To Steam or not to Steam

[ShneekeyTheLost]

That is the question I asked myself, then I crunched a bunch of numbers and I found this:

ASSUMING you are using the sum and total of your steam boiler's steam on engines, I worked out the break-even point for Biofuel, and it... rather surprised me.

Basically, biofuel in a boiler is about twice as efficient as biogas engines in terms of how quickly it eats up saplings, once you take into consideration the 10:3 ratio of biomass to biofuel from a Still.

At optimum efficiency.

So, if you're starting a boiler from 'cold', your break even point would be just under twice as long as it took to heat up in the first place (1.875 times, to be precise).

This further assumes that you are using the sum and total of your steam boiler's engines for MJ production and have a use for all that energy. If you don't... then you've got that much of your potential wasted, since the boiler consumes fuel at a steady rate even if you aren't using the steam it is producing.

In other words, Railcraft calling the 3 x 3 Firebox to be 'excessive'... there's more than a grain of truth to that. If you don't need that much MJ, then you're wasting quite a bit of fuel, even if it is 'renewable'. There's also the problem of consuming approximately 1 sapling every 16 seconds, I don't know if an Arboretum/Logger combo can sustain that kind of drop rate.

So, is Steam efficient? Absolutely. But make sure you need that kind of power supply before building it, make sure you're going to be running it for long enough to be worth the investment in resources before building it, and make sure you can sustain the fuel consumption.

And hey, if you're already drowning in saplings and other things that can be turned into biofuel, and you don't really care about efficiency because you're getting in far more than you will ever use anyways... you can quite easily create a power supply potential which you will be able to 'grow into' and give you quite a lot of growing room.

 

[Bgraywolf]

, I just ran those same numbers myself this morning. I was very concerned that I had made a mistake pushing from biogas to Biofuel but I was happy that the numbers had played out. To make matters a little more complicated, I am using Forestry on the Easy Config. Now to hook up some Magma Crucibles to Plug into GregTech Thermal Generators which was why I needed the massive MJ increase to begin with.

I do I have one question though, I have experimentially worked out how many Forestry Tree farms I need but do you have any math available on that?

 

[Peppe]

If you have gregtech, then liquid methane should be your fuel of choice. Two forestry rubber tree farms can run three 36 tank HP boilers.

Each tree farm can run 2 industrial centrifuges. Stack one on top of the other and you only need one logger. Each centrifuges will make 4 methane every 250 seconds. Four methane can keep the 36HP boiler running 227 seconds, so you need about 1.1 centrifuges per 36 HP boiler. You can even run all the centrifuges off a couple gas turbines + some eu to spare if you want to process some of the other byproducts. Use a transposer to get the liquid fuel and save the cells. You can make the whole system a closed loop with an electric engine to power the transposer.

I built the above to run one boiler, but thinking of moving everything around and putting 3 boilers and big methane tank in a central chunk. Maybe even having it all in one chunk stacking the farms, boilers, and tanks vertically to make sure everything the boilers would need is always available to them.

 

[whythisname]

So the conclusion is that you only should go steam if you need all that power?

I think that mostly depends on what type of fuel you're using and what engines you're comparing it with though. I think a Peat fired boiler will reach that "go steam" point a lot sooner because Peat fired engines are so weak. Maybe Peat engines are a match in terms of efficiency (because they work a long time with only a little Peat), but they still take up a lot of resources to build and set up in large quantities (mostly because they aren't really intended for that).

btw, is doing Biofuel -> Steam -> Lava -> EU really more efficient then just doing Biofuel -> EU? It's kinda what I've been pondering about. Sure it looks cool, but from a resource perspective it's quite an expensive setup compared to how it could be done.

 

[ShneekeyTheLost]

I do I have one question though, I have experimentially worked out how many Forestry Tree farms I need but do you have any math available on that?

That's... a lot more complicated, because it involves a lot more variables. You're now looking at how many saplings drop out of a tree, which is randomized, but dependent on how many leaf blocks spawn per tree and the percentage chance of a sapling dropping per leaf block.

Then you need to try and calculate how frequently trees will spawn in an Arboretum setup, since that tends to be the limiting factor rather than the logger's speed (unless you've got a Forester also involved in the process), which is a randomized process as well.

I'm sure there's a way to calculate it, but I don't have the percent chance of the random factors involved to be able to calculate anything I would consider reliable enough. I'm fairly certain, however, that if you had a Forester, you'd be able to keep a 36 HP boiler running with one farm.

