Glossary of Terms

Aggregation (Initial)

In the Initial Aggregation a specific date (normally the tenth day before the date of the aggregation run) is selected.For each usage factor that is associated with the selected date the aggregation process will:

Determine the appropriate derived load profile

Multiply the usage factor by each of the 96 coefficients to obtain 15-minute interval consumptions

Apply loss factors to the interval consumptions

Sum the interval consumptions according to supplier and SSAC

Amp (A)

The unit of electric current

An amp is the measurement of current flowing in an electrical circuit.

Annual Load Factor

Total annual units (Day kWh and Night kWh) /Maximum Demand (MD) x 8760 (total hours in year).

ARIS

Old Business Process Modelling tool used to map ROI Market Process Diagrams. No longer in use.

Associated Supplier Unit

Supplier Unit allocated to a Trading Site. Demand is settled on gross basis with the Generator Units on that Trading Site.

AUF

Actual Usage Factors

Actual Usage Factor is a statement in kWh of the actual consumption for a given Timeslot at a Meter Point since the previous read-date, extrapolated to an annual consumption based on the applicable derived profile. As an example, if we take the reading on 24th June the sum of the interval coefficients between 28th February and 24th June is 0.3. As the actual usage (or consumption) is 3600, then the usage factor is Obtained by dividing 3600 by 0.3. Therefore the usage factor is 12000.

Autoproducer Site

Sites where Export Data is netted off Import for that site for DUoS billing purposes.

BSA

Business Solution Assessment

Assurance Body assesses compliance and suitability of New Supplier’s business processes, IT Systems & recording mechanisms.

BSC

Business Service Centre (within ESBN)

Technology expertise provided by BSC to Networks.

CA

Cancellation Agreement

“Cancellation Agreement is a flag indicating that an old supplier agrees to a cancellation of a change of supplier.”

Capita (formerly Northgate (NMS))

Capita is an old third party service provider to ESBN. The messaging HUB was managed by Capita on behalf of Networks and were responsible for routing XML market messages in and out of SAP. The EMMA was provided to Market Participants by ESB Networks via Capita. This service is now managed by Atos.

CCR

Code Change Request

An accelerated change process to introduce new code values for non transactional codes that already exist in the retail market design.

CER

Commission for Energy Regulation

The commission responsible for the regulation of the electricity market in Ireland.
Now known as CRU.

CHP

Combined Heat and Power

CMS

Central Market Systems

The Central Market System (CMS) is operated by ESB Networks. CMS communicates with Market Participants’ systems via a message Hub called the Market gateway.

CO

Connection Object

A Connection Object is a building or a house where service connection is made.

CoLE

Change of Legal Entity

SAP term for change of customer, formerly known as Change of Tenancy. A change of Legal Entity occurs when a customer moves out of a premise and another customer takes over the same premise.A Change of Legal Entity can take place where the incoming customer wishes to remain with the existing supplier or where the incoming customer chooses to go to a new supplier. Networks need to be aware of the Change of Legal Entity as they need to agree a MIC with the customer. Supply to the premise is not de-energised in a change of tenancy situation.

Connection Point

Means the physical point(s) at which the Customer’s (or generator’s as appropriate) facility is joined to the Distribution System (or Transmission System as appropriate).

CoS

Change of Supplier

This occurs when a customer wishes to change supplier. The customer contacts their new supplier who must send on the request to MRSO. MRSO validates the request and advises both the old and new supplier.

CRU

Commission for the Regulation of Utilities

The commission responsible for the regulation of the all utilities, including the electricity market, in Ireland.

CSSN

Customer Service Special Needs

A code used within the market design to identify a customers special needs. In ROI and NI it includes Visually Impaired, Speech Impaired, Hearing Impaired, Elderly, Language Difficulty, Learning Difficulty, Mobility Impaired and in NI only Dexterity Impaired is also a special need code used.

Customer Type

There are two types of Customer defined in the Retail Electricity Market. A Customer must be one or other of these types but not both.

Customer types are:

• Customers as Persons
• Customers as Organisations

DA

Data Aggregation

This is the process of accumulating energy for settlement purposes for a generator or for all MPRN’s registered to a supplier, by using actual meter readings or estimates which are re-aggregated to actual meter readings at a later date.

Daytime Load Factor

Daytime Load Factor is a better indicator of Load Factor as Maximum Demand (MD) is only measured for 13 hours each day and day units are measured for 15 hours.

Daytime Load Factor =

100% x

Total Day Units (kWh) / Maximum Demand (MD) x 15 hours x 365.

DC

Data Collector

A business unit within ESB Networks that deals with all meter reading activities.

De-Energise

“This is a term which is used to describe the disconnection of a business partner from the network. Means the movement of any isolator, breaker or switch, or the removal of any fuse whereby no active power or reactive power can be transferred to or from the Customer’s (or generator’s) installation through the Connection Point, and “De-energisation” and “De-energising” shall be construed accordingly.”

