Forms of energy

• Potential: Stored energy
• Kinetic: Energy of motion
• Chemical: Energy stored in the bonds of atoms and molecules
• Nuclear: Energy stored in the nucleus of an atom
• Gravitational: Energy stored in an object's height
• Radiant: Electromagnetic energy travels in transverse waves
• Thermal: Vibration and movement of atoms and molecules within substances
• Electrical: Delivered by charged particles called electrons, typically moving through a wire

Energy Classification

Energy Classification Definitions

Primary energy is the energy as it is available as resources: coal, uranium, oil, gas, etc.

Secondary energy is converted into a transportable form, e.g. electricity, gasoline and diesel, or heat.

Final energy is delivered secondary energy: gasoline at the fuel pump, electricity in your home.

Useful energy is the energy that goes towards the desired output as opposed to waste energy. For example, when you run in internal combustion gasoline engine, some energy is lost as heat.

Based on this post from Hannah Ritchie

Energy Classification

• Primary vs. Secondary vs. Final vs. Useful Energy
  • See post from Hannah Ritchie mentioned above
• Renewable and Non-Renewable Energy

  Renewable energy is energy derived from natural processes that are replenished at a rate that is equal to or faster than the rate at which they are consumed, e.g. energy generated from solar, wind, geothermal, hydropower and ocean resources.

• Clean vs Dirty Energy
  • Clean energy is a broader category, e.g. may include nuclear, waste heat capture, etc.
• Commercial and Non-Commercial
• Conventional and Non-Conventional
  • Conventional tends to be a moving target

Energy Losses

Calculating Energy Shares

• Direct vs. Substitution Methods for calculating shares of primary energy

  • See yet another post from Hannah Ritchie

• direct calculations look at the energy supplied via, for example, oil and natural gas, but does not take account of the energy lost in conversion processes.

• substitution method essentially omits the energy wasted in creating that eventual, useful energy that was consumed

Energy Shares

Energy Shares

Energy Shares

Energy Shares

Calculating Energy Shares

From Hannah Ritchie's post:

• Low-carbon’s share in direct primary energy = % of total primary energy consumption (including all of the inefficiencies of fossil fuel production)

• Low carbon’s share in substituted primary energy = % of useful energy (once we subtract all of the wasted energy in the burning of fossil fuels)

Renewable Energy Generation

Renewable Energy Generation is Growing Fast

Clean vs. Dirty Energy

This will be the first and (I hope) last pie chart we use in this class

US Primary Energy

 Source site link

Canadian Primary Energy Production

Measurement Classifications

"Wherever mechanical force is expended, an exact equivalent of heat is always obtained"
   - James Prescott Joule, 1843

Richard Feynman on units of energy

Units

• Newton (N) = $kg$ $\cdot$ $\frac{m}{s^2}$
• Joule (J) = 1 N $\cdot$ m = $kg\frac{m^2}{s^2}$ = Watt $\cdot$ Second
  • J = Watt $\cdot$ s.
• What is a Watt?
  • Hint: Watt=Work/time
• How many J's do average Albertans use annually?
  • 130,000,000,000 J
• Perhaps, we should choose a different unit?
  • 130,000,000,000 J = 130 GJ
• What about for all Albertans?
  • Scale up to a petajoule, PJ, or ${10}^{15}$ Joules

Units

Where might you run into some of these units?

• check you phone/laptop charger (Apple 29W charger, for e.g.)

• check your breaker panel at home - you'll see breakers in amps (15A, 20A, 30A, 40A and maybe 100A breakers)

  • Household circuits are 120 volts or 240 volts (think pressure of the electricity)
  • Amps multiplied by volts equals watts, so a 15A breaker at 120 volts (usual room outlets) have a capacity of 15*120=1,800W.

• check your hairdryer (1500W?)

How much energy do appliances use?

Units

Where might you run into some of these units?

• check you phone/laptop charger (Apple 29W charger, for e.g.)

• check your breaker panel at home - you'll see breakers in amps (15A, 20A, 30A, 40A and maybe 100A breakers)

  • Household circuits are 120 volts or 240 volts (think pressure of the electricity)
  • Amps multiplied by volts equals watts, so a 15A breaker at 120 volts (usual room outlets) have a capacity of 15*120=1,800W.

• why are you likely to blow a breaker if you run the toaster and the kettle at the same time?

Units in practice

Mechanical energy measurements: kWh

Thermal energy: Btus and Calories

Commercial measures: toe and tce

• toe (tonne of oil equivalent) is the amount of energy released by burning one tonne (metric ton) of crude oil
  • 1 toe $\approx$ 7.25 barrel of oil equivalent
  • 1 toe = 41.87 gigajoules (GJ)
  • 1 toe = 39,683,205 Btu (39.7 mmBtu)
• Converting the other way:
  • One tonne of gasoline is 1.070 toe
  • One tonne of diesel oil is 1.035 toe
  • One tonne of Liquefied petroleum gas (propane) is 1.130 toe
• 1 ton of coal equivalent = 1 tce = 29.3076 GJ

Conversion Factor Reference

 Source: IEA (2019), "World energy balances".

Energy Accounting

 International Recommendations for Energy Statistics (IRES).

Energy Balance

 International Recommendations for Energy Statistics (IRES).

You need to know the TPES formula here:

 Source: IEA (2019), World energy balances.

Accounting in Practice: Canadian natural gas

 Source: IEA (2024)

Energy Flow Visuals

 Source data: IEA (2022), Sankey diagrams, Canada

Energy Use by Sector and Source

 EIA Energy Facts Explained