Energy

Question 1

Define Energy

Answer 1

Energy is the capacity to perform work.

You cannot waste or lose energy. Energy is not produced, it is only converted from one form to another.

Question 2

Define Work

Answer 2

Work is the application of force (𝐹) over a distance (𝑠)

Question 3

Conservation of Energy:

Answer 3

• the total amount of energy in any isolated system remains constant Energy conservation
• the practice of decreasing the quantity of energy used

–> after some time, the quality of this energy changes

Question 4

Define exergy

Answer 4

• exergy is the energy that is available to be used
• is measured in Joule
• is defined relative to an equilibrium reference
• can be identical to energy (e.g., for electricity)
• can be much less (e.g. for lukewarm water)

Question 5

Examples of energy conversions

Answer 5

▪ from chemical into electric (fossil power plant)
▪ from electric into light (lamp)
▪ from movement into electric (dynamo)
▪ from electric into movement (motor)
▪ from chemical into heat (furnace)
▪ etc

Question 6

Sources of primary energy

Answer 6

• fossil fuels (coal, oil, gas, peat)
• biomass (wood, rapeseed)
• renewable (solar, wind, hydro)
• nuclear

Question 7

Main forms of secondary energy

Answer 7

• muscle (animals, slaves, workers)
• electricity
• fuel oil
• heat
• waste (plastics, etc)

Question 8

Define Biofuels

Answer 8

fuel made from biomass, such as corn, sugarcane, rapeseed, soybean oil, palm oil

Generations:
* 1st: from food and feed
* 2nd: from residues and wastes
* 3rd: from algae
* 4rd: synthetic

Question 9

Low-carbon energy

Answer 9

carbon capture and storage (CCS)

Question 10

What Energy trends are there?

Answer 10

A definite trend towards clean energy:
- low carbon
- renewable

energy reduction:
- energy saving
- use of waste energy

opposite trends:
* heavier cars
* more stuff
* more people