Demand Value

Demand values, expressed in kW or kVAr are four times the value of kWh or kVArh recorded during any demand period. The Demand Values are 15-minute demands and these are identified by the time of the end of the Demand Period.

De-minimus

De-minimus is the term for the minimum threshold for a generator’s capacity before it is required to be a participant in the Wholesale Market. The De-minimus threshold is currently set at 10 MW.

Designated disputes

Designated disputes are defined in the Distribution Use of System Agreement as occurring when:

• there is an error in the information used for the calculation or an arithmetic error in the calculation of Use of System Charges by the Company which is apparent on the face of the account and/or

• the Company chooses not to use the half-hourly data (whether actual or estimated) for the purposes of Settlement in calculating Use of System Charges and the User disputes the accuracy or validity of the data actually used.

All other disputes are termed non-designated.

Device

Device

A device is a meter or a timeswitch. A physical object used to measure, modify or control consumption: includes Meters, Loggers and Ripple Control Relays.

Device Location

Device Location

The physical location of the Device is e.g. switchroom or outside box.

DG

Device Group

Group of individual devices that make up a logical unit. For example, in the device group “integrated water meter” there are two separate water meters which are installed together (as a unit), but count separately and are billed individually. This subdivision facilitates data entry. For example, if you enter the number of a device in a group during installation, all of the other devices in that group are automatically displayed for processing.

Distribution connected

Generator Unit is connected to a Distribution System.

Distribution Losses

Electric power distribution losses include losses between sources of supply and points of distribution and in the distribution to consumers.

Distribution System

All electric lines, plant, transformers, switchgear etc which is specified as part of the DSO’s distribution system.

DLF/DLAF

Distribution Loss Factor/Distribution Loss Adjustment Factor

DLF This loss factor accounts for distribution network losses as settlement is struck on generated rather than consumed electricity. Loss factors normally depend on the voltage level at which the connection is made and vary between day and night. For NQH Customers connected at LV, the day period covers the time from 08:00 to 23:00 in Winter and 09:00 to 24:00 in summer. For QH customers, LV 38Kv and MV customers and Generators, daytime is from 08:00 to 23:00 all year round. The night period covers the remaining time in each case. Distribution loss factors applying to the interval are applied in order to determine the consumption prior to the losses. This is achieved by multiplying the consumption by the loss factor.

DR

Discussion Request

DR can be raised by CRU, Market Participant or RMDS with the purpose of initiating a change to one or more of the base-lined market design documents or processes. The DR will be assessed and impacted by all necessary parties. Changes may be made if necessary. If the DR is approved, it becomes a Market Change Request.

DSO

Distribution System Operator

Means the board in its capacity as distribution system operator licensed pursuant to section 14(1)(g) of the Act.

DUoS

Distribution Use of System

DUoS Group is a code which denotes the distribution use of system tariff applying to the MPRN.

EAI

Economic Activity Indicator

Economic Activity Indicator is a code indicating the type of activity undertaken by the customer in the premises. The code will be a 4 digit NACE.

EFT

Electronic Funds Transfer

A mechanism for making payment or transferring money.

Eirgrid

Independent electricity Transmission System Operator (TSO) in Ireland and the Market Operator in the wholesale electricity trading system.

Embedded Generator

A generator that does not specifically generate electricity for the Transmission network, e.g. Hospital.

EMMA

Electricity Market Message Application

Application to send and receive market messages in a secure and reliable manner with ESB Networks.

EPUS

Ex Post Unconstrained Schedule.

ESBN

ESB Networks

ESB Networks Ltd is the independent Distribution System Operator for Ireland. It provides connection and metering services for all electricity customers.

EUF

Expected Usage Factors.

ex ante

from before

“Beforehand”, “before the event”. Based on prior assumptions. A forecast.

ex post

from after

"Afterward”, “after the event”. Based on knowledge of the past. Measure of past performance.

Exchange Member

A company admitted as a member to SEMO px to allow day-ahead and intraday trading in the SEM wholesale electricity market.

Firm/Non-Firm Flag – set to yes or no

“A yes value indicates that there are special Firm/Non-Firm calculations required at the Trading Site for which this is the Supplier Unit. If the Trading Site Supplier Flag is set to no, it should be noted that this Supplier Unit can only be used to aggregated demand quantities at a specified Trading Site with Firm/Non-Firm calculations. This can be known as a Unique Associated Supplier Unit.”

Generation

Production of active electricity.

Generation Site

Site defined under a Connection Agreement containing one or more generators, at which active power is generated.

Generation Unit ID

the IDs of the Generation Unit(s) within that Trading Site.

Generator

A power plant or similar entity which generates electricity.

Generator Unit

Each participant Generator in the SEM must register at least one generator unit with the SMO. MRSO are required to send data to the SMO at aggregated to Generator unit level. Each Generator unit must be part of a Trading site. Each generator- both participant and non-participant- will receive aggregated data at generator unit level.

IGG

Industry Governance Group

The Industry Governance Group (IGG) oversees the ongoing operation of the retail electricity market. RMDS acts as the secretariat for the IGG and associated sub-groups. The IGG is chaired by the Commission for the Regulation of Utilities (CRU).

Installation

Installation

Grouping of devices, billing and technical data at a meter point.

Interconnector Unit

Registered Unit which handles the settlement of Interconnector transactions for an Interconnector User holding transmission capacity. Multiple Interconnector Units can be associated with an Interconnector.

Interval (IM)

Interval Hour

Meter reading obtained on a quarter hourly basis, downloaded each night by telecoms link. Interval was previously referred to as Quarter Hourly (QH)

IOS

Indicative Operations Schedule is run by 1600 on D-1.

IPT

Inter Participant Testing

The purpose of Inter-Participant Testing (IPT) is to gain assurance that the Participant can correctly operate the key scenarios that it will meet in the Market using its declared systems, business processes and operational staff within normal, operational conditions.The scenarios to be exercised are defined in the form of storyboards and are approved by the industry for this purpose. This technique requires a central testservice, which is provided by RMDS and is available coincident with pre-planned market testing or otherwise at about a month’s notice, therefore planning and coordination are essential for managing:

• The schedule for testing, including any re-tests;
• Test data; and
• Problem processing.

The tests are run by the Participant and RMDS, both of whom will produce appropriate evidence of each test step to support the test outcomes. This will include, but is not limited to, message prints, screenshots, reports and file and database prints.

ITA

Integration Test Assessment

Verifies that the Participant has carried out satisfactory testing of their systems and processes. (Large Suppliers only)

Kilovolt (kV) = 1000 volts

This is the term normally used for medium and high voltages, e.g. 20 kV = 20,000 volts.

Kilovolt-Ampere (kVA) = 1000 volt-amperes

This is a term used to describe the level of ‘apparent’ power imported/consumed by a customer. It is the basis of the customer’s Maximum Import Capacity (MIC) contract with ESB Networks.

Kilowatt (kW) = 1000 watts (W)

kW is the term normally used for ‘active/real’ electric power, sometimes referred to as ‘Demand’ or ‘Load’. Electric power is made up of two components ‘active/real power (kW)’ and ‘reactive/wattless power (kVAr)’. When these are combined they give the ‘apparent’ power (kVA). The term Maximum Demand (MD) is the highest electricity demand recorded during a specific period – this term applies only to large businesses on the Maximum Demand tariff.

Kilowatt hour (kWh): = 1000 watts for 1 hour

This is the basic unit of electricity consumption. It is the real/active electric load (kW) used over time. In simple terms 1 kWh is the amount of energy consumed by a device (e.g. electric heater) rated 1kW (1000 watts) for 1 hour. A further example is ten 100-watt light bulbs used for 1 hour. It is the basic unit of electricity consumption used by ESB Customer Supply to ‘bill’ customers for the ‘active/real’ power used.

LEU

Large Energy User

Liberty Meter

Client Payment Solution for PrePayment

Load Factor

Load Factor is the ratio of average electricity consumption to the peak consumption in a Business premises, during a specific period. It indicates if the electricity consumption in a Business is stable or has extreme peaks. The lower the load factor the more ‘peaky’ the loads. A very poor load factor would be less than 20%.

Load Profile

Standard Load Profiles describe how consumption is allocated over time. A load profile is a set of coefficients that describe the pattern of consumption over a calendar year. As MRSO will be aggregating consumption on a 15-minute basis there will be 96 coefficients for each day and 35,040 coefficients in a load profile in a 365-day year. Each of these coefficients is expressed a proportion of annual consumption meaning that these coefficients will sum to 1 for a 365 day year. This means that if MRSO has a statement of consumption for a meter point register expressed as an annual volume then this can be multiplied by the coefficient for any given 15 minute interval to obtain the assumed consumption for that interval. This can then be aggregated. Over a year, because the coefficients sum to 1 the annual consumption will be entirely aggregated.

LV

Low Voltage

ESBN defines as 230 volts – phase to neutral to 400 volts – phase to phase.

Maximum Demand

The highest Demand Value registered over a period of time for tariff and other purposes.

MCC

Meter Configuration Code

Meter Configuration Code is a code to indicate the functionality present in a meter at a site as required by the Supplier to be delivered by the combination of registers physically installed at a meter point. It does not describe the technical attributes of the meter(s).

MCR

Market Change Request

A Market Change Request (MCR) is one of 3 types of change control request which form part of the change management process for the retail market. An MCR is always preceded by a DR (Discussion Request). Briefly, a DR can be raised by CRU Market Participant or RMDS with the purpose of initiating a change to one or more of the base-lined market design documents or processes. The DR will be assessed and impacted by all necessary parties. Changes may be made if necessary. If the DR is approved, it becomes a Market Change Request. The Design Administrator, working in conjunction with the requesting party, is responsible for ensuring that a Market Change Request (MCR) is issued within the agreed timeframe.

MEC

Maximum Export Capacity

Maximum Export Capacity is a pre-determined agreement on the limit of the amount of electricity which may be generated and exported from a Generator site to the grid. The unit of measurement for MEC is kVA (kilovolt ampere).

Megawatt (MW) = 1000 kilowatts (kW)

Megawatt is sometimes used as a unit of measurement: for large electric loads to business customers.

Megawatt (MW) = 1000 kilowatts (kW)

Megawatt is sometimes used as a unit of measurement: for large electric loads to business customers.

Megawatt hour (MWh) = 1000 kilowatt hours (kWh)

Megawatt hour is sometimes used as a unit of measurement: for electricity consumption to large business premises.

MESN

Medical Equipment Special Needs

A code used within the market design to identify the type of medical equipment held by a customer. It includes Life Support, Non life support and Medical institution in ROI and Electric Chair Lift, Electric Hoist, Electric Mattress/Bed, Vital Medicine Requiring Refrigeration, Home Dialysis, Multiple Sclerosis, Nebuliser, Peg Tube Feeding Pump, Oxygen Concentrator, Total Parental Nutrition Machine, Patient Vital Signs Monitoring Systems, Electric Pressure Stair Lift, Suction Pump, Ventilator in NI.

Meter Configuration Code

Meter Configuration Code

Meter Configuration Code is a code to indicate the functionality required by the Supplier to be delivered by the combination of registers physically installed at a meter point. It does not describe the technical attributes of the meter(s).

Meter Works Request

A request made by a customer, either via a Market Participant or to ESB Networks directly, to perform technical works at a meter point.

Meter Works Type

Meter Works Type is a code to indicate what work is required or completed (e.g. install, remove, exchange or reconfigure meter).

Metering Equipment

Meters, time-switches, measurement transformers, metering protection and isolation equipment, circuitry and their associated data storage and data communications equipment and wiring which are part of the Active Energy and Reactive Energy measuring equipment at or relating to a site.

MIC

Maximum Import Capacity

Maximum Import Capacity is defined as the maximum rate of energy use (power) to be borne by the connection as agreed between ESB Networks and the customer (in kVA). The MIC is on the basis of a year. Maximum Import Capacity (MIC) is the level of electrical capacity contracted between a business owner and ESB Networks. The unit of measurement for MIC is Kilovolt Ampere (kVA). In billing, the PSO charge for all business customers is based on the contracted MIC level. In addition, customers on Maximum Demand tariffs also pay a Service Capacity charge based on their MIC. If these customers exceed their MIC, they are liable to an excess capacity charge.

MM

Market Message

Messages sent between Supplier and ESB Networks.

MO

Meter Operator

The Meter Operator is an activity which resides in ESB Networks Business, this role is responsible for all meter and capital works for the entire electricity market.

MP

Meter Point

The meter point is the Service Delivery Point on the network. It applies to each service delivery point where there is a Connection Agreement between the Distribution System Operator (Networks) and a customer or generator. In most cases, this is the point of connection to the network.

MP/MPs

Market Participant(s)

Market Participant(s) of the Irish Electricity Market.

MPD

Market Process Diagram

Retail Market Business Process between Market Participants and ESB Networks.

MPDs

Market Process Diagrams

Process flow diagrams illustrating all organisations, business units and market messages within a market process. Currently there are 36 market process diagrams.

MPRN

Meter Point Reference Number

This is the unique identifier for each Service Delivery Point on the network. It applies to each service delivery point where there is a Connection Agreement between the Distribution System Operator (Networks) and a customer or generator. In most cases, this is the point of connection to the network. The MPRN identifies the supplier who has accepted financial responsibility for the energy traded at the service delivery point. At any time there will be only one supplier for each MPRN. It defines the point at which a metering configuration can stand alone in terms of the accurate recording of consumption. In the case of unmetered supplies, it defines the point on the network where accurate estimates of the consumption can be provided for settlement. Meter Point Reference Number is the unique and unchanging reference Number (MPRN) number of a meter point. The MPRN will include a two digit code indicating the distribution system to which the Meter Point is connected and a one digit check digit which is calculated.

MRA

Meter Point Registration Agreement

The agreement which is entered into between a supplier and MRSO for the provision of energy to a named MPRN.

MRMS

Meter Reading Management System

MRSO

Meter Registration Services Operator

The creation of this activity is directly related to the de-regulation of the electricity business in Ireland. MRSO is responsible for the operation of the Meter Point Registration System (MPRS).This is the system used for registering a customer to a supplier and making the supplier responsible for the energy delivered to a particular Meter Point. It provides meter point registration, data processing and data aggregation on behalf of the markets. Even though MRSO is located within Networks; it is ‘Ring fenced’ within the company i.e. it operates independently of Networks as it is servicing all the markets. For each interval Meter Point, MRSO maintains a record of all the data to be used in aggregation. This data consists of:

• The Supplier registered to the Meter Point
• The Supplier Sub Aggregation Code (SSAC). This describes the trading arrangement under which the Supplier will settle for import.
• The Distribution Loss Factor. This loss factor accounts for distribution network losses as settlement is struck on generated rather than consumed electricity. Loss factors normally depend on the voltage level at which the connection is made and vary between day and night.
• The Transformer Loss Factor. This accounts for any losses which occur in transformers fitted on the network side of the meter. A limited number of meter points have such transformers and the loss factor is applied prior to aggregation.
• The kW demand values supplied by the Data Collector (ESB Profile Data Services) for each interval. Data is polled on a daily basis, validated and stored in the MV90 operated by the Data Collector and uploaded to the SAP system used by MRSO. In a minority of instances readings cannot be obtained within 10 working days of the consumption date and in these cases the Data Collector will provide an estimate or substitute reading For each Meter Point, MRSO maintains a record of all the data to be used in aggregation. This data consists of:
• The Supplier registered to the Mater Point
• The Supplier Sub Aggregation Code (SSAC)
• The Distribution Loss Factor
• The Standard Load Profiles
• The Usage Factors

MSD

Maximum Demand Site

Tariffs for larger users are designed to encourage customers to control or reduce electricity demand at daytime peaks. Maximum Demand tariff is structured to reflect not only the amount and rate of electricity used by also the time of day it is used.

MSQ

Market Schedule Quantity in units of MW determined by EPUS.

MV

Medium Voltage

10,000 volts (10kV) or 20,000 volts (20kV).

NI

Northern Ireland

NIAUR

Northern Ireland Authority for Utility Regulation

An independent non-ministerial government department set up to ensure the effective regulation of the Electricity, Gas and Water and Sewerage industries in Northern Ireland.

NMS / Capita

Northgate Managed Services / Capita

NMS (now known as Capita) is a third party service provider to ESBN. The messaging HUB is managed by NMS on behalf of Networks and is responsible for routing XML market messages in and out of SAP. The EMMA is provided to Market Participants by ESB Networks via NMS.

Non- Firm Access

A Generator has non-Firm access where it operates under a connection agreement which provides a Firm Access Quantity which is less than the Maximum Export Capacity at the relevant Connection point. Where Generators have price effecting Export, their aggregated Export data is sent by Eirgrid to the SMO not MRSO.

Non-Interval (NIM)

Non-Interval Hour

Meter data that is collected manually by the Data Collector. Non-Interval was previously referred to as Non Quarter Hour (NQH).

Non-Participant Generator

These are exporters that do not participate in the market. Generators with an MEC of less than 10 (MW). Must be QH. If it occurs that they are non QH must be with PES. SME Subject Matter Expert.

NPA

Non-payment of Account

This term is used in the context of de-energisations where a customer would be de-energised for non payment of account.

NQH

Non Quarter Hour

Meter data that is collected manually by the Data Collector. The term NQH has been replaced by the more generic Non-Interval (NIM).

Participant Generator

These are exporters that participate in the market. They are above the Deminimus set by the regulator – currently the Deminimus is any generator >= 10MW. This threshold roughly translate to an MEC of 10.000 kva. Exporters may also have an MEC of less than 10,000 kva but choose to participate in the market. Must be QH.

Participant ID

The identifier of the owner of the Supplier Unit.

Participant Name

The name of the owner of the Supplier Unit, generally the company name.

PDS

Profile Data Services

Refers to ESB Profile Data Services (PDS), one of the Meter Data Providers in the SEM. PDS are responsible for the provision of QH Meter data to Market Operators (MRSO) in accordance with guidelines set down by the T &SC.

PES

Public Electricity Supplier

In the new market Customer Supply will have the role of Public Electricity Supplier (PES). The PES will operate under different license conditions to other independent suppliers. These conditions will be set by CRU. Among the conditions will be the requirement, under agreed circumstances, to offer a supply on published terms to most customers on request.

PMP

Prepayment

Prepayment (solution offered by ESBN).

Power Factor = 1 or less

This is a term used to describe the relationship between ‘active/real’ power (kW), ‘reactive/wattless’ power (kVAr), and ‘apparent’ power (kVA). Power factor is always 1 or less. If the power factor is 1 then the ‘active/real power’ (kW) being used is equal to the ‘apparent’ power (kVA).If the power factor is less than 1, e.g. 0.98, then some ‘reactive/wattless’ power is being consumed. ESB Customer Supply will only charge for reactive/wattless power when the power factor goes below 0.95, e.g. 0.94.

