Instead of always looking for ideas, lets try and ask this: What problem in your industry would be a successful startup if someone decided to solve it?
Currently, most indoor and greenhouse grows will have the lights on during the day and off at night, exactly opposite of when energy is cheapest. Batteries (any type, whatever works) could allow for purchasing energy at cheap levels (at night) and using that energy during the day.
An alternative would be to hire a night crew and operate entirely when enrgy is cheapest.
What about installing light pipes to enable sunlight for work lighting during the day, so you can still have a day crew, and just turning the lights on at night