That actually made me laugh. It might cost more than in other US states, but is almost free comparing to most of Europe [1]. Average size of cars and engines, larger car with larger engine use more gas, also tell a lot of price compared to income, and it you compare traffic in Europe and America you will also see that Americans pay way to little for gas
[1]https://www.statista.com/statistics/221368/gas-prices-around...
I think you're likely still saving money on the electric portion of your driving, as CA rates seem to be slightly lower than MA rates from a cursory Google search.
But most of the difference is that our vehicle is nowhere near as efficient as yours. The 9kW/h battery only goes about 18-20 miles on a charge, and it costs more than the $1 that you pay to get that many miles.
Snark aside, when we got our Chevy Spark EV in 2013, we switched to the EV rate plan and it has saved us a lot. I work at home too, and but the peak hour use on the EV plan is quite small, so the higher rate is balanced out by having the car automatically charge during off-peak.
Perhaps solar would help solve your daytime rate problem? Or a car with more battery?
So we pay roughly the same amount per mile with electricity as for gas — and I'm in CA, where gas is expensive. We do save a tiny bit when we get to charge for free or at a subsidized rate somewhere. But I think most of the savings comes from not wearing down our brake pads on the hills in our neighborhood, and not having so many moving parts to wear out. These savings are not huge when amortized over the number of miles driven.