Ontology: Add energy system

[l-emele]

Description of the issue

We should define a class energy system.

Ideas of solution

If you already have ideas for the solution describe them here

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

[l-emele]

We probably need an system superclass here. Wikipedia defines system as; _A system is a group of interacting or interrelated entities that form a unified whole._

But probably there is a generic _system_ definition in one of the ontologies we import and we can build on our energy system definition. @jannahastings : Any ideas?

[jannahastings]

For reasons that are not entirely clear to me, the class _system_ that is in use within the OBO Foundry community of ontologies is defined in the _Relation_ ontology: http://www.ontobee.org/ontology/RO?iri=http://purl.obolibrary.org/obo/RO_0002577. This appears to have been a placeholder while the discussion was going on about where to place the class within BFO, but in the meantime it is already being used.

This class is defined as: "A material entity consisting of multiple components that are causally integrated. "

It is used, for example, in the environment ontology (ENVO), in which it is the parent of 'environmental system', the core entity in this ontology.

[stap-m]

Sounds good to me. Can't we just import it?

[stap-m]

A very first try: An energy system is a system of spatially distributed but interacting energy sources and sinks.

[l-emele]

Is _spatially distributed_ really necessary for that definition? Especially when thinking about energy system models with model a whole country as a single point (i.e. without spatial extent).

[stap-m]

I put in spatially distributed because I wanted to exclude something like that https://de.wikipedia.org/wiki/Stromkreis#/media/Datei:Stromkreis_elementar.svg which is not an energy system in the OEO sense...
Also, the energy system model is not the system itself.

[stap-m]

Anyway, spatially distributed is also very vague... Maybe we can find a more precise description.

[l-emele]

Also, the energy system model is not the system itself.

Good point! Model do always have abstraction from reality, and in my single point model example all spatial information abstracted away. So having this in mind, I am not arguing anymore against including something _spatial_ in the definition.

What about _spatially extended_?

[stap-m]

What about spatially extended?

sounds good

[l-emele]

In #155 we talked already about a supply system class. It might be a subclass of energy system.

[stap-m]

In #155 we talked already about a supply system class. It might be a subclass of energy system.

Or vice versa...

[jannahastings]

Sounds good to me. Can't we just import it?

We can import the class 'system', yes. We already have a RO module, so we can just add this into it.

[l-emele]

What will be the superclass of system? Is it an object aggregate?

[jannahastings]

The parent is material entity. So they bypass the object / object aggregate distinction.

[stap-m]

supply system seems to be defined from an economical point of view, whereas energy system more from a technical point of view. And supply system could refer to other "products" then energy, too, I think.

https://github.com/OpenEnergyPlatform/ontology/issues/155#issuecomment-645427507

Here the currently proposed definitions:

• An energy system is a system of spatially extended linked energy sources and sinks.
• A supply system is a system that connects producers and consumers.

Can they both be subclasses of system without being disjoint?

[l-emele]

In my understanding if me do not explicitly state Disjoint With they are not disjoint. So no problem in my view.

[stap-m]

Ok, implementation time :)
@jannahastings can you import system from RO?

[jannahastings]

Apologies for the delay in getting to this! Now I included 'system' in the ro-module, please see the recent PR.

[akleinau]

@stap-m then your proposed classes can be implemented now?

[akleinau]

I'll make a pull request