Steam Power Plant: is a plant in which thermal energy coming from liquid, solid and gas fuels, are used to produce steam required in steam turbines for generating electricity.
Gas Power Plant: is a plant in which thermal energy coming from gas and liquid fossil fuels are used to produce hot gas (smoke) required in gas turbines for generating electricity.
Combined Cycle Power Plant: is a plant which uses the heat contained in the exhaust gases from gas turbine, as well as the electric energy produced in gas turbines, to produce steam in a recovery boiler. The produced steam is, in turn, used in a turbo generator to generate electric energy.
Diesel Power Plant: is a plant which consumes gas oil for launching a diesel engine. Mechanical energy coming from this engine is converted into electrical energy by the generator coupled with it.
Hydroelectric Power Plant: is a plant which uses potential energy of the water accumulated behind dams or energy coming from the flow of a river in water turbines to generate electricity.
Wind Power Plant: farms of wind turbines which generate electricity from wind power, and supply it to the national grid, are technically called wind power plants.
Practical Power: is maximum power capacity of the generator in the installation location, with regard to environmental conditions (height above sea level, ambient temperature and relative humidity).
Maximum Practical Power: practical power in winter (or practical power in the coldest day of the year).
Minimum Practical Power: practical power in the summer (or in the hottest day of the year).
Average Practical Power: the average practical power of the electricity generation units in a season
Normal Power Output: is a power that is produced by a unit in normal conditions, with no technical problems, and no adverse effects on the unit, as well.
Maximum Generation during Peak Time: is maximum power output of the units during the peak load in a specified time period which may be lower or equal to total output of the units.
Gross Power Generation: sum of the energy produced by generators of a power plant in a specified time period (e.g. within a year) which is measured on the output terminals of generators in KWh or MWh.
Unit's Internal Consumption: The amount of electrical energy, consumed by the auxiliary and peripheral equipment of a unit in a specified time period in order to steer the unit (whether in run mode or stop mode), is referred to as unit's internal consumption.
Plant's Internal (Technical) Consumption: Total internal consumption (in a specified time period in KWh) which directly affects generation is called plant's internal (technical) consumption.
Plant's Internal (Non-Technical) Consumption: is the energy used inside plant, including energy consumption for lighting passageways and auxiliary equipment of units, regardless of the fact that the required energy is generated inside the unit itself or comes from other sources.
Unit's Net Power Generation: is the difference between gross energy produced by the unit and its internal consumption in a specified time period in KWh or MWh.
Plant's Net Power Generation: Net power generation refers to gross electricity generation in KWh or MWh minus plant's internal energy consumption in a specified time period.
Coincidental Peak Load: in a fully incorporated electric power system, daily, weekly, monthly and annual coincidental peak load refers to total loads of regions (in MW) in the moment of system peak load. If the incorporated system doesn't cover the whole country, coincidental peak load is obtained by calculating the sum of the peak load of the incorporated system and loads of separated regions coincidentally. Due to the difference in peak hours of different regions related to the same incorporated system, coincidental peak load is less than total peak load of regions.
Non-Coincidental Peak Load: is the peak loads consumed in different regions of the country in a specified time period. The peak loads of the regions are not necessarily coincidental.
System Load Factor: The ratio of the total energy generated in a specified time period (generally, a one-year period) to the product of system peak load and the length of time in hours (generally, 8760 hours). System load factor = 100 * total energy generated in the system in a year / (peak load * 8760 hours)
Unit Load Factor: The ratio of the total energy, generated in a unit during a specified time period (generally, a one-year period) to the product of unit's practical power and hours of operation in a given time period. Unit Load Factor = plant load factor is the weighted average of the plant units load factors.
