shown to be more efficient than Level 1 but by the more modest margin of 2.3% on average."

 

Typically due to what are called "(I**2)R" losses. Higher voltages deliver power more efficiently than lower voltages.

Bob Wilson

 

Wow, so much info in this thread. Can I ask for an updated calculation if someone has already done it?

I live in San Francisco and have solar and also switched to the EV-A plan for California. Under the EV-A plan, I would pay 11.6 cents in Summer and 11.9 cents in Winter.

I was going to do some calculations to compare my Electric vs Gas costs, but not sure I will get the correct formula. So if someone has already done the homework and don't mind sharing, it would be greatly appreciated.

Thanks in advance.

 

Something wrong with the break-even chart I posted on page 4?

 

Excellent table.

Bob Wilson