It's recently occurred to me that what with the very expensive electricity with PG&E (minimum $0.30/kwh, up to $0.60) I'm probably in the territory where it could be cheaper to not charge but to only use gas. I'm still charging for now because I prefer the experience of driving on battery, but now that this has gotten into my head I'm wondering if anyone else thinks about it?
I pay less than half of your lowest rate KwH, but I did the calculation long ago and came up with $0.30/KwH @ $4/gal is breakeven for me. I mainly use this calculation to determine if I should pay for a recharge, when I'm out and about. If the charge is FREE, that's a no-brainer. You need to flip though your car options screen to find your electricity consumption per KwH, before you can make the necessary calculations for electricity vs gas usage. I'm averaging around 4 miles/KwH. That's going to vary by how you drive and where you drive. You can do a reverse equivalent calculation from there. The other variable is your actual gas mileage, because that will influence your breakeven calculations too. Hope this helps...
Calculations for the car are here 2023 Toyota Prius Prime Initial parameters 30 kWh per 100 miles and 50 miles per gallon (2 gallons per 100 miles). Translating into finance: 1 gallon is equivalent to 15 kWh ? 4 or 0.3*15=4.5 approximate parity ? 4 or 0.6*15=9 gasoline is twice as profitable. In each specific case, you will have to compare the costs of the car's mileage per day, based on the car's mileage on electric power + mileage on gasoline.
I don't run those numbers yet. I've got plenty of other things that are more pressing in my neighborhood. If electric bills showed the rates posted above, I'd pay a lot more attention and start calculating all the options currently available. But I'd also be thankful I'm only dealing with 6 kW per charge and not having to keep track of how much of a possible 75 or more kW might be spinning the meter. Or the other possible addon fees of solar install and payoff time tables, incentives or lack there of, and if the grid tied solar utility buy back is gonna end. They don't even offer that in my neck of the woods yet.
I made a spreadsheet (nobody who knows me will be shocked to hear). I'm paying 0.12/kWh here. My break-even point (where electricity and gas cost the same) is around $1.30 a gallon in the summer, $1.60 a gallon in the winter. This is based on an EV efficiency of 2.25 miles/kWh winter, 3.0 miles/kWh summer, and a gas efficiency of 52 MPG summer and 47 MPG winter. I doubt we'll ever see dollar gas again, so gas is road-trip-only for me. (Also, the above is assuming that I am paying regular rates for my power, when in fact it is mostly free due to solar generation. So hitting my actual break-even point would require free gas for most of the year. )
I'm sorry, do you mean $1.30 per liter, gallon, or imperial gallon? I haven't seen prices like that since I was in Saudi Arabia; a long time ago. Or are you trying to say that would have to be the cost of gasoline for you to break-even? We're usually trying to calculate the opposite. How much should we pay for an electrical charge and wait vs just driving the car on gasoline? Because there's no way we're going to find gas for $1.60/gal.; but electricity cost vary widely from charging station to charging station. The question is keep driving or charge up and take a break... The cost of the solar generation system needs to be added to the overall fuel cost calculations, if you want to be honest about the total cost of operations of the car. YMMV
Correction to your calculation Your Summer Ratio per 100 miles Gasoline 1.92 gallons, Electricity - 33.3 kWh 1 gallon = 17.34 kWh By setting the kWh cost at 0.12, a gallon must be equal to or less than 2.08 Your Winter Ratio per 100 miles Gasoline 2.13 gallons, Electricity 44.4 kWh 1 gallon = 20.85 kWh By setting the kWh cost at 0.12, a gallon must be equal to or less than 2.5
For last 8 years since my first plug-in (2017 PP) our electricity rate for EV was about same as gas cost for HV. Some period had higher gas but most of the time electricity was higher slightly. I knew this but regardless of cost swings, I continued to charge. With Gen4 Prius Prime (2017-2022), the initial cost was low enough such that saving on fuel by using electricity was not much of incentive for me. Less dependence on gasoline was good enough reason for me even paying a bit more than for equivalent gas. The thing has changed now we have solar and more electricity we use, quicker the initial investments get paid off. For that reason, I just jumped on a bandwagon and bought a BEV, Chevy Equinox EV to switch our daily drive fully electric. We are keeping our current PHEV, Escape for now for a long road trips. It has served us well. In period we used, it was cheaper to drive it HV than EV, but we kept daily charge. Most of our daily drive around town up to 40 miles are EV now. Here is EV vs HV real cost for our past PHEV at the period we had it. $Cost/Mile 22 Escape PHEV 2022-2025 EV($0.099) vs HV($0.085) 21 Prius Prime 2021-2022 EV($0.045) vs HV($0.063) 20 Prius Prime 2020-2021 EV(0.046) vs HV($0.034) 17 Prius Prime 2017-2020 EV(0.043) vs HV($0.047)
