Losses of Energy Transfer

[NormanZielke]

Description of the issue

I would implement three concepts for losses of energy transfer.

1. charging losses
2. discharging losses
3. self-discharging losses

Ideas of solution

Energy losses as new entity with subconcepts.
Energy losses occur due to irreversible and/or inefficient transformation processes and physical effects.
They can be caused by various mechanisms, depending on the type of energy storage device.

1. charging losses
   Charging Losses are losses of Energy which occured by transfering energy to an energy storage.

2. discharging losses
   Discharging Losses are losses of Energy which occured by transfering energy from an energy storage.

3. self-discharging losses
   Self-discharge losses in energy storage refer to the inevitable energy losses that occurs when an energy storage device loses energy without transfering energy actively from it.

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]

This is related to #1414.

[l-emele]

I think, it is helpful to define a general energy loss first. Here is a first proposal: An energy loss is a process attribute that describes the difference of usable energy input and output of an energy transformation.

[NormanZielke]

According to #1414 and your defintion of energy loss, i have a new approach.
Two proposals for Charging losses:

1. Charging Losses are energy losses that describes the share of non-usable ernergy of an energy transfer
   of the input energy to an energy storage process.

Or i think a better approach could be:

2. Charging Losses describes the difference between the input energy and the useful changing
   state of charge for an energy storage process.

[stap-m]

I think, it is helpful to define a general energy loss first. Here is a first proposal: An energy loss is a process attribute that describes the difference of usable energy input and output of an energy transformation.

Good point.
We have waste heat in OEO: Waste thermal energy is thermal energy that is the physical output of an energy transformation process and that is released into the environment unused. We shoud somehow mention or relate it.

Further, besides energy that is not usable there might be a share of energy that might be reusable in side applications, but is not.

What about: Energy loss is a process attribute that describes the share of energy that is (unintentionally) transformed into non-usable or unused energy, e.g. waste thermal energy, during an energy transformation or transfer process.

[NormanZielke]

What about: Energy loss is a process attribute that describes the share of energy that is (unintentionally) transformed into non-usable or unused energy, e.g. waste thermal energy, during an energy transformation or transfer process.

With @stap-m 's contribution, I have adapted my definition.

Charging Loss is an Energy loss, that describes the difference between the input energy and the useful changing
state of charge for an energy storage process during a charging process.

Discharging Loss is an Energy loss, that describes the difference between the changing
state of charge for an energy storage process and the useful output energy during a discharging process.

[l-emele]

I thought about this again. Consider the following example:

You have 10 J of electrical energy. You charge a battery, 9 TJ are stored energy in the battery, and 1 TJ are charging losses. Then you discharge the battery, you get 8 TJ of electrical energy and 1 TJ of discharging losses. So both charging losses and are also energies. Following its definition a process attribute¹ needs to be an occurent. But energy (and also energy amount value) is a continuant.

Footnotes

1. A process attribute is a dependent occurrent that existentially depends on a process. ↩

[areleu]

I thought about this again. Consider the following example:

You have 10 J of electrical energy. You charge a battery, 9 TJ are stored energy in the battery, and 1 TJ are charging losses. Then you discharge the battery, you get 8 TJ of electrical energy and 1 TJ of discharging losses. So both charging losses and are also energies. Following its definition a process attribute1 needs to be an occurent. But energy (and also energy amount value) is a continuant.

Footnotes

1. _A process attribute is a dependent occurrent that existentially depends on a process._ [↩](#user-content-fnref-1-d506783eb58717610ffcf34e43535d40)

I consider that process attributes should be able to refer to the quantification of different dimensions of processes. The process comprises of a net amount of "actual" energy that changes across its duration. But its magnitude can be divided in an arbitrary way depending on how it flows during the process itself. Different quantities of energy can be used to describe the same process, these can be things like losses of a battery charging or the calories burned when biking home. Both examples describe energy of some process without considering the total energy involved respectively. So I would argue that assigning it a number that refers to the attributes of particular processes should be possible and these descriptions (actual energy and quantified energy) should be able to coexist. The three would look something like this:

Process>has attribute>quantified energy(i.e. losses)>has quantity value>some value

This is one of the points that I am trying to get across in #1812 . Realized energy is differentiated from potential energy by the fact that the former can be quantified arbitrarily.

[areleu]

I think, it is helpful to define a general energy loss first. Here is a first proposal: An energy loss is a process attribute that describes the difference of usable energy input and output of an energy transformation.

I would suggest using this as an elucidation and do the description more concise and less "mathematical". Something like:

An energy loss is a process attribute that describes the amount of non-usable energy of an energy transformation.

What about: Energy loss is a process attribute that describes the share of energy that is (unintentionally) transformed into non-usable or unused energy, e.g. waste thermal energy, during an energy transformation or transfer process.

With @stap-m 's contribution, I have adapted my definition.

Charging Loss is an Energy loss, that describes the difference between the input energy and the useful changing state of charge for an energy storage process during a charging process.

Discharging Loss is an Energy loss, that describes the difference between the changing state of charge for an energy storage process and the useful output energy during a discharging process.

Same suggestion, keep the detailed explanation in the elucidation and add a concise description:

Something like Charging loss is an energy loss of a charging process.

The reason I suggest this is that, to me it seems that the more specific descriptions are prescribing the concept of losses. I mean they are constraining it to a single model:losses = input_energy - output_energy. Which is probably always true and that I suggest adding it as an elucidation. But it excludes other possible models which wouldn't surprise me that exist (When dealing with electric circuits efficiencies often have complex definitions).

[carstenhoyerklick]

Some output of OEO-DEV 81:

• Process attributes are occurents, energy is a continuant
  -- Energy loss (in J) cannot be a process attribute, but relative energy losses (in percent) can.
  -- There are other types of energy lost than thermal waste energy: electromagnetic radiation, chemical recombination, vibrations...
  -- Def of waste thermal energy / waste heat: Waste thermal energy is thermal energy that is the physical output of an energy transformation process and that is released into the environment unused.
• Revisit exisiting process attributes
• Possible definition: Energy loss is energy, that is the physical output of an energy transformation process that is not used.

[madbkr]

If I understand all of this correctly, then there are two general approaches:

1. process attribute
This requires the definition to work with relative energy losses (in percent) because energy is an occurent. I would propose a definition inspired by the existing process attributes:

Relative energy loss is a process attribute that indicates the percentage of non-usable energy produced in an energy transformation, e.g. waste thermal energy. (optional: This occurs due to irreversible and/or inefficient transformation processes and physical effects )

2. energy approach
This allowes to work with energy loss. But - at least for me - I feel like we would be describing energy lost rather than energy loss. I would suggest a small change to the last formulated one:

Energy loss is energy that is the physical output of an energy transformation process that is not usable, e.g. waste termal energy.

I would suggest this because "that is not used" sounds to me like we could use it but don't want to.