Glossary

BETTA
British Electricity Transmission and Trading Arrangements – the extension of the NETA market rules to include Scotland

BOAI
Bid Offer Acceptance Instruction – a short term instruction issued by National Grid in the UK to alter the contracted generation plan (the PN).

BSC Party
Balancing and Settlement Company Parties – all licenced electricity generators, suppliers and distribution businesses must become BSC Parties in order to participate in the UK market.

Communications Server
The Sentinel module that imports data from files and creates and exports files from data within the Sentinel database.

Constraints
Constraints are a subset of Events. Constraints are Events that have an effect on the plant availability and are used by Sentinel in the calculation of Technical Availability.

Control Point
The location from which the generation asset is operated, usually the power station or in the case of wind farms, a central control centre.

Data conditioning
The process whereby data from plant historian software is validated and averaged or totaled over the settlement period

DR
Disaster Recovery – the term is usually associated with a plan or system that allows normal operation of the business processes with minimal interruption.

ECV
Energy Contract Volume – the information about electricity contracts (price and energy per half hour) notified to Elexon by the Sentinel CNS.

EDL
Electronic Data Logging – a system which connects to National Grid which is used to communicate short term system balancing instructions to the Control Point. It is also used to update plant parameters (such as plant generation maximum rates of change) to National Grid.

EDT
Electronic Data Transfer – a system which is used by an EMC to communicate generation plans and bids and offer data to National Grid

Elexon
The UK electricity market’s regulator, delivering the Balancing and Settlement Code. All electricity contracts struck in the market must be notified to Elexon.

EMC
Energy Management Centre – the location where the electricity is traded for all generation assets of the energy firm.

Events
Events are plant issues with actual and forecast sets of start and end times that are required to be stored and used in the calculation of a physical or commercial calculation within Sentinel.

FTP
File Transfer Protocol – a messaging protocol that allows the reliable and secure transfer of information in files between computers.

GT
Gas Turbine.

LDAP
Lightweight Directory Access Protocol – a messaging protocol that allows applications to access information about users and their security permissions across different computer operating systems.

MEL
Maximum Export Limit – the commercial upper limit of generation for a generation unit in the UK.

MVR
Meter volume reallocations – information submitted to Elexon by Sentinel CNS that allocates the energy produced on behalf of one energy account to another.

National Grid
The UK electricity market technical system operator, whose statutory duty is to balance power supply and demand in the UK.

NETA
New Electricity Trading Arrangements – the England and Welsh electricity market introduced in 2001

OPC
Open Process Control – an industry standard open architecture for interfacing to a PLC or data historian such as PI.

Plant Historian
A software application that stores data directly from plant meters to be used for operation of the plant and analysis of its operation.

PK
Position Keeping – used to describe a Sentinel software module that allows monitoring of actual plant performance (the position) against targets originating with a system operator or the energy firm’s traders.

PLC
Programmable Logic Control – a digital computer used for the control of machinery, such as valves etc.

PN
Physical Notification – the generation dispatch plan notified to National Grid in the UK.

PPA
Power Purchase Agreement – a contract between a power generation company and a third party for the supply of electricity. Often the third party supplies the fuel for the power station; for gas fired power stations this is called a Gas Tolling Agreement (GTA).

Ramp Rates
The set of data describing the possible rates of change of power generation.

Scheduler Server
The Sentinel module that executes Sentinel models on configured schedules, on events (such as new data being imported) or on demand.

Security Server
The Sentinel module that ensures that only authorized personnel can access configured functions and data within the Sentinel system.

SEL
Stable Export Limit – the commercial lower limit of generation for a generation unit in the UK.

SO
System Operator – the organization whose responsibility it is to operate the electricity grid or grid segment.

UPM
User and Parameter Maintenance – a module within Sentinel that allows security, system configuration and parameters to be viewed and updated.

XML
eXtended Markup Language – a language that defines the rules for a file format that is both human and machine readable.