If you had a variable electric contract (rare but possible), you were paid to use electricity during those hours. Got a battery at home? You can be paid to charge it during the day, and paid again to discharge it at night.
Imagine software that could run on EVs, Powerwall-type batteries, computers/tablets/smartphones, and so on, which would automatically charge and discharge for passive income. Essentially algorithmic trading, but with power instead of stock. You'd just have to configure any necessary time ranges and charge percentages, e.g. maybe your EV needs to be at 25% by 8am and again by 5pm on weekdays in order to make your daily commute.
Maybe some EVs will start to come with built-in crypto miners to burn negatively priced power when the battery is at capacity. Maybe Lyft/Uber and Waymo/Cruise will take advantage of it by increasing and lowering rates based on the price of power (if they don't already).