Factorio Forums

Yes, it's 212MJ per tank

Hm. If it is 250 MJ instead of 2.5... it would sound quite matching... But where is my calculation error? Are the units multiplied by 100 or the heat capacity per unit? Units sounds logical.

All I found was Does base_area=250 mean it is 250 * 10 (= pressure/level)?
Perhaps "a unit" is 0.01, that means we have 250000 units? It is just displayed as "2500.00"?

PS: For correct tests if this is really 212 MJ I would say you need about 10 or more tanks to reduce internal calculation errors.

ssilk wrote: PS: For correct tests if this is really 212 MJ I would say you need about 10 or more tanks to reduce internal calculation errors.

Don't have that many spare capacitors.
Also, the number sits well with me.
212/250=0.85
0.85 can be the efficiency of the steam engine, or the temperature difference between the boiling water and environment (100-15).
Probably the latter.

Anyway, this is mostly useless information since there are no electric boilers in the game, so even with liquid tanks taking 20x less space than equal capacitor bank (and I'm not even comparing production costs!), it is still impossible to store solar energy that way.

ssilk wrote:

User_Name wrote:One water tank stores 210 MJ of energy (that is equal to 42 capacitors, but take much less space)

Sorry for my stupid question, but how have you found that out?

My calculation ( https://forums.factorio.com/wiki/inde ... gy_storage ) is much less (2.5 MJ).

I already thought, that it must be much more. So - again - I just want to ask how you found that out.

Can you correct the wiki?
It still says 2.5Mj, which is 85 times off the real value.

I corrected it, but this bugs me in two directions. A) you can change it yourself. Just need an account B) I still want to know, how this is calculated.

Sorry to dig this up, but the calculation is rather simple.

Tank has 2500 units of water.
Steam engine generate at 100% efficiency.

Energy contained in fuel is converted by the boilers to hot water, which is just a liquid form of energy. This water holds energy at ratio of 1KJ/degree/unit_of_water. Since water is set to have a maximum temperature of 100 degree and minimum of 15 degree, the most energy that can be in a unit_of_water is 85 KJ. Therefore, the steam generator can extract at most 85 KJ of energy from a unit_of_water. The tank therefore held 2500x85KJ = 212500 KJ or 212.5 MJ.

This agrees nicely with all the tests that I've done and also makes sense when you look at the way steam generator works. They generate 510 KW while consuming 6 units_of_water/s => (510 KJ/s) / (6 units_of_water/s) = 85 KJ / unit_of_water. The dimensional analysis also make sense (KJ/s) / (Water/s) = KJ/Water. Since steam generator does not generate power when given water at 15 degrees, but does so at maximum performance when given water at 100 degree, it can only be deduced that 100 degree water holds 85 KJ / unit_of_water. QED

Ah. Yes, this is by degree! Thanks.

Edit:
https://forums.factorio.com/wiki/inde ... emperature

I corrected the right usages of work and energy. (Hope so)

Help me understand the advantage of using a system like this vs simply overloading your electric generation. Thanks for the clever build!

Nice Necro
But here's my answer : How can you know you'll get a particularly deadly attack one particular night (or even day) ? A setup with let's say 25% comfort margin is nice, but if you're unlucky with biter attacks and have your lasers shoot a lot, you might not recharge your accus as much as you'd want. The problem is you'll notice you're short of stored energy when all your factory, defenses included, will instantly stop working in the middle of the night. And you'll be totally helpless until the sun is high enough to provide you decent power.

With such a system, you have a backup that will always be ready for the unexpected moment. And it might save your butt, because even if you don't produce enough power to run your factory at full speed, you can at least have enough to power your laser turrets

This is mine.

viewtopic.php?p=148688#p148688

It's not simple or low tech, but, it's designed with laser turrets in mind. So, it takes 0.20s to turn on fully, and will stay on for a configurable amount of time before it is eligible for shut down, so that even power cycling won't diminish turret output. I don't know if that's what OP meant by 'clock' or not, but it's faster than taking several "seconds".

Simple and brilliant.

i do something very similar.

i use a set up where i have a longer belt track for the coal meaning the boiler gets more than one fuel (incase of inserter needing fuel) then i have a inserter removing excess fuel so that there is only fuel in the boiler that its actually using. it costs extra space and belts but the redundancy is worth it.