energy
(physics) a thermodynamic quantity equivalent to the capacity of a physical system to do work; the units of energy are joules or ergs
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent handle energy with its form, quantity, unit and conversion, and keep energy separate from power and from everyday uses of the word.
In physics, a conserved quantity equivalent to the capacity of a physical system to do work, existing in forms such as kinetic, potential, thermal, chemical, electrical and radiant energy, measured in joules.
What it is for: Explaining physical change and powering everything people do, from food to electricity.
It can be measure it, in joules or kilowatt-hours; convert it between forms, with losses; store it, in batteries, fuels and reservoirs; transmit it, as electricity or heat.
Distinguishing features
Conserved in isolated systems
Different from power, which is energy per time
Converted between forms, never created
Activation energy and alternating current are related concepts, not forms
What it looks like
Not visible itself; seen through its effects: motion, heat, light, electric current.
Physical character
SI unit: joule J - 1 kWh = 3.6 MJ
food energy: 1 kcal = 4.184 kJ
How it is recognised
Values in J, kWh, cal or eV
Meters on electricity and gas supplies
Power (W) is a rate, not energy
Related models
is confused with - rate of energy transfer
is measured by - useful output over input
is supplied as - energy carriers
is a kind of - SI derived quantity
In practice
Families and kinds
kinetic and potential
thermal
chemical
electrical
radiant
nuclear
Identifiers
SI unit symbol J joule
Standards and regulation
SI Brochure
Energy market and metering regulation
Energy labelling and efficiency law
Failure modes and hazards
Confusing kW and kWh
Stored energy hazards: batteries, pressure, height
Electrical shock and arc flash
Analytical facets
- substance
- energy
- origin
- natural
- agency
- inert
- mobility
- not-applicable
- scale
- not-applicable
- affordances
- observable
Also called
+136
Where this came from
oewn:2024 · CC BY 4.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Form and quantity What energy and how much.
Form and amount are the basic facts.
Form
Kinetic, thermal, chemical.
Form
The form of energy.
- In what form is the energy? definition
- What system holds it? definition
Amount
Joules or kWh.
Amount
The quantity and unit.
- How much energy, in which unit? measurement
- Is this energy or power? boundary
Conversion Changing form.
Every conversion has losses.
Process
How it converts.
Conversion
The conversion process.
- Which conversion takes place? definition
- How efficient is it? measurement
Losses
Heat and other losses.
Losses
Where energy is lost.
- Where is energy lost? measurement
- Can losses be reduced? action
Storage and supply Keeping and delivering energy.
Storage and supply shape energy systems.
Storage
Batteries, fuels, reservoirs.
Storage
How energy is stored.
- How is energy stored, and how much? measurement
- What hazards does the store present? boundary
Supply
Electricity and fuels.
Supply
Supply and metering.
- How is it supplied and metered? definition
- What does it cost per kWh? measurement
Safety Released energy.
Uncontrolled release of energy causes injury.
Hazards
Electrical, thermal, mechanical.
Hazards
Hazards from stored energy.
- Which hazards come from this energy? boundary
- How is it isolated before work? action
Limits
Standards and limits.
Limits
Applicable limits.
- Which safety standards apply? provenance
- Who is qualified to work on it? boundary
What the second pass must settle
- Should forms of energy be separate entries?
- How should energy carriers be linked?
- The registry entry has merged aliases such as alternating current; should they be split off?