Ontology: potentials should get included in the oeo

[akleinau]

Description of the issue

Potentials are described in the oeo scenario factsheets but not in the ontology and should be included: theoretical, technical, economic, developable potential

Current state of discussion (11/11/20)

There are two fundamentally different ideas:

1. Implement potential as a disposition.

For this, we have the following classes and relations:

• potential: _A potential is a disposition that identifies the upper limit of a usable entity from a certain source._
• theoretical potential: _A theoretical potential is a type of potential that identifies the physical upper limit of a usable entity from a certain source._
• technological potential: _A technological potential is a type of potential derived from a theoretical potential, taking account of the annual efficiency of the respective conversion technology and the additional restrictions regarding the area that is realistically available for energy generation._
• economic potential: _An economic potential is a type of potential that identifies the proportion of the technological potential that can be utilized economically (based on economic boundary conditions)._
• developable potential: _A developable potential is a type of potential that describes the fraction of the economic potential that can be developed under realistic conditions (regulations, environmental and social restrictions)._
• sustainable potential: _A sustainable potential is a type of potential that takes into account all aspects of sustainability, which usually requires careful consideration and evaluation of different ecological and socio-economic aspects. The differentiation of the sustainable potential is blurred, since ecological aspects may already have been considered for the technological or economic potential, depending on the author._
• wind energy, solar energy, geothermal heat: has disposition some theoretical potential, has disposition some technological potential, has disposition some developable potential, has disposition some economic potential, has disposition some sustainable potential
• biofuel: has disposition some technological potential, has disposition some developable potential, has disposition some economic potential, has disposition some sustainable potential
• potential: is about some spatial region

2. Implement has potential as an object property.

• Basic idea: Processes are related to quantity values via has potential
• has potential: _A relation between a process and the upper limit of its usable output._
• Subrelations like has technological potential can be implemented analogous to the subclasses above

Why should we chose the disposition- or the object-property-solution?

• linking potentials to material entities (1) doesn't work for cases like solar/wind/geothermal energy or CO₂ storage, potentials always belong to a process, e.g. the potential to produce electricity from wind (see https://github.com/OpenEnergyPlatform/ontology/issues/481#issuecomment-713609471)
• CO₂ storage: There are different views how this works with potentials:
  
  
  
  • The CO2 storage potential is the upper limit of CO2 input into the geological formation the potential is given for. The output of the CO2 storage process would be the (unintentional) leakage of CO2 from the storage site back into the atmosphere. (see https://github.com/OpenEnergyPlatform/ontology/issues/481#issuecomment-717818045)
  
  
  • The CO2 that is stored is an output of the process of storing CO2 (see https://github.com/OpenEnergyPlatform/ontology/issues/481#issuecomment-717809440)
  
  

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]

Wikipedia defines potential as: _Potential generally refers to a currently unrealized ability._

The WBGU has in this document detailed descriptions of potentials (Box 3.1-1).

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

Pointing out the obvious: potentials come in two flavours, stocks (e.g. mineral resources and reserves) and flows (e.g. annual electricity production), measured in Joules and Watts.

[Vera-IER]

I like the descriptions from that WBGU document. Slighly changed from that source a definition for a generic potential could be:
A potential identifies the upper limitof the energy available from a certain source.

[stap-m]

I also like the WGBU clarification. But I think its not the theoretical potential, but the technological and economical potentials that are relevant for our models. I.e., there is more energy available than usable: A potential identifies the upper limit of energy usable from a certain source.? And maybe implement two subclasses technological potential and economical potential?

The characteristic of potentials of being "upper limit / maximum value" seems to be corresponding to the concept of the "capacities" classes. This could help for the classification.

[Vera-IER]

I like the definition with "usable".
I agree that the subclass theoretical potential is not needed. Maybe we could also add sustainable potential as a 3rd subclass.

