Regenerative Fuel Cell

[Temstar]

One of the thing that bothers me a bit about the current in game fuel cells is the fact that they consume LFO and spit out Ec, and the LFO is just gone. In real life fuel cells mass is not lost, the fuel cell will produce some kind of waste product. If it was running on LH2 and LOX the waste product would be water which is actually very useful.

I propose we make some small changes to the game to reflect this - make fuel cells generate a new resource - fuel cell waste product that's equal in weight to the LFO consumed. Assuming you have the correct waste product tank on board, the fuel cell waste product is then stored in the tank. If you don't have a waste product tank or if your tanks are full then the waste is simply lost as it is now.

Then, the two fuel cells will have a toggle to turn on and off regenerative cycle. If regenerative cycle is active, the fuel cell is turned on and the craft have an excess of electrical power than the fuel cell will start to consume Ec and waste product to produce LFO, essentially running the normal fuel cell reaction in reverse. The reverse reaction will of course be much less efficient, perhaps needing 300% of the power to covert a set amount of waste product back to LFO compared to the amount of power you get running the reaction in the normal direction.

This then essentially allows you to use LFO and Waste Product tanks to form an enormous low efficiency battery perfect for power hungry applications like ISRU or Rover or ion propulsion through the night.

[Sir_Robert]

That's pretty cool. I like your idea

[KerbonautInTraining]

Yes! I do feel this is more suited to a mod though.

Only problem I see is having to add dedicated parts for the tanks, so I'd pair it with interstellar fuel switch.

[Cornholio]

This sounds like a very cool idea, but I've always gotten this feeling that Squad tries not to add forms of resources at all costs.

[LorenLuke]

The issue I have with this is, if it's without a waste product, then you can just sorta get fuel/ox from nothing (generator on launch pad, solar panels, etc.). Alternatively, we have this: just replace the word 'waste' with 'ore', and you've just described an ISRU.

[Nich]

 love this idea. No idea if that is how they actually work or would you need an Electrolus machine to go back to LFO?

[Temstar]

4 hours ago, LorenLuke said:

The issue I have with this is, if it's without a waste product, then you can just sorta get fuel/ox from nothing (generator on launch pad, solar panels, etc.)

Without waste product as input you won't be able to run the reverse reaction.

32 minutes ago, Nich said:

love this idea. No idea if that is how they actually work or would you need an Electrolus machine to go back to LFO?

Generally a manned long duration spacecraft (like ISS) will already have electrolysis equipment onboard so they can run it as long as the plumbing is in place. They generally won't though because water is already pretty useful for a manned spacecraft. There are proper regenerative fuel cells that can run the reaction in either directions equally efficiently but it's not very common yet.

[RocketSquid]

This is a good idea. It has been sort-of implemented in universal storage.

[Nightside]

12 hours ago, Temstar said:

... If it was running on LH2 and LOX the waste product would be water which is actually very useful...

21 minutes ago, RocketSquid said:

This is a good idea. It has been sort-of implemented in universal storage.

It has been exactly implemented in Universal Storage. Along with a bunch of other realistic life support machines.

 

[Aperture Science Employee]

Love this idea. +rep I believe the current fuel system is more of a "gamey" aspect, rather than simulation.

[MKI]

10 hours ago, Cornholio said:

This sounds like a very cool idea, but I've always gotten this feeling that Squad tries not to add forms of resources at all costs.

I have that feeling too.

 

Personally the Electrical system in game right now is pretty basic. Batteries and  Fuel Cells are both very different than how they work in real life. I like the idea of getting more use out of the Fuel Cells since currently they are very basic input-output systems which is nice and simple but not very practical or realistic.

I am always a proponent of changing the electrical systems to be more logical, even if that makes things a little more complicated logic wise, but hopefully not part wise. I dislike the idea of having extra tanks just to make this system work.

[KrazyKrl]

My 2 cents:

The fuel cells should have a "local only" type of resource that is hidden from the resources panel. Name it something like "Electrolysis Byproduct".

You may not transfer this resource to any other part. Each fuel cell has its own max capacity of waste.

When using fuel cell waste to create LFO; small cells should be about 50% efficient, large cells should be 70% efficient. You will still lose a significant portion of the LFO you split in the first place. The power drain is double what a fuel cell can supply when reversed.

You cannot reprocess the waste of the fuel cell unless that fuel cell has waste to use.

[SnakyLeVrai]

On 2/25/2016 at 0:49 PM, Temstar said:

Then, the two fuel cells will have a toggle to turn on and off regenerative cycle. If regenerative cycle is active, the fuel cell is turned on and the craft have an excess of electrical power than the fuel cell will start to consume Ec and waste product to produce LFO, essentially running the normal fuel cell reaction in reverse

I'd like to make sure everyone understand the do's and don't about fuel cell regeneration... I've sketched up some SCIENCE! about it, it's a little more complex than just using extra fuel cell energy to make LFO back from water.

 

 

[John FX]

I could see this being useful if life support was a thing the user was using, if not it`s just pointless complexity for no reason.

