Simple Electrolyzer Oxygen Production System – electrically self-sustained with little automation

The purpose of this guide is to present a straight-forward electrolyzer room design, built with early/mid game items, that uses no automation, and that will reliably produce oxygen for your base.

This guide also has a section on how to decontaminate polluted, germy water, into clean, germ-free water, to adequately supply the electrolyzer with the water it needs.

INTRODUCTION

Depending on your colony size, sooner or later oxygen production will become a problem as you burn thru your last reserves of algae and slime. The Electrolyzer becomes then the main option to reliably produce oxygen and keep your base going. However, as you may have realized right now, the electrolyzer requires a lot more planning than the Oxygen Diffuser and the Algae Terrarium, and getting an electrolyzer system that works can be tricky.

There are many electrolyzer designs out there, with all kind of exotic features. You may have tried one or several of them with some (or no) success, and maybe wonder why your electrolyzer is not producing enough oxygen when maybe it should.

The purpose of this guide is to present a straight-forward electrolyzer room design, built with early/mid game items, that uses no automation, and that will reliably produce oxygen for your base.

This guide also provides a solution to supplies the electrolyzer with clean, germ-free water, made from polluted water (which is abundant in the map). My water system is also simple, but uses some automation. If you already figured out the water supply, you can skip that section.

BASIC ELECTROLYZER PRINCIPLES

There’s a basic principle of the elctrolyzer that is important to understand in order to figure out how it works: namely, that, provided with power and water, it will produce 888g/s of Oxygen and 112g/s of Hydrogen, or:

888g/s Oxygen + 112g/s Hydrogen = 1000g/s (1kg/s) of TOTAL gas

The second principle to consider is that a single gas pump can only pump 500g/s of gas.

So, if your electrolyzer produces 1000g/s of gas, you will need at least two gas pumps to remove it: 1000g/s of gas come in, 1000g/s of gas come out, simple as that.

A lot of designs ignore this basic principle and that’s why they can't maximize the electrolyzer utilization. Some designs use only one gas pump which can’t pump out all the gas that the electrolyzer produces. Other designs do use two gas pumps, but intend one of them to be the “oxygen pump” and the other to be the “hydrogen pump”, and you can see from the numbers above that a single pump (500g/s) is not enough to remove all the oxygen produced (888g/s).

And what happens when you don’t remove all the gas around the electrolyzer? The excess gas will accumulate inside the room, increasing the gas pressure, until the electrolyzer eventually stops working with the “Max Pressure Reached” message; and depending on the room design, this can happen more or less often, downing the electrolyzer for a great part of the cycle.

ELECTROLYZER ROOM DESIGN (GAS)

Now that we understand the basic principles, we can go ahead with the room design, which is shown in the picture below:



The design is straight-forward: in a tiny, sealed room, you have one electrolyzer and two gas pumps. That’s it.

The output of each pump is plumbed to a gas filter, the filtered gas set to hydrogen (which will be used for power generation), and the rest of the gas is assumed to be oxygen (which in the steady state, will be). The oxygen output will be passed thru a frozen biome before is routed to the base.



The reason why I am filtering hydrogen and not oxygen is because if any other gas (than hydrogen) is pumped to the Hydrogen Generator, the machine will be damaged. When you first build it, the room will likely have other gases in (like Carbon Dioxide), which are not a big deal if they later get pumped to your base, but can otherwise damage the generator.

Also note that the filter outputs are connected to a gas duct, then meet somewhere and turn into a single pipe. This is because gas ducts allow two simultaneous gas flows to combine into one. Whereas, if you connect one gas output to the other, and from there out to the mains, the output blocks don’t allow two simultaneous gas flows to combine, hence the output of one gas filter can block the other one.

The reason why the oxygen needs to be routed first thru a frozen biome, is because it comes out of the Electrolyzer at 70C. If you pump hot oxygen into your base, it will get very hot soon and you will have a bunch of issues associated with that. Fortunately, you don’t need to go crazy in the frozen biome: a simple loop (as shown below) will cool the oxygen down to something reasonable, and you can expand that loop later on as needed.

