Glossary of electric industry, energy & cooperative terms

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Sales
The amount of kilowatt-hours sold in a given period of time; usually grouped by classes of service, such as residential, commercial, industrial, and other. Other sales include public street and highway lighting, other sales to public authorities and railways, and interdepartmental sales.

Sales for Resale
Energy supplied to other electric utilities, cooperatives, municipalities, and Federal and State electric agencies for resale to ultimate consumers.

Sash
The wooden frame in which window glass in mounted; also, the complete unit with the glass. Check for weather stripping.

Scheduling Coordinators
Entities certified by the Federal Energy Regulatory Commission that act as a go-between with the Independent System Operator on behalf of generators, supply aggregators (wholesale marketers), retailers, and customers to schedule the distribution of electricity.

Scheduled Outage
The shutdown of a generating unit, transmission line, or other facility, for inspection or maintenance, in accordance with an advance schedule.

Seasonal Energy Efficiency Rating (SEER)
A rating used to compare the average annual cooling efficiency of one system to another using average efficiency over time and a range of temperature under which an air conditioner or heat pump operates. A minimum SEER of 14 is recommended.

Securitization
A proposal for issuing bonds that would be used to buy down existing power contracts or other obligations. The bonds would be repaid by designating a portion of future customer bill payments. Customer bills would be lowered, since the cost of bond payments would be less than the power contract costs that would be avoided.

Securitize
The aggregation of contracts for the purchase of the power output from various energy projects into one pool which then offers shares for sale in the investment market. This strategy diversifies project risks from what they would be if each project were financed individually, thereby reducing the cost of financing. Fannie Mae performs such a function in the home mortgage market.

Service Area
The geographic locality where a utility is required or has the exclusive right to supply electricity to ultimate consumers. Service area is also known as service territory or franchise area.

Service Charge
An amount designed to recover some of the fixed costs of providing electric service, whether or not any energy is consumed. These costs include accounting expenses, such as meter reading and bill preparation, and the continuing ownership expenses on services and meters.

Shake
A thick hand-split shingle, re-sawed to form two shakes, usually edge-grained.

Sheathing
The structural covering, usually wood boards or plywood, used over studs or rafters of a structure. Structural building board is normally used only as wall sheathing.

Shingles
Roof covering of asphalt, asbestos, wood, tile, slate or other material cut to stock lengths, widths and thicknesses.

Short Ton
A unit of weight equal to 2,000 pounds.

Siding
The finish covering the outside wall of a frame building, whether made of horizontal weatherboards, vertical boards with battens, shingles, or other material.

Sill
The lowest member of the frame of a structure, resting on the foundation and supporting the floor joists or the uprights of the wall. The member forming the lower side of an opening, as a doorsill, windowsill, etc.

Small-Power Producer (SPP)
Generates electricity from facilities much smaller than those of base-load power plants; used biomass, solid waste, geothermal energy or renewable resources as its primary energy source. Under the Public Utility Regulatory Policies Act (PURPA), a small power production facility (or small power producer) generates electricity using waste, renewable (water, wind and solar), or geothermal energy as a primary energy source. Fossil fuels can be used, but renewable resource must provide at least 75 percent of the total energy input. (See Code of Federal Regulations, Title 18, Part 292.)

Soffit
Usually the underside of an overhanging cornice.

Soffit Vent
Provides air circulation near the floor of the attic.

Solar Power
Energy generated by the sun through the collection, transfer and storage of the sun’s heat.

Space Heating
Heating inside of a building or room.

Spinning Reserve
Extra electric-generating capacity in operating power plants, available in case another power plant suddenly stops generating.

Spot Purchases
A single shipment of fuel or volumes of fuel, purchased for delivery within 1 year. Spot purchases are often made by a user to fulfill a certain portion of energy requirements, to meet unanticipated energy needs, or to take advantage of low-fuel prices.

Stability
The property of a system or element by virtue of which its output will ultimately attain a steady state. The amount of power that can be transferred from one machine to another following a disturbance. The stability of a power system is its ability to develop restoring forces equal to or greater than the disturbing forces so as to maintain a state of equilibrium.

Standard Industrial Classification (SIC)
A set of codes developed by the Office of Management and Budget, which categorizes business into groups with similar economic activities.

