There is no clear way of representing aggregates

[areleu]

Description of the issue

In regard to my question from the dev meeting 47. I am wondering what is the best approach to deal with information aggregates, specially those at a regional level. It is clear to me that we can model, for example, a power generating unit and associate a power capacity(power rating) to it, this can also be extended to a powerplant to which likewise we can assign a power capacity as its nameplate capacity. These two concepts have a relationship has part which helps to do the assigment of the capacities of the instances of power generating unit to an instance of power plant¹. An example the of the power plant level on the wild is the data of Strommarktdaten

The problem arises when dealing with data aggregated to national or regional levels. There is no equivalent way of representing the total installed capacity of (.i.e.) a country. Strommarktdaten reports this on a yearly basis for their own technological aggregation approach.

This extends not only for power plant capacities but as I meantioned in the meeting. Also for consumption of specific sectors like the electric vehicle sector. The parallels can be done using the capacity of a electric motor

How would I represent something like the electric power demand associated to all the instances of electric motor within the boundaries of Germany ?

¹ I do not think that this can happen thorugh the reasoner as quantity value of is not extensible through the has part property. But this is not an issue, as long as the relatiohship can be made I think this is a compromise we can deal with.

Ideas of solution

I have some ideas but, yet have to develop them further. I will write them in this issue when I have them figured out. Roughly I would suggest adding an energy transformation unit that represents the national installed capacity of a country (I have my doubts with national as I think this class should be able to contain an arbitrary 2D spatial region)

Workflow checklist

• [x] I discussed the issue with someone else than me before working on a solution
• [x] I already read the latest version of the workflow for this repository
• [x] 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]

What about introducing a special object property here. Something like has aggregate value: A relation between an entity and a quantity value that indicates that the quantity value is a result of some kind of aggregation.

Then we can express for your use case (e.g. in the OEKG or the intended composed module) something like: 'maximum value' and 'is aggregate value of' all ('power capacity' 'is quantity value of some ('energy transformation unit' 'located in' Germany)).

This probably needs some further refinement, but I hope it provides the gist of my proposal.

[stap-m]

We once introduced aggregation type, which we should apply here.