[akleinau]

theoretical, technical, economic and developable potential are directly listed in the factsheets I have (SzenDB Szenarienraster excel sheets) so they should either get changed too or we should implement them

[Vera-IER]

okay...it also not a disadvantage to have more subclasses. just a tiny bit more work ;-)

[Vera-IER]

So the definitions for the subclasses could be (slighly changed from WGBU report):

Theoretical potential: The theoretical potential is a thype of potential that identifies the physical upper limitof the energy available from a certain source.
Technological potential: The technological potential is a type of potential derived from the theoretical potential, taking account of the annual efficiency of the respective conversion technology and the additional restrictions regarding the area that is realistically available for energy generation.
Economic potential: The economic potential is a type of potential that identifies the proportion of the technological potential that can be utilized economically (based on economic boundary conditions).
Developable potential: The developable potential is a type of potential that describes the fraction of the economic potential that can be developed under realistic conditions (regulations, environmental and social restrictions). source

[l-emele]

I agree with @stap-m's general definition for potential and @Vera-IER's definitions for the potential subclasses.

[stap-m]

For sustainable potential WGBU proposes: _"This potential of an energy source covers all aspects of sustainability, which usually requires careful consideration and evaluation of different ecological and socio-economic aspects. The differentiation of the sustainable potential is blurred, since ecological aspects may already have been considered for the technological or economic potential, depending on the author."_
Is this too vague for an ontology? 😕 Anyway, I think this woud be a nice completion.

Since theoretical potential is not really usable, change the def of potential to: _A potential identifies the upper limit of energy available or usable from a certain source._?

[Vera-IER]

Yes I think we can add the sustainable potential to complete the list of potentials. To make it Arestotalian we could write:
The sustainable potential is a type of potential that takes into account all aspects of sustainability, which usually requires careful consideration and evaluation of different ecological and socio-economic aspects. The differentiation of the sustainable potential is blurred, since ecological aspects may already have been considered for the technological or economic potential, depending on the author.

And changing the general potential def like @stap-m proposed sounds also good to me.

[Vera-IER]

Can we relate all these potential terms to
wind energy
solar energy
hydro energy?
And it would also be nice to relate it to biomass, but I didn't found a class biomass in the OEO...

[stap-m]

And it would also be nice to relate it to biomass, but I didn't found a class biomass in the OEO...

We have biofuel.

[Vera-IER]

Okay let's relate it to biofuel then.
What would be a nice object property to relate them? Maybe is connected to?
And where can we place potential in the OEO? Under quantity value?

[l-emele]

I would not limit the potential to energy, so I propose: _A potential is a quantity value identifies the upper limit of a quantity available or usable from a certain source._

[Vera-IER]

Sounds good to me. Just correcting a typo:
_A potential is a quantity value that identifies the upper limit of a quantity available or usable from a certain source._

[sfluegel05]

If we define potential is a quantity value we can use has quantity value:
biofuel has quantity value some theoretical potential.
Is theoretical potential the right term to go with? I used it here because all the other potentials are dependent on other factors beside the fuel itself.
And is there a reason to stop at biofuel? I would suggest to do this relation for fuel in general.

[Vera-IER]

Is theoretical potential the right term to go with?

For wind and solar energy we can relate all potential terms to them, but for biofuels I would exclude the theoretical potential. Biofuels are already the product of a conversion process of biomass, so I would relate technological potential (and the ones below) to biofuels.

And is there a reason to stop at biofuel?

Yes. For fossil energy forms the term energy reserves is used instead of potential.

[l-emele]

For fossil energy forms the term energy reserves is used instead of potential.

For fossil there is also the term energy resources: https://www.hartenergy.com/opinions/energy-terms-reserves-vs-resources-121086

But let's keep focused: this issue is neither about resources nor about reserves. If these terms are needed please create a separate issue.

[Vera-IER]

I forgot that a potential can also be related to geothermal heat to complete the list of renewable energy potentials.

[l-emele]

I forgot that a potential can also be related to geothermal heat to complete the list of renewable energy potentials.

A potential can be related to _any_ energy carrier.

[sfluegel05]

So for biofuel we get (has quantity value some technological potential) or (has quantity value some developable potential) or (has quantity value some economic potential) or (has quantity value some sustainable potential) which means that a biofuel has to have at least one potential that is not a theoretical potential. This got a little long but I didn't find a more elegant way to say this. Is that what we want to express?

