Glossary of Terms - B

• B/D - Barrels per Day. Usually used to quantify a refiner's output capacity or an oilfield's rate of flow.
• Backdrafting - The flow of air down a flue/chimney and into a house caused by low indoor air pressure that can occur when using several fans or fireplaces and/or if the house is very tight.
• Backup Energy System - A reserve appliance; for example, a standby generator for a home or commercial building.
• Backwardation - Market situation in which futures prices are lower in each succeeding delivery month. Also known as an inverted market. The opposite of contango.
• Bagasse - The fibrous material remaining after the extraction of juice from sugarcane; often burned by sugar mills as a source of energy.
• Baghouse - An air pollution control device used to filter particulates from waste combustion gases; a chamber containing a bag filter.
• Balance of System - In a solar energy system, refers to all components other than the collector. In terms of costs, it includes design costs, land, site preparation, system installation, support structures, power conditioning, operation and maintenance costs, indirect storage, and related costs.
• Balance Point - An outdoor temperature, usually 20 to 45 degrees Fahrenheit, at which a heat pump's output equals the heating demand. Below the balance point, supplementary heat is needed.
• Band Gap - In a semiconductor, the energy difference between the highest valence band and the lowest conduction band.
• Band Gap Energy - The amount of energy (in electron volts) required to free an outer shell electron from its orbit about the nucleus to a free state, and thus promote it from the valence to the conduction level.
• Band-to-Band Auger Recombination - Recombination of an electron and a hole occurring between bands of the same energy in which no magnetic radiation is emitted.
• Banker's Acceptance - A draft or bill of exchange accepted by a bank; payment is guaranteed by the accepting institution.
• Barge - A vessel, either motorized or towed, used to carry products in navigable waterways. Inland river barges that carry oil products generally hold 25,000 barrels. Ocean-going barges range in size up to 120,000 barrels.
• Barrel - A unit of volume measure used for petroleum and refined products. 1 barrel = 42 U.S. gallons.
• Barrier Energy - The energy given up by an electron in penetrating the cell barrier; a measure of the electrostatic potential of the barrier.
• Basal Metabolism - The amount of heat given off by a person at rest in a comfortable environment; approximately 50 Btu per hour (Btu/h).
• Base Bill - A charge calculated through multiplication of the rate from the appropriate electric rate schedule by the level of consumption.
• Base Load - The minimum load experienced by an electric utility system over a given period of time.
• Base Load Unit - A generating unit that normally operates at a constant output to take all or part of the base load of a system.
• Base Power - Power generated by a utility unit that operates at a very high capacity factor.
• Base Rate - The portion of the total electric or gas rate covering the general costs of doing business unrelated to fuel expenses.
• Base Year - The first year of the period of analysis. The base year does not have to be the current year.
• Baseline Forecast - A prediction of future energy needs which does not take into account the likely effects of new conservation programs that have not yet been started.
• Baseline Performance Value - Initial values of Isc, Voc, Pmp, Imp measured by the accredited laboratory and corrected to Standard Test Conditions, used to validate the manufacturer's performance measurements provided with the qualification modules per IEEE 1262.
• Baseload Capacity - The generating equipment normally operated to serve loads on an around-the-clock basis.‹ The minimum amount of electric power delivered or required over a given period of time at a steady rate.
• Baseload Demand - The minimum demand experienced by a power plant.
• Baseload Plant - A plant, usually housing high efficiency steam-electric units, which is normally operated to take all or part of the minimum load of a system, and which consequently produces electricity at an essentially constant rate and runs continuously.‹ These units are operated to maximize system mechanical and thermal efficiency and minimize system operating costs.‹ examples include coal fired and nuclear fueled power plants.
• Basic Service - The four charges for generation, transmission, distribution and transition that all customers must pay in order to retail their electric service.
• Basis - The differential that exists at any time between the cash, or spot, price of a given commodity and the price of the nearest futures contract for the same or a related commodity. Basis may reflect different time periods, product forms, qualities, or locations. Cash minus futures equals basis.
• Basis Risk - The uncertainty as to whether the cash-futures spread will widen or narrow between the time a hedge position is implemented and liquidated.
• Batch - A measured amount in which crude oil and refined product shipments are sent through a pipeline.
