APES Energy Test

Energy

The ability to do work or make something move.

Work (Formula)

Work = Force × Distance.

Power (Formula)

Power = Energy / Time (Rate at which work is done).

Joule (J)

The basic metric unit of energy. (1 N · m).

Watt (W)

The unit of power. (1 Joule/second).

Kilowatt-hour (kWh)

A unit of energy (not power), used for household electricity bills. (1 kWh = 3,600,000 Joules).

British Thermal Unit (BTU)

The energy required to heat 1 lb of water by 1°F.

1st Law of Thermodynamics

Energy is conserved; it cannot be created or destroyed, only converted.

2nd Law of Thermodynamics

When energy changes form, some quality is lost (usually as waste heat); entropy increases.

1st Law Efficiency

Work Done / Energy Used.

2nd Law Efficiency

Minimum Energy Needed / Actual Energy Used (indicates potential for savings).

Cogeneration (Combined Heat and Power)

Using a fuel to generate electricity and using 'waste' heat for useful heating. Efficiency can reach 90%.

Typical efficiency of a Coal Power Plant

30-40%.

Typical efficiency of an Incandescent Light Bulb

5% (95% lost as heat).

EROEI

Energy Return on Energy Investment (Energy Obtained / Energy Invested).

Hard Path

Finding more fossil fuels and building larger power plants (Quantity over Quality).

Soft Path

Energy efficiency, conservation, and renewable sources.

Negawatt

A theoretical unit representing a watt of energy saved through conservation.

Coal formation

From ancient swamp vegetation (terrestrial plants) buried and compressed over millions of years.

Stages of Coal formation

Peat → Lignite → Sub-bituminous → Bituminous → Anthracite.

Primary pollutants from burning coal

CO₂, Sulfur Dioxide (SO₂), Nitrogen Oxides (NOₓ), Particulates (PM), Mercury, and Arsenic.

Methylmercury

Formed when mercury from coal enters aquatic ecosystems; highly toxic and bioaccumulates in fish.

Acid Mine Drainage

When water interacts with sulfur in coal mines to form sulfuric acid, leaching metals into groundwater.

Mountaintop Removal

A destructive mining technique where the top of a mountain is removed to access coal seams.

Centralia, PA case study

An underground coal mine fire that has been burning for 50+ years, resulting in town abandonment.

Formation of Oil and Natural Gas

From ancient marine microorganisms (phytoplankton) buried under ocean sediment.

Region with largest Oil Reserves

The Middle East (Venezuela, Saudi Arabia).

Country with largest Natural Gas Reserves

Russia.

Cleanest burning fossil fuel

Natural Gas (Methane); emits ~60% less CO₂ than coal.

Fracking (Hydraulic Fracturing)

Injecting water, sand, and chemicals at high pressure to crack rock and release trapped gas/oil.

Risks of Fracking

Groundwater contamination, induced earthquakes, and high water usage.

Tar Sands (Oil Sands)

Deposits of sand/clay containing Bitumen (thick, sticky heavy oil); major reserves in Alberta, Canada.

Keystone XL Pipeline

A controversial pipeline designed to transport Tar Sands oil from Canada to US refineries.

Hubbert Curve

A graph projecting the point of peak oil production followed by decline.

Methane Hydrates (Clathrates)

Methane trapped in ice crystals on the ocean floor; huge potential energy but risky to extract.

ANWR controversy

Debate over drilling for oil in the Arctic National Wildlife Refuge, a fragile ecosystem.

Major Oil Spills

Exxon Valdez (1989, Alaska) and Deepwater Horizon (2010, Gulf of Mexico).

Nuclear reactor energy generation

Fission (splitting an atom).

Primary fuel for nuclear reactors

Uranium-235 (must be enriched).

Function of Control Rods

Absorb neutrons to slow down or stop the chain reaction.

Function of Containment Building

Concrete/steel shell designed to prevent radiation from escaping into the environment.

Output of a nuclear Cooling Tower

Water vapor (steam); NOT radioactive.

Breeder Reactor

A reactor that creates more fissile fuel (Plutonium-239) than it consumes.

Types of radiation emissions

Alpha (α, blocked by paper), Beta (β, blocked by foil), Gamma (γ, requires thick lead/concrete).

Half-Life

The time taken for 50% of a radioactive isotope to decay.

Safe radioactive waste consideration

10 Half-Lives.

Storage of High-Level Waste in the US

On-site at power plants (in pools or dry casks).