Power Plant/Region/Country Utilization Factor: The ratio of total energy generated in a power plant, region or country during a specified time period (generally, a one-year period) to the product of plant/region/country's practical power and length of given time period in hours.
coefficient of utilization = 100 * gross energy output/ (8760 * practical power)
readiness factor =100 * (practical power / power output)
unavailability factor = 100 *(practical power / total non-produced power)
emergency output factor = 100 * (practical power / emergency outputs and constraints)
emergency output rate = 100 * (emergency outputs and constraints/ emergency outputs and constraints + spinning reserve + power output)
Special Heat Rate: The amount of heat consumed to generate a kilowatt hour of electricity is referred to as Special heat rate that is represented with kilocalorie per kilowatt hour.
Heating Value: is the amount of heat which is produced by the combustion of a unit quantity of fuel, and measured in terms of calories or Btu.
Thermal Efficiency: regarding the fact that thermal energy derived from one kilowatt-hour of electricity is 860 kcals constantly, the efficiency of thermal
power plants or units is computed using the following formula:
100 * (thermal energy consumption per one kilowatt-hour of generated electricity/ 860)
Peak Power Output: is the power which the unit has generated at the time of peak
.Imported Power or Energy (Imports): is the total power or energy which isimported via trans-regional lines. This figure is displayed with a minus sign in National Dispatching Reports.
Reserve: is the difference between power capacity and power generated at the peak time.
Spinning Reserve: is the difference between power capacity and power generated by units in the circuit at the peak time.
Non-Spinning Reserve: is the power capacity of the unit or units currently outside the circuit but ready for operation.
Product Reserve: is the ratio of spinning and non-spinning reserve to total practical capacity, at the time of peak, which indicates the amount of immediate production capacity that can be made available in case of emergency and sudden load changes.
Exported Power or Energy (Exports): is the total amount of power or energy taken out via trans-regional lines (This figure is displayed with a plus sign in National Dispatching Reports).
Equivalent of Frequency Falling: is a part of the energy or power required for consumption that is reduced from system nominal load or added to it, due to frequency decrease or increase below or above its nominal limit.
Demand: The total load required by the system which is attained by adding up the total load produced including sum of gross power generation, power imported from neighboring countries, Equivalent Frequency Falling, and Equivalent to the blackout applied. Demand is determined as peak power and energy in a period of time.
Total Load Factor: can be calculated by the following formula:
100*(24*Total demand/ consumed power)
Improved Demand: Sum of network demand and equivalent of applying industrial management is called improved demand.
Non-Produced Energy due to Internal Limitations: The energy which is not produced by the power unit because of defects and limitations occurred to the unit or auxiliary equipment.
non-produced energy due to internal limitations based on seasonal practical power = amount of limitations on seasonal practical power *time of limitations
Non-Produced Energy due to External Limitations: The energy which is not produced by the power unit because of defects and limitations applied to the plant by external factors (grid, fuel, water resources behind dams, etc.) in which the plant operation plays no role.
Calculation Method: Non-produced energy due to external limitations based on seasonal practical power equals to time of limitations multiplied by the amount of limitations on seasonal practical power
Dedicated Power Plants: These plants belong to large scale industries (like Mobarakeh Steel Company, Isfahan Steel Company, Sarcheshmeh Copper Industries, etc.). They generate electric power, and may exchange energy with electricity networks owned by the Ministry of Energy.
Share of Electricity Consumption in Final Energy Consumption: electric energy consumption divided by final energy consumption
Amount of Local Contaminants in Electricity Generation: the emission of particulates like NOX, SOX, COD, and BOD divided by gross generation in Kilowatt-hour (each separately), and the unit of measurement is ppm and ppp.
Reserve Factor: The country's electricity reserve factor in terms of
percentage is calculated using the following relationship:
reserve factor = (actual capacity of all power plants – maximum demand) * 100/ maximum demand
Reserve Shortage Factor: Reserve shortage factor in terms of percentage is calculated using the following relationship:
reserve shortage factor = (maximum demand)/ (100 *(( actual capacity of all power plants – maximum demand) – 26))
Plant Average Performance: Average hours of performance in the units of a power plant
Specific Water Consumption of a Hydroelectric Power Plant: is the average amount of water passing through the dam valves needed for generating a unit of electric energy.
