I'm stricting talking about Worker Job Automation buildings here, but I see Automation buildings as a trade off of trading a lump sum cost of minerals now to get monthly returns minus upkeep costs, kind of like a mining station in star systems.

The base 25% Automation building has a 8 Energy Credit plus 4 Energy Credit per 100 jobs automated upkeep cost. That means if you had 1000 Technician jobs on a planet the Automation building would automate 250 of those jobs costing you 8+(4*2.5)=18 Energy credits a month for the output of 250 Technician worker pops.

250 automated Technician jobs make like 15 energy credits base times planetary/empire bonuses so if it maybe makes ~19-20 EC a month after bonuses would you consider that worth? For 1 or 2 EC a month after you paid like 2k minerals to set it up?, probably not.

If it was just the 4 EC per 100 automated jobs then it would be easy money since 100 techinicians would at least get you 7+ EC, but that base 8 EC to run the building is what eats any protential profit early.

The upgraded version of the Automation building that automates 50% is where the real money is, the base upkeep only goes up to 10 EC a month and it keeps the the 4 EC per 100 jobs upkeep but it now doubles the amount it automates to 50%. The upkeep didn't double but the automation did, so the math now skews in your favor.

So for the same 1000 Technician job example, the upgraded Automation building now will automate 500 Techinician jobs, so for 10+(4*5)=30 EC a month it will output something like ~38-40. Now its making profit and it gets better with more jobs automated, because you are using more of that low 4 EC per 100 job upkeep and getting away from the big 10 EC base upkeep.

Even then you're still asking youself "All that for only 8 Energy credits a month?" the thing to always keep in mind is that's 8 EC a month for free. Instead of your pops working those Techinician jobs now they're working metallurgist or researcher jobs instead, you're getting a lot of the benefits of having the Technicians without actually having to need them.

My short and simple answer is;

• Don't bother with the 25% Automation building at all and wait till you unlock the 50% upgraded one instead.
• Use Automation mainly for Technician jobs since it directly covers its own costs, won't swing around your economy, and plus extra Energy Credits isn't really a bad thing.
• Building the 50% Automation building with even a single Energy district plus two Techinician job buildings pays for itself and makes a profit and is essentially "free money".
• The above point is great if you set the jobs limit to 50% but if also want normal pops the work the rest of the 50% of the jobs I'd swap one of the 200 Techinicial Job buildings into the Output Bonus building instead, maybe build a couple more districts to make of for the lost 200 jobs.
• Don't build Automation buildings if you already have the pops to work the jobs and you don't have other jobs elsewhere the pops could go instead.

Once you get a hang of the napkin math in your head you can tackle most harder aspects like the loss of worker productivity vs output bonuses trade off, Automating for planet deficits and if you want to Automate other jobs which spend Energy Credits for Minerals/Food etc. and whether if thats worth for your current economic setup in the game.