Technical Terms

Company No.: 731568-V
C-l nspection
Daily available capacity
dB(A) or dBA or dBa or dB(a)
Effective capacity
Equivalent availability factor
Flue gas desulphurization (FGD) clean-coal technologies
GCV British thermal units, a measurement of the energy content in fuel, and is used in the power, steam generation, heating and air conditioning industries
Major gas turbine overhaul and hot gas path inspection for the Alstom 13E2 gas turbines used in the SEV Power Plant and the GB3 Power Plant. The major overhaul is conducted periodically based on the unit’s equivalent operating hours

Combined cycle gas turbine, a gas fired electricity generation plant which uses waste heat to run a steam turbine. Most of the gas fired power stations use this technology
Cooling water, water used, usually in a heat exchanger, to reduce the temperature of liquids or gases
The committed availability declared by the relevant IPPs (as required under the respective PPA) to TNB on a daily basis
A-weighted decibels, which is an expression of the relative loudness of sounds in air as perceived by the human ear. In the A-weighted system, the decibel values of sounds at low frequencies are reduced, compared with unweighted decibels, in which no correction is made for audio frequency. This correction is made because the human ear is less sensitive at low audio frequencies, especially below 1,000 hertz, than at high audio frequencies
The issuance of despatch instruction or signal communicated to IPP by the grid system operator or the control centre directing (manually or automatically) the facility to commence, increase, decrease or cease the generation and delivery of electrical energy into grid system
Capacity in MW of power generation for a power plant or m3/day of water production for a water production plant calculated based on a company’s effective equity interest in the respective plant
In respect of a power plant, the effectiveness of the power plant to convert the fuel it consumes to electricity. For coal plants, the efficiency is around 30%-35%, and for CCGT power plants, the efficiency is within the range of 45% -60% depending on the technology used
A performance measure of generation facility calculated based on the actual plant availability taking into consideration unscheduled outages and scheduled outages
Flue gas desulphurization is a set of technologies and equipments employed for removal of sulphur dioxide from the flue gas resulted from coal-fired boiler combustion by using seawater
Feed water, water used to supply (‘feed’) a boiler to generate steam or hot water
Gross calorific value on an as received basis, measured in kcal/kg. The gross calorific value (GCV) is an important property defining the energy content and thereby efficiency of fuels, such as coals. The GCV of a fuel is a measure of heat produced combusting a specific quantity of the fuel under specific laboratory conditions
Company No.: 731568-V

Generating or generation or installed capacity
kcal/kg kg kJ km kV kW
mg mmbtu mmscfd MT or tonne
The contractual available capacity as declared by the IPP, IWP or IWPP on its COD
Gigajoule, a metric term used for measuring energy use. A gigajoule is equal to 1 billion joules. A joule can be defined as the work required to produce 1 watt of power for 1 second
Gigawatt hour is equivalent to a steady power of 1 gigawatt for 1 hour. Gigawatt hours are often used as a measure of the output of large electricity power station
Hectare, a metric unit of area defined as 10,000 square metres (100 m
by 100 m) and is primarily used for land measurement High pressure, for steam boilers; above 15 PSI; for water boilers; above 800 PSI
Heat recovery steam generator, an energy recovery heat exchanger that recovers heat from a hot gas stream. It produces steam that can be used in a process (co-generation) or used to drive a steam turbine (combined cycle)
Intermediate pressure, for steam boilers; 15 PSI; for water boilers; between 300 PSI to 800 PSI Kilo calories per kg, Unit of Calorific Value Kilogramme, 1,000 grams Kilojoule, unit of energy equal to 1,000 joules Kilometre, 1,000 m
Kilovolt, 1,000 V Kilowatt, a measure that indicates the rate at which energy is generated or used. The kilowatt is equal to one thousand (1,000) watts
Kilowatt hour, is a standard unit of electricity or consumption equivalent to 1,000 watts over 1 hour
Pound, a unit of mass, 0.45359237 kg Liquefied natural gas; natural gas that has been converted to liquid form for ease of storage and transport
Low pressure, for steam boilers; below 15 PSI; for water boilers; below 300 PSI Metre, a unit of length equivalent to approximately 39.37 inches Milligramme, 0.001 grams 1 million BTU Million standard cubic feet per day Metric tonne, a unit of a mass equal to 1,000 kg (2,205 pounds)
Company No.: 731568-V

Power reserve margin PSI
Scheduled outage
sq ft sq metre
Super-critical steam parameters
Thermal efficiency
Unscheduled outage Megawatt, a measure that indicates the installed capacity of a power station. 1 megawatt is equal to 1 million watts
Cubic metre, a volume measurement equal to 1,000 litres. 1 cubic metre of water weighs 1 tonne
Nephelometric turbidity units, a unit used to describe turbidity. Nephelometric refers to the way the instrument, a nephelometer, measures how much light is scattered by suspended particles in the water. The greater the scattering, the higher the turbidity
Open cycle gas turbine, a power plant that consists of a single gas turbine that is connected to an electricity generator via a shaft

A measure of available capacity over and above the capacity needed to meet normal peak demand levels
Pounds per square inch
Refrigeration tonne, the amount of heat removed by an air conditioning system that would melt 1 tonne (2000 Ibs.) of ice in 24 hours. This is equivalent to 12,000 BTU/hour
Planned interruption of the electricity generating capacity of the facility that is required for inspection, preventive maintenance or corrective maintenance, repair, replacement or improvement of the facility or any part thereof as set out in the PPAs
Square feet, the area of a square whose sides measure exactly 1 feet
Square metre, the area of a square whose sides measure exactly metre
A thermodynamic expression describing the state of water where there is no clear distinction between the liquid and the gaseous phase at higher pressure and temperature range, above its critical point
A performance measure of power generation facility measured over the ratio of electricity output over heat input calculated by dividing the total generated electricity output by the heat energy consumed in generating that output
Unplanned interruption in the capability of the power plant to generate capacity and electrical energy to the grid

Volt, a unit for electric potential (voltage)


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