• Batch Process - A process for carrying out a reaction in which the reactants are fed in discrete and successive charges.
• Batching Sequence - The order in which shipments are sent through a pipeline.
• Batt/Blanket - A flexible roll or strip of insulating material in widths suited to standard spacings of building structural members (studs and joists). They are made from glass or rock wool fibers. Blankets are continuous rolls. Batts are pre-cut to four or eight foot lengths.
• Battery - An energy storage device composed of one or more electrolyte cells.
• Battery Energy Storage - The three main applications for battery energy storage systems include spinning reserve at generating stations, load leveling at substations, and peak shaving on the customer side of the meter. Battery storage has also been suggested for holding down air emissions at the power plant by shifting the time of day of the emission or shifting the location of emissions.
• Bbl - The abbreviation for barrel.
• Bcf - The abbreviation for 1 billion cubic feet.
• Beam Radiation - Solar radiation that is not scattered by dust or water droplets.
• Bear - One who anticipates a decline in price or volatility. Opposite of a bull.
• Bear Market - Market in which prices are in a declining trend.
• Bear Spread - 1) The simultaneous purchase and sale of two futures contracts in the same or related commodities with the intention of profiting from a decline in prices but, at the same time, limiting the potential loss if this expectation is wrong. This can usually be accomplished by selling a nearby delivery and buying a deferred delivery. 2) A delta-negative options position comprised of long and short options of the same type, either calls or puts, designed to be profitable in a declining market. An option with a lower strike price is sold and one with a higher strike price is bought.
• Benefits Charge -The addition of a per unit tax on sales of electricity, with the revenue generated used for or to encourage investments in energy efficiency measures and/or renewable energy projects.
• Bid - A motion to buy a futures or options contract at a specified price. Opposite of offer.
• Bilateral Contract - A direct contract between the power producer and user or broker outside of a centralized power pool.
• Bimetal - Two metals of different coefficients of expansion welded together so that the piece will bend in one direction when heated, and in the other when cooled, and can be used to open or close electrical circuits, as in thermostats.
• Bin Method - A method of predicting heating and/or cooling loads using instantaneous load calculation at different outdoor dry-bulb temperatures, and multiplying the result by the number of hours of occurrence of each temperature.
• Binary Cycle - Combination of two power plant turbine cycles utilizing two different working fluids for power production. The waste heat from the first turbine cycle provides the heat energy for the operation of the second turbine, thus providing higher overall system efficiencies.
• Binary Cycle Geothermal Plants - Binary cycle systems can be used with liquids at temperatures less than 350 F (177 C). In these systems, the hot geothermal liquid vaporizes a secondary working fluid, which then drives a turbine.
• Biochemical Oxygen Demand - The weight of oxygen taken up mainly as a result of the oxidation of the constituents of a sample of water by biological action; expressed as the number of parts per million of oxygen taken up by the sample from water originally saturated with air, usually over a period of five days at 20 degrees centigrade. A standard means of estimating the degree of contamination of water.
• Bioconversion - The conversion of one form of energy into another by the action of plants or microorganisms. The conversion of biomass to ethanol, methanol, or methane.
• Bioenergy - The conversion of the complex carbohydrates in organic material into energy.
• Biogas - A combustible gas created by anaerobic decomposition of organic material, composed primarily of methane, carbon dioxide, and hydrogen sulfide.
• Biogasification or biomethanization - The process of decomposing biomass with anaerobic bacteria to produce biogas.
• Biomass - As defined by the Energy Security Act (PL 96-294) of 1980, "any organic matter which is available on a renewable basis, including agricultural crops and agricultural wastes and residues, wood and wood wastes and residues, animal wastes, municipal wastes, and aquatic plants."
• Biomass Energy - Energy produced by the conversion of biomass directly to heat or to a liquid or gas that can be converted to energy.
• Biomass Fuel - Biomass converted directly to energy or converted to liquid or gaseous fuels such as ethanol, methanol, methane, and hydrogen.
• Biomass Gasification - The conversion of biomass into a gas, by biogasification (see above) or thermal gasification, in which hydrogen is produced from high-temperature gasifying and low-temperature pyrolysis of biomass.
• Biophotolysis - The action of light on a biological system that results in the dissociation of a substrate, usually water, to produce hydrogen.
• BIPV (Building-Integrated PV) - A term for the design and integration of PV into the building envelope, typically replacing conventional building materials. This integration may be in vertical facades, replacing view glass, spandrel glass, or other facade material; into semitransparent skylight systems; into roofing systems, replacing traditional roofing materials; into shading "eyebrows" over windows; or other building envelope systems.
• Bituminous Coal - The most common coal.‹ It is dense and black (often with well-defined bands of bright and full material).‹ Its moisture content usually is less than 20 percent.‹ It is used for generating electricity, making coke, and space heating.‹ Comprises five groups classified according to the following ASTM Specification D388-84, on a dry mineral-matter-free (mmf) basis for fixed-carbon and volatile matter and a moist mmf basis for calorific value.
• Blackout - A power loss affecting many electricity consumers over a large geographical area for a significant period of time.
• Black-Scholes Model - An options pricing formula initially derived by Fisher Black and Myron Scholes for securities options and later refined by Mr. Black for options on futures.
• Blocking Diode - A diode used to restrict or block reverse current from flowing backward through a module. [UL 1703] Alternatively, diode connected in series to a PV string; it protects its modules from a reverse power flow and, thus, against the risk of thermal destruction of solar cells.
• Boiler - A vessel or tank where heat produced from the combustion of fuels such as natural gas, fuel oil, or coal is used to generate hot water or steam for applications ranging from building space heating to electric power production or industrial process heat.
• Boiler Feedwater - The water that is forced into a boiler to take the place of that which is evaporated in the generation of steam.
• Boiler Horsepower - A unit of rate of water evaporation equal to the evaporation per hour of 34.5 pounds of water at a temperature of 212 degrees Fahrenheit into steam at 212 degrees F.
• Boiler Pressure - The pressure of the steam or water in a boiler as measured; usually expressed in pounds per square inch gauge (psig).
• Boiler Rating - The heating capacity of a steam boiler; expressed in Btu per hour (Btu/h), or horsepower, or pounds of steam per hour.
• Bone (Oven) Dry - In reference to solid biomass fuels, such as wood, having zero moisture content.
• Bone Dry Unit - A quantity of (solid) biomass fuel equal to 2,400 pounds bone dry.
• Book Transfer - Transfer of title without actually delivering the product.
• Booster Pump - A pump for circulating the heat transfer fluid in a hydronic heating system.
• Boot - In heating and cooling system distribution ductwork, the transformation pieces connecting horizontal round leaders to vertical rectangular stacks.
• Boron - A chemical element, atomic number 5, semi-metallic in nature, used as a dopant to make p-semiconductor layers. The chemical element commonly used as the dopant in solar photovoltaic device or cell material.
• Bottled Gas - A generic term for liquefied and pressurized gas, ordinarily butane, propane, or a mixture of the two, contained in a cylinder for domestic use.
• Bottoming-cycle - A means to increase the thermal efficiency of a steam electric generating system by converting some waste heat from the condenser into electricity. The heat engine in a bottoming cycle would be a condensing turbine similar in principle to a steam turbine but operating with a different working fluid at a much lower temperature and pressure.
• Boule - A sausage-shaped synthetic single-crystal mass grown in a special furnace, pulled and turned at a rate necessary to maintain the single-crystal structure during growth.
• Box Spread - An options market arbitrage in which both a bull spread and a bear spread are established for a riskless profit. One spread includes put options and the other includes calls.
• Brayton Cycle - A thermodynamic cycle using constant pressure, heat addition and rejection, representing the idealized behavior of the working fluid in a gas turbine type heat engine.
• Break - A rapid and sharp price decline.
• Breakeven Point - The underlying futures price at which a given options strategy is neither profitable nor unprofitable. For call options, it is the strike price plus the premium. For put options, it is the strike price minus the premium.
• British Thermal Unit (BTU) - The amount of heat required to increase the temperature of a pound of water 1o Fahrenheit. A Btu is used as a common measure of heating value for different fuels. Prices of different fuels and their units of measure (dollars per barrel of crude, dollars per ton of coal, cents per gallon of gasoline, cents per thousand cubic feet of natural gas) can be easily compared when expressed as dollars and cents per million Btus.
• Broadband Communications - The result of utilities forming partnerships to offer consumers "one-stop-shopping" for energy-related and high-tech telecommunications services.
• Broker - 1) An individual who is paid a fee or commission for acting as an agent in making contracts, sales, or purchases. 2) A floor broker is a person who actually executes trading orders on the floor of an exchange. 3) An account executive, registered commodity representative, or customers' man who deals with customers and their orders in commission house offices. See also Futures Commission Merchant.
• Brownout - A controlled power reduction in which the utility decreases the voltage on the power lines, so customers receive weaker electric current. Brownouts can be used if total power demand exceeds the maximum available supply. The typical household does not notice the difference.
• BS&W - Bottom sediment and water, often found in crude oil and residual fuel.
• Btu - See British thermal unit.
• Building Overall Energy Loss Coefficient-Area Product - The factor, when multiplied by the monthly degree-days, that yields the monthly space heating load.
• Building Overall Heat Loss Rate - The overall rate of heat loss from a building by means of transmission plus infiltration, expressed in Btu per hour, per degree temperature difference between the inside and outside.
• Bulb Turbine - A type of hydro turbine in which the entire generator is mounted inside the water passageway as an integral unit with the turbine. These installations can offer significant reductions in the size of the powerhouse.
• Bulge - A rapid advance in futures prices.
• Bulk Density - The weight of a material per unit of volume compared to the weight of the same volume of water.
• Bulk Power Market - Wholesale purchases and sales of electricity.
• Bulk Power Supply - Often this term is used interchangeably with wholesale power supply. In broader terms, it refers to the aggregate of electric generating plants, transmission lines, and related equipment. The term may refer to those facilities within one electric utility, or within a group of utilities in which the transmission lines are interconnected.
• Bull - One who anticipates an increase in price or volatility. Opposite of a bear.
• Bull Market - Market in which prices are in an upward trend.
• Bull Spread - 1) The simultaneous purchase and sale of two futures contracts in the same or related commodities with the intention of profiting from a rise in prices but at the same time limiting the potential loss if this expectation is wrong. This can be accomplished by buying the nearby delivery and selling the deferred. 2) A delta-positive options position composed of both long and short options of the same type, either calls or puts, designed to be profitable in a rising market. An option with a lower strike price is bought and one with a higher strike price is sold.
• Bunker C Fuel Oil ç (or bunkering fuel) - Fuel used for ships. Generally refers to a No. 6 grade of residual fuel oil with an API gravity about 10.5o.
• Burner Capacity - The maximum heat output (in Btu per hour) released by a burner with a stable flame and satisfactory combustion.
• Burning Point - The temperature at which a material ignites.
• Bus (electrical) - An electrical conductor that serves as a common connection for two or more electrical circuits; may be in the form of rigid bars or stranded conductors or cables.
• Busbar - The power conduit of an electric power plant; the starting point of the electric transmission system.
• Busbar Cost - The cost of producing electricity up to the point of the power plant busbar.
• Business Day - For electric utilities, as determined by the North American Electric Reliability Council (NERC), the business day typically begins at 6 A.M. (the hour ending 0700) for a 24-hour period. Holidays are also determined by NERC and are separate from U.S.-designated holidays.
• Buy Through - An agreement between utility and customer to import power when the customer's service would otherwise be interrupted.
• Buyer's Market - A condition of the market in which there is an abundance of goods available and hence buyers can afford to be selective and may be able to buy at less than the price that previously prevailed. See seller's market.
• Buying Hedge - Also called a long hedge. Buying futures contracts to protect against possible increased costs of commodities that will be needed in the future.
• Bypass - An alternative path. In a heating duct or pipe, an alternative path for the flow of the heat transfer fluid from one point to another, as determined by the opening or closing of control valves both in the primary line and the bypass line.
• Bypass Diode - A diode connected across one or more solar cells in a photovoltaic module such that the diode will conduct if the cell(s) become reverse biased. [UL 1703] Alternatively, diode connected anti-parallel across a part of the solar cells of a PV module. It protects these solar cells from thermal destruction in case of total or partial shading of individual solar cells while other cells are exposed to full light.