Just charge EVs, and then discharge them during the afternoon and evening.

Peak energy prices are approximately double that of off-peak.

For example, if 50% of a standard Tesla 3 battery could be reserved for this, 31kWh, you could make about $8 per day, or $2,900/year, plus be contributing hugely to grid stability.

It could be as simple as setting cars to discharge back into the grid any remaining power from 4PM-8PM (depending on user preference), and charging from 11PM - 7AM.

It seems totally reasonable for regulators, grid operators, carmakers to collaborate and create standards and mechanisms for car owners to charge and discharge based on their typical driving needs and live pricing.

Look at the enthusiasm for GPU mining - people will flock to getting their cars to do this.