Rename storage capacity to energy storage capacity

[lumi321]

Description of the issue

The capacity to store energy is currently called storage capacity, which can be missleading and may be overseen, when searching for energy storage capacity. Therefore, I suggest to rename storage capacity to energy storage capacity.
Furthermore, storage capacity is currently just a quantity value, although the definition already refers to a maximum value¹. Hence, I suggest to make it a subclass of maximum value.

Ideas of solution

Rename storage capacity to energy storage capacity.
Then, make energy storage capacity a subclass of maximum value.

Workflow checklist

• I discussed the issue with someone else than me before working on a solution
• I already read the latest version of the workflow for this repository
• The goal of this ontology is clear to me

I am aware that

• every entry in the ontology should have a definition
• classes should arise from concepts rather than from words

Footnotes

1. "Storage capacity is the quantity value stating the maximum energy an energy storage object can store." ↩

[l-emele]

I agree. The existing class describes an energy storage capacity and there are other storage capacities like the water storage capacity of an water tank.

[chrwm]

I also fully agree with your proposal - changing the label and making it a subclass of maximum value.

I then would miss a concept for energy storage content/level that does not refer exclusively to the theoretical maximum energy capacity of an energy storage, but also to an energy storage value between 0 and 100% of the max possible energy storage capacity.
E.g. if I'd like to annotate the energy storage content/level in context of modelling outputs, which will be between 0 and 100% of its energy storage capacity

[l-emele]

I like your idea. However, I think can distinguish between two concepts:

• How much energy is actually stored, so a value in an energy unit. So the battery has a storage capacity of 10 kWh, but the current energy storage content is only 5 kWh. I would label this energy storage content.
• A value between 0 and 100% indicating the storage level (like the battery level indicator on the smartphone). I would label this energy storage level.

[chrwm]

So then: energy storage content would be connected to energy -> has some energy amount value ?
And energy storage level would be without unit, e.g. referring to a relative value %?
If yes, one could name it storage level so that it is more universal, e.g. could be used in the context of storage level of water tank, grain silo, ...

[l-emele]

If yes, one could name it storage level so that it is more universal, e.g. could be used in the context of storage level of water tank, grain silo, ...

That is true, but this brings a problem: A quantity value is always a quantity value of something and this something is in this case very broad. This probably requires something like an object with an storage function.

So I suggest, that we keep it for the moment narrow and define only the one that are related to energy storage. Proposals:

• An storage level is an utilisation value that measures how much of an energy storage capacity is currently utilised.
• An energy storage content is an energy amount value that measures the quantity of energy stored in an energy storage object.

This implies the axioms:

• energy storage content' SubClassOf: 'energy amount value'
• energy storage content' SubClassOf: 'quantity value of' some 'energy storage object
• energy storage level' SubClassOf: 'utilisation value'
• energy storage level' SubClassOf: 'quantity value of' some 'energy storage object'

Via their parent classes, energy storage content and energy storage level will also inherit the following axioms:

• energy storage content' SubClassOf: 'has unit' some 'energy unit'
• energy storage level' SubClassOf: 'has unit' some fraction ¹

Footnotes

1. Or at least it should inherit this. However, the axiom 'fraction value' SubClassOf: 'has unit' some fraction is missing despite the very obvious definition: A fraction value is a quantity value that has a fraction as it's unit. fraction value is the parent class of utilisation value. ↩

[chrwm]

Can we make it more concise, such as:

• An storage level is an utilisation value that measures the utilisation/usage/exploitation how much of an energy storage capacity is currently utilised.

The temporal dimension of "currently" is implied in utilisation value with "instantaneous share".

With the proposed definition of 'energy storage content' and the axioms, I agree.

[l-emele]

Okay, then I think we are ready to implement. Who will implement? @lumi321? Or maybe @u-mueller?

[u-mueller]

• An storage level is an utilisation value that measures the utilisation/usage/exploitation how much of an energy storage capacity is currently utilised.

Following your discussion and considering its starting point, shouldn't the definition be:

• An engergy storage level is a utilisation value that measures the utilisation/usage/exploitation of energy storage capacity.

If so, should we think of renaming the class storage capacity to energy storage capacity and storage unit to energy storage unit since the definitions also only refer to engery storage?

Later on we could add superclasses storage capacity, storage object, storage capacity etc. with more general definitions if needed.

[l-emele]

Following your discussion and considering its starting point, shouldn't the definition be:

* _An **engergy** storage level is a utilisation value that measures the utilisation/usage/exploitation of energy storage capacity._

If so, should we think of renaming the class storage capacity to energy storage capacity and storage unit to energy storage unit since the definitions also only refer to engery storage?

I agree.

[u-mueller]

Ok, then I'll implement.