Ancillary Services

The additional services necessary to ensure the security and reliability of the power system. The ancillary services traded competitively on the wholesale market are the three classes of reserve (primary secondary contingency) and regulation. The fast-start ancillary service is procured by Energy Market Company (EMC) on contract based on regulated prices.

Black-start Ancillary Service

Black-start ancillary service is a service to ensure that there is initial generation for system restoration following a complete blackout

CCGT

Combined-cycle gas turbine.

Contestable Consumers

Those consumers that have the right to choose to purchase electricity from a retail supplier directly from the wholesale market or indirectly from the wholesale market through the Market Support Services Licensee (MSSL) SP Services. Consumers qualify to be contestable based on their level of electricity consumption.

Contingency Reserve

A reserve class that can be called upon within a 10 minutes response time.

Co-optimisation

The process used by the market clearing engine (MCE) to ensure that the cheapest mix of energy reserve and regulation is purchased from the market to meet electricity demand in each dispatch period.

Degeneracy issue

A mathematical degenerate state where a set of two or more solutions arise from the same objective function.

Demand Forecast

The demand forecast reports the electricity consumption of Singapore in each half hour. The forecast excludes transmission losses and generation from exempted embedded generators.

Dispatch Schedule

A schedule produced by the market clearing engine (MCE) every half-hour that is the basis for the supply of energy reserve and regulation in the market.

DR

Disaster recovery plan.

DRC - Daily Routine Check

Daily Routine Check performed on a daily basis by the Pricing team

EMC and PSO Fees

These fees are the approved administrative costs for EMC and the PSO to operate the NEMS in each fiscal year. These fees are recovered from both generators and retailers based on per MWh generated or consumed.

EMGrid

Visualisation tool used by EMC's Pricing team to view the connectivities of the physical network. This is based on the NWStat files as well as the outage files provided by the Power System Operator (PSO).

EMView

A tool developed by EMC's Pricing team to view the results of the Market Clearing Engine (MCE).

Energy

In physics energy (from the Greek - energeia or energos) is a scalar physical quantity that describes the amount of work that can be performed by a force an attribute of objects and systems that is subject to a conservation law. Eight different forms of energy exist to explain all known natural phenomena. These forms include (but are not limited to) kinetic potential thermal gravitational sound light elastic and electromagnetic energy. The forms of energy are often named after a related force.
From Wikipedia the free encyclopedia

Fast-start Ancillary Service

A generation facility that is able to synchronise with the power system and begin generationat a defined level within a specified time.

Full Retail Competition (FRC)

A situation in the retail market in which all consumers are contestable consumers i.e. have the right to choose to purchase electricity from either a retail supplier directly from the wholesale market or indirectly from the wholesale market through the MSSL SP Services.

Generation Settlement Facility (GSF)

This is used in the standing data frontend for generation units that are less than 10MW in size. Embedded generators are usually classified as GSFs but not all GSFs are embedded generators. Currently the units in the GSF category are Banyan Utility ISK IUT Pfizer and Schering-Plough.

Gigawatt (GW)

A measure of electrical power equal to one thousand megawatts. GWh represents the number of gigawatts produced or consumed in an hour.

GT

Open-cycle gas turbine.

HEUC

Hourly energy uplift charge.

HSFO

180-centistoke high sulphur fuel oil (180-CST HSFO). The relevant oil benchmark for Singapore's electricity industry.

Interruptible Load (IL)

Interruptible load means the load reduction capacity of a load facility that can be called upon by the Power System Operator to ensure the secure operation of the transmission system. Contestable consumer of electricity that participates in the wholesale market and allows its supply of ectricity to be interrupted in the event of a system disturbance in exchange for reserve payment.

Load

The consumption of electricity.

Market Clearing Engine (MCE)

A linear computer program used to calculate the spot market quantities and prices to determine the generating schedules in accordance to the Market Rules.

Market Energy Price (MEP)

Nodal Energy Price

Market Participant (MP)

A person who has an electricity licence issued by the Energy Market Authority (EMA);and has been registered with EMC as a market participant.

Megawatt (MW)

A measure of electrical power equal to one million watts. MWh represents the number of megawatts produced or consumed in an hour.

MEUC

Monthly energy uplift charge.

MNN

MNN=MEP
Market Network Node or Nodal energy prices are the prices received by generators. Nodal prices are determined according to the demand and supply characteristics of each of the injection nodes (market network nodes - MNNs) on Singapore's electricity network.
This is also called the Market Energy Price.

NEMS

National Electricity Market of Singapore.

Net treatment of non-reserve charges for non-injecting embedded generators

Since December 2007 non-reserve charges (EMC fees PSO fees and Monthly Energy Uplift Charges [MEUC]) for non-injecting generation facilities will be administered on their amount of net withdrawal (consumption) from the grid. To qualify for this treatment an embedded generator requires approval from the EMA and registration with EMC as a non-injecting generation facility.

Nodal Energy Price

Market Energy Price

Nodal Pricing

A market structure in which prices are calculated at specific locations or nodes in the power system to reflect the demand and supply characteristics of each location. Nodal pricing is also commonly referred to as locational marginal pricing.

Non-contestable Consumers

Consumers that are supplied by the Market Support Services Licensee (MSSL) SP Services at a regulated tariff. These consumers have not been given the right to choose to purchase electricity from either a retail supplier directly from the wholesale market or indirectly from the wholesale market through the MSSL SP Services.

OT

Other facilities i.e. incineration plants operated by the National Environment Agency that convert energy from incinerated refuse.

Period

Each half hour that the MCE runs. The MCE runs every half an hour throughout the day resulting in 48 trading periods each day.

POF

Probability of Failure = Standing Probabilty of Failure

Power System

Power System means the system comprising the transmission system and generation facilities and load facilities connected to the transmission system.

Price Separation

A large price deviation between two adjacent dispatch network nodes normally caused by transmission circuits.

Primary Reserve

A reserve class that can be called upon within an 8-seconds response time.

Regulation

Generation that is on stand-by to fine-tune the match between generation and load. Regulation means in relation to a generating unit the frequent adjustment to its output so that any power system frequency variations or imbalances between load and the output from generation facilities can be corrected. A frequency following service.

Reserve

Reserve means generation capacity or load reduction capacity that can be called upon to replace scheduled energy supply that is unavailable as a result of a forced outage or to augment scheduled energy as a result of unexpected demand or other contingencies. Stand-by generation capacity or interruptible load that can be drawn upon when there is an unforeseen disruption of supply.

Reserve Price

The reserve price is the market price for the three classes of reserve products (primary secondary and contingency). Reserves are the stand-by generation capacity or interruptible load that can be drawn on when there is an unforeseen disruption to supply. The cost of reserve products is borne by generators.

Retail Market

The transactions made between retail companies and end consumers.

Secondary Reserve

A reserve class that can be called upon within a 30-seconds response time.

Short Term load forecast (STLF)

Short Term load forecast
- Sent to MCE once a day
- Forecast of the following 14-day's average system load for each half-hourly period

SHUB

Singapore hub or SHUB means the MNN at which all energy taken from the transmission system by load facilities is deemed to be withdrawn and all energy injected onto the transmission system by generation facilities referred to in section 5.1.3 of Chapter 2 is deemed to be injected.

ST

Steam turbine

Terawatt (TW)

A measure of electrical power equal to one million megawatts. TWh represents the number of terawatts produced or consumed in an hour.

Trading Date

Any calendar day since 1 January 2003 when electricity prices are traded in the NEMS. One trading day consists of 48 trading periods.

Trading Month

Any calendar month since 1 January 2003 when electricity prices are traded in the NEMS. One trading month may contain up to 31 trading days.

Trading Quarter

Each year consists of four quarters. Q1 is from January to March Q2 is from April to June Q3 is from July to September Q4 is from October to December.

Trading Week

A trading week starts on a Sunday and ends on a Saturday e.g. 26 January to 1 February 2003 formed one week. Typically each trading week contains 7 days. However some trading weeks may contain less than 7 days e.g. in 2003 Week 1 and Week 53 had only 4 days each.

Uniform Singapore Energy Price (USEP)

The Uniform Singapore Energy Price (USEP) is the uniform price of energy that applies for settlement purposes for all energy injections or withdrawals that occur in Singapore's electricity network. It is the weighted-average of the nodal prices at all off-take nodes in each half hour.

Very short term load forecast (VSTLF)

Very short term load forecast
- Sent to MCE every period
- forecast of the following 7-hour's average system load for each half-hourly period

Vesting Contract

A vesting contract is a regulatory instrument imposed on generators by the Energy Market Authority (EMA) with the objective of mitigating the potential exercise of market power when the supply side of the industry is concentrated among a small number of generators. Introduced in the National Electricity Market of Singapore in 2004 about 55% of the market is currently vested with the remaining about 45% competitively determined by market forces via the spot market.

Vesting Contract Hedge Price (VCHP)

The vesting contract hedge price (VCHP) is calculated by the Market Support Services Licensee (SP Services) every three months using the average 180-CST HSFO prices in the preceding 3 months. It is determined using the long run marginal cost of the most efficient technology in the Singapore power system i.e. the combined-cycle gas turbine (CCGT). EMC's settlement system uses the VCHP to settle the vesting quantity between the Market Support Services Licensee (SP Services) and the generation companies.

Vesting Contract Hedge Quantity (VCHQ)

The VCHQ is the vesting contract hedge quantity allocated to contestable consumers.

WEP

The Wholesale Electricity Price (WEP) is the net purchase price paid by retailers inclusive of all administrative costs incurred in the wholesale market. This price consists of the following cost components: USEP AFP HEUC MEUC EMC fees and PSO fees.

WEQ

Withdrawal energy quantity (in MWh) deemed to be withdrawn at the Singapore HUB.