Would "TIme of Use" make sense for me?
https://www.psegliny.com/files.cfm/rates_resi.pdf
I am on Standard Rate 180 now.
The answer is "maybe". It truly depends on the amount of energy you use in total, as well as what times of day you use it. If you're like some of us, there is also seasonal variation as to how much electricity you use, e.g when air conditioning is on in the summer the amount you use and when you use it may change dramatically like it does for me here in SoCal. In my case, SDG&E only allows its customers to change the rate plan once a year, so you really need to consider seasonal variation before making a change. Net is, you will have to go through your own calculations, as no one here can give you a solid answer.
I went through this planning myself before ordering my MS in early September. I'd suggest you:
- Get a handle on your own electrical usage by time-of-day, and understand seasonal variation
- Establish what you think is an average and max charge (kWh) you will need to do each day with your MS based on the miles you expect to drive. Use the tools others have suggested above to get a handle on that.
- Think through and decide on what type of electrical service (240V? What Amperage?) you are going to use to charge your EV... There are many trade offs between what your physical home situation may allow, cost, as well as how long it will then take you to charge your vehicle based on that service you have put in place -- e.g. If you only have 110V, it could take days to recharge an "empty" S90, or only a few hours on 240V depending on amperage. Read the charging section on the Tesla site and search for other threads on the subject as well -- lots of resources to gain a comfort level with your options.
Note: A Tesla allows you to set the TOD when charging begins each day, but not a "stop time". Assuming your power isn't interrupted, it will stop when it reaches the % charge you've set (probably 90% or less most days, but that's a whole other discussion you'll find in other threads). E.g. My MS checks every day at midnight when my rates are lowest and begins charging itself if needed. I have a 240V 100-amp circuit along with an optional dual charger for my S90D, and in theory could almost charge it completely within the 5-hour window I have each day when my rates are lowest (at about 25% of the utility rate I pay mid-afternoon at peak rate every day)... I don't drive that much that it's that important, but I went through the thought process just-in-case as I'd suggest you do as well.
- Then, when you have those data points together, you can build yourself a little spreadsheet to see if converting to another plan with your utility makes sense or not, and/or perhaps you'd be better off to have a higher amp circuit to cut down on charge time so you can "refuel" more during the window when it costs the least...
If you call your utility, they may also be able to offer some additional planning tools or guidance, once you have a handle on anticipated additional kWh you expect you will need with your new car each day. SDG&E here has a set of webpages to walk its customers through some of the basics interpreting your bill, etc., but I had to then apply all the Tesla-specific stuff to it. Good luck.
