S

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 utilities, cooperatives, municipalities and Federal and State agencies for resale to ultimate consumers. Wholesale sales. May be subject to FERC regulations

Scheduled Interchange
Electric power schedules to flow between control areas. Typically, this is the net of all sales, purchases and wheeling transactions between those areas at a given time.

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

Scheduling Penalty
A penalty assessed for differences between the amount of gas scheduled and the amount of gas tendered for delivery.

Secondary Recovery
All methods of oil and natural gas extraction in which energy sources extrinsic to the reservoir other than pumps or pumping units are used.

Scheduling
Operating a power system to balance generation and loads; managing the accounting, billing and information reporting for such operations.

SEC
Securities and Exchange Commission

Sectors
The retail power market is commonly divided into several sectors for energy planning. These can include residential, commercial, industrial, agricultural, public agency and street lighting.

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.

Security
The ability of the bulk electric power system to withstand sudden disturbances and remain in operation.

Security Coordinator
The entity that provides the security assessment and emergency operations coordination for a group of control areas. Security Coordinators must not participate in the wholesale or retail merchant functions.

Self-Generation
A generation facility dedicated to serving a particular retail customer, usually located on the customer's premises. The facility may either be owned directly by the retail customer or owned by a third party with a contractual arrangement to provide electricity to meet some or all of the customer's load.

SEPA
Southeastern Power Administration. A power marketing and electric transmission agency of the United States government with headquarters in Elberton, Georgia.

Service Area
The territory in which a utility system is required or has the right to supply service to ultimate customers.

Service Classification
See RATE SCHEDULE.

Service Connection (Service Pipe)
The pipe that carries natural gas from a main to a customer's meter.

Service Obligation
The obligation of a natural gas company to perform the services required by law or certificate regardless of whether the company has contractual duties.

Service Voltage
The voltage level at which a customer is connected to the electric transmission and distribution system.

Shaft Horsepower
Energy created through rotational or motive force through a coupling.

Shaping
The scheduling and operation of generating resources to meet changing load levels. Load shaping on a hydroelectric system usually involves the adjustment of water releases from reservoirs so that generation and load are continuously in balance.

Shareholder Value
A measure of the economic value of a business entity, where the economic value is equal to the net present value of expected cash flows discounted at the cost of capital. Unlike other financial measures, shareholder value encompasses the time value of money and addresses aspects such as risk, investment requirements and accounting methods.

Small Power Producer (SPP)
Under the Public Utility Regulatory Policies Act (PURPA), a small power producer (or small power production facility) 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.)

Smart Grid
An automated electric power system that monitors and controls grid activities, ensuring the two-way flow of electricity and information between utilities and consumers—and all points in between. The smart grid allows the utility to quickly detect and resolve problems, prevent and shorten power outages, improve service reliability and give customers information to better manage their energy use.

Solar Generation
The use of radiation from the sun to substitute for electric power or natural gas heating.

Source-Specific Gas Sales Contract
A contract that commits the seller to deliver natural gas, usually within a stated maximum and minimum, from specific described and committed natural gas reserves or sources.

Special Contracts
Any contract that provides a utility service under terms and conditions other than those listed in the utility's tariffs. For example, an electric utility may enter into an agreement with a large customer to provide electricity at a rate below the tariffed rate in order to prevent the customer from taking advantage of some other option that would result in the loss of the customer's load. This generally allows that customer to compete more effectively in their product market.

Special Protection System
A protection system designed to perform functions other than the isolation of electrical faults. Also called "remedial action scheme."

Specific Gravity
As applied to natural gas, specific gravity is the ratio of the weight of a given volume to that of the same volume of air, both measured under the same conditions.

Spill
Release of water from a reservoir over a spillway rather than putting it through turbines to generate electricity. A spillway is the overflow structure of a dam.

Spinning Reserve
Unused capacity available from units connected to and synchronized with the grid to serve additional demand. The spinning reserve must be under automatic governor control to instantly respond to system requirements.

Splitting Schedules
An interchange schedule where power is scheduled in from one source and out to multiple destinations.

Spot Market
Commodity transactions in which the transaction commencement is near term (e.g., within 10 days) and the contract duration is relatively short (e.g., 30 days).

Spot Purchases
A short-term single shipment sale of a commodity, including electricity or gas, purchased for delivery within one year, generally on an interruptible or best efforts basis. Spot purchases are often made to fulfill a certain portion of energy requirements, to meet unanticipated energy needs, or to take advantage of low prices.

Spot-start Swap
Generally speaking, a spot-start swap begins two business days after the swap has been agreed to by the counterparty and the market maker.

Stability
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 Conditions
The basic temperature and pressure for measurement of natural gas volumes.

Standard Deviation
A measure of the volatility of an underlying instrument. It is a statistical quantity that measures the magnitude of the daily price change of that asset.

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.

Standard Metering Base
Standard conditions, plus agreed corrections, to which all natural gas volumes are corrected for purposes of comparison and payment.

Standards of Conduct
Requirements under FERC's marketing affiliate rule, which prohibit discrimination in favor of the pipeline's own marketing affiliates and which require pipelines to submit reports detailing compliance with the rules.

Standard Options Contract
A contract that adheres to an established set of standards regarding the size of the contract, the strike prices, expiration dates and other conditions.

Standby Charge
A set unit fee payable at the outset by the recipient of a service based on total entitlement imposed on each unit of natural gas not purchased from, but transported by, the pipeline (similar to a "demand" charge). The charge is intended to recover fixed costs otherwise recoverable in the sales commodity charge.

