For some reason I can't produce power. Steam is running but not puffing any air and no performance is coming out. Ive tried switching the connection settings etc. No idea why the factory isn't outputting energy....

Can you provide screenshots of the inside and outside of your setup?

Its just the very basic setup and i can't get power to output. Pipe running inside. 1 boiler and 2 steam inside. Power line running to factory. Nothing will output... I've been trying to see if some other mod is conflicting with this. But can't figure it out.

there's an arrow on the substation right by the entrance, make sure power is pointing out of the building not in by rotating it

Yes I have tried that and still throws no power. Do any mods conflict...angels, bobs, yuokois?

If you don't want to provide screenshots, we'll have to troubleshoot this the slow and arduous way, the "Is your computer turned on? Have you tried plugging it in?" way.

Some questions:

If you place a lamp inside the building, does it light up? Is the light bright or dim?

If you place the same steam setup in the overworld (without any factory buildings attached) and connect a lamp to it, does the lamp light up?

Yet another option would be to give me the save and your mods folder so I can test your issue myself.

Derp i figured it out. There is a separate keybind for input/output mode... I thought rotate keybind to change arrow direction would move the output but you have to hit the keybind for the mod..... my bad

Uhm, i have the exact same issue, build a large steam engine setup inside a lvl1 factory, feed it with water and fuil from outside (no probs) changed the arrow at the substation to output but get no power out!
Strangely the steam engines are running at full speed like there would be something that consumes ALL power...

Another issue regarding accumulators, they aren't working at all regardless if energy is produced inside the factory or substation arrow pull energy from outside :-(

Could it be that you've set your energy transfer rate to maximum or something? A large transfer rate needs a similarly large energy buffer to work, and your engines will need to work full time for a couple of minutes before they fill up that buffer. That wouldn't explain why the outside isn't getting power though, so would you mind providing some screenshots of your setup? Inside and outside?

Accumulators are known not to work in factory buildings, since the inside of the factory is powered by an accumulator too and accumulators do not charge each other. You'll have to put your accumulators in the overworld.

so the substation inside the factory building actually is some sort of accumulator?
well, i used the default transfer rate, also some time (~20min) after feeding the steam engines i actually notice that i get not the amount of energy outside what is produced in the inside (right after i notice that the accumulators inside didn't work at all!) - at least "no energy" wasn't true, but i get a fraction of energy out of what is produced in the inside! (no matter how long i wait!)
have tried to test this with energy interface in editor = doesn't work at all!
(well, the energy interface might be also considered an accumulator - regardless the settings...)

screenshots doesn't help here, please troubleshot it yourself - you know your mod (how it actually works and why not as intended) better than we! ;-)
the steamengine setup was just as large as it could fit inside a lvl1 factory + some storage tanks for the steam - with feeding water and fuel from the sides (not below, used that space for accumulators)
and again, default buffer size, many minutes between finished & running steam engine setup and first notice of the result that not only accumulators didn't work but that i get only a fraction of the energy provided inside on the outside! - with a large factory running low because it hasn't enough energy from the factory building ;-)

oh, that's sad - is there no way of reading the energy consumption from inside the factory building (maybe trough the substation) and forward it to the outside?
even with delay and simplified ("rounding" consumption numbers - to reduce UPS hit) would already be great :-)
well, haven't tested the situation if a factory building would charge outsided accumulators... (as long that it doesn't work, there's no sense to produce any energy inside the factory building anyway!)

Post scriptum:
regardless this major drawback, your mod and how you realized things is impressive - as i started with factorio i minded about factory buildings but had no idea how to realize - you actually did it and i would miss it hardly if it will go down at some time! - tough i hope the devs implement something like this sooner or later :-)

btw, i saw the thread about polution production - would like it if there could be a way to read polution inside and get it outside :-)

Look, if I knew how to find the cause of this without a screenshot, then I wouldn't be asking you for a screenshot, right? Many Factorissimo2 players have built steam plants in factory buildings without any issues at all, so if it's not working for you then there must be something you're doing differently and not telling me, and a screenshot or savegame is what I need to find out what that is.

One new hunch though - you're using default buffer size for a power plant? I can fit 36MW worth of steam engines inside a Mk1 factory building, but the default throughput is only 10MW. Try increasing your throughput limit and tell me how it goes.

is there no way of reading the energy consumption from inside the factory building (maybe trough the substation) and forward it to the outside?

Not really, you can't just put energy inside an electric network without a device to connect it to. The current method (using accumulators as buffers) is better anyway, because it doesn't create or destroy any power at all; the energy is transferred between the inside and outside buffers without loss.

(as long that it doesn't work, there's no sense to produce any energy inside the factory building anyway!)

The outside buffer has a different energy priority than the inside buffer; while the inside buffer is basically a regular accumulator, the outside buffer of a factory is not, and power-producing factories will feed power-consuming factories. Vanilla accumulators also work perfectly in the overworld, and will charge from and discharge to factory buildings as appropriate.