I'm in the UK and with solar and battery, and having an EV there are tariffs out there where the levellised cost you'll pay is approaching 7p per kWh. Intellig

I'm in the UK and with solar and battery, and having an EV there are tariffs out there where the levellised cost you'll pay is approaching 7p per kWh. Intelligent Octopus Go is one example - between 23:30 and 05:30 all of your electricity usage is 7p per kWh, for the entire house. For this, you give up controlling when your EV is charged as Octopus either control it through the car, or through a compatible charger. When your car is plugged in, they build a charging schedule when the grid is cheapest and greenest. You give them an "I need to add this % of charge and it to be done by this time tomorrow morning" and it just works it out. On days with a glut of renewable generation (i.e., it's very windy, or very sunny) you will get half hour slots at 7p during the day as well. Now comes the solar and PV element - their "outgoing octopus" export scheme pays 15p per kWh, so in the summer you can build a nice credit buffer from exported excess energy, and then in the winter, charge the battery whenever the cheap rate is active and given a big "enough" battery, most of your usage will cost you 7p + 5-10% (efficiency losses from AC/DC/AC conversion). The payback period for Solar + Battery, especially in the UK where we aren't saddled with high tariffs for panels, is coming down markedly. It used to be well in excess of a decade, but is between 5-10 years now.