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 to replace normally scheduled power that becomes unavailable.

Station
A site that contains one or more power generating units.

Station Service
The electric supply for the ancillary equipment used to operate a generating station or substation.

Station Service Generator
A generator, usually found in hydroelectric plants, used to supply electric energy for station service equipment.

Steam Coal
Also known as "thermal coal," this is coal used in electric utility power plants, district steam heating plants and industrial steam boilers to produce electricity or process steam or both.

Steam Generation Plant
A thermal electric generating plant which creates steam to drive a turbine.

Steam Turbine
See TURBINE.

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.

Storage Energy
The energy equivalent of water stored in a reservoir above normal bottom elevation.

Storage Facility
Facility used for the storage of natural gas; usually a cavern carved out of natural salt domes or depleted natural gas reservoirs into which natural gas can be reinjected and produced with minimal loss.

Storage Reservoir
A reservoir which has space for retaining water from springtime snowmelts. Stored water is released as necessary for purposes such as power generation, fish passage and irrigation.

Storage, Underground
The utilization of subsurface facilities for storing natural gas that has been transferred from its original location for the primary purposes of conservation, fuller utilization of pipeline facilities, and more effective and economic delivery to markets.

Streamflow
The rate at which water passes a given point in a stream, usually expressed in cubic feet per second (cfs).

Strike Price
The set price at which a position will be established or cash settlement made if the buyer exercises the option. See OPTION for more detail.

Subbituminous Coal
Young black coal with high moisture content of between 15 and 40 percent by weight. In the U.S. the most often cited example is the Power River Basin coal found in Wyoming and Montana. Heating value varies from 7,000 Btu/lb to slightly over 9,000 Btu/lb. This type of coal is considered by many to have the largest reserves by weight around the world. Countries such as Indonesia and Malaysia have much more subbituminous coal that bituminous coal. Sulfur value is typically quire low, and ash is also usually low. Volatile matter is usually high, and can exceed 40 percent of the weight of the cal "as received."

Submetering
The practice of remetering purchased energy beyond the customer's utility meter, generally done when natural gas or electricity is distributed to building tenants through privately-owned or rented meters.

Subsidization
The imposition of costs on one customer or class of customers that are attributable to services provided to other customers or classes of customers, who therefore pay less than the appropriate actual costs for the services they receive.

Substation
Facility equipment that switches, changes or regulates electric voltage. An electric power station which serves as a control and transfer point on an electrical transmission system. Substations route and control electrical power flow, transform voltage levels, and serve as delivery points to industrial customers.

Sulfur
One of the elements present in varying quantities in coal and fuel oil (residual oil) which contributes to environmental degradation when coal or oil 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.

Superconductor
A material that becomes a perfect conductor of electricity when chilled to cold temperatures. Developments beginning in 1986 have raised the threshold temperature to levels which, in the near future, may provide wires capable of conducting large electric currents without line loss. Almost all substances have some resistance to electrical currents and this causes the loss of some of the electrical power generated. Only a superconducting wire could prevent such line losses because a current that is started in a superconductor can flow forever.

Superconductivity
The flow of electric current without resistance in certain metals and alloys at temperatures near absolute zero. Perpetual motion on an atomic scale; the conduction of electricity without the slightest power loss - perfect conductivity.

Supervisory Control and Data Acquisition (SCADA)
A system of remote control and telemetry used to monitor and control the transmission system.

Supplemental Regulation Service
A method of providing regulation service in which the control area providing the regulation service receives a signal representing all or a portion of the other control area's ACE.

Supply-Side
Activities conducted on the utility's side of the customer meter. Activities designed to supply electric power to customers, rather than meeting load though energy efficiency measures or on site generation on the customer side of the meter.

Surface Mine
Also known as a "strip mine," this refers to a mine where the coal seam lies sufficiently close to the surface to extract the coal by removing the overburden to uncover the seam, sweeping the seam clean of sand and other adulterating materials, and excavating the coal for shipment to utility, industrial and metallurgical facilities.

Surge
A sharp transient increase of current, voltage or power flow in an electric circuit or across an electric system.

Surplus Energy
Energy generating capability that is beyond the immediate needs of the producing system. This energy may be sold on an interruptible basis or as firm power.

Sustainability
An approach to business that creates long-term stakeholder value by embracing opportunities and managing risks deriving from economic, environmental and social developments. In short, sustainability is the result when responsible actions lead to long-term success.

Switching Station
Facility equipment used to tie together two or more electric circuits through switches. The switches are selectively arranged to permit a circuit to be disconnected, or to change the electric connection between the circuits.

SWPA
Southwestern Power Administration. A power marketing and electric transmission agency of the United States government with headquarters in Tulsa, Oklahoma.

Synchronize
Process of connecting two previously separated alternating current Apparatuses after matching frequency, voltage, phase angles, etc.

Synchronous
A piece of rotating equipment whose electrical output is at the same frequency and time relationship as the power grid.

System
A combination of generation transmission and distribution components comprising an electric utility or group of utilities.

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

System Integration (of new technologies)
The successful integration of a new technology into the electric utility system by analyzing the technology's system effects and resolving any negative impacts that might result from its broader use.

System Lambda
The marginal, variable production cost of electricity at a given level of system output.

System Operator
A person authorized to operate or supervise the operation of the bulk electric system.

System Personnel
Those people who have the capability to affect system operations and who must abide by the authority vested in the System Operator. May include power plant operators, system maintenance personnel, power schedulers, power marketers, etc.