I agree with Orzelek that I think turret energy costs are too high right now. I think they should go back to what they were (1/2 of current).
While you are correct, Peter, that if you go heavy on the Econ stations and devote their resource income to powering Matter Converters, you can get 2.4M energy with 13 planets, or 4.2M energy if you include the Energy Collectors.
Defending those 13 worlds with Mk I + Mk II basic turrets (Needle, MLRS, Laser, Missile, Sniper) will cost 240,000 energy per planet, or about 3.2M energy total.
That leaves you with 1,000,000 energy to fund your offensive fleet. You endgame fleet will usually take need between 500,000-1,000,000 energy, so it's almost exactly enough.
But you have no energy left over for Golems, Spirecraft, Fortresses, Mk III, IV, or V turrets, Spire Fleet, etc. Your economy is lacking, because you are running 31 Matter Converters for -6,200 metal/sec. The 9,000 Knowledge you spent on the best economic improvement isn't actually helping - you're just breaking even. The higher salvage from Econs helps, but not much compared to what you are spending for the energy you need.
On the other hand, those defenses are at barely adequate levels. 12 worlds captured is 240 AIP. Including max AIP reduction, on Diff 7 you're at the floor at ~60 AIP, on diff 9+ you're at roughly 110.
At Diff 7, the wave size for the Vanilla AI will be about 200-300 ships, mostly Mk I. These defenses will easily hold off waves like that.
At Diff 9, the wave size will be 500-600 ships, 50% Mk I, 50% Mk II. This will probably be enough to pass the turrets and destroy your command station, even under a Mk I FF.
From testing earlier today, when using the basic set of Mk I turrets:
300 Mk I triangle ships can kill an unshielded non-Military Command Station even under ideal circumstances (aka, maximum distance for turrets to shoot).
350-400 Mk I Bombers can destroy a non-Mil CS under a Mk I FF. Took around 600 of the other triangle ships.
400 Mk II Bombers can destroy a non-Mil CS under a FF past a set of basic Mk I + Mk II turrets. It took about 700-800 of the other Mk II triangle ships.
(Note: This did not include the benefits from mines, Grav turrets, tractors, HBCs or other non-basic turrets)
Mk III Military Command Stations can hold off more than double the listed numbers. Log stations were better by around 10%.
AI type can result in up to doubling the average wave size (Neinzul, Mad Bomber, and their ilk).
By the time AIP hits 200 or so (normal endgame), normal waves have a good chance of destroying their target. Exowaves, CPAs, general threat - all these will also overwhelm your basic defenses.
This means you need to isolate planets, so they can't be attacked directly, and you can use that extra energy elsewhere. Each isolated/protected planet lets you put Mk III turrets on 2 worlds, or adds 800 metal/sec to your economy. Which means that, for best performance, you want to protect as many planets as possible, behind as few entry points as possible. Say, behind 1 or two chokepoints - and only on those maps that support chokepoints - at which point, we've come full circle to what distributed defenses was supposed to prevent.
I don't say your are wrong - Going full Econ is one way to get enough energy. If you are playing Fallen Spire, it's the best way to go. You'll have the territory, AIP isn't a problem, and the economic boosts are so very helpful. But in a normal low-AIP game, where a player might only capture 10-15 worlds total, requiring 12 of them just for basic defenses is... limiting. Currently, the human player covers for inadequate fixed defenses through efficiency (mines, drones) and the fleet. I would prefer that there be other viable strategies as well.
As an alternative to reducing energy costs, what if you could spend Knowledge to unlock improved Energy Collectors, like you can Metal Harvesters? A Mk II that gets 250,000 and a Mk III that gets 400,000, and auto-replaces the existing models - just like Harvesters.