ELECTROLYZER ROOM DESIGN (ELECTRICITY)

The electrical system for the electrolyzer room is also relatively simple, and is shown below:



If you do the numbers, the Hydrogen Generator (which uses 100g/s of Hydrogen to produce 800W of electricity) in theory can comfortably power all items in the electrical system; and, in average, it kind of does. However, you will see when the system first starts that the hydrogen gas supply is not 100% constant, so the generator will be turning on and off intermittently – inadequate for our system to function, because it needs continuous power.

In order to supply the system with adequate/constant power, I am using a Jumbo Battery and a Power Transformer connected as shown above.

The function of the Jumbo Battery is straight-forward: it charges with the excess power coming from the Hydrogen Generator when its working, or from the power supplied by the Power Transformer.

The Power Transformer is the other key component for this system to work. It not only supplies the system with power when it’s needed, but it also blocks power (from the generator or battery) to exit the system. In other words, power can come in whenever it’s needed, but it can’t come out. It acts like a water/gas bridge, allowing flow of electricity in only one direction (or like a diode, in electrical terms).

And this “greedy” power scheme turns out to do exactly what we want: we want the oxygen system to work for the full cycle, it takes priority over other systems, and we don’t want it to share any of its power generation and/or battery with the rest of the network.

ELECTROLYZER ROOM DESIGN (WATER)

This picture shows the water plumbing supply to the electrolyzer, which is straight-forward: just a supply of clean water to the electrolyzer.

ELECTROLYZER ROOM PERFORMANCE

As I mentioned in my introduction, there are many designs out there, some of them a lot more sophisticated than mine, and surely someone could debate that this or other design may work better.

So, how do you know if this system is performing as expected? Do we get a “feeling” for how any electrolyzer design is actually performing?

Luckily, we do not need to debate and/or discuss our feelings on this or any other design. If you go to your electrolyzer, and you click on the “Properties” tab, it will tell you exactly what you need to know:



The Properties tab will show you the uptime percentage of you electrolyzer for the current and past few cycles. The higher the uptime it is, the better the utilization is for your design. As you can see from above, my design performs well, and I am happy enough with it.

A design with issues will have an uptime in the 40%-70% range, and that’s an indication that your electrolyzer has poor utilization, so the 888g/s of oxygen that you were expecting won’t be produced; and the Game will let you know via the “Insufficient Oxygen Generation” message.

A good performing electrolyzer system will have the electrolyzer and both gas pumps performing in the high nineties uptime range.

Now, despite the high uptime of the electrolyzer and gas pumps, the Hydrogen Generator will have a slightly lower uptime than them. This fact makes evident the intermittent operation of our Hydrogen Generator, which why we are compensating with the Jumbo Battery and the Power Transformer for those times the generator is not working.

OXYGEN DISTRIBUTION AND FURTHER CONSIDERATIONS

After you loop the gas duct thru the Frozen Biome, you are ready to distribute the cooled oxygen to your base. Depending on your base design, you may need more/less ducting and air vents to adequately distribute the oxygen, so I will leave that to you.

Now, at this point it’s very likely that you have sealed your base to the rest of the map, in order to protect it from other toxic gases and heat. This is great, but creates a series of other problems down the road now that you are pumping oxygen into it: blocked air vents, excessive condensation and accumulation of carbon dioxide in the bottom of your base.

I have not identified a “silver bullet” solution for these problems, but here are some tips I found useful to manage them:
1) Build mesh and airflow tiles throughout your base, in order to allow the gases to move more freely and condensation to fall somewhere it’s more manageable.
2) Use a Carbon Skimmer to process the Carbon Dioxide that accumulates at the bottom of your base.

WATER SUPPLY (INTRODUCTION)

I do realize this guide is quite long already, but I felt that without addressing how to provide adequate and reliable water supply to the electrolyzer, the solution would be incomplete. If you already figured out how to supply your system with clean water, you can skip this section.

Clean water is readily available at the beginning of the game, but at this point you are probably down to your last reserves or out. Polluted water, on the other hand, is abundant in the map and also “created” by your duplicants after they use the showers and lavatories, so it’s an attractive option to supply your electrolyzer with an abundant source of water.

