Energy

Question 1

2 main types of energy

Answer 1

• potential: energy in storage (ex. gravity, chemical, nuclear)
• kinetic: energy in motion (ex. electrical, sound, thermal)

Question 2

3 main pathways of energy transfer

Answer 2

• convection: hot air rises, cold air sinks
• conduction: mol by mol transfer of heat
• radiation: energy passes thru space

Question 3

Laws of Thermodynamics

Answer 3

1. energy can’t be created or destroyed, but can be converted from one form to another
2. Energy use results in dissipation, dispersion, or conversion (changes quality and quantity, but never consumed)

Question 4

entropy

Answer 4

quality of energy where low entropy is higher quality energy

Question 5

why energy is important

Answer 5

• all biogeochemical and physical actions require energy, has the capacity to change position, physical composition, and temp of matter, able to do work,

Question 6

Earth’s energy systems require:

Answer 6

• gravitational energy: holds everything downhill, used to induce motion, dictates structure of the atmosphere
• geothermal: originates in the core of the planet, rise thru the layers of the Earth, moves tectonic plates, radiogenic heat
• solar energy: primary engine for most essential processes, most energy on Earth’s surface comes from the sun, insolation is absorbed and sustains life

Question 7

features of energy

Answer 7

• Earth’s energy system is open (allows energy to be exchanged) and balanced
• laws of thermodynamics can’t be avoided
• energy production is conversion and storage
• energy use is conversion and release of energy
• energy expense enables production and use
• scale of use (parts of energy systems are global and local)
• nature of impacts (some energy sources don’t do a lot, some are damaging)
• system design (how pathways allow energy to move)
• societal considerations (sometimes isn’t interested in energy forms)

Question 8

non-renewable energy sources are:

Answer 8

• finite in supply in long-term storage
• may be depleted
• cannot be restored in the practical sense

Question 9

renewable energy sources are:

Answer 9

• involving short-term storage
• can be readily restored but can also be depleted
• most are perpetually available but spatial and temporal variability

Question 10

energy system design

Answer 10

• non-renewable based
• centralized vs distributed (a single place where energy is produced and distributed or multiple, smaller places which cuts down on waste)
• wasteful and inefficient (emit heats and other waste)
• lack of full-cost accounting (cost fo energy production should consider waste production too)

Question 11

non-renewable energy

Answer 11

finite quantity, unable to be replenished, unsustainable, will be depleted

Question 12

renewable energy

Answer 12

supplies of energy generally not depleted by usage, may be sustainable with the right regulation and maintenance

Question 13

2 main types of non-renewable energy:

Answer 13

• combustible fossil fuels (ex. coal, oil, natural gas)
• fissionable materials (ex. nuclear)

Question 14

improvements in energy efficiency that delay transition from non-renewables:

Answer 14

• reducing impacts and saving money
• invention of energy-efficient things

Question 15

tidal power

Answer 15

energy is drawn from the interaction between solar and lunar gravity on the rotating world ocean, alternating land- and seaward currents generate electricity (tide comes in and again when it goes out, turbines are driven by this direction), perpetually available, has potential impacts on tidal zone habitats, only a few, ideal locations

Question 16

wave energy

Answer 16

produced when electricity generators are placed on the surface of the ocean and energy can be derived from the waves as they move across water, equipment is susceptible to erosion in water, potential is huge but low actualization

Question 17

hydropower

Answer 17

flowing or falling water spins turbines, forms largest percentage of global renewable energy, has expensive construction costs, a reservoir may be required

Question 18

env consequences of hydropower

Answer 18

• damage to ecosystems and species
• displaces humans
• reduces downstream flows (which leads to fish habitat degradation)
• reservoirs become sediment traps
• danger of dap collapse and downstream flooding
• alters streamflow regimes
• increases waterborne diseases and evaporation losses

Question 19

geothermal power

Answer 19

uses energy from Earth’s interior, heat pumps are placed in the ground and pump cold water down to make warm water come up and heat is circulated, expensive to install, very efficient, has a lot of potential, perpetually available

Question 20

direct solar power

Answer 20

energy is generated from solar heating via heliostats and photovoltaic cells that concentrate solar power, perpetually available, heliostats are used to warm water and drive turbines, dependent on the length of days and weather patterns

Question 21

passive solar heating

Answer 21

captures sunlight within the building’s materials and releases heat during periods of the absence of the sun, highly efficient, cost-effective, restrictive building design,

Question 22

indirect solar power

Answer 22

energy produced by processes that the sun influences, ex. wind, biomass, biofuels

Question 23

wind power

Answer 23

blades of turbines catch the wind and spin, generator converts mechanical energy into electricity which can be transmitted, can be on land or offshore, perpetually available, differential heating of the surface by the sun results in pressure variations that drive winds

Question 24

biomass burning

Answer 24

energy produced by burning living and dead plants and animal wastes, potentially renewable when managed properly, used on smaller scales, releases various pollutants and disproportionately affects female health

Question 25

biofuels

Answer 25

produced by milling, liquifying, fermenting, saccharification, distillation, and denaturation, mixing biofuels with other things (like fossil fuels) reduces the impact of fossil fuels but promotes deforestation (ex. methanol, ethanol, biogas)

Question 26

hydrogen power

Answer 26

uses water as a renewable storage medium and requires electrolysis to free H from O which is energy intensive, only considered renewable if renewable energy is sued to power the reaction, insufficient infrastructure to drive transition to hydrogen fuel

Question 27

nuclear fusion

Answer 27

energy is produced by a reaction between two nuclei merging to form one larger nucleus, fusion reaction has been created but cannot be controlled, it becomes self-sustaining which may lead to unlimited power,

Question 28

global energy use

Answer 28

has increased due to pop and economic growth, major disparity between developing and developed nations, greater demand for power, major energy sources are still fossil fuels, energy systems decentralization is necessary to transition away from fossil fuels

Question 29

energy co-generation

Answer 29

combined heat and power, uses steam to generate electricity and provide heating, has a lot of expansive potential, divides water into heat and electricity which can be used for diff things

Question 30

micropower generation

Answer 30

make every building its own power source, everyone makes the energy that they require individually (ex. solar panels)

Question 31

ecological economics

Answer 31

considers that our econ systems are part of the global ecosystem and that preservation of resources is critical to human development, econ system is based on resources and the ecol effects of this are far too extensive

Question 32

energy conservation

Answer 32

using less energy, improving things so they waste less energy

Question 33

energy efficiency

Answer 33

using less energy for a task