Ampere - (Symbol I)

The common unit of measurement of an electrical current.

Alternating Current (AC)

A current that flows alternately in one direction and then in the reverse direction. In North America, the standard for alternating current is 60 complete cycles each second. Such electricity is said to have a frequency of 60 hertz. Alternating current is used in power systems because it can be transmitted and distributed more economically than direct current.

Breaker/main line switch

A protective device located on an electrical circuit to interrupt the flow of abnormally large current. A circuit breaker is the most common means of providing overload and fault protection for customers and utilities.

Capacity

In the electric power industry, capacity has two meanings:
1. System Capacity: The maximum power capability of a system. For example, a utility system might have a rated capacity of 5000 megawatts, or might sell 50 megawatts of capacity.
2. Equipment Capacity: The maximum power capability of piece of equipment. For example, a generating unit might have a rated capacity of 50 megawatts.

Current (electric)

The flow of electrons in an electrical conductor. It is the rate of movement of the electricity, measured in amperes.

Demand

The rate at which electric energy is delivered to, or received by, a system or a piece of equipment. It is expressed in kilowatts, kilovolt amperes or other suitable units at a given time. The primary source of “demand” is the power-consuming equipment of customers.

Distribution System

The portion of an electric system dedicated to delivering electric energy to an end-user. The distribution system “steps down” power from high-voltage transmission lines to a level that can be used in homes and businesses.

Electricity

Positive and/or negative charges at rest or in motion; it is a property of the basic particles of all materials consisting of electrons and protons; a form of energy generated by heat, light, friction, chemistry or induction which has chemical, magnetic and radiant effects.

Electric Power

Is measured in a unit called the WATT and is equal to the volts multiplied by the amperes that are in phase with each other in an electric circuit.

Generation

The process of producing electric energy by transforming other forms of energy; also, the amount of electric energy produced, expressed in watt-hours (Wh).

Guy

A wire or rope support for a pole or tower.

Hertz (Hz)

The unit of frequency for alternating current, formerly called cycles per second. The standard frequency for power supply in North America is 60 Hz.

Insulation

Refers to poor conductors of electricity used to cover wires and components to prevent short circuits and accidental shock hazards.

Kilovolt Amperes (KVA)

A unit of power - the volt ampere, VA, is a unit of apparent power that equals one watt. It is commonly used in industrial transformers.

Kilowatt (kW)

The unit of electric power equal to 1,000 watts or about 1.34 horsepower; for example, it is the amount of electric energy required to light 10 100-watt light bulbs.

Kilowatt Hour (kWh)

The commercial unit of electrical energy, commonly used in marketing electric power; the energy produced by one kilowatt acting for one hour. For example, 10 100-watt light bulbs burning for one hour would consume one kilowatt hour of electricity.

Load

The total amount of electricity required to meet customer demand at any moment. The load equation fluctuates depending on electricity use throughout any given day.

Megawatt (MW)

A unit of power equal to one million watts; for example, it is the amount of electric energy required to light 10,000 100-watt light bulbs.

Service Drop

A device used to connect wires from the power lines to the point of entry to building.

Substation

A station in a power transmission system where electric power is transformed to a more conveniently used form. The station may consist of transformers, switches, circuit breakers and other auxiliary equipment. Substations route and control electrical power flow, transform voltage levels, and serve as delivery points to industrial customers.

Surge

A sudden increase in voltage or electrical current.

Step Down

A process used to reduce electrical energy from a higher voltage to a lower voltage, as in a step down transformer.

Step Up

A process used to increase electrical energy from a lower voltage to a higher voltage, as in a step up transformer.

Volt (V)

Refers to the unit of measurement of electromotive force. It is equivalent to the force required to produce a current of one ampere through a resistance of one ohm. It is the unit of measure for electrical potential. It is generally measured in kilovolts (kV).

Voltage

The force that causes free electrons to move in a conductor. Unit of measurement is the volt (V).

Watt (W)

The unit used to measure production/usage rate of all types of energy; the unit for power. A watt is an electric unit of power or a rate of doing work.

Roles in the Alberta Electrical Industry

Distribution

The system of lines, transformers and switches that connect the transmission network and customer load. It is the portion of an electric system that is dedicated to delivering electric energy to an end user at relatively low voltages. In Alberta, distribution companies perform the following jobs:

• purchase, install, read, and verify the meters within the service territory;
• provide billing arrangements for the distribution portion of a customer’s bill, which are pre-determined with the retailers. Companies bill the retailers—not the customers;
• provide information to the power pool and retailers about power consumption throughout the distribution system. This is called Load Settlement;
• build, operate and maintain distribution wires within the service territory;
• provide emergency response to power outages and downed wires;
• perform connections and disconnections, at the request of the retailer; and,
• ensurie a default power supply is provided to inactive customers. This may be assigned to a retailer.

Generation

The process of producing electric energy by transforming other forms of energy, such as steam, heat or falling water. Also, the amount of electric energy produced, expressed in kilowatt-hours (kWh) or megawatt-hours (MWh). In Alberta, the market is open to any generation company.

Marketers

Own the rights to the generation created at the generation plant thru the means of a contract called a Power Purchase Agreement.

Transmission

The network of high voltage lines, transformers and switches used to move electrical power from generators to the distribution system. This network is also used to interconnect different utility systems and independent power producers together. Transmission is considered to end when the energy is transformed for distribution to the consumer. In Alberta, administration of the system is provided by the Transmission Administrator, a single independent entity. 

Regulator

The Alberta Utilities Commission, or AUC, adjudicates and regulates matters related to utilities to ensure that development, transportation and monitoring are in the public interest.

Retailers

• Sell electrical energy. In Alberta, retailers perform the following jobs:
• purchase power on behalf of the customer, and negotiate a financial arrangements to minimize price risk. This is called energy procurement;
• make arrangements with the distribution company to perform standard meter reading services;
• maintain records and accounts, which includes processing accounts, producing and delivering bills;
• ensure the customer is connected to the distribution and transmission system to receive power; and,
• respond to customer inquiries and complaints regarding retail service.

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