Relating potential to forms of energy like wind energy or geothermal heat could be tricky because they are currently object of restructuring (#522)

[stap-m]

[...] Is that what we want to express?

Actually, biofuel can have all kinds of potential: in theory, you can cut all trees and burn them. Thechnologically and economically, you can't cut _all_ trees, but a share. And from the sustainable point of view, you better to keep some more... to oversimplify it.
So, it's rather and than or.

[l-emele]

Potentials are not limited to energy (carriers) and fuels but to a lot of different types of classes. For example there are also potentials for carbon capture and storage (CCS) see e.g. here.

[Vera-IER]

Yes true, but CCS is not a part of the ontology yet, right? Shall I open a issue for that? I think it would be good to have CCS and especially BECCS processes in the OEO.
Regarding the potentials I think its most important to relate potentials to the renewable energy forms (wind, solar, hydro, biofuel, goethermal), because these assumptions influence the energy model results strongly and are often harmonized between different models when working together.

[l-emele]

We need the potential concept for the fact sheets. In there it is not limited to the energy potentials.

[Vera-IER]

If we relate potential to the renewable energies now, it's not limited to those ones right? I mean we still have this generic definition of potential - if someone wants to add another relation in the future it would not be problematic, no?

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

Regarding the potentials I think its most important to relate potentials to the renewable energy forms (wind, solar, hydro, biofuel, geothermal), because these assumptions influence the energy model results strongly and are often harmonized between different models when working together.

The same is true for fossil resources. The economic potential of natural gas from hydraulic fracturing (to name one example) has a huge influence on model results in certain regions.

If we relate potential to the renewable energies now, it's not limited to those ones right?

Only if you put the term "energy" into every single definition.

Quoting myself:

Pointing out the obvious: potentials come in two flavours, stocks (e.g. mineral resources and reserves) and flows (e.g. annual electricity production), measured in Joules and Watts.

All current definitions seem intended at flows (like solar radiation), yet are formulated such that they apply only to stocks.

A potential identifies the upper limit of energy usable from a certain source.

To calculate the upper limit of _energy_ usable from solar radiation, you would have to integrate over the life time of the sun (approx. 5 billion years). You want power (Watts), not energy (Joules).

[stap-m]

To calculate the upper limit of energy usable from solar radiation, you would have to integrate over the life time of the sun (approx. 5 billion years).

Huge theoretical potential... 🌞
@0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q if you don't agree with the definition, a suggestion for a precise _definition_ would be helpful.

The latest version is: _A potential is a quantity value that identifies the upper limit of a quantity available or usable from a certain source._

[stap-m]

The latest version is: _A potential is a quantity value that identifies the upper limit of a quantity available or usable from a certain source._

Maybe _quantity or rate_, istead of just quantity? quantity value should include both, depending on the unit.

[stap-m]

@jannahastings you proposed to connect an "entity in reallity" to quantity values, https://github.com/OpenEnergyPlatform/ontology/issues/434#issuecomment-648837549. Does this make sense for potentials, too? E.g. being a quality?
The same question could also be raised for capacity-subclasses of quantity value, btw.
E.g. wind energy _has_quality_ (technical potential _has_quantity_value_ (potenial _has value_ 40 and _has unit_ GW))

Also, we need relations, that refer the potentials to areas (any ideas what else?), e.g. technical potential of wind energy in Germany. We have covers, but it just refers to models and publications.

[jannahastings]

I think the examples of potentials are _very_ complex, but ultimately, they are still the potentials OF something, and that something is the entity in reality that they should be related to. They are attributes of some material (the source). Future-pointing attributes such as these in BFO are not qualities but are called dispositions or (more broadly) _realizable_ dependent continuants. Given the above discussion, I would agree with the above formulation except for that relation, so instead:

wind energy _has_disposition_ (technical potential _has_quantity_value_ (potenial _has value_ 40 and _has unit_ GW))

Could we use the property _is_about_ to link the potential to Germany? Or something slightly more complex such as _is_about_ some ( _located_in_ Germany) ?

[l-emele]

I think the examples of potentials are very complex, but ultimately, they are still the potentials OF something, and that something is the entity in reality that they should be related to.

That is also my understanding.