I always assume the water is drunk or ejected.

[lajoswinkler]

Efficiency <1 would have to be implemented so that the resource mechanics don't form a perpetuum mobile, but I like the idea.

[Choctofliatrio2.0]

Maybe the more times you change cycles, the less efficient it gets, eventually rendering the reverse part useless. You could still turn fuel to electricity, just not the other way around.

[Snark]

On 2/27/2016 at 6:13 AM, lajoswinkler said:

Efficiency <1 would have to be implemented so that the resource mechanics don't form a perpetuum mobile, but I like the idea.

It's easy to make.  Suppose that the output of the fuel cell is "fuel cell waste" (whether you call it water or not, I don't care).  LFO becomes electricity + waste.  Adding electricity to the waste makes LFO.  Set up the conversion so that the round-trip isn't 100% efficient on electricity (i.e. it takes more electricity to convert the waste back into LFO than you got out in the first place) or for mass (you lose a little LFO on each cycle).

The neat thing about all this is that you don't even need to write any code to do it.  You could implement all of this in a simple snippet of ModuleManager config.  For the lazy modder, the simplest solution to "waste storage" is to give the fuel cells themselves a reasonable amount of waste storage capacity.

The ModuleManager config would do the following:

• Add a new resource type, "Fuel Cell Waste" (or you could just call it "water")
• Add some fuel cell waste storage capacity to the fuel cells
• Tweak the LFO-to-electricity converter for fuel cells so that it generates fuel cell waste as a non-obligatory output (meaning "just vent it if there's no storage capacity")
• Add a new converter module to fuel cells that can turn fuel cell waste plus electricity into LFO

 

[Alshain]

I think this would be breaching a little too much into Life Support which Squad has firmly said "No" to many times.  While it may not technically be life support, many of those mods do waste management too.  I would say, just use the mod, we aren't getting life support, and KSP is never going to be a 100% accurate simulation... it isn't meant to be.

Edited February 28, 2016 by Alshain

[Renegrade]

On 2016-02-26 at 6:45 PM, SnakyLeVrai said:

I'd like to make sure everyone understand the do's and don't about fuel cell regeneration... I've sketched up some SCIENCE! about it, it's a little more complex than just using extra fuel cell energy to make LFO back from water.

I just adore those diagrams, by the way

[SnakyLeVrai]

2 hours ago, Snark said:

It's easy to make.  Suppose that the output of the fuel cell is "fuel cell waste" (whether you call it water or not, I don't care).  LFO becomes electricity + waste.  Adding electricity to the waste makes LFO.  Set up the conversion so that the round-trip isn't 100% efficient on electricity (i.e. it takes more electricity to convert the waste back into LFO than you got out in the first place) or for mass (you lose a little LFO on each cycle).

The neat thing about all this is that you don't even need to write any code to do it.  You could implement all of this in a simple snippet of ModuleManager config.  For the lazy modder, the simplest solution to "waste storage" is to give the fuel cells themselves a reasonable amount of waste storage capacity.

The ModuleManager config would do the following:

• Add a new resource type, "Fuel Cell Waste" (or you could just call it "water")
• Add some fuel cell waste storage capacity to the fuel cells
• Tweak the LFO-to-electricity converter for fuel cells so that it generates fuel cell waste as a non-obligatory output (meaning "just vent it if there's no storage capacity")
• Add a new converter module to fuel cells that can turn fuel cell waste plus electricity into LFO

 

Maybe a ModuleManagered tank could be repurposed into a water tank, fuel cells don't show a lot of volume for storing water

 

Oh and:

1 hour ago, Renegrade said:

I just adore those diagrams, by the way

Thanks  

[Snark]

2 hours ago, SnakyLeVrai said:

Maybe a ModuleManagered tank could be repurposed into a water tank, fuel cells don't show a lot of volume for storing water

Also a good idea, (though personally I get confused by parts that look like one thing but do something else, would be nice if the model or texture somehow looks different).

Could do both:  the fuel cells themselves could have a fairly small waste capacity, then you could add tankage if desired to capture more of the output.

[QPDO]

Universal Storage Guys! If you need it install it It also has Elektrons

[lajoswinkler]

21 hours ago, Alshain said:

I think this would be breaching a little too much into Life Support which Squad has firmly said "No" to many times.  While it may not technically be life support, many of those mods do waste management too.  I would say, just use the mod, we aren't getting life support, and KSP is never going to be a 100% accurate simulation... it isn't meant to be.

As I recall, there are some things that were a no-no and now they're stock.

Life support in its simplistic style (one resource: nutrients) would be a great thing for the game.

[SnakyLeVrai]

Fuel cells are a great way to provide some autonomy when you don't have a lot of light... or for roving by night, during an eclipse...

Coupled with some PB-NUK and a Water to LFO converter, they could show some interest on far worlds, coupled with a few batteries to provide short bursts of energy when transmitting SCIENCE!^TM. And space stations might appreciate it too, only you don't have a way of "reloading the fuel cell" when in space. ISRU only works on the ground. I've made a comparison here: