GALLON - A volumetric measure equal to 4 quarts (231 cubic inches) used to measure fuel oil. One barrel equals 42 gallons.
GAS - Gaseous fuel (usually natural gas) that is burned to produce heat energy. The word also is used, colloquially, to refer to gasoline.
GAS UTILITY - Any person engaged in, or authorized to engage in, distributing or transporting natural gas, including, but not limited to, any such person who is subject to the regulation of the Public Utilities Commission.
GASIFICATION - The process where biomass fuel is reacted with sub- stoichiometric quantities of air and oxygen usually under high pressure and temperature along with moisture to produce gas which contains hydrogen, methane, carbon monoxide, nitrogen, water and carbon dioxide. The gas can be burned directly in a boiler, or scrubbed and combusted in an engine-generator to produce electricity. The three types of gasification technologies available for biomass fuels are the fixed bed updraft, fixed bed downdraft and fluidized bed gasifiers. Gasification is also the production of synthetic gas from coal.
GASOHOL - In the United States, gasohol (E10) refers to gasoline that contains 10 percent ETHANOL by volume. This term was used in the late 1970s and early 1980s but has been replaced in some areas of the country by terms such as E-10, Super Unleaded Plus Ethanol, or Unleaded Plus.
GASOLINE - A light petroleum product obtained by refining oil, and used as motor vehicle fuel.
GAS SYNTHESIS - A method producing synthetic gas from coal. Also called the FISCHER-TROPSCH PROCESS.
GENERAL LIGHTING - Lighting designed to provide a substantially uniform level of illumination throughout an area, exclusive of any provision for special visual tasks or decorative effects. [See California Code of Regulations, Title 24, Section 2-5302]
GENERATING STATION - A power plant.
GENERATION COMPANY (GENCO) - A regulated or non-regulated entity (depending upon the industry structure) that operates and maintains existing generating plants. The Genco may own the generation plants or interact with the short term market on behalf of plant owners. In the context of restructuring the market for electricity, Genco is sometimes used to describe a specialized "marketer" for the generating plants formerly owned by a vertically-integrated utility.
GENERATION DISPATCH AND CONTROL - Aggregating and dispatching (sending off to some location) generation from various generating facilities, providing backups and reliability services. Ancillary services include the provision of reactive power, frequency control, and load following.(Also see "Power Pool" and "Poolco" below.)
GEOTHERMAL ELEMENT - An element of a county general plan consisting of a statement of geothermal development policies, including a diagram or diagrams and text setting forth objectives, principles, standards, and plan proposals, including a discussion of environmental damages and identification of sensitive environmental areas, including unique wildlife habitat, scenic, residential, and recreational areas, adopted pursuant to Section 65303 of the Government Code.
GEOTHERMAL ENERGY - Natural heat from within the earth, captured for production of electric power, space heating or industrial steam.
GEOTHERMAL GRADIENT - The change in the earth's temperature with depth. As one goes deeper, the earth becomes hotter.
GEOTHERMAL STEAM - Steam drawn from deep within the earth.
GH2 - Gaseous hydrogen. At room temperature (above -253° C or 20 K, to be exact) hydrogen is gaseous independent of the pressure.
GIGAWATT (GW) - One thousand megawatts (1,000 MW) or, one million kilowatts (1,000,000 kW) or one billion watts (1,000,000,000 watts) of electricity. One gigawatt is enough to supply the electric demand of about one million average California homes.
GIGAWATT-HOUR (GWH) - One million kilowatt-hours of electric power. California generated about 290,000 gigawatt-hours of electricity in 2004.
GLAZING - A covering of transparent or translucent material (typically glass or plastic) used for admitting light.
GLOBAL CLIMATE CHANGE - Gradual changing of global climates due to buildup of carbon dioxide and other greenhouse gases in the earth's atmosphere. Carbon dioxide produced by burning fossil fuels has reached levels greater than what can be absorbed by green plants and the seas graphite storage
GRAPHITE STORAGE - Carbon is able to adsorb hydrogen. The amount of adsorbed hydrogen depends on temperature, pressure and the quality/ structure of the carbon used. Carbon structures in the nanometers range (one nanometer corresponds to 10-9 meters), e.g. balls, tubes or fibers, seem to be very promising. The developments are in a very early stage.
GREENHOUSE EFFECT - The presence of trace atmospheric gases make the earth warmer than would direct sunlight alone. These gases (carbon dioxide [CO2], methane [CH4], nitrous oxide [N2O], tropospheric ozone [O3], and water vapor [H2O]) allow visible light and ultraviolet light (shortwave radiation) to pass through the atmosphere and heat the earth's surface. This heat is re-radiated from the earth in form of infrared energy (longwave radiation). The greenhouse gases absorb part of that energy before it escapes into space. This process of trapping the longwave radiation is known as the greenhouse effect. Scientists estimate that without the greenhouse effect, the earth's surface would be roughly 54 degrees Fahrenheit colder than it is today - too cold to support life as we know it. See GLOBAL CLIMATE CHANGE.
GREENHOUSE EFFECT (relating to buildings) - The characteristic tendency of some transparent materials (such as glass) to transmit radiation with relatively short wavelengths (such as sunlight) and block radiation of longer wavelengths (such as heat). This tendency leads to a heat build-up within the space enclosed by such a material.
GRID - A system of interconnected power lines and generators that is managed so that the generators are dispatched as needed to meet the requirements of the customers connected to the grid at various points. Gridco is sometimes used to identify an independent company responsible for the operation of the grid.
GRID - The electric utility companies' transmission and distribution system that links power plants to customers through high power transmission line service (110 kilovolt [kv] to 765 kv); high voltage primary service for industrial applications and street rail and bus systems (23 kv-138 kv); medium voltage primary service for commercial and industrial applications (4 kv to 35 kv); and secondary service for commercial and residential customers (120 v to 480 v). Grid can also refer to the layout of a gas distribution system of a city or town in which pipes are laid in both directions in the streets and connected at intersections.
GROSS AREA - The area of a surface including areas not belonging to that surface (such as windows and doors in a wall).
GROSS NATIONAL PRODUCT (GNP) - The total market value of the goods and services produced by a nation before deduction or depreciation charges and other allowance for capital consumption and is widely used as a measure of economic activity.
GWh - Gigawatt hours. The standard unit of measure for the total amount of energy produced over a period of time. One gigawatt is 1,000 MW.