Dynamic tariffs (aka real-time or wholesale plans) are becoming more common in the UK an EU. These are usually priced by 30-min periods and announced 24h in advance. More modern utilities will offer apps that control when your car is charged (in exchange for cheaper rates). But I agree, optimizing this is fun too. I'm building support for configuring Tesla Powerwall systems based on dynamic tariffs.
If you have the option, the best time to charge your car would be during the day when there is abundant solar.
If you have the option, the best time to charge your car would be during the day when there is abundant solar.