PQ

Participant Questionnaire

The Participant Questionnaire (PQ) is a textual document that seeks to ascertain, through a number of questions, a high level view of the Participant's aspirations and preparedness to operate in compliance with the Market Design or with the Market Design Release, as appropriate.

PQ pairs

Price / Quantity Pairs

The Quantity represents the average MW level of energy to be supplied over a trading period. The price represents the minimum payment required for each MWh delivered. Incremental price/quantity pairs for generation and demand side unit bids. For generators these values provide a measure of incremental running costs and are net of unit load (i.e. net of “load behind the meter”).

Predictable Unit

Generation Unit that is dispatchable or controllable (e.g. most thermal units).

Premise

This a sub-division of a connection object such as an apartment.

Price Effecting Export

Export is Price Effecting if a Generator is Dispatchable or Controllable and a SEM Participant.

Price Effecting Import

Import is Price Effecting if a Generator site is Dispatchable or Controllable and a SEM Participant, and the Generator does have firm access Import on Participant Demand Customer is not Price Effecting. Where sites have price effecting Import, their aggregated Import Data is sent by Eirgrid to the SMO not MRSO.

Price Taker

A participant who is not eligible to set price in either the ex-ante or ex-post market schedule. (All Autonomous Units are Price Takers).

PSO

Public Service Obligation

Levy by Customer supply

QH

Quarter Hourly Meter

Meter reading obtained on a quarter hourly basis, downloaded each night by telecoms link. The term QH has been replaced by the more generic Interval (IM).

Regional Structure

Postal Regional Structure is a list of all the valid streets, cities, and counties (combinations) which is used to verify addresses.

Register

A device, normally associated with a Meter, from which it is possible to obtain a reading of the amount of Active Energy or Reactive Energy that has been supplied by a circuit, or a Demand Value.

Registration Request

A request made by a customer to a market participant requesting energy supply. Market participant contacts ESB Networks via market message to request registration of the customer.

ReMCoDS

Retail Markets Co-Ordination Design Service

Joint activity between ESB and NIE Networks and is run by a small team drawn from the RMDS and CDA functions.

ReMCoSG

Retail Markets Co-Ordination Steering Group

Formally established under the direction of UR and CRU and provides a forum for the overall governance and strategic guidance of the Co-ordinated retail markets in RoI and NI.

ReMCoWG

Retail Markets Co-Ordination Working Group

Formally appointed by the ReMCoSG and provides a forum for all market participants to input into the development and implementation of any of the co-ordination workstreams in RoI and NI as decided upon by the RAs.

Renewable Generator Unit

A generator unit which produces electricity via renewable fuels, ie wind, hydro.

RMDS

Retail Market Design Service

Retail Market Design Service (RMDS) is a ringfenced function within ESB Networks and is responsible for all aspects of the retail market design.The role of RMDS involves the cost effective support for and delivery of quality systems that will help achieve the Commission’s objectives of encouraging competition in supply markets and quality of service to all customers.

RMP Extranet

Retail Market Participant Extranet Website

The extranet provides Suppliers with data associated with a particular MPRN and to facilitate the operation of a competitive electricity market.

ROI

Republic Of Ireland

SAP-ISU

SAP application for Utilities business

Passes the message to the Messaging HUB for routing to the required Market Participant.

SAR

Self-Assessment Return

The Self-Assessment Return (SAR) is a spread sheet with a number of worksheets. It provides a concise way for the Participant to provide more detailed information about the Participant’s documented business processes and IT applications. The Participant can also identify where specific Market Design requirements are covered within these processes and/or systems and where they have been tested.

Semopx

Semopx

EirGrid plc and SONI Limited in their respective roles as a NEMO designated by the Regulatory Authorities provide day-ahead and intraday trading for the SEM wholesale electricity market.

Settlement Unit

All consumption and production is aggregated under a Settlement Unit by MRSO.

SFTS

Secure File Transfer Service

Secure File Transfer Service employs SFTP (secure file transfer protocol) to transfer data between a client and server. SSH (secure shell) is used to establish a connection between a client and server that acts like an encrypted tunnel. This encrypted tunnel protects any data files that are sent via this secure connection. ESBN uses this to transfer sensitive data to suppliers.

SIC

Standard Industrial Classification

A system for classifying industries by a four-digit code. This is used in the UK.

