Hydrogen energy storage and power delivery: a useful strategy for Super Sustainable.

[blakemw]

An unconventional way to store and deliver energy is with Hydrogen Gas.

• 1 kg of hydrogen produces 8 kJ of energy in a hydrogen generator.
• A gas pipe delivers up to 8 kW of power, as much as 4 conductive wires, while being very cheap, unobtrusive and incapable of overloading.
• The 4 gas pipes that fit behind a Smart Battery would store 32 kJ of energy: 60% more than a Smart Battery.
• A Gas Reservoir stores as much energy as 60 Smart Batteries while taking a tiny fraction of the space, and with zero power drain and zero heat.

60 Smart Batteries = One Gas Reservoir.

So having established that Hydrogen has real potential for both power delivery and energy storage, how does it actually work in practice?

Most players will end up making a SPOM, a SPOM naturally exports hydrogen, an idealized 2 Electrolyzer SPOM would produce 1776 W, and consume 1200 W, exporting 576 W - real SPOMs may export less (or potentially more, with skulduggery). This exported hydrogen can be stored in pipes and reservoirs. The amount of hydrogen exported can be increased by feeding intermittent or low-grade power into the SPOM, for example Manual Generators, Solar Panels and power from metal volcano tamers. Gas Reservoirs have enough capacity to store energy for cycles.

 

An example:

 

In my latest game I have a 2 electrolyzer 100% uptime SPOM (which is fed with cold geyser water, hence not insulated), and 3 Manual Generators connected to it for idlers to run on and train their athletics+machinery. The Manual Generators are automated by a 60/0.2 Timer Sensor that kicks them off once a minute to look for higher priority errands.

 

 

The hydrogen exported is sent by a bridge into the Hydrogen Generators that guarantee power to the SPOM, any excess goes into a pair of Gas Reservoirs, from there it is split to three destinations: a Metal Refinery, Glass Forge and the main base power circuit.

 

Also the particular design of SPOM I use needs to burn all the hydrogen to not get hydrogen in the oxygen pipes: yes, I know designs like hydras are immune to this problem but hydras are boring, so I use a gas-backing-up-sensor, a Gas Pipe Element Sensor in the middle of a double bridge, that sends a green signal if the hydrogen is no longer flowing, causing the main circuit Hydrogen Generators to burn excess hydrogen.

 

Priority

In the previous example I'm not really doing much with priority. In the same game, I have a hydrogen powerplant in space.

This is the same SPOM design, without the Oxygen Gas Pumps. This design exports only a small amount of oxygen. The powerplant is fed power from two of the Solar Panels: because there is only 480 W of power draw it can't absorb much extra power, so most the exported power is the primary power generation potential of the electrolyzer.

 

The Hydrogen Generator of course has first dibs on the hydrogen gas, and there's a Gas Pipe Element Sensor that shuts off the powerplant if the hydrogen is not being consumed. The excess hydrogen is used to power a radbolt material research setup (will later also feed an Interplanetary Launcher), and leftover hydrogen is used for Oxylite production, the Oxylite is also a dump for oxygen from the primary SPOM.

 

 

Here the priority and storage really shines: the hydrogen first goes into a Gas Reservoir which can store hydrogen if neither downstream setup is operating right now, from there it goes with priority into a second Gas Reservoir which is an energy reserve for the radbolt system, which I like to have an uninterrupted power supply, the radbolt circuit has a potential load of 1.56 kW and the Gas Reservoir stores enough energy to run it at full bore for 1.28 cycles, or it can power the Radbolt Storage alone for 16.7 cycles. Once that Gas Reservoir is full, the surplus hydrogen powers the Oxylite Refinery, which disposes of excess oxygen produced by the primary SPOM allowing it to export more hydrogen, and all the oxylite is used freely in rockets.

A system of wires, transformers and batteries cannot casually have this level of energy storage and priority is also more annoying to implement, generally requiring Smart Battery and Transformer or Power Shutoff, and certainly the idea of having a 1.2 MJ energy reserve just in case, is quite absurd, as illustrated by the earlier example of the 60 Smart Batteries, which would drain 40 W and produce 30 kDTU/s of heat.

In some of my games I've used Super Sustainable rules for the entire game, and gone with full hydrogen power grids, where power is delivered across the map in hydrogen pipes instead of wires. This of course is basically limited to maps with multiple watery geysers.

 

Limitations

The most obvious limitation is a dependency on water, to the extent you're running a SPOM anyway, that is free energy storage potential and the combination of Idler Gym and SPOM is something I often use, because it's pretty great. And Watery Geysers are powerful energy production options, the 3 high-output Watery Geysers have the most energy generation potential of any geysers/vents/volcanos in the game, except for Volcano, and the half-output Geysers (CSV and cool water geysers) have slightly more power potential has a Natural Gas or Hydrogen Vent. So if you are on a wet map, a hydrogen power backbone is completely practical, but you are ultimately limited in scale by water production.
 

Specifically with regard to storage, the main limitation is that there are several other forms of energy that are even better than hydrogen, natural gas is 11% energy denser than hydrogen - though the generator is much messier -, and coal is less energy dense but is far more storable, and the generator is relatively clean. Of course like hydrogen, all of these have constraints on how quickly they can be produced, but to the extent you have them, they are good as energy reserves. So basically the common scheme where coal is used as backup power and to accomodate surges is genuinely pretty good.

This setup really shines when playing under Super Sustainable rules as all those other energy reserve options are eliminated, and it allows storing vast amount of idler power generation for when you can get around to utilizing it, in a normal game you probably won't care about idler power generation because there are plenty of alternative power generation. Also it is worth noting there are no downsides to feeding Manual Generator power into the SPOM, rather than directly onto the circuit, either way you get the full 400 W, but when fed into the SPOM you can delay consuming it until later.

 

[speckle21]

I love the thought put into this!