I'd also say that one farm with a forester would be cheaper than two farms, considering tree farms don't stack very well due to the size of the trees themselves, and you're actually wanting to optimize empty space because it's the leaf blocks you are after rather than the logs.

 

[Peppe]

So the conclusion is that you only should go steam if you need all that power?

I think that mostly depends on what type of fuel you're using and what engines you're comparing it with though. I think a Peat fired boiler will reach that "go steam" point a lot sooner because Peat fired engines are so weak. Maybe Peat engines are a match in terms of efficiency (because they work a long time with only a little Peat), but they still take up a lot of resources to build and set up in large quantities (mostly because they aren't really intended for that).

btw, is doing Biofuel -> Steam -> Lava -> EU really more efficient then just doing Biofuel -> EU? It's kinda what I've been pondering about. Sure it looks cool, but from a resource perspective it's quite an expensive setup compared to how it could be done.

Only about 10 times better worst case...
Biofuel directly to EU is 30k EU.

Biofuel -> steam is 290k MJs -> 14 Lava (half a lava left over) -> 280k EU in geothermal or 420k EU in gregtech thermal generator.

 

[ShneekeyTheLost]

Only about 10 times better worst case...
Biofuel directly to EU is 30k EU.

Biofuel -> steam is 290k MJs -> 14 Lava (half a lava left over) -> 280k EU in geothermal or 420k EU in gregtech thermal generator.

To elaborate on this:

It requires 320 Steam/t to produce 100 Eu/t in a Steam Turbine (after the 6.11.0.0 patch which returned the Turbine to the original output). That same 320 Steam can also be producing 64 MJ/t

More importantly, however, are the numbers he went over already, how much energy is produced per bucket of biofuel.

Assuming a max size (and thus most efficient) LP boiler which is already heated up to optimal temperature:

1 bucket of Biofuel will produce energy for 4040 ticks, and produce 360 Steam/t for a total of 1,454,400 steam.

This will translate into 290880 MJ from steam engines or 454500 EU from a Turbine

Now, in a Magma Crucible, using Cobblestone as your conversion of choice (being the LEAST efficient by a very generous margin), it requires 20,000 MJ to turn one cobblestone into one bucket of lava, which produces 20,000 EU in a Geothermal Generator, so you are getting a 1:1 ratio of MJ to EU conversion. So in this case, the Steam Turbine is actually more energy efficient means of converting energy.

However, if we use Nethrrack to turn into lava instead of Cobble, you're only spending 8,000 MJ to produce 20,000 EU, so instead of a 1:1 ratio, we now have a 2:5 ratio, meaning it becomes much more viable to use this method to produce EU, generating a total of 7,27,200 EU out of that one bucket of Biofuel.

Any of these methods, however, are FAR more efficient than the bio generator, which will only produce 32,000 EU out of that same bucket of biofuel.

 

[Peppe]

To elaborate on this:

It requires 320 Steam/t to produce 100 Eu/t in a Steam Turbine (after the 6.11.0.0 patch which returned the Turbine to the original output). That same 320 Steam can also be producing 64 MJ/t

More importantly, however, are the numbers he went over already, how much energy is produced per bucket of biofuel.

Assuming a max size (and thus most efficient) LP boiler which is already heated up to optimal temperature:

1 bucket of Biofuel will produce energy for 4040 ticks, and produce 360 Steam/t for a total of 1,454,400 steam.

This will translate into 290880 MJ from steam engines or 454500 EU from a Turbine

Now, in a Magma Crucible, using Cobblestone as your conversion of choice (being the LEAST efficient by a very generous margin), it requires 20,000 MJ to turn one cobblestone into one bucket of lava, which produces 20,000 EU in a Geothermal Generator, so you are getting a 1:1 ratio of MJ to EU conversion. So in this case, the Steam Turbine is actually more energy efficient means of converting energy.

However, if we use Nethrrack to turn into lava instead of Cobble, you're only spending 8,000 MJ to produce 20,000 EU, so instead of a 1:1 ratio, we now have a 2:5 ratio, meaning it becomes much more viable to use this method to produce EU, generating a total of 7,27,200 EU out of that one bucket of Biofuel.

Any of these methods, however, are FAR more efficient than the bio generator, which will only produce 32,000 EU out of that same bucket of biofuel.