Could we use the property is_about to link the potential to Germany? Or something slightly more complex such as is_about some ( located_in Germany) ?

Is the potential always dependent to some kind of region? I think so, but I am not sure after this a bit confusing discussion.

[Vera-IER]

Is the potential always dependent to some kind of region? I think so, but I am not sure after this a bit confusing discussion.

Yes I agree. For some renewable energies the potential is even given by the available land area (for example suitable rooftop area for PV or agricultural land area for biomass cultivation). I would like the property refers to the most to link potentials to regions. But this property does not exist yet, should we look for an existing ones?

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

Is the potential always dependent to some kind of region?

Yes. Potentials without geographic references are useless. If an explicit reference is missing, it is implied (usually "global" or what ever region the report/paper/data base is focused on).

[sfluegel05]

@jannahastings you proposed to connect an "entity in reallity" to quantity values, #434 (comment). Does this make sense for potentials, too? E.g. being a quality?
E.g. wind energy _has_quality_ (technical potential _has_quantity_value_ (potenial _has value_ 40 and _has unit_ GW))

What exactly would be the entity in reality here? wind energy is (currently) a quality. So can a quality be an entity in reality or is "reality" limited to material entities? In that case, maybe air could be a good replacement for wind energy.

[jannahastings]

So can a quality be an entity in reality or is "reality" limited to material entities?

Qualities are entities in reality :-). In fact so are processes etc., any of the major categories we classify things beneath. The distinction I was trying to make (I think) was between quantity values and the entities that they are quantities of.

[stap-m]

Could we use the property is_about to link the potential to Germany? Or something slightly more complex such as is_about some ( located_in Germany) ?

The relation should finally refer to values/instances. This could be a country but also less specific spatial regions, maybe just coordinates?! I don't know what's the best way here: relate it via _is about_ to spatial region or directly create a data property?
Btw, this is related to #475

[sfluegel05]

I think it would be nice to relate it to instances and then give these instances a specific location. That would make it possible to specify a location in different ways (or even give no concrete location and just say is about Germany).

[sfluegel05]

In the last dev-meeting we agreed to use an external ontology for geographical term, so I think a relation is about some spatial region for potentials should be enough.

To summarize the discussion so far:
We have the following classes:
potential: _A potential is a disposition that identifies the upper limit of energy usable from a certain source._
theoretical potential: _A theoretical potential is a type of potential that identifies the physical upper limit of energy usable from a certain source._
technological potential: _A technological potential is a type of potential derived from a theoretical potential, taking account of the annual efficiency of the respective conversion technology and the additional restrictions regarding the area that is realistically available for energy generation._
economic potential: _An economic potential is a type of potential that identifies the proportion of the technological potential that can be utilized economically (based on economic boundary conditions)._
developable potential: _A developable potential is a type of potential that describes the fraction of the economic potential that can be developed under realistic conditions (regulations, environmental and social restrictions)._
sustainable potential: _A sustainable potential is a type of potential that takes into account all aspects of sustainability, which usually requires careful consideration and evaluation of different ecological and socio-economic aspects. The differentiation of the sustainable potential is blurred, since ecological aspects may already have been considered for the technological or economic potential, depending on the author._

Additionally, we have some relations:
wind energy, solar energy, geothermal heat: has disposition some theoretical potential, has disposition some technological potential, has disposition some developable potential, has disposition some economic potential, has disposition some sustainable potential
biofuel: has disposition some technological potential, has disposition some developable potential, has disposition some economic potential, has disposition some sustainable potential
potential: is about some spatial region

Is there anything missing?

[l-emele]

As we discussed above, potential is not limited to energy. It is more generic.

[stap-m]

This should be reflected in the defs. @l-emele any suggestions?
From my side, the relations are ok for the moment. We can still add the disposition to more classes later.

[akleinau]

this issue has 42 comments. Maybe it is a good idea to define an upper limit like 30 comments, after which an issue should be discussed in a dev meeting as it got too complex?

[Vera-IER]

To make the definitions more general, we could change this part "the upper limit of energy usable" into "the upper limit of a usable commodity" in the definitions. So for example the potential def would be:
_A potential is a disposition that identifies the upper limit of a usable commodity from a certain source._

[l-emele]

Do we have already a definition for commodity? I don't think so.