Simdracs

SEM Implementation of Metered Data Reading, Aggregation, Communication and Storage

SIMDRACS Overview SEM Implementation of Metered Data Reading, Aggregation, Communication and Storage. The participants in the SIMDRACS project are:
• The Regulatory Authorities
• SONI
• NIE T&D
• ESB Networks
• ESB National Grid
• SEM Implementation Team

The key areas of scope being managed via SIMDRACS are to:

• Co-ordinate the delivery of all metered energy data across all four Metered Data Providers to the SEM central market systems under the timelines for SEM Settlement;
• Co-ordinate the description of meter operation standards across all Metered Data Providers and feed into the Grid Code / Metering Code Harmonisation work streams;
• Co-ordinate the decision and timeframe for ESB PES metered data aggregation under SEM. The SIMDRACS project has drafted a Memorandum of Understanding which determined the scope, timelines and roles and responsibilities for each of the above parties.

The definition of wholesale market requirements is managed by the CRU and the SEM and issues associated with this definition will be raised to them, using the SIMDRACS forum. ESB Networks can raise issues in this regard for resolution by CRU and SEM. The wholesale market is subject to a design freeze since early June.

A draft discussion document entitled "Impact of AIP on ROI Retail Market" was issued to the Market in early June. All key design issues were included in the second draft of the document and a walk through of each of the issues was held at a special IGG on June 22nd 2006. Feedback has been received from Market Participants and the SIMDRACS Co-Ordinator. New requirements have been received for the Regulatory Authority and a review of design issues has been carried out by ESB Networks.

ESB Networks AIP Programme has formally written to CRU/SIMDRACS to get agreement to proceed with the detailed design based on what has been discussed with the IGG.

The SIMDRACS Board held a meeting on August 18th to discuss the updated draft document received from SIMDRACS and also the updated Baselined Requirements documents from SEMIT.

SMO

Single Market Operator

The Single Market Operator (SMO) administers the market functions of the SEM. It is managed as a joint venture between EirGrid and SONI and is licensed and regulated by the CRU and the NIAER.

SOLR

Supplier of Last Resort

The Customer Supply business will be the supplier of last resort. This includes accepting customers regardless of credit history; if another supplier ceases in the market all of their customers revert to the supplier of last resort. Revision to Customer Supply is essential because all customers are required to have a supplier who has a connection agreement with ESB Networks.

SOTO

Supplier Timeout

Supplier has received market message 131[S] to re-schedule non-completed fieldwork and Supplier has not re-scheduled within 10 days.

SSAC

Supplier Sub-Aggregation Code

This describes the trading arrangement under which the Supplier will settle for import. SSAC is a sub-aggregation code that specifies the aggregation class to which data will be aggregated for a supplier.

Standing bid data

Standing bid data is bid data defined for a given weekday which is used for that day if no bid has been submitted.

SToD

Seasonal Time of Day

Legacy NI Metering [the tariff comprising different rates applicable according to the period of the day and the season of the year].

Supplier

Any participant in the SEM who has a license to supply electricity in accordance with rules governing same.

Supplier Unit

This is a new term created as a result of the SEM. Each participant supplier in the SEM must register at least one supplier unit with the SMO. MRSO are required to send data to the SMO at aggregated to Supplier unit level.

Supplier Unit ID

The identifier which will be used to group aggregated demand quantities. If the Trading Site Supplier Unit Flag is set to yes, then only specified MPRNs can be included in this aggregation.

T & SC

Trading & Settlement Code

Tibco

Messaging Hub

Hub responsible for routing XML market messages into or out of SAP.

Token Meter Details

Token meter details relate to token meter information used by a site operative to program token meters. This information is made up of values for total debt, emergency credit and recovery rate.

Trading Day

The Trading Day runs from 0600 to 0600 (usually 24 hours, but can be 23 or 25 hours if daylight saving conditions apply).

Trading Site ID

If the Trading Site Supplier Flag is yes, the Trading Site ID will be provided.

Trading Site Supplier Flag

Set to yes or no. A yes value indicates this is a Trading Site Supplier Unit and can only be used to aggregate demand quantities at a specified Trading Site.

Trading Site Supplier Unit

A Trading site Supplier Unit is a company with both a generator license and a supplier license. They generate electricity at a site and supply electricity to the same site. There may be multiple QH Import MPRNs registered to a trading site supplier unit.

Transformer Loss Factor

This accounts for any losses which occur in transformers fitted on the network side of the meter. A limited number of meter points have such transformers and the loss factor is applied prior to aggregation.

Transmission ID

This will denote the type of unit (NPED or PED).

Transmission System

Means the system of electric lines comprising wholly or mainly the licensed Transmission System Owner’s high voltage lines and electric plant which is used for conveying electricity from a generating station to a substation, from one generating station to another from substation to another or to or from any interconnector or to final customers (but shall not include such lines which the Board may with the approval of the Commission, specify as part of the Distribution System) and shall include any interconnector owned by the Board.

