H2 storage modelled to a satisactory level of detail?

[SabineHaas]

During #804 I wrote information on H2 storage modelling with MVS. I am not sure whether it needs a greater level of detail.

Could for example the Compressed Air Energy Storage (CAES) custom component of oemof help to model the compression in H2 storages?

Can the additional demand for cooling and/or compression just be modelled with a sink or should we connect it to the storage component?

[smartie2076]

@SabineHaas this is something you can also show @ciaradunks

[ciaradunks]

If the hydrogen is produced from an electrolyser, which I'm assuming would generally be the case (if linked with RE sources), the output pressure is usually around 40 bar. H2 is usually stored at around 300/350 bar, so a compressor would be needed before the storage. But also, the pressure of H2 required for refuelling stations is 350 bar for buses, trucks etc. and 700 bar for passenger cars. This means that a compressor would be needed anyway if the H2 was going directly to the demand (not through the storage), or an additional compressor is required between storage and demand usually too.

Because of this, I would suggest having a simple compressor component seperate to the storage, where it can be modelled as a transformer component (two inputs: 40 bar h2 and electricity, one output: compressed h2). And the specific compression energy is calculated using inlet/outlet pressures and temperatures. Could this be possible? @SabineHaas @smartie2076

[smartie2076]

We can certainly define a conversion asset with two inputs and one output (for that we need to fix #799, #802, #599). I am not clear yet as to how we calculate the compression energy, or if we do so at all. Would we translate this into efficiencies? If we had new parameters like inlet/outlet pressures and temperatures, we would need to introduce new csv files with new parameters. We should try to avoid that, as then the MVS is less compatible with the EPA.

[ciaradunks]

Yes what we could have is a specific electricity consumption per kg of H2, so it would depend on the input flow. If we didn't want extra parameters, we could assume (beforehand) one set of the above parameters and define a constant electricty consumption. But this is heavily dependant on what pressure the H2 is being compressed from/to, so stating the pressures somewhere is important. This could be calculated beforehand, though, and then the only parameter would be how much input elec. flow there is for every one unit of input H2. Does that make sense?