garygid said:
On Net Metering, there is no incentive to charge at night, but I usually do so.
To clarify, Net Metering is an addition to your "otherwise applicable rate". So if you have a flat rate, the time of day doesn't affect the cost of electricity, that you pay. Charging during the day does affect and cost us all as a society since the peak power load during the day is met with peaker plants that have higher emissions (pollution) than the baseload plants which run pretty much full output 24x7. Also on peak power is more expensive to the utility and will eventually get reflected in future rate hikes as the utility's costs go up.
Charging during the day often means your EV and it's batteries are warmer or hotter. There may be a slight increase in charging power so for running a fan in the garage, or for EVs that have active cooling for the batteries - fans, liquid cooling, or in the case of the NiMH GM EV1, it actually ran the car's air conditioner to cool the batteries during charging. Never could toilet train that car. It kept peeing air conditioner condensate (water) on the garage floor every time I charged. Some of us resorted to putting a cargo mat on the floor to catch the piddles from the EV1!
Time Of Use (TOU) rate schedules, if they work for you, and they work VERY NICELY for PV + EV let you take advantage of expensive power during the day by reducing your daytime usage with the PV panels and usually driving the meter backwards. At night you consume less expensive electricity with the EV. Having an EV helps to shift most of your power usage to the night. And you learn a few other trivial tricks to save more, like doing laundry off peak.
If you have PV + EV, definitely check out the Time Of Use (TOU) rate schedules, and see if they work for you. For most people who have a utility bill over $100 month the TOU rates should create some substantial savings if it's natural to shift some of your electricity consumption. I still run the Air Conditioner occasionally on peak when I need it. Otherwise there's not much point in buying an AC! At the on peak rates, it costs a few dollars, but the savings from the other summer days when I don't run it, the savings during the winter and the savings for charging the EV at night work out to a large net savings.