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# How much EU is a BC fuel bucket worth in a steam boiler?

Discussion in 'General FTB chat' started by MeIsBob0, Feb 8, 2013.

1. ### MeIsBob0New Member

Currently I am using my fuel in petroleum generators which give 384k EU per one bucket of fuel. I am curious if using the fuel in a steam boiler will give more/less or about the same amount of EU. One would think since a steam boiler/turbine is more complicated to setup/run you would get more, however based on my calculations (which may or may not be accurate) it appears you get far less than this.

Formulas Pasted from the railcraft wiki:
Math

• Base Fuel Usage Per Tick (base) = ( (6.4 - numTanks * 0.08) / ( 16 LP or 8 HP ) ) * numTanks
• Heat Adjust Fuel Usage Per Tick = base + base * (8 - 8 * heat%)
• Steam/tick = ( 10 LP or 20 HP ) * numTanks
• 1 MJ = 5 Steam
• BuildCraft Fuel = 96000
Unfortunately, no units are given as to what this '96000' next to fuel equals, so I am under the assumption that it is the number of "fuel usages" it has. I am also assuming the most efficient setup is being used, so 36 high pressure tanks and they are already at 100% heat value. So then the math would be:

Base Fuel Usage Per Tick (base) = ( (6.4 - numTanks * 0.08) / ( 16 LP or 8 HP ) ) * numTanks
base = ((6.4 - 36 * 0.08)/(8)) * 36 = 0.122... (this is the number of fuel usages per tick of the boiler)

Heat Adjust Fuel Usage Per Tick = base + base * (8 - 8 * heat%)
0.122... + 0.122... * (8 - 8 * 100%) = 0.122... (the tank is at 100% heat so the base rate does not change)

Now we multiply this fuel usage per tick times the number of fuel usages 1 fuel bucket has:
0.122... * 96000 = 1173.33... (this is the number of ticks one fuel bucket should last)

Now, how much steam will the boiler produce in 1173.33... ticks?
36 tanks * 20 steam/tick * 1173.33... ticks = 844800 steam

Now, how much EU is this steam worth? A steam turbine converts steam to EU at 100 eu/t consuming 320 eu/t therefore:
844800 steam * (100 eu/320 steam) = 264000 EU

This is significantly less than the 384000 EU you get from burning it in a petroleum generator, which is also far easier. These calculations also do not take into account the massive amounts of fuel you must burn inefficiently to even get to 100% heat in a large boiler setup. However, this is under the assumption that the '96000' value given to fuel is the number of 'fuel usages' it has, and not something else.

I have tried to test this in-game, however, much to my dismay, boilers output steam even when nothing is being burned within them, making it difficult to tell exactly how much steam the fuel is producing. This makes sense though since something that is hot will still boil water.

Has anyone else devised a better way to test this or have more concrete math showing how much EU you can get?

EDIT: My math is incorrect, see posts 4 and 5. One fuel bucket = 1,363,636 EU

2. ### HrulginNew Member

You could use an iron tank to hold the steam and get a measure to the millibucket that way, i believe.

3. ### MeIsBob0New Member

The problem is, how much steam does one bucket of BC fuel create? Its already simple to calculate how much EU the steam stored in the iron tank would create.

I ran a quick and dirty test just to get some ballpark numbers. I got a 36 HP boiler up to about 600C (I got impatient, takes forever to fully heat up), I put in 16 fuel buckets, and then had 3 steam turbines turning that into EU. After the 16 buckets had been used up, there was about 6.2 million EU in the MFSU.

6.2 million EU / 16 buckets of fuel = 387500 EU per bucket

Which is a far more reasonable number, and this is despite the fact that the boiler was only at ~60% of total heat capacity. However, all the effort and cost of creating the machinery/heating up the boiler makes me wonder if it is still worth it over petroleum generators. I'll test again at 100% heat capacity when it gets there.

This also means that my math was incorrect somewhere along the line. It could potentially be my assumption that BC Fuel = 96000 means 96000 fuel usage ticks.

4. ### retep998NoLifeBunnyWiki Staff

Lets do your calculations again. I'll use low pressure for this example.
Base Fuel Usage Per Tick (base) = ( (6.4 - numTanks * 0.08) / ( 16 LP or 8 HP ) ) * numTanks = ((6.4-36*0.08)/(16))*36 = 7.92
Heat Adjust Fuel Usage Per Tick = base + base * (8 - 8 * heat%) = 7.92+7.92*(8-8*1) = 7.92
Steam/tick = ( 10 LP or 20 HP ) * numTanks = 10*36 = 360
Steam = 96000/7.92*360 = 4,363,636
EU = 4,363,636*100/320 = 1,363,636
MJ = 4,363,636*8/40 = 872,727
Your calculations are apparently wrong. The boiler is a vastly superior way to burn fuel.

5. ### MeIsBob0New Member

After double checking my calculations, the poster above me is correct. +Internets to you good sir.

