Tell me I'm wrong but...

[namiasdf]

Okay, here's the gist of it.

I am running 80 combustion engines off of biofuel. That's 5 x 80 MJ/t. That energy is used to generate lava. It takes 24000 MJ to produce one bucket of lava. If I'm providing 400 MJ/t to 16 magma crucibles, I should be able to produce a bucket of lava every 24000MJ/400MJ/t which is 60t or 3 seconds.

A bucket of lava produces 30k EU per bucket in a thermal generator. This means that I produce 30 000 EU/3s or 10 000 EU/s. I can consume that EU at a maximum rate of 58x24 EU/t or 1392 EU/t or 27840 EU/s.

Okay never mind.

Next up. Centrifuging 16 buckets of lava takes 750 seconds. If I have 5 centrifuges running full time, that's 80 buckets of lava every 750 seconds consumed, additionally 75000x5 EU is consumed, so 375000 EU/750 seconds or 25 EU/t. (Oh wait, that's how much it should be...)

If I am producing a bucket of lava every three seconds, in 750 seconds I should produce 250 buckets of lava, three times the amount required by the centrifuging. Even if I cut that in half, that's still a profit of 125-80 = 45 buckets.

But it seems that my production net rate is negative. I have no idea why. I am not really consuming much EU for other purposes during this time period (i.e. I run 9 electrical engines, 45 EU/t if I'm not mistaken, to power my quarry, but that's barely double what the centrifuging process consumes.)

Am I missing something about the mechanics of magma crucibles?

 

[Whovian]

I should just warn you, Electrical Engines are extremely inefficient. Perhaps this is part of the cause?

 

[namiasdf]

They're convenient, which is what I need them for. Been busy doing other things. Plus their turn off/on easy. I just have them attached to a redstone cell with a gate that emits a signal when there is "room for energy" in the cell.

But it's besides the point. I should be netting positive amounts of lava which I am not, according to my calculations anyways.

 

[Grydian2]

My first thought is that the magma crucible cant produce a bucket in 3 seconds. Maybe thats the issue? further if you use netherack you would get a massively better ratio of MJ to EU

 

[namiasdf]

16 magma crucibles being feed 400 MJ/t collectively produce a bucket of lava every three seconds. You can think of it this way then:

16 magma crucibles running at 400/16 = 25 MJ/t (This is the rate that one magma crucible is running at), round down to 24 MJ/t due to conductive piping loss, gives 24000 MJ / 24 MJ/t = 1000t = 50s

Every 50s each magma crucible provides one bucket of lava. 50/16 ~ 3 or 3.125 buckets per second, to be more precise.[DOUBLEPOST=1373173234][/DOUBLEPOST]Netherrack isn't "sustainable". Quote on quote, anyways.

I know you can run quarries for days.

 

[Abdiel]

16 magma crucibles running at 400/16 = 25 MJ/t (This is the rate that one magma crucible is running at)

I don't have a running FTB instance to confirm right now, but TE wiki says that the maximum speed of a crucible is 20 MJ/t. So your crucibles aren't able to use all the power you send to them to create lava.

 

[namiasdf]

It's 30 MJ/t in FTB

 

[atheneftw]

combustion engines generate 6 mj/t btw not 5

 

[namiasdf]

5MJ/t off of biofuel, iirc.

 

[PoisonWolf]

Or just get one demonic queen and all your lava issues will be solved lol.

 

[Martok]

Your numbers seem sound, and your math looks correct, but if you're using lava to power the centrifuges as well, you're using substantially more lava: 750s/process*20t/s*32EU/t/(30000eu/bucket)=16 buckets/process. So for every 16 buckets of lava you centrifuge, you need another 16 to power it. If you're using another 45 EU/t elsewhere in your base, 45EU/t*20t/s*750s/process/(30000EU/bucket) = 22.5buckets/process.

So, if you are using the same lava as power, you should actually be consuming 182 buckets in 750 seconds. Still you have 62 buckets unaccounted for.

Time to isolate the problem. Turn off the centrifuges and see how long it take to fill a tank with lava. If you're not getting the 0.33 buckets/s check for choke points. I don't know the flow rates of the liquid carrying pipes, but 0.33 seems like it should be within the limit. Other than that, see if maybe the magma crucibles are not getting their cobble fast enough.

If you are getting the 0.33 buckets/s, check centrifuges, and compare the input to the output. One thought, if a centrifuge's 32eu/t is interrupted, it usually starts the process over again, though no resources are lost. But it might be different for still lava...