Glossary by "O"
Obligation to serve
A regulatory obligation of a utility to provide electric planning services for all customers and to assure adequate supply of electricity now and in the future.
Those hours or other periods defined by NAESB business practices, contract, agreements, or guides as periods of lower electrical demand.
Times when demand for electricity is highest (a.k.a peak demand). Typically on-peak times occur during weekdays during the hottest summer months, when normal demand is high and when air conditioning is operating. Similarly, in some areas on-peak times may be in the winter when high normal demand is combined with high heating-related power use.
Ontario Independent Electricity System OperatorAcronym(s): OIESO
A not-for-profit independent (Canadian) corporation that monitors the system and identifies what is required to maintain reliability in the future, reporting on these recommendations through regular publications. The IESO 1. assesses generation and transmission facilities’ adequacy, 2. prepares the Ontario Reliability Outlook, which reports on the progress of interrelated generation, transmission and demand-side projects underway to meet Ontario’s reliability requirements and 3. coordinates emergency preparedness for the province’s electricity systemSource: ESA Technical Working Group
Markets in which energy end-users can pay to have energy that purchased from a third party transmitted via transmission systems owned by other entities. Open access prevents a transmission owning utility from controlling the energy supply. Open access differs from direct access in that direct access refers to acquisition of actual energy, whereas open access refers only to access to transmission systems used to transport it.Source: ESA Technical Working Group
Open access same time information serviceAcronym(s): OASIS
An electronic posting system that the transmission service provider maintains for transmission access data and that allows all transmission customers to view the data simultaneously.
Open access transmission tariffAcronym(s): OATT
Electronic transmission tariff accepted by the U.S. Federal Energy Regulatory Commission requiring the Transmission Service Provider to furnish to all shippers with non-discriminating service comparable to that provided by Transmission Owners to themselves.
A battery to which nothing is connected.Source: ESA Technical Working Group
The difference in electric potential (voltage) between the terminals of a cell or battery when the circuit is open (i.e., nothing is connected).Source: ESA Technical Working Group
Operating expenseAcronym(s): OPEX
A category of expenditure that a business incurs as a result of performing its normal business operations. One of the typical responsibilities that management must contend with is determining how low operating expenses can be reduced without significantly affecting the firm’s ability to compete with its competitors. Also known as “OPEX”.Source: Investopedia
A document that identifies specific steps or tasks that should be taken by one or more specific operating positions to achieve specific operating goal(s). The steps in an operating procedure should be followed in the order in which they are presented, and should be performed by the position(s) identified. A document that lists the specific steps for a system operator to take in removing a specific transmission line from service is an example of an Operating Procedure.
The voltage level by which an electrical system is designated and to which certain operating characteristics of the system are related; also, the effective (root-mean-square) potential difference between any two conductors or between a conductor and the ground. The actual voltage of the circuit may vary somewhat above or below this value.
Operations and maintenanceAcronym(s): O&M
Expenses related to operation and maintenance of equipment or facility.Source: ESA Technical Working Group
The cost of an alternative that must be forgone in order to pursue a certain action. Put another way, the benefits you could have received by taking an alternative action.Source: Investopedia
Any interruption of current flow (and thus electric service) in a T&D system. Note that most parts of the electric grid are designed to allow current flow to be routed around affected parts of the grid to reduce or avoid service interruption. See also forced, planned, sustained, scheduled and unplanned outage.Source: ESA Technical Working Group
A condition involving generation output that exceeds the system demand. Aside from adverse effects on the grid (stability) overgeneration is undesirable because excess energy has no value if it is not put to productive use. In fact, in some cases “negative prices” are used to encourage use of excess energy.Source: ESA Technical Working Group
Overlap regulation service
A method of providing regulation service in which the Balancing Authority providing the regulation service incorporates another Balancing Authority
Chemical reactions resulting in release of electrons by an electrode’s active material. The opposite of reduction.Source: ESA Technical Working Group