Yucca Mountain

The proposed permanent underground storage site for US nuclear waste (canceled/stalled).

Three Mile Island accident (1979)

Partial meltdown due to pump failure/human error; small release; stopped new US plant orders.

Chernobyl accident (1986)

Complete meltdown and explosion in Ukraine; massive radiation release.

Fukushima accident (2011)

Earthquake + tsunami disabled cooling pumps; three reactors melted down.

Passive Solar design

Building orientation and materials used to heat a home without pumps/fans.

Photovoltaic (PV) Cells

Silicon wafers that convert sunlight directly into electricity.

Active Solar

Using mechanical pumps/fans to circulate fluids heated by the sun.

Main drawback of Wind Energy

Intermittent (wind doesn't always blow), visual/noise pollution, bird/bat deaths.

Largest source of renewable electricity in the US

Biomass or Wind/Hydro depending on year.

Drawbacks of Hydroelectric Dams

Flood habitat upstream, disrupt fish migration, sediment buildup.

Geothermal Energy

Using heat from the Earth's interior; high efficiency, location-specific.

Hydrogen Fuel Cell

A device that combines Hydrogen (H₂) and Oxygen (O₂) to produce electricity and Water (H₂O).

OTEC

Ocean Thermal Energy Conversion; uses temperature difference between warm surface and cold deep water to generate power.

Baseload power

The minimum amount of power the grid needs 24/7, usually supplied by coal or nuclear.

Peaker Plants

Plants that turn on quickly to meet high demand, usually natural gas.

Smart Grid

A modernized grid with two-way communication between utility and consumer to manage demand efficiently.

Net Metering

A system where solar panel owners can sell excess electricity back to the grid.

Sector consuming the most energy in the US

Industrial (32%), Transportation (28%).

Percentage of US energy from non-renewable sources

~88% (roughly 81% fossil fuel + nuclear).

Iodine-131 (Human Health Impact)

A radioactive isotope that bioaccumulates in the thyroid gland (mimicking iodine), causing cancer.

Strontium-90 (Human Health Impact)

A radioactive isotope that bioaccumulates in bones (mimicking calcium), causing leukemia and bone cancer.

Thermal Pollution

The release of waste heat (warm water) into water bodies; it lowers Dissolved Oxygen (DO) levels and stresses aquatic life.

Capacity Factor

The fraction of time a power plant actually operates in a year (Nuclear is high ~90%; Wind/Solar are lower).

Subsistence Energy

Energy gathered by individuals for immediate needs (wood, charcoal, animal waste); predominant in developing nations.

Commercial Energy

Energy sources that are bought and sold (coal, oil, natural gas); predominant in developed nations.

Low-Level Radioactive Waste (LLW)

Items contaminated with small amounts of radiation (clothing, tools, rags) from hospitals or labs; stored in steel drums/shallow trenches.

Sieverts (Sv) / Rems

Units used to measure the biological *dose* or damage of radiation on human tissue.

Becquerels (Bq) / Curies

Units used to measure the rate of radioactive *decay* (activity) of a material.

Bitumen

A thick, sticky, heavy oil found in Tar Sands that must be refined to be useful.

CAFE Standards

Corporate Average Fuel Economy; government regulations that require vehicles to meet a minimum fuel efficiency (mpg).

Moderator (Nuclear)

A component (usually water) used to slow down neutrons so they can trigger fission.

Nuclear Fusion

Joining light nuclei (like Deuterium and Tritium) to form Helium; releases massive energy with no meltdown risk or high-level waste.

Concentrated Solar Power (CSP)

Technology that uses mirrors to concentrate sunlight to heat a fluid and make steam for turbines (unlike PV which creates electricity directly).

Transformer (Grid)

A device that increases voltage for efficient transmission and decreases it for safe use in homes.

Anthracite Coal

The highest quality of coal: metamorphic, hardest, highest energy content, and low sulfur.

Lignite Coal

A low quality coal (below sub-bituminous); crumbly, low heat energy, and low sulfur.

Kinetic vs. Potential Energy

Kinetic is energy of motion (wind, flowing water); Potential is stored energy (chemical bonds in fossil fuels, water behind a dam).

LED Efficiency

Light Emitting Diodes convert 85–95% of energy into light, compared to only 5–15% for incandescent bulbs.

Nuclear power plant diagram (no term j an image to study)