03011 Energy Definitions

Coal, oil and gas are called fossil fuels, because they derive from fossil remains of beings from long ago. The chemical energy within them is a kind of stored sunlight originally accumulated by ancient plants. Our civilization runs by burning the remains of humble creatures who inhabited the Earth hundreds of millions of years before the first humans came on the scene. Like some ghastly cannibal cult, we subsist on the dead bodies of our ancestors and distant relatives. — Dr. Carl Sagan, Billions and Billions

iPermie is not a detailed scientific treatise on energy. It discusses energy from the viewpoint of a lay person hacking a permaculture design for his or her life. In that context, here are some basic energy definitions which will be useful for your understanding of the documents and concepts in this section.

AC Short for alternating current, the kind of electricity you use when you plug something into a wall outlet that draws power from a generator or the electrical grid.

Amp Short for “ampere,” it measures the volume of electrical current flowing through an electrical circuit.

Barrel When applied to oil, a barrel equals 42 gallons. Outside of the United States, the unit of measure for oil is cubic meters or metric tonnes.

BOE Abbreviation for “Barrel of Oil Equivalent”. It measures the amount of energy contained in one barrel of oil. The actual energy content of a BOE depends on the kind of oil it contains, as different grades of crude oil yield different amounts of energy. The common average reported and often used in general calculations is 1 BOE = 1.7 megawatts of electricity = 6,000 cubic feet of natural gas = 6 gigajoules.

BPD Barrels per day, a common method of reporting oil production by well, field, province, world.

BTU British Thermal Unit. The amount of energy needed to raise the temperature of one pound of water one degree (specifically, from 39 degrees to 40 degrees Fahrenheit.)

Carrying Capacity The amount of life that a given territory can support. Fossil fuels can be used to artificially increase the carrying capacity of territory.

DC Short for Direct Current, the type of electricity you get from a battery.

Depletion Rate The rate at which oil production in a well, province, country or other area of measurement declines after production has peaked. This is sometimes referred to as the “decline rate”. “Depletion” refers to the problem of declines in oil production.

Energy storages A term used in permaculture to describe any stockpiles of energy at a given site. This refers more to storages of resources in general than it does to gasoline or diesel. This is because permaculture views material resources as embodied energy, held in a pattern that is useful to the residents of a site.

EROEI Acronym for Energy Returned on Energy Investment. Because of the Laws of Thermodynamics, when analyzed on a full life cycle basis, this is always a negative number, that is, we always get less energy out of a system than we have to put into it to generate the energy because all energy transactions, without exception, lose energy. Oil works so well for us, in making an apparent energy profit, because the original energy investment was millions of years ago in the form of ancient sunlight.

Gigajoules 1 billion joules.

Gigawatt One billion watts, or one thousand megawatts.

Horsepower 1 horsepower equals 746 watts.

Hubbert Theory A theory regarding oil production, developed by Dr. M. King Hubbert of the Colorado School of Mines, which postulates that oil production follows a bell shaped curve. It rises to a peak and then declines as fast as the original drive towards the peak.

Joule Scientific unit that has mostly replaced the BTU for scientific calculations. It equals one watt second.

Kilowatt 1000 watts. It is about equal to 1.34 horsepower. It equals 3.6 megajoules.

Kwh Abbreviation for kilowatt hour, or the consumption of electricity involved with the expenditure of 1,000 watts for one hour. It equals 3,412 BTUs.

Life Cycle Analysis A method of analysis that attempts to quantify the total energy and materials embodied in the production of any given product or the workings of any system.

MBTU 1,000 BTUs. It equals 293.07 watts.

Megawatt One million watts, or 1,000 kilowatts.

MmBD Abbreviation for Million Barrels/Day, a measure of oil

production.

Peak Oil Common name of the theory, first articulated by Dr. Hubbert, that world oil production would peak and then enter a terminal decline.

R-value A measure of thermal resistance. Materials with a high R-value slow the transfer of heat energy. Increasing the thickness of the insulating material slows the transfer of heat energy.

TANSTATEF Acronym for the phrase — “There ain’t no such thing as the energy fairy.” In other words, there is no miracle waiting in the wings to save us from our energy follies.

Terawatt One trillion watts, or one thousand gigawatts. The total power used by humans worldwide in a year is estimated at 16 terawatts.

Volt Volt is a measure of electromotive force. If we compare electricity to water in a hose, volt is a measure of the water pressure.

Watt Amps times Volts equal Watts. This is a measure of the work that electricity can do. There are 3.414 BTUs per watt.

The Three Methods of Heat Movement:

Radiation Transferal of heat energy through electro-magnetic waves. Sunlight is an example of heat transferal by radiation. It always moves from hot to cold.

Conduction Transferal of heat energy through a solid material. The direction of transfer is always heat to cold. That is, heat will always move towards cold.

Convection Transferal of heat energy by the motion of fluids (which includes air and wind), heat always moving towards cold.