Energy: Some Basics

Vocabulary terms and definitions related to thermodynamic laws, energy units, policy, and conservation efforts based on the lecture notes.

Work

Exerting force over a distance.

Energy

The ability to do work.

First law of thermodynamics

States that energy cannot be created or destroyed, only converted from one kind to another.

Second law of thermodynamics

States that energy always tends to go from a more usable (higher-quality) form to a less usable (lower-quality) form, often involving entropy.

Joules

The SI unit for energy, representing the energy required to move $1\,\text{meter}$ with $1\,\text{Newton}$ of Force.

Calories

A unit used in foods representing the energy to heat $1\,\text{kg}$ of water by $1\,^\circ\text{Celsius}$.

British Thermal Unit (BTU)

A US term representing the energy required to heat $1\,\text{pound}$ of water by $1\,^\circ\text{Fahrenheit}$.

Kilowatt-hour (kW-h, kWh)

A US term for electrical energy output and a billing term for electricity use.

Heat Engines

Systems used by electricity generation plants to produce work from heat by burning fuel.

Fossil Fuels

Non renewable energy sources that account for $90\%$ of US energy consumption, including petroleum oil, natural gas (methane), and coal.

Energy Conservation

The practice of using less energy in everyday activities, such as carpooling or turning off lights when leaving rooms.

Energy Efficiency

Designing equipment to yield more energy output from a given amount of input energy, such as using passive light in buildings.

Cogeneration

Processes designed to capture and use waste heat to increase the overall efficiency of a typical power plant from $33\%$ to $75\%$.

Current US Energy Policy

A strategy focused on finding more fossil fuel, building larger power plants, and using energy as freely as historically done without anticipating production reductions.

Energy Policy for the 21st century

A strategy to promote conventional and alternative energy (wind, solar, geothermal, hydrogen, biofuels), provide for local infrastructure, and promote conservation measures.

Energy Sectors

The three categories where energy consumption is distributed: Residential/commercial, Industrial, and Transportation.