However, passing the polluted water thru the Water Sieve is not enough. If you click the germs layout button, you will see that polluted water is rife with germs, and they won’t be killed by the water sieve nor the electrolyzer.



If you pass on this germy water to the electrolyzer directly from the Water Sieve, it will work ok, but the oxygen gas created by it will have all the germs, and you don’t want to blow this germy oxygen gas to your entire base.

So, you have to kill all the germs in the water before you send it to the electrolyzer, and the way to do that is to expose it to a disinfectant. That can be done by passing the water thru a Liquid Reservoir which sits inside a room full of chlorine gas.

Again, there are many designs for a Chlorine Room with all kinds of features. The design I will present here is simple and adequate enough to provide a steady supply of clean, germ-free water to the Electrolyzer.

WATER SUPPLY PRINCIPLES

The gist of the many water purification schemes (mine and others), is simply that the germy water that enters the Chlorine Room stays inside the room long enough for all the germs in it to die, which, depending many factors, could be a little less than one full cycle (but more if you want to be sure).

To understand why my design and other designs work or not, here are some key principles of the Water Supply components:
The Water Sieve produces 5kg/s of water
The Liquid Reservoir has a capacity of 5,000kg of liquid
The Liquid Reservoir has an input/output rate of (maximum) 10kg/s of liquid
The Electrolyzer uses 1kg/s of water
A full cycle is 600 seconds.

If you do some math, you will see that it takes more than one cycle for a single Water Sieve to fill the Liquid Reservoir, which is great for our purposes. However, the unrestricted output of the liquid reservoir can empty the entire tank in less than a cycle, which is not to our advantage.

WATER SUPPLY PURIFICATION DESIGN

The principle my design uses is not one that maximizes water output, but one that reduces water flow to a trickle that is just enough to supply the electrolyzer with a constant water supply, and that ensures that water flow thru the Chlorine Room is delayed long enough so that the “new”, germy water entering the room spends one or more cycle inside the room before it exits.



The Chlorine Room design shown below has the following key components:
Liquid Reservoir: stores germy water and exposes it to chlorine
Liquid Shutoff: allows flow when the Liquid Reservoir fill level is above 95%, and shuts at 10%
Liquid Valve: limits the outflow of water to 5kg/s (adjustable)



So the water flow sequence is this: water from the Sieve enters the top of the Liquid Reservoir and starts to fill it up. When the reservoir is 95% full, the Liquid Shutoff allows water flow to the Liquid Valve, which limits the water flow to an appropriate range adequate for the electrolyzer to function and slow enough to keep the water in the Chlorine room long enough for the germs to die.

The Liquid Shutoff is the only automation item in this entire design, and the automation wiring is shown above. We need a NOT gate to invert the logic output from the Liquid Reservoir, as we want to allow water to flow out when the tank is 95% full, and stop water flow if the tank is nearly empty, at 10% capacity.



The Liquid Valve can be adjusted further down to a flow of 1kg/s, and that will still meet the electrolyzer requirements. You can try different adjustments and see what works better for you, but you should not exceed 5kg/s, which is our fill rate from the Water Sieve, and the rate that also ensures that water spends enough time inside the Chlorine Room so that germs die.



Note that, in the very long term, both the Liquid Shutoff and Liquid Valve become redundant; but they are very necessary items when your system starts and re-starts.

Also, this system is not by any means perfect. I noticed that at the very beginning a few germs do escape; but normally they clear out after a couple of cycles.

I do use this system to supply water for lavatories and showers, which combined have a higher demand than the electrolyzer. For higher demand applications, what I do is connect two of these systems in series: i.e., water inflow and outflow is still limited, but as water leaves one Liquid Reservoir, it goes into a secondary Liquid Reservoir, thus ensuring that the water spends a lot of time inside the Chlorine Room (you could even add a tertiary Liquid Reservoir, just to be 100% sure).

FILLING THE CHLORINE ROOM WITH CHLORINE

There are many ways to fill the Chlorine Room with chlorine, so here I will quickly present a method that works, but you may choose another method of your preference.

