Desptite the trophy mentioning office zones, you dont need to wait that long.
As soon as you have the "Worthy Village" Milestone (around a thousand pop) unlocked, you can create a Zone covering all of your city. Than set it for industry to "Agriculture Specialisation" and for commercial to "Organic and Local Producre". The trophy will pop after some time, when all the buildings are transformed.
This will also make the "Organistic" trophy pop, and if you set the Residential Specialisation to "Self Sufficient Buildings" als the "Super Self Sufficient" trophy will pop as well.
I had only Wind-Power at that time, no idea if it would make a difference to have a Coal Power Plant.
Oviously you can make a save before hand, and reload after. But it shouldn´t take more than 10 minutes anyway to get to that point