Standby Facility
A facility that supports a utility system and is generally running under no-load. It is available to replace or supplement a facility normally in service.

Standby Service
Support service that is available, as needed, to supplement a consumer, a utility system, or to another utility if a schedule or an agreement authorizes the transaction. The service is not regularly used.

Steam-Electric Plant (Conventional)
A plant in which the prime mover is a steam turbine. The steam used to drive the turbine is produced in a boiler where fossil fuels are burned.

Stocks
A supply of fuel accumulated for future use. This includes coal and fuel oil stocks at the plant site, in coal cars, tanks, or barges at the plant site, or at separate storage sites.

Stranded Benefits
Benefits associated with regulated retail electric service which may be at risk under open market retail competition. Examples are conservation programs, fuel diversity, reliability of supply, and tax revenues based on utility revenues.

Stranded Costs
The cost utilities incur when, for instance, a customer the utility was required to serve under a regulatory environment contracts with a new electricity provider in a deregulated environment. The utility may have needed to build a substation, add transmission line or incur other costs to serve that customer in its regulated service territory. When the customer chooses another electricity supplier in a deregulated industry, the utility must bear the stranded costs, unless protected by law.

String, Stringer
A timer or other support for cross members in floors or ceilings. In stairs, the support on which the stair treads rest; also stringboard.

Strip Heat (Resistance Heating)
A form of electric heating used in climates where heat is seldomly used, like Florida. Air is blown over electrically heated metal coils and circulated into the living space.

Stud
One of a series of slender wood or metal vertical structural members placed as supporting elements in walls and partitions.

Subbituminous Coal
A coal whose properties range from those of lignite to those of bituminous coal and are used primarily as fuel for steam-electric power generation. It may be dull, dark brown to black, soft and crumbly at the lower end of the range, to bright, jet black, hard, and relatively strong at the upper end. Subbituminous coal contains 20 to 30 percent inherent moisture by weight. The heat content of subbituminous coal ranges from 17 to 24 million Btu per ton on a moist, mineral-matter-free basis. The heat content of subbituminous coal consumed in the United States averages 17 to 18 million Btu per ton, on the as-received basis (i.e., containing both inherent moisture and mineral matter).

Subsidiary
A business firm controlled by another company, called the parent company, but having its own business entity, charter, officers and board of directors. When the parent company owns all of the subsidiary’s stock, the subsidiary is termed a wholly owned subsidiary.

A utility’s ownership of subsidiaries allows it to participate in activities, such as exploration and development of new resources, while reducing financial risks to customers. If a subsidiary fails to produce a profit, its shareholders bear a large part of the burden.

Substation
An assemblage of equipment designed for switching, changing or regulating the voltage of electricity. This definition does not include service equipment, line transformers, line-transformer installations, or minor distribution or transmission equipment.

High electrical voltages from 69,000 to 765,000 volts are required to move electricity through transmission lines across great distances. Electric motors and appliances are not designed to use electricity at these high voltages, so voltage reductions must take place at a substation near a community served or along the transmission line serving a very large customer.

Sulfur
One of the elements present in varying quantities in coal which contributes to environmental degradation when coal is burned. In terms of sulfur content by weight, coal is generally classified as low (less than or equal to 1 percent), medium (greater than 1 percent and less than or equal to 3 percent), and high (greater than 3 percent). Sulfur content is measured as a percent by weight of coal on an "as received" or a "dry" (moisture-free, usually part of a laboratory analysis) basis.

Surge Suppressor
An electronic device that protects electric equipment from short-term, high-voltage flows of electricity such as lightning strikes; also called spike suppressor.

Switching Station
A type of substation whose function is to switch circuits in and out of service. When it is necessary to de-energize a circuit (to disconnect the system from problems such as line faults or short circuits, or to perform routine maintenance), it is desirable to keep as much of the system in operation as possible. Switching stations allow workers to sectionalize or cut off only the affected circuit while leaving the majority of the system operations. Nearly all circuits are connected to the system through circuit breakers that trip open automatically when a line fault occurs. The circuit breakers can also be operated manually.

System (Electric)
Physically connected generation, transmission, and distribution facilities operated as an integrated unit under one central management, or operating supervision.

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Page last updated: Friday, March 5, 2010