However, if you are using a large boiler, you should have a vast amount of fuel ready to burn as a lot of fuel is consumed inefficiently to heat it up. I have calculated that any fuel burnt below ~68% heat level* would've provided more EU in a petroleum generator. Past this point, the fuel burnt in the boiler gets more and more efficient, up to 1,363,636 EU per bucket, about 3.55 times more efficient.

*Calculated assuming a 36 HP boiler

6. ### DragonchampionNew Member

What would these calculations be for 1 lava cell (1k heat)? All this math makes my head hurt... >.<

7. ### MeIsBob0New Member

You can find out how much EU anything will give by multiplying its heat value by 14.2045 (the ratio of EU to heat)*. Keep in mind this assumes the boiler is at 100% heat level. Lower heat levels will make your fuel less efficient.

*This number is derived by 1,363,636 EU/96000 heat.

8. ### DragonchampionNew Member

Is there a way to increase heat values of a liquid in the configs? 1k for lava when everything else is at LEAST 4k seems... underwhelming.

9. ### AbdielNew Member

Lava was intentionally nerfed a few patches ago. It is practically free in the Nether, it is easier to harvest than dirt... not to mention something like coal.

10. ### DragonchampionNew Member

But it does require a significant investment, including a way to transmit it from the nether. even with that, I still think it should be around 3k heat. If it was, I'd reduce the values for geothermals again and rely completely on steam; besides, steam looks cooler if I do say so myself. Kinda like a massive heart beating in the center of an energy complex... and it has a danger of exploding, too. I love the sense of danger from my energy.

11. ### AbdielNew Member

I don't want to start an argument, but any sane way I can think of of pumping lava from the nether is still cheaper and simpler to set up than fully automating any other fuel source in the quantities required for a boiler. Feel free to prove me wrong.

12. ### DragonchampionNew Member

Well, you're right. But in the end it's our opinions. I personally want to give players on my server a reason to use different sources of power rather than sticking constantly to solar all the time. So the question is... is there a config file I can edit to modify the heat of lava?

13. ### AbdielNew Member

Not that I know of. There is a config to reduce the yield of solars though. Also, from personal experience, if you do that, everybody will switch to using lava. Especially if you increase the yield of that. Only with both solar and lava power nerfed into near uselessness I've actually seen people experiment and come up with their own designs. (Well most of them starting with a Steve's treefarm feeding a boiler of some sort, but that at least requires some non-trivial setup to get running.)

14. ### DragonchampionNew Member

Alright, I'll try that. Thanks, Abdiel.

15. ### HydraNew Member

With the amount of lag that Nether pumps create you really REALLY don't want players to have an incentive to pump Lava from the Nether. On our server it's banned for that reason.

Railcraft lava heat values was nerfed because it caused the problem that with the amount of heat lava would give, a boiler could 'feed' itself with lava (thanks to Magma Crucibles being able to melt cobble into lava). You were able to create a perpetuum mobile that way, a boiler that would create energy out of nothing.

16. ### DragonchampionNew Member

Bumping this topic to ask another question.

We have the estimated value for fuel in a boiler in EU. But what about MJ?

If I was to power a fully-heated up Boiler with 1 bucket of fuel, how long would that boiler last before it stats to lose heat? And how many buckets would it take to last several weeks of real life time?

17. ### MilConDoinNew Member

Assuming 36HP boiler:
1 boiler at max heat produces 9.09090... MJ/fuelunit, resulting in ~872727 MJ/bucket.
1 boiler uses 15.84 fuelunits/t, thus dividing 96000 fuelunits by that gives a runtime of 6060.6060.. ticks per bucket (equalling 303.0303... seconds per bucket or ~5 minutes). 1 week is ~10k buckets.

18. ### OmicronNew Member

That question is easily answered, the math for fully heated up boilers is very straightforward:

heat units consumed per tick = ( (6.4 - numTanks * 0.08) / ( 16 LP or 8 HP ) ) * numTanks

Solving this equation for a 1 LP boiler returns 0.395 HU/t, for a 36 HP boiler 15.84 HU/t. Then, knowing that a bucket of Buildcraft fuel has 96,000 HU, you can calculate how many ticks it will last.

In this example, ca. 243,038 ticks (3 hours 22 minutes 30 seconds) in a 1 LP boiler and ca. 6,061 ticks (5 minutes and 3 seconds) in a 36 HP boiler.

EDIT: curses, ninja'd again!

19. ### MrZwijNew Member

Cool. I've got parallel diesel generators and HP boilers running. Sounds like I need to move to strictly boilers and steam turbines (and automate my blast furnaces better).

20. ### MeIsBob0New Member

If this is the case, could you not also do this?
Lava->Geothermal Generator->EU->Electric Engines->MJ->Magma crucible->Lava

And end up with more power than you started with? I haven't looked at the numbers, just theoretical.