[Vera-IER]

Not yet, but it's already planned to include commodity it in #339.

[sfluegel05]

I like the change to commodity. Is this ready for implementation then?

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

theoretical potential: _A theoretical potential is a type of potential that identifies the physical upper limit of energy usable from a certain source._

What's the theoretical potential of solar energy for some geographic area then? The irradiation of that area?
That's not a commodity, because that would imply it can be bought and sold. How do you sell sunshine? Same for wind, hydro, and geothermal (flows as opposed to stocks).

It would work from technological potential on down, because that implies some transformation (and commodification), but not for theoretical potential.

[Vera-IER]

I see your point. Do you have an idea for a better wording?
Or shall we use a combination of energy and comodity?:
_A potential is a disposition that identifies the upper limit of energy usable or of a commodity usable from a certain source._

[stap-m]

What about smth like _usable entity_ instead of energy / commodity?

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

Do you have an idea for a better wording?

Reading this thread again, I think that the whole disposition direction is wrong. To say that the potential of oil production is an attribute of the oil strikes me as odd. For solar/wind/geothermal, this relation breaks down entirely, since there's no material. For CO₂ storage, it's the absence of material that counts.
We are not talking about the potentials of oil, wind energy, or CO₂ storage, but about the potentials to _produce_ oil (as in primary energy carrier), to _produce_ electricity from wind, and to _store_ CO₂. So these are processes that can have quantity values (Joules, Watts, tonnes) attached to them through a bunch of relations has (theoretical|technical|economic|developable|sustainable|…) potential.

[stap-m]

Reading this thread again, I think that the whole disposition direction is wrong. To say that the potential of oil production is an attribute of the oil strikes me as odd. For solar/wind/geothermal, this relation breaks down entirely, since there's no material. For CO2 storage, it's the absence of material that counts.

Are you referring to the fact, that a disposition needs an independent continuant as bearer? That's a valid point.
Btw, quantity values are generically dependent continuants and thus also dependent on an independent continuant as bearer, not on processes... although the def of has quantity value is vague here. Did we do that intentionally to include processes or is that an accident? 👀

[jannahastings]

The relationship between quantity values as generically dependent continuants and the things they are measures of or counts of is _is about_ , not dependence. They can be _is about_ any sort of entity.

They _depend_ on a different sort of thing -- a kind of bearer which is generic, hence the _generic_ in the name _generically dependent continuant_. This typically means how is the value encoded or stored.

[sfluegel05]

We are not talking about the potentials of oil, wind energy, or CO2 storage, but about the potentials to _produce_ oil (as in primary energy carrier), to _produce_ electricity from wind, and to _store_ CO2. So these are processes that can have quantity values (Joules, Watts, tonnes) attached to them through a bunch of relations has (theoretical|technical|economic|developable|sustainable|…) potential.

This is an interesting view on the topic. In accordance with our "quantity value-scheme" (https://github.com/OpenEnergyPlatform/ontology/issues/434#issuecomment-648837549) which was the reason we classified potentials as dispositions in the first place, we could say that the process is the entity in reality and the has ... potential relations are subrelations of has quantity value.

[sfluegel05]

For definitions we could use the term output, although I'm not sure if this makes the distinction towards has output clear enough. The definitions would look like this:

has potential: _A relation between a process and the upper limit of its usable output._
has technological potential: _A relation between a process and the upper limit of its usable output derived from a theoretical potential, taking account of the annual efficiency of the respective conversion technology and the additional restrictions regarding the area that is realistically available for output generation._

[l-emele]

It's not necessary an input. The CO2 storage potential is more an input than an output.

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

The CO2 storage potential is more an input than an output.

The CO₂ that is stored is an output of the process of storing CO₂, so has potential would work. But there is neither "conversion" nor "generation", and the CO₂ isn't "usable", so has theoretical potential wouldn't.

