Key Concepts in Energy Conservation and Resources

energy conservation

The practice of reducing energy consumption through using less energy service.

tiered rate system

A pricing structure for energy where the cost per unit increases with higher consumption levels.

peak demand

The maximum energy demand during a specific period, typically during high usage times.

passive solar design

Architecture that uses the sun's energy for heating and cooling without mechanical systems.

thermal mass

Materials that absorb and store heat energy, helping to regulate indoor temperatures.

potentially renewable

Resources that can be replenished but may not be sustainable in the long term.

nondepletable

Energy resources that cannot be exhausted, such as solar and wind energy.

renewable

Energy sources that are replenished naturally over short periods, like solar and wind.

biofuel

Fuel derived from organic materials, such as plant or animal waste.

modern carbon

Carbon derived from recently living organisms, contributing to a closed carbon cycle.

fossil carbon

Carbon that comes from fossil fuels, contributing to increased atmospheric CO2.

carbon neutral

Achieving a net-zero carbon footprint by balancing emitted and absorbed carbon.

net removal

The process of removing more carbon from the atmosphere than is emitted.

ethanol

A type of alcohol used as a biofuel, often produced from corn or sugarcane.

biodiesel

A renewable fuel made from vegetable oils or animal fats, used in diesel engines.

flex-fuel vehicle

A vehicle that can run on more than one type of fuel, typically gasoline and ethanol.

hydroelectricity

Electricity generated by the movement of water, typically from dams.

run-of-the-river

A hydroelectric generation method that does not require a large reservoir.

water impoundment

The storage of water in a reservoir for hydroelectric power generation.

tidal energy

Energy generated from the movement of tides, harnessed through turbines.

siltation/sedimentation

The accumulation of sediments in water bodies, which can affect water quality and flow.

active solar energy

Solar energy that is collected and converted into usable energy through mechanical means.

photovoltaic solar cell

A device that converts sunlight directly into electricity using the photovoltaic effect.

wind energy

Energy harnessed from wind using turbines to generate electricity.

wind turbine

A device that converts wind energy into mechanical power or electricity.

geothermal energy

Energy derived from the heat stored beneath the Earth's surface.

ground source heat pump

A system that uses the stable temperature of the ground to heat and cool buildings.

fuel cell

An electrochemical cell that converts chemical energy from a fuel into electricity.

electrolysis

A process that uses electricity to split water into hydrogen and oxygen.

smart grid

An electricity supply network that uses digital technology to monitor and manage the transport of electricity.

fossil fuel

Natural fuels formed from the remains of ancient plants and animals, such as coal, oil, and natural gas.

nonrenewable energy resource

Energy sources that cannot be replenished in a short time frame, such as fossil fuels.

nuclear fuel

Material used in nuclear reactors to produce energy through nuclear fission.

commercial energy source

Energy sources that are sold in the market, such as electricity and gasoline.

subsistence energy source

Energy sources used for basic needs, often gathered or produced locally.

EROEI

Energy Return on Energy Invested; a measure of the amount of usable energy gained from an energy resource relative to the energy expended to obtain it.

energy carrier

A substance or system that stores and delivers energy in a usable form.

turbine

A machine that converts kinetic energy from fluid flow into mechanical energy.

electrical grid

A network of transmission lines and substations that deliver electricity from producers to consumers.

combined cycle

A power plant that uses both gas and steam turbines to generate electricity.

capacity

The maximum output that a power plant can produce under specific conditions.

capacity factor

The ratio of actual output over a period of time to the maximum possible output.

cogeneration (combined heat and power)

The simultaneous production of electricity and useful heat from the same energy source.

coal

A combustible black or brownish-black sedimentary rock used as a fossil fuel.

petroleum

A liquid fossil fuel composed of hydrocarbons, used for fuel and as a raw material in the chemical industry.

crude oil

Unrefined petroleum extracted from the ground, used to produce various fuels.

oil sands (tar sands)

A mixture of sand, clay, water, and bitumen, a heavy black viscous oil.

bitumen

A thick, sticky form of crude oil found in oil sands.

CTL (coal to liquid)

A process that converts coal into liquid hydrocarbons for use as fuel.

energy intensity

The amount of energy consumed per unit of economic output, often measured in joules per GDP.

Hubbert curve

A model that predicts the production rate of a resource over time, typically used for oil.

peak oil

The point at which global oil production reaches its maximum rate, after which production will decline.

nuclear fission

The process of splitting an atomic nucleus to release energy, used in nuclear reactors.

fuel rod

A cylindrical tube containing nuclear fuel used in a nuclear reactor.

control rod

A device used in nuclear reactors to control the fission rate by absorbing neutrons.

radioactive waste

Waste material that contains radioactive substances, requiring careful disposal.

Curie

A unit of radioactivity defined as the activity of one gram of radium-226.

nuclear fusion

The process of combining atomic nuclei to release energy, as occurs in stars.

methane hydrates (clathrates)

Ice-like structures that trap methane gas, found in ocean sediments and permafrost.

fracking

A method of extracting natural gas or oil from underground by injecting high-pressure fluid.