Transmission Use of System Charges (TUoS)

A demand customer’s supplier is responsible for paying Transmission Use of System (TUoS) charges in accordance with CRU-approved methodology. Current TUoS charges for suppliers in respect of their demand customers are set out in the Statement of Charges document. Demand Transmission Service (DTS) includes three classes of service or tariff schedules under which charges to suppliers are levied for Use of System (Network Charges &System Services Charges) associated in serving their demand customers who are connected either to the transmission or distribution system. For a better understanding of Use of System Charges levied, please refer to the Supplier page on this website and the Transmission Use of System Charges page.

TSO

Transmission System Operator

The transmission system comprises the high voltage electricity network used for bulk transport of electricity. The Transmission System Operator (TSO) is responsible for the operation, development and ensuring the maintenance of the system and for offering terms for the connection to and use of the system.

UC

Usage Class

Classification for billing which is defined in the installation. In conjunction with the rate category and the rate type it is used to define the rate. Example: energy use is broken down as follows: household use, agricultural use, commercial use, other uses.

UMR

Unmetered

UMS

Unmetered Site

UNM

Unmetered

UoS

UoS is generally used where the intention is to group DUoS and TUoS under one non-specific heading meaning either use of the entire electrical network system or use of either the Transmission or Distribution part of the system without specifying which.

Usage Factor

A usage factor is a statement of consumption during a specified read period for a timeslot at a meter point expressed as an annualised volume. Annualised means that the consumption is stated in terms of kWh per Year. There are essentially four types of usage factor used in aggregation:

• Actual Usage Factor. This is obtained from meter readings and represents the consumption between the meter readings prorated to an annual volume. In some circumstances actual usage factors are calculated as a result of estimated meter readings and these are calculated and treated no differently to those calculated from readings.

• Estimated Usage Factor. This is calculated from previous consumptions and is used in the absence of actual usage factors (i.e. usually for initial Market Settlement until a reconciliation can be calculated from a meter reading).

• Initial Estimated Usage Factor. This is used for a new connection or when there is a change to the connection characteristics. The value to be used will depend on the DUoS Group, load factor and meter configuration. Research will be conducted to determine the appropriate values for each applicable combination of these characteristics.

• De-Energisation Estimated Usage Factor. This is zero, because the meter point is de-energised.

All usage factors are associated with a time period. For actual usage factors the time period is that between the meter readings. For estimated usage factors the time period is that since the last meter readings and is open-ended (i.e. the usage factor is used until the next reading is obtained and an actual usage factor can be calculated).

UT

Usage Type

Key for the rate time zone to which a register is set with respect to installation and billing.

Variable Unit

Generation Unit that is not dispatchable or controllable (e.g. usually wind power units).

Volt (V)

The unit of electrical voltage

A volt is the electrical force required to push current through an electrical circuit. Most domestic homes in Ireland are supplied at a nominal voltage of 230V (single phase). Most businesses are supplied at a nominal voltage of 400V (three phase), which is frequently referred to as ‘Low Voltage’.

Vulnerable Customer

Vulnerable Customers are defined by CRU as:

1. critically dependent on electrically powered equipment, which shall include but is not limited to life protecting devices, assistive technologies to support independent living and medical equipment, or

2. particularly vulnerable to disconnection during winter months for reasons of advanced age or physical, sensory, intellectual or mental health.

Watt (W)

The unit of electric power

A watt is the unit of measurement of ‘active/real’ power. The power used in a basic electrical circuit is the volts multiplied by the amps, e.g. 1 volt passing a current of 1 amp through a basic circuit means that 1 watt of electric power is consumed.

Wattless Unit (kVArh)

1000 reactive volt-amperes for 1 hour

It is the unit of measurement for ‘reactive/wattless’ power consumed. As stated, electric power is made up of two components ‘active/real’ power (kW) and ‘reactive/wattless’ power (kVAr).When these are combined they give the ‘apparent’ power (kVA). ‘Reactive/ wattless’ power is measured on its own electricity meter in large business premises. Large motors require ‘reactive/wattless’ power to operate correctly. Business owners can reduce/eliminate reactive power by fitting power factor correction equipment.

Wattless Unit (kVArh)

1000 reactive volt-amperes for 1 hour

It is the unit of measurement for ‘reactive/wattless’ power consumed. As stated, electric power is made up of two components ‘active/real’ power (kW) and ‘reactive/wattless’ power (kVAr). When these are combined they give the ‘apparent’ power (kVA). ‘Reactive/ wattless’ power is measured on its own electricity meter in large business premises. Large motors require ‘reactive/wattless’ power to operate correctly. Business owners can reduce/eliminate reactive power by fitting power factor correction equipment.

Webforms

A simple Webform application on the EMMA (Electricity Market Message Application) used by MPs with low volumes of market messages to send/view messages or alternatively an MP can implement and use their own back end systems to process messages to/from the EMMA.