🤔

This is more free association than a concrete suggestion:
Would it be useful to define a magnitude of a process, that is specific to the process? For energy transformation that would be power, for consumption that would be the amount of what is consumed per unit time, etc. The potentials would then be the upper limits to the magnitudes. This would encapsulate the specifics of the processes and allow for a orthogonal definition of potentials, which would be handy for future-proofing for processes to be added (CO₂ storage isn't in there yet. Water withdrawal becomes popular with energy models looking into sustainability aspects.)

Not sure how to implement this cleanly in terms of classes and attributes, though.

[l-emele]

The CO2 storage potential is the upper limit of CO2 input. The process where the CO2 comes from is irrelevant.

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

The CO2 storage potential is the upper limit of CO2 input.

Input into what?

[l-emele]

Of the thing the potential is given for, e.g. the geological formations in Germany.

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

We moved past that in the discussion. We're at potentials of processes, therefore: "[t]he CO₂ that is stored is an output of the process of storing CO₂".

It still ends up in the geological formation, but basing the definition on the processes allows for a generalised definition of potentials (maybe).

[l-emele]

I disagree. In my understanding the output of the CO2 storage process would be the (unintentional) leakage of CO2 from the storage site back into the atmosphere.

[l-emele]

this issue has 42 comments. Maybe it is a good idea to define an upper limit like 30 comments, after which an issue should be discussed in a dev meeting as it got too complex?

We could also think about handing over this topic to our steering committee as this is the original purpose of the OEO-SC.

[stap-m]

Or discuss it at the next dev-meeting first, as originally proposed. Afterwards we can still forward it to the SC, if needed.

I'd propose to close this issue now and reopen it at the next meeting.

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

I disagree. In my understanding the output of the CO2 storage process would be the (unintentional) leakage of CO2 from the storage site back into the atmosphere.

1. I think this discussion is moot in the context of this issue, since the more specific potentials don't work for CCS for other reasons.

2. As a general point:
   That depends on how the process boundaries are defined, and that's completely arbitrary. Our model (REMIND) uses four different processes for modelling CCS (in addition to energy conversion processes with carbon capture):

        ccscomp         "compression of co2"
        ccspipe         "transportation of co2"
        ccsinje         "injection of co2"
        ccsmoni         "monitoring of co2"

Fugitive CO₂ emissions in that setup result from the ccsmoni process.

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

We could also think about handing over this topic to our steering committee as this is the original purpose of the OEO-SC.

Or discuss it at the next dev-meeting first, as originally proposed. Afterwards we can still forward it to the SC, if needed.

I'd propose to close this issue now and reopen it at the next meeting.

What's the point here? I didn't have the impression that discussing an issue with lots of people who haven't read through the issue before is particularly effective or efficient.

I don't think that we are talking past one another and struggle with ambiguities that are cleared up more easily in direct communication. In my view we had a couple of proposals that all were rejected because they didn't give a proper definition of potentials that fulfils all requirements. Having a dozen people chew the fat about it will most likely not yield a solution either.

As for the steering committee, what would be their assignment here? There's no decision to be made or dispute to settle. So they should come up with a working solution, because we couldn't? If so, more power to them. But I think that's not the case.

[sfluegel05]

I tried to summarize the discussion so far in the first comment. Maybe this helps for a discussion in the dev-meeting.

[l-emele]

Definition proposals from OEO dev meeting 11:

• _A flow potential is a quantity value that describes the upper limit of an input or output value of a process in an n-dimensional region per time unit. For example the wind flow potential of Germany is the amount of energy available to wind power plants in Germany._
• _A stock potential is a quantity value that describes the upper limit of a stock value of a source or sink in an n-dimensional region. An example is the coal potential of Germany that is the amount of coal available in the soil in Germany._

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

I can't help but notice that no @OpenEnergyPlatform/oeo-general-expert-formal-ontology was assigned to this issue, and I think one should be.

• _A flow potential is a quantity value that describes the upper limit of an input or output value of a process in an n-dimensional region per time unit. For example the wind flow potential of Germany is the amount of energy available to wind power plants in Germany._

• What's with the _n-dimensional region_? There's no such thing in the ontology. Should it be?
  I guess it's supposed to be spatial region. Is there any instance in which potentials are not defined over an area, but either for a point, a line, or a volume? Fossil resources and CO₂-storage could be defined for different strata, but is anybody doing it? And if so, wouldn't it be more straight-forward to include this in an annotation (or some such) to the potential, like all those strings attached to technological potential and so on?
• This is a differential quotient, not an average, so it should read "per unit time", not "per time unit".
• "Wind flow potential"? I'd say wind energy potential.

