Energy and Climate Change Glossary
1. 1.5 Degree Warming Target
An often-quoted consensus on the limit of what we should view as acceptable warming.
2. 235U
Isotope primarily used for nuclear power. Found in low levels within rock, soil, and water.
3. Abundance of Energy Sources
Includes solar, wind, global fossil fuel consumption, biomass, geothermal, and hydro.
4. Adaptation
Deals with the consequences of climate change. Examples include relocating affected populations, increasing water conservation, and restoring critical habitat.
5. Areas in the US Best Suited for Solar Energy
Southwest
6. Biofuel
Produced from biomass and used as transportation fuels. Any fuel that derives from recently grown biomass. Advantages: Abundant agricultural resources, reduction in emissions, inexpensive. Disadvantages: Limited supply, deforestation, competing demands.
7. Main Biofuels
Ethanol (feedstock: any biomass with some pre-treatment) and biodiesel (feedstock: vegetable oils and animal fats).
8. Biomass Energy
Different types of biomass used for energy production include wood, waste incineration, landfill gas, crops, and alcohol fuels. Landfill gas is extracted from wells, can be used for natural gas vehicles, and can produce electricity. Environmental Concern: Deforestation. Use: Making a comeback.
9. Borehole-Heat Exchangers
Heat pumps for space heating and cooling.
10. Carbon Capture and Storage (CCS)
The process of capturing waste CO2, transporting it to a storage site, and depositing it where it will not enter the atmosphere, normally underground. Problems: Risk of CO2 leaking out, many sources of CO2 emissions are hard to capture, and it doesn’t deal with past emissions.
11. Climate Change Risks are Inequitable
Not every country is as vulnerable as another. At the same time, how do we assign responsibility for climate change and its effects?
12. Closed Carbon Cycle
CO2 from the atmosphere goes into growing plants, where the carbon is stored. When these are burned, it goes back to the atmosphere.
13. Cloud Enhancement
Generate more clouds that reflect incoming solar radiation.
14. Control Rods
Neutron-absorbing rods that help control the nuclear reaction by limiting the number of free neutrons.
15. Coolant Fluid
Transports heat away from fuel rods to prevent overheating. Loss of coolant can lead to a meltdown (e.g., Fukushima). Loss of coolant is less problematic in fusion reactors because helium is not radioactive.
16. Cost of Energy Sources
Fossil fuels, hydro, biomass, geothermal, wind, and solar. Levelized cost summarizes overall competitiveness by summing costs over lifetime and dividing by electricity produced over lifetime.
17. Doped Silicon
Heart of a PV cell. PV cells have n layers (excess of electrons) and p layers (excess of positively charged holes). Electrons migrate from the n layer to the p layer, generating an electric field and electrical current.
18. Enhanced Oil Recovery (EOR)
Using the CO2 captured during CCS to help remove oil from depleted oil fields.
19. Enhanced Weathering
Chemical reactions with rocks neutralize CO2.
20. Environmental Concerns of Different Renewable Energy Sources
Hydropower: Biodiversity. Solar Energy: Land use. Wind Turbines: Bird deaths.
21. EROI (Energy Return on Energy Invested)
Energy you get out over process energy put in.
22. Existing Geothermal Technologies
Hydrothermal systems (extracting energy from existing hydrothermal reservoirs), hot dry rock (a new technology in which cold water is pumped, and heat from Earth’s internal hot dry rock material is used to generate energy), and borehole-heat exchangers. Advantages: Low emissions of CO2. Disadvantages: Induced seismic activity. Use: Overall, it has increased, but US use has decreased.
23. Fission
Split of a nucleus of a heavy atom into smaller fragments. Advantages: Low carbon electricity. Disadvantages: Radioactive wastes.
24. Main Components of a Fission Reactor
Fuel rods (a cylindrical tube that encloses UO2 fuel within a nuclear reactor), control rods, and coolant fluid.
25. Fossil Fuels
A hydrocarbon fuel derived from living matter.
26. Fusion
Light nuclei join to form a heavier nucleus (e.g., hydrogen fusion supplies the energy emitted by the Sun). Advantages: No CO2 production, abundant resource, few radioactive waste products, no meltdown hazard. Disadvantages: We do not have the technology yet. Challenges: Confinement. Two technologies being developed to try to make fusion a usable energy source are magnetic and inertial confinement.
27. Geoengineering
Manipulation of Earth’s climate system to counteract the effects of climate change caused by greenhouse gas emissions. Schemes: Space reflectors, cloud enhancement, spraying aerosols in the stratosphere, ocean fertilization, and enhanced weathering.
28. Geothermal Energy
Dry steam extracted is used to drive a turbo-generator.
29. Half-Life
Length of time required for half of the radioactive atoms in a sample to decay.
30. Highest Emitter of CO2 Today
China
31. Highest Emitters of CO2 Historically
Europe and US
32. How Does the Power of Wind Vary as Velocity Changes?
KE = 0.5 p v^3. Power increases as the cube of velocity. Wind turbines are more effective if placed higher above the ground surface because wind speed is faster.
33. Hydropower
Run-of-river spins the turbine by capturing the kinetic energy of the moving water, and the generator turns mechanical energy into electrical energy. Advantages: Abundant energy. Disadvantages: Effect on biodiversity. Use: Was a dominant source but has decreased.
34. Kyoto Protocol
Controlling global warming by setting greenhouse gas emissions targets for developed countries.
35. Meeting 1.5 Degree Warming Target
Start decreasing emissions now.
