OT- But, are you sure about that, that at no time in the future you will receive a TOU rate option, or that there are no benefits to night charging, beyond a preferred rate?
No, I am not. In fact, I am asking in this post whether there is benefit in terms of battery life in charging at night.
Virtually all American utilities, and the electric grids they connect to, experience their highest demand in the day, particularly on hot afternoons, due to demand for Air conditioning. They generally meet demand spikes by operating the most costly, least efficient (in terms of energy conversion) plants, typically low efficiency "peaker" natural gas plants.
Here is a link to our electricity provider, Rappahannock Electric Cooperative (REC)
. I do not know what their demand curve looks like, but it seems to me that they have been taking rural customers off the hands of the larger utilities that no longer want to deal with them. If the great majority of REC's customers are rural, I would be not too surprised to see peak wintertime demand occur in the early hours of the morning when all the heat pumps and emergency resistive heaters are on. But I am sure you are correct that the peak demand during most of the year is during the daytime.
So, while your rates may not reflect this (yet) you would almost certainly be reducing both the total CO2 output of the grid you connect to, and the total cost of providing electricity to all ratepayers, by charging at night, as it sounds like the marginal reduction in your own efficiency of electricity production and use, by night time charging, would likely be far less.
There are a lot of assumptions in what you say regarding how electricity is generated around here. Most of the base electricity generation comes from coal with some nuclear. While I do not know the exact make-up of peakers in the area, I do know that there is a 600 MW pumped-hydro peaker in VA. I'm pretty sure this peaker is used to allow the utilities time to bring coal power on and off-line. I'm not aware of any natural gas peakers in the region, but there may be some. We do not have natural gas lines in the immediate vicinity, but neither do we have power plants (except for a few solar arrays).
The point is that my electricity is produced by either coal or nuclear with peaking done using hydro. If we can more efficiently use the PV solar that we produce *and* more efficiently charge the EV that we have, then I have *reduced* the amount of electricity that I will consume overall and hence the amount of coal that is burned. And in either case this house will be a net producer during the daylight hours most days.
It's unfortunate that your utility does not have rates that reflect this reality, and provide you a fair return for the premium product you provide, peak demand kWh.
We *just* got an electronic meter last June which is capable of tracking time of electricity usage, so I am hopeful that they will soon offer more attractive rate plans.
Most all BEV/PHEV drivers now face similar situations, with other failures of market signaling, as is the case when we are given the opportunity to replace paid off-peak charging at night with "free" public opportunity charging.
If you are plugging in during the day, when you could just as easily wait till you got home, to charge overnight, you are almost certainly imposing both short term economic costs on others, and long-term environmental costs, on everyone on the planet, present and future.
I'm not sure whether you are referring to a singular or plural "you", but I am proposing to charge during the day in the wintertime and at night in summertime to try to improve battery life, both of which are possibly off-peak for my utility. I expect any improvements in battery life would have a very positive long-term effect on the environment.
I am not trying to suggest what the correct action is to take in any of these situations, I'm just pointing out that your decision, may not always be based exclusively, on immediate cost considerations.
I hope you will agree that the essence of the question in this post pits the long-term cost, both to me and to society in general, of the battery against the short-term savings that I could gain by charging when the sun shines. It is all about conservation.