• _A stock potential is a quantity value that describes the upper limit of a stock value of a source or sink in an n-dimensional region. An example is the coal potential of Germany that is the amount of coal available in the soil in Germany._

• Coal is by definition not in the soil. "… available for production in Germany" will do.
• This presupposes that the stock value of "the amount of coal available […] in Germany" is included in the ontology, in order to attach the quantity value, right?

[l-emele]

* What's with the _n-dimensional region_?  There's no such thing in the ontology.  Should it be?
  I guess it's supposed to be `spatial region`.

Yes, it should be a spatial region. I forgot yesterday the precise label of that region class.

Is there any instance in which potentials are not defined over an area, but either for a point, a line, or a volume? Fossil resources and CO2-storage could be defined for different strata, but is anybody doing it? And if so, wouldn't it be more straight-forward to include this in an annotation (or some such) to the potential, like all those strings attached to technological potential and so on?

Spatial region has currently the subclasses zero-dimensional region (a point), two-dimensional region (an area) and three-dimensional region (a volume). This is why I called this yesterday _n-dimensional_, A one-dimensional region covering a line is currently missing, but if needed we can definitely create one. But that is topic for a different issue.

* This is a differential quotient, not an average, so it should read "per unit time", not "per time unit".

Right.

* "Wind flow potential"?  I'd say `wind energy potential`.

That is about the label of potential subclasses of potential. There are more than one way to find a proper label. One is to derive it from the parent label, that would be the wind flow potential, the other way is to use a label that is close a term that is used in the domain like wind energy potential. Important: the two options are not exclusive, we can e.g. label the class wind flow potential and additionally give the class the alternative term wind energy potential. One example in our ontology is the class wind rotor which can also be found by its alternative term wind turbine.

• _A stock potential is a quantity value that describes the upper limit of a stock value of a source or sink in an n-dimensional region. An example is the coal potential of Germany that is the amount of coal available in the soil in Germany._

* Coal is by definition not in the soil.  "… available for production in Germany" will do.

* This presupposes that the stock value of "the amount of coal available […] in Germany" is included in the ontology, in order to attach the quantity value, right?

To me, this term available for production would imply something like a technological potential, but the example is about a potential in general. What about _... amount of coal available below the surface of Germany._?

[stap-m]

I'd exclude the example from the def. There is an annotation "example of usage", where the example can be included.
And let's remove the terms "value" from the def.
I adjusted as follows:
_A flow potential is a quantity value that describes the upper limit of an input or output of a process in a spatial region of reference per unit time._
_A stock potential is a quantity value that describes the upper limit of a stock of a source or sink in a spatial region of reference._

And I'd rather not implement a class wind energy/flow potential. We have relations for that.

[l-emele]

I'd exclude the example from the def. There is an annotation "example of usage", where the example can be included.
And let's remove the terms "value" from the def.
I adjusted as follows:
_A flow potential is a quantity value that describes the upper limit of an input or output of a process in a spatial region of reference per unit time._
_A stock potential is a quantity value that describes the upper limit of a stock of a source or sink in a spatial region of reference._

I agree.

And I'd rather not implement a class wind energy/flow potential. We have relations for that.

Good point. Procedural suggestion: We implement the potential classes and then close this issue.

For the _application_ of these classes we should create a separate issue. Also we should keep in mind that we decided yesterday that concrete realisations of potentials (like wind energy potential in Germany) will be individuals. I forgot that, too, when writing my last comment.

[Vera-IER]

Procedural suggestion: We implement the potential classes and then close this issue.

Do you mean by potential classes only the flow potential and the stock potential or also their subclasses like theoretical/technical/economic flow potential and so on?

[l-emele]

Procedural suggestion: We implement the potential classes and then close this issue.

Do you mean by potential classes only the flow potential and the stock potential or also their subclasses like theoretical/technical/economic flow potential and so on?