36. Meeting 2 Degree Warming Target
Start decreasing emissions by 2040.
37. Mitigation
Reduces the amount of carbon we put into the atmosphere today. Examples include increasing energy efficiency, carbon capture, and changing to non-fossil fuel energy sources.
38. Non-Financial Costs of Different Renewable Energy Sources
Environmental and intermittency.
39. Nuclear Fuel Cycle
Mining, refining, enrichment, power generation, and reprocessing.
40. Ocean Acidification
When CO2 dissolves in seawater, it reacts with water to form carbonic acid, which lowers ocean pH. Chemical Reaction: CO2 + H2O. Low pH damages aquatic environments (many fish and amphibians cannot survive), can cause leaching of heavy metals into water supplies, prevents eggs from hatching, and can cause some fish to die.
41. Ocean Fertilization
Add nutrients to the ocean to capture CO2.
42. Paris Agreement
Set important targets such as keeping warming below 2 degrees C.
43. pH
Hydrogen ion concentration. Scale of acidity from 0 to 14. It tells how acidic or alkaline a substance is. More acidic solutions have lower pH.
44. Photosynthesis
CO2 + H2O to CH2O + O2
45. Power Density
The rate of doing work per unit area or volume.
46. PV Cell
A cell that converts sunlight directly into electricity. Solar panels absorb sunlight, coils get heated, and fluid carries heat energy to the hot water heater. Advantages: No direct CO2. Disadvantages: Intermittent. Use: Was nothing but has grown.
47. Radioactive Waste Disposal
It is important to bury radioactive waste in a place that is dry and surrounded with impermeable material. It’s necessary to wait at least 50 years before burying radioactive waste to allow a decrease in heat production. Waste Disposal Sites in Operation in the USA: 77 locations, including the Waste Isolation Pilot Plant in NW. Proposed Waste Disposal Site: Yucca Mountain.
48. Radioactivity
Radioactivity causes mutations that alter genes. The higher the amount, the higher the risk.
49. Reducing CO2 Solutions
Ocean fertilization and enhanced weathering.
50. Renewables Barriers
Costs (decreasing though), low EROI, low power density, and politics.
51. Risks Associated with Climate Change
Sea level rise, extreme weather, agriculture, ecosystems/biodiversity, and ocean acidification.
52. Solar Insolation
A measure of the quantity of solar radiation received on the surface of the earth in a particular region or space in a particular period of time. Some lands with high solar insolation are not suited for solar power projects due to environmental concerns, military purposes, and population density.
53. Solar Radiation Solutions
Space reflectors, cloud enhancement, and spraying aerosols in the stratosphere.
54. Space Reflectors
Put mirrors in low orbit around Earth to reflect a portion of incoming solar radiation.
55. Spraying Aerosols in the Stratosphere
Tiny particles that reflect a portion of incoming solar radiation.
81.Stabilization wedges: Combine approaches to make up for difference between energy growth and stable emissions.
82.Use of biomass energy: It is making a comeback.
83.Use of geothermal energy: Overall, it has increased. US decreased. 84.Use of solar energy: It was nothing, but it has grown. 85.Use of water energy: It was a dominant source but it has decreased. 86.Use of wind energy: The fastest growing in the last two decades. 87.Water energy: Run of river spins the turbine by capturing the kinetic energy of the moving water, and the generator turns mechanical energy to electrical energy.
88.Wave advantage and disadvantage: Reliable energy source. Impacts on marine environment.
89.Two technologies being developed to try to make fusion a usable energy source?: Magnetic and inertialconfinement.
90.What challenges must be overcome to make a fusion reactor possible?: Confinement.
91.What chemical reaction causes ocean acidification?: CO2 + H2O
92.What geologic factors are most important in selecting a burial site for radioactive waste?: It is important to bury it in a place that is dry and surrounded with impermeable material.
93.What makes development of fusion attractive as an energy resource?: It is an abundant resource that produces no CO2, has few radioactive waste products, and has no melt-down hazard.
94.What process supplies the energy emitted by the sun?: Hydrogen fusion
95.What waste disposal sites are in operation in the USA?: 77 locations. Waste Isolation Pilot Plant in NW is one.
96.What waste disposal sites have been considered?: Proposed location at Yucca Mountain.
97.Where does 235U come from?: Low levels within rock, soil, and water.
98.Why are some lands with high solar insolation not suited for solar power projects?: Environmental concerns, military purposes, population density.
99.Why are the layers important for PV cells?: Electrons migrate from a n layer to a p layer generating an electric field and electrical current.
100.Why are wind turbines more effective if placed higher above the ground surface?: Wind speed is faster.
101.Why is a loss of coolant so problematic in a fission reactor?: Radioactivity release energy as heat. Coolant transports the heat away. If lose coolant water, then it gets too hot and melts.
102.Why is pH important for marine and other aquatic organisms?: Low pH damages aquatic environments (many fish, amphibians cannot survive), can cause leaching of heavy metals into water supplies, eggs don’t hatch, some fish die.
103.Why is radioactivity dangerous?: Radioactivity causes mutations that alter genes. The higher the amount, the higher the risk.
104.Why wait at least 50 years before burying radioactive waste?: To allow decrease in heat production.
105.Why would loss of coolant not be such a problem for a fusion reactor?: Because He is not radioactive.
106.Wind advantage and disadvantage: No direct CO2. Intermittent.
107.Wind energy: Wind moves turbine which turns kinetic energy to mechanical energy, and the generator turns mechanical energy to electrical energy.