Glossary of Energy Terms "M"

Magneto Hydro Dynamics (Mhd): A means of producing electricity directly by moving liquids or gases through a magnetic field.

Manufactured Gas: Gas produced by certain processes from oil, coal or coke.

Marginal Cost: In the utility context, the cost to the utility of providing the next (marginal) kilowatthour of electricity, irrespective of sunk costs.

Market–Based Price: A price set by the mutual decisions of many buyers and sellers in a competitive market.

Marketer: An agent for generation projects who markets power on behalf of the generator. The marketer may also arrange transmission, firming or other ancillary services as needed. Though a marketer may perform many of the same functions as a broker, the difference is that a marketer represents the generator while a broker acts as a middleman.

Marsh Gas: A common term for gas that bubbles to the surface of the water in a marsh or swamp. It is colorless, odorless and can be explosive.

mcf: Thousand cubic feet as in one thousand cubic feet of natural gas having an energy value of one million British thermal units. A typical home might use six mcf in a month.

MEF: See Modified Energy Factor.

Mechanical System: See HVAC system.

Megawatt (MW): An amount of power available at a given second is measured in megawatts. A unit of energy equivalent to one thousand kilowatts (1,000 kW) or one million (1,000,000) watts.

Megawatthour (MWh): An amount of power available over a given hour is measured in megawatthours. A megawatthour is the amount of electricity that would supply the monthly power needs of a typical home having an electric hot water system. A unit of energy equivalent to one thousand kilowatthours.

Meter: A device for measuring levels and volumes of a customer's gas and electricity use.

Methane: A light hydrocarbon that is the main component of natural gas and marsh gas. It is the product of the anaerobic decomposition of organic matter, enteric fermentation in animals and is one of the greenhouse gases. The chemical formula is CH4.

Methanol: Also known as methyl alcohol, wood alcohol, chemical formula CH3OH. A liquid formed by catalytically combining carbon monoxide (CO) with hydrogen (H2) in a 1:2 ratio, under high temperature and pressure. Commercially, it is typically made by steam reforming natural gas. Also formed in the destructive distillation of wood.

Methyl Tertiary Butyl Ether (MTBE): An ether manufactured by reacting methanol and isobutylene. The resulting ether has a high octane and low volatility. MTBE is a fuel oxygenate and is permitted in unleaded gasoline up to a level of 15 percent. It is one of the primary additives used in reformulated gasoline.

Microwave: Electromagnetic radiation with wavelengths of a few centimeters. It falls between infrared and radio wavelengths on the electromagnetic spectrum. The radio wave beam can deliver electrical energy over long distances.

Middle Distillates: A general classification of fuels that includes heating oil, diesel fuel and kerosene.

Midgrade Gasoline: Gasoline having an antiknock index, i.e., octane rating, greater than or equal to 88 and less than or equal to 90. Note: Octane requirements may vary by altitude.

Mil: One–tenth of one cent, or $0.001.

Minimum Generation: Generally, the required minimum generation level of a utility system’s thermal units. Specifically, the lowest level of operation of oil–fired and gas–fired units at which they can be currently available to meet peak load needs.

mmcf: Million cubic feet as in one million cubic feet of natural gas.

Modified Energy Factor (MEF): The MEF is the official energy efficiency metric used to compare relative efficiencies of different clothes washers. The MEF considers the energy used to run the washer, heat the water, and run the dryer. The higher the MEF, the more efficient the clothes washer.

This metric has the same units as the energy factor (EF): ft3/kWh/cycle. MEF is the quotient of the capacity of the clothes container, C, divided by the total clothes washer energy consumption per cycle, with such energy consumption expressed as the sum of the machine electrical energy consumption, M, the hot water energy consumption, E, and the energy required for removal of the remaining moisture in the wash load, D. The equation is: MEF = C / (M + E + D). ENERGY STAR qualified clothes washers must have a minimum MEF of 1.80. The minimum Federal standard requirement for clothes washers is an MEF of 1.26.

Monopoly: The only seller with control over market sales.

Monopsony: The only buyer with control over market purchases.

Motor Gasoline: A complex mixture of relatively volatile hydrocarbons with or without small quantities of additives, blended to form a fuel suitable for use in spark–ignition engines. Motor gasoline, as defined in ASTM Specification D 4814 or Federal Specification VV–G–1690C, is characterized as having a boiling range of 122 to 158 degrees Fahrenheit at the 10 percent recovery point to 365 to 374 degrees Fahrenheit at the 90 percent recovery point. Motor gasoline includes conventional gasoline; all types of oxygenated gasoline, including gasohol; and reformulated gasoline, but excludes aviation gasoline. Note: Volumetric data on blending components, such as oxygenates, are not counted in data on finished motor gasoline until the blending components are blended into the gasoline.

Motor Gasoline (Leaded): Contains more than 0.05 grams of lead per gallon or more than 0.005 grams of phosphorus per gallon. The actual lead content of any given gallon may vary. Premium and regular grades are included, depending on the octane rating. Includes leaded gasohol. Blendstock is excluded until blending has been completed. Alcohol that is to be used in the blending of gasohol is also excluded.

Motor Gasoline (Unleaded): Contains no more than 0.05 grams of lead per gallon and no more than 0.005 grams of phosphorus per gallon. Premium and regular grades are included, depending on the octane rating. Includes unleaded gasohol. Blendstock is excluded until blending has been completed. Alcohol that is to be used in the blending of gasohol is also excluded.

Motor Gasoline Blending: The mechanical mixing of motor gasoline blending components, and oxygenates when required, to produce finished motor gasoline. Finished motor gasoline may be further mixed with other motor gasoline blending components or oxygenates, resulting in increased volumes of finished motor gasoline and/or changes in the formulation of finished motor gasoline (e.g., conventional motor gasoline mixed with MTBE to produce oxygenated motor gasoline).

Motor Gasoline Blending Components: Naphthas (e.g., straight–run gasoline, alkylate, reformate, benzene, toluene, xylene) used for blending or compounding into finished motor gasoline. These components include reformulated gasoline blendstock for oxygenate blending (RBOB) but exclude oxygenates (alcohols, ethers), butane, and pentanes plus. Note: Oxygenates are reported as individual components and are included in the total for other hydrocarbons, hydrogens, and oxygenates.

Motor Gasoline Grades: The classification of gasoline by octane ratings. Each type of gasoline (conventional, oxygenated, and reformulated) is classified by three grades: regular, midgrade, and premium. Note: Gasoline sales are reported by grade in accordance with their classification at the time of sale. In general, automotive octane requirements are lower at high altitudes. Therefore, in some areas of the United States, such as the Rocky Mountain States, the octane ratings for the gasoline grades may be two or more octane points lower.

• Regular gasoline: Gasoline having an antiknock index, i.e., octane rating, greater than or equal to 85 and less than 88. Note: Octane requirements may vary by altitude.
• Midgrade gasoline: Gasoline having an antiknock index, i.e., octane rating, greater than or equal to 88 and less than or equal to 90. Note: Octane requirements may vary by altitude.
• Premium gasoline: Gasoline having an antiknock index, i.e., octane rating, greater than 90. Note: Octane requirements may vary by altitude.

Municipal Electric Utility: A power utility system owned and operated by a local jurisdiction.

Municipal Solid Waste: Locally collected garbage, which can be processed and burned to produce energy.

Municipal Utility: A provider of utility services owned and operated.

Municipalization: The process by which a municipal entity assumes responsibility for supplying utility service to its constituents. In supplying electricity, the municipality may generate and distribute the power or purchase wholesale power from other generators and distribute it.