Also these subclasses but not things like wind energy potential.

[Vera-IER]

I summed up the subclasses for flow potential and slighly addjusted their definitions:
flow potential: _A flow potential is a quantity value that describes the upper limit of an input or output of a process in a spatial region of reference per unit time._
subclasses:
theoretical flow potential: _A theoretical flow potential is a type of flow potential that identifies the physical upper limit of an input or output of a process in a spatial region of reference per unit time._
technological flow potential: _A technological flow potential is a type of a flow potential derived from a theoretical flow potential, taking account of the annual efficiency of the respective conversion technology and the additional restrictions regarding the area that is realistically available for energy generation._
economic flow potential: _An economic flow potential is a type of flow potential that identifies the proportion of the technological potential that can be utilized economically (based on economic boundary conditions)._
developable flow potential: _A developable flow potential is a type of flow potential that describes the fraction of the economic potential that can be developed under realistic conditions (regulations, environmental and social restrictions)._
sustainable flow potential: _A sustainable flow potential is a type of flow potential that takes into account all aspects of sustainability, which usually requires careful consideration and evaluation of different ecological and socio-economic aspects. The differentiation of the sustainable potential is blurred, since ecological aspects may already have been considered for the technological or economic potential, depending on the author._

If you agree to the definitions, we would need to do the same for stock potential, right?
Then implement them and open a new issue for the relations sounds good to me.

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

Spatial region has currently the subclasses zero-dimensional region (a point), two-dimensional region (an area) and three-dimensional region (a volume). This is why I called this yesterday _n-dimensional_, A one-dimensional region covering a line is currently missing, but if needed we can definitely create one. But that is topic for a different issue.

Nope, I didn't "see things." It's there. https://github.com/OpenEnergyPlatform/ontology/blob/062f910c32821d0e1d075dd524b23e8399a4f49c/src/scripts/iao/iao.owl#L2529-L2539

But my point is that potentials will _only_ be defined over areas, never over points, lines, or volumes. At least I can't think of any useful application for those. So the definitions would be more specific and less ambiguous if they were defined over an area instead of any spatial region.

flow potential: _A flow potential is a quantity value that describes the upper limit of an input or output of a process in a two-dimensional spatial region of reference per unit time._
stock potential: _A stock potential is a quantity value that describes the upper limit of a stock of a source or sink in a two-dimensional spatial region of reference._

And could we please include the alternative terms _point_, _line_, _area_, and _volume_ for the spatial regions? What was good enough for Euclid should also be good enough for BFO. ;)

flow potential: _A flow potential is a quantity value that describes the upper limit of an input or output of a process in a reference area per unit time._
stock potential: _A stock potential is a quantity value that describes the upper limit of a stock of a source or sink in a reference area._

[l-emele]

EDIT: Just two counter examples: You can definitely give a wind energy potential for Germany in the atmosphere up to a height of 200 m. So this is a 3-dimensional region. Also the worldwide coal potential has a 3-dimensional reference region as the Earth is a 3-dimensional object and the coal potential is definitely not limited to the coal lying on the Earth's surface.

The consensus in the dev meeting was n-dimensional, not 2-dimensional. Let's stick with that consensus.

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

You can definitely give a wind energy potential for Germany in the atmosphere up to a height of 200 m. So this is a 3-dimensional region. Also the worldwide coal potential has a 3-dimensional reference region as the Earth is a 3-dimensional object and the coal potential is definitely not limited to the coal lying on the Earth's surface.

Sure, one can. But nobody does – as far as I know. But who cares about usability …

[l-emele]

Just one further example, this time from literature.

Global geothermal technical potential is comparable to global primary energy supply in 2008. For electricity
generation, the technical potential of geothermal energy is estimated to be between 118 EJ/yr (to 3 km depth) and
1,109 EJ/yr (to 10 km depth).

Source: Executive Summary of Chapter 4 of the IPCC Special Report on Renewable Energy Sources and Climate
Change Mitigation, page 404.

The IPCC provides here a geothermal technical potential for spherical shells which are 3-dimensional regions.

[stap-m]

Then let's stick with spatial region and implement.