Gregtech thermal generator adds an extra 50% to lava's EU value. So cobble conversion becomes almost equal to the turbine with no ongoing costs vs replacing turbine rotors. Using netherrack you would get over 1 million EU, but use netherrack like a fuel source abundant as it may be.

 

[slay_mithos]

Your numbers are blowing my mind away...

But there is still something to consider.
That is the initial cost of both setups.

For early game, when you barely have more than 4 or 5 stacks of iron, a full size boiler and all the rest is not feasible, so you might start with the lower entry cost at first, upgrading progressively as you get your hands on enough to make all the setup.

One thing is for sure, I will definitely invest on a boiler once I know where I want to put my power room...

 

[ShneekeyTheLost]

Your numbers are blowing my mind away...

But there is still something to consider.
That is the initial cost of both setups.

For early game, when you barely have more than 4 or 5 stacks of iron, a full size boiler and all the rest is not feasible, so you might start with the lower entry cost at first, upgrading progressively as you get your hands on enough to make all the setup.

Oh certainly. Which is why, in my guide for MJ energy production, I list Steam as the Tier 3 option.

One thing is for sure, I will definitely invest on a boiler once I know where I want to put my power room...

I'd also be certain that I'm going to actually be using that level of energy production before building one. Early in the game, one or two Hobbyist Steam Engines might be all you need to keep everything powered. As you progress, you might want a couple of Biogas or Magmatic Engines, or maybe some Combustion if you have a plethora of oil nearby. It's not until you are trying to run a full-bore industrial facility which requires 40+ MJ/t to run that a steam boiler is going to start looking like an attractive option.

 

[Peppe]

Well with biofuels conversion to EU so terrible just about any usage outside the bio generator will be more efficient.

Cheap setup is biogass engines right into magma crucibles. Comparing biogas to biofuel you can get about 166k MJ of biogass vs equivalent amount converted to biofuel burned in just a 1 tank boiler gives 162k. That is a small efficiency hit, so you could go right to a single tank boiler if you want to skip having biogass engines and start your MJ production with commercial/industrial steam engines.

As you build up to bigger boilers with more tanks the efficiency approaches the 290k mentioned earlier in the thread. I would not plan to increment your boiler too often as the heat up time and fuel cost is a major deterrent. I would probably shoot for 8-12 tank first boiler then build a large storage tank and get the materials together for a 36 tank one.

I always go high pressure as well. To me it is more resource efficient and uses the same amount of fuel for the output level (One 36 HP boiler = two 36 LP).

 

[ShneekeyTheLost]

Well with biofuels conversion to EU so terrible just about any usage outside the bio generator will be more efficient.

Cheap setup is biogass engines right into magma crucibles. Comparing biogas to biofuel you can get about 166k MJ of biogass vs equivalent amount converted to biofuel burned in just a 1 tank boiler gives 162k. That is a small efficiency hit, so you could go right to a single tank boiler if you want to skip having biogass engines and start your MJ production with commercial/industrial steam engines.

I would say that a single tank boiler isn't really worth bothering with, but that's just me

As you build up to bigger boilers with more tanks the efficiency approaches the 290k mentioned earlier in the thread. I would not plan to increment your boiler too often as the heat up time and fuel cost is a major deterrent. I would probably shoot for 8-12 tank first boiler then build a large storage tank and get the materials together for a 36 tank one.

I'd say going for the 18 tank boiler first, so you've got the same 3x3 fuelbox to build on top of, but other than that, I concur entirely.

I always go high pressure as well. To me it is more resource efficient and uses the same amount of fuel for the output level (One 36 HP boiler = two 36 LP).

Well, here's the thing about HP boilers... they take twice as long to heat up, and eat up twice as much fuel. Sure, if you absolutely need that level of MJ output, by all means go for it. However, if you're trying to find ways to use all the energy coming out of a LP boiler as it is, then an HP boiler is probably not going to be as efficient because most of the additional energy production will simply be wasted. Having said that, a 18 HP boiler has the same production as a 36 LP boiler, with room to grow if you need it. So if you are just wanting a 18 LP boiler and think even that might be too much, HP boilers might not be so good an idea. But if you've got a plan for what to do with all the energy a 36 LP boiler can generate, then an 18 HP boiler can meet those needs, and still have room to grow. They take some planning and calculation. The question to ask should be: Do I really need that much power generation, or will I in the near future? Another thing to consider if you are using in-line energy cells as buffers is that they only really output 50 MJ/t, so make sure you don't have more than that 'upline' or you'll end up throttling your power output.