APES Unit 6 Nonrenewable Energy: How We Power Society and the Tradeoffs We Make

Energy resource

Any natural resource that can be used to do work (e.g., move vehicles, run factories, heat buildings, generate electricity).

Renewable resource

A resource replenished naturally on a human time scale (years to decades, sometimes longer) if managed sustainably (e.g., solar, wind, moving water, geothermal, sustainably harvested biomass).

Nonrenewable resource

A resource that forms so slowly (often over geologic time) that it is not replaced within a human lifetime once used (e.g., fossil fuels, uranium).

Fossil fuels

Nonrenewable fuels (coal, petroleum, natural gas) formed from ancient organic matter altered by heat and pressure over millions of years; combustion releases CO2 and other air pollutants.

Externality

A cost (or benefit) of an energy system not included in the market price, such as health impacts from air pollution, ecosystem damage from mining, or climate impacts from greenhouse gases.

Primary energy

Energy in its raw form as found in nature (e.g., coal, crude oil, sunlight).

Secondary energy

Energy produced by converting primary energy into a more convenient form (e.g., electricity, gasoline).

Electricity (energy carrier)

A versatile form of secondary energy used to deliver energy to end users; it is not an energy resource itself and must be generated using a primary resource (coal, natural gas, uranium, wind, etc.).

Resource

The total amount of a material that exists (known and unknown), regardless of whether it can currently be extracted economically.

Reserve

The portion of a resource that can be extracted economically with current technology at current prices; reserves can grow or shrink as prices and technology change.

Energy consumption

The amount of energy used over time by individuals, cities, or the world; strongly influenced by population, standard of living/economic activity, and technology choices.

Per-capita energy use

Average energy use per person; helps explain why total emissions/energy demand depend on more than just population size.

Transportation sector (energy use)

Major energy-use sector dominated by petroleum-based liquid fuels (gasoline, diesel, jet fuel) because they are energy dense and easy to store and transport.

Electric power sector

The sector that converts primary fuels/resources (e.g., coal, natural gas, uranium, wind) into electricity used by homes, businesses, and industry.

Energy transition

A long-term shift in the dominant fuels and technologies a society uses (often toward more convenient or lower-emission systems) driven by cost, availability, regulation, and infrastructure.

Energy conservation

Reducing energy use by changing behavior (e.g., driving less, turning off lights).

Energy efficiency

Providing the same service with less energy input (e.g., LED lighting, better insulation, efficient motors).

Rebound effect

When efficiency improvements lower the effective cost of energy services, causing people to use more (e.g., driving more because fuel cost per mile drops).

Thermal pollution

Warming of natural water bodies from discharged waste heat (common in power plant cooling), which can lower dissolved oxygen and harm aquatic life.

Combined-cycle power plant

A natural gas power plant design that uses a gas turbine plus a second steam turbine powered by hot exhaust, producing more electricity from the same fuel (higher efficiency).

Methane leakage

Release of methane (a potent greenhouse gas) during natural gas drilling, processing, and transport; can significantly increase natural gas’s total climate impact.

Hydraulic fracturing (fracking)

Technique used to extract shale gas by injecting high-pressure fluid to fracture rock; concerns include water use, wastewater disposal, well integrity/groundwater risks, and induced seismicity from wastewater injection.

Nuclear fission

Splitting a heavy atomic nucleus (commonly uranium) into smaller nuclei, releasing heat and neutrons; the heat is used to make steam that spins a turbine to generate electricity.

Control rods

Reactor components that absorb neutrons to slow or stop the nuclear chain reaction, helping regulate power output and maintain safety.

Half-life

The time required for half of a radioactive isotope to decay; after one half-life, 50% remains (not “safe”), so long half-lives imply long-term hazardous waste isolation needs.