The basic layout is shown below: chlorine gas is obtained from one of the chlorine pockets in the map and pumped into the Chlorine Room, where a Gas Pump filters chlorine, recirculates it to the room, and expels everything else out, until only chlorine is left. The gas pump only needs to run once at the beginning, and then can be turned off permanently after the room is full of chlorine.



One disadvantage of this system is that requires some planning. You need to have all the items inside your Chlorine Room built, plumbed and wired before you pull the trigger and start filling the room with Chlorine. Otherwise, if your duplicants enter/exit the room to finish up any work there, some of the chlorine gas will escape every time they do.

You could, of course, use a water-lock or other devices that would allow your duplicants to come in and out as they please without any loss of gas. But once the room is fully built, plumbed and running, your duplicants don’t really need to go in to do any servicing; and note how I deliberately left the Liquid Valve outside the Chlorine Room, so if you want to do any flow adjustments, you can do them from the outside.

CONCLUSION

Well, hope you find the information in this guide useful.

Here are some key concepts I hope you can take from this guide that will help you to setup your electrolyzer system, and some that you can expand for other applications:

1) The electrolyzer system presented here maximizes oxygen production and is simpler than other competing designs.

2) The “greedy” power system, with the Power Transformer connected to the main network and the Battery on the load side of the transformer, ensures adequate, self-sustained electrical function of the electrolyzer system. This “greedy” power system can have multiple applications around your base where an uninterrupted power supply is wanted.

3) The water purification system presented here is also of a simple design, uses very little automation, and is perfectly adequate for the electrolyzer system; it also can be scaled up with multiple tanks in series for other high-demand applications around your base.

[AlligatorScrublord]

valve filters and pressure sensor filters might reduce power consumption and allow it to output just a little

[The Fierce Ninja]

I never thought about killing germs with chlorine gas, I always thought you had to run it through a machine or heat it till the germs are burned out and re-condense. Truth be told, I haven't played the game in forever as I keep dying before I even get plastic but now I may decide to play again and see if this helps me progress further. Thanks for the amazing tip man!

[SleepyTiger]

Thank you! I'm sure this will enable me to not die in the first 25 cycles, lol, great designs!

[Panic]

A very well done and perfectly explained Guide! Thanks a lot for your work
Happy New Year

[Cypherwulfe]

Have you tried using the valve filter trick? Works like a charm, and is 100% free energy wise.

[afcq5]

casey, I looked at some other designs that use Shut-off arrangements for filtering and I kind of know what you mean. Some of these designs use the fact that two different gases can't combine in the same duct tile, which is very clever. However, these concepts can malfunction under specific set of circumstances and would be particularly vulnerable to starts and stops.

My guess, you gain a little bit of power savings but you loose reliability. In my case, I would take reliability any day. In my opinion, the late-game challenges are very hard, and the less you have to worry about the other systems (such as the oxygen machine working), the best you are setup for late-game success.

[afcq5]

casey, at full production (Electrolyzer 99% uptime) the lower filter uses only 72W (60% uptime) because most of the time is bypassing oxygen; so the filter are actually only using 192W, plus you get the peace of mind that the system will always operate correctly.

Some time ago I ran some calculations and found out that my design produces 99% the power it uses, so it only takes about 7W (seven watts) from the network. It would be nice if we could push it's independence to 100% (possible?), but for most cases 7W is an acceptable burden to have the oxygen issue resolved.

Finally, note that my design is meant to be (materials-wise) cheap to build and low-tech, so that players can easily sort the mid-game oxygen crunch.

However, I do think that what you are proposing may be arranged into a viable solution. What's on your mind?

[caseyas435943]

Shut offs are cheaper power wise and do the same thing as the fillers. 10W instead of 120W each. So your air maker would be 220W cheaper using 2 of them instead of 2 fillers.

[Cypherwulfe]

I like creating an upside down funnel. Bottomless oxygen design. One pump at the top, pumping out hydrogen, the oxygen is free to flow down as it wills.

[this thing]

why not make it slightly bigger to create a little "pool" for the hydrogen at the top, that'd work as a mechanical filter. Would waste less power as well. I guess this guide helps explaining the mechanics of electrolyzers, so that later in game you could build a more effective design with more oxygen output.