If u would only use 1/4 of the farm (one corner), u only have a energy usage of about 1/4, excluding the base' 43kW without growing lights. And yes, some sort of automation (auto-farming, logistics-transportation, crafting loop, ...) would be nice.
I put all growing lights in one device-category, so its recommended to use the

key while aiming the lamp u want to use to access it directly.

Very interesting information! Nice research on using a farm to grow Bio Fuel to power the greenhouse, with a little profit. (Though, in real life, this would never work as it's essentially a form of perpetual motion device. Plants would never grow fast enough to replace the energy that went into growing them.) Though, harvesting 324 Grow Plots sounds like a lot of work, even only once every 24 Hr.