The statistics appeared in this chapter have been provided as registers by the Ministry of Energy on two topics of "water" and "electricity".

 1. Water

 This section includes information on "underground waters", "reservoir dams", and "length of networks and number of water and sewage extensions". Statistics on water were added to the Statistical Yearbook of Iran in 1346.

    Statistics on underground waters have been provided by Water Resources Management Organization; statistics on reservoir dams have been supplied by the Bureau for the Exploitation of Dams and Water Supply Networks of the Ministry of Energy; and  statistics on the Length of networks and number of  water  and sewage  extensions have  been obtained from the Water and Sewage Engineering Company.

 2. Electricity

 Electric power industry-related data was first collected in 1343 by the then Ministry of Water and Power (renamed the Ministry of Energy in 1353). Since 1346, the Ministry has regularly provided the annual statistics on the power industry comprising power generation, transmission, distribution, and consumption. The statistics, a part of which appears in some tables of this yearbook, are presented in various annual publications released by the Ministry.

 Moreover, through two successive censuses of population and housing in 1365 and 1375, the SCI collected data on residential units and households benefiting from piped water and electricity which are reflected in Chapter 9, “Construction and Housing,” of the yearbook.

 Definitions and concepts

 Water basin:  see  Chapter 1 ,  Definitions   and concepts.

 Water produced: the amount of water gained  from  various  (surface and underground) water resources  such as wells, springs, subterranean canals, dams and river basins.

 Dam: a barrier built against the flow of water to reserve water or change the direction of flow for procuring water for drinking, industry, irrigation and electricity generation, etc.

Reservoir dam:  usually a large dam made against the flow of water to reserve it for following purposes:  procuring water for irrigation, drinking, industry, creating hydraulic height for generating electricity, etc.

 Large reservoir dam: refers to all dams with a height of 15-metre or more as well as 10-to-15 metre high dams having a reservoir with a volume of 1 million cubic metres or more and/or a capacity of flood discharge of 2000 cubic metres per second. 

 Inflow: annual volume of water entered the reservoir of a dam through the river.

 Outflow: total annual volume of water discharged from different outlets of a dam (weir, silt ejector channels,  take-out gates, drainage channels and evaporation).

 Water extension: refers to the part of branched-off water pipes, containing pipe, related accessories, with a profile appropriate to the water metre and the extension capacity of public water, which connects a private water distribution line or public water distribution network from installation place of extension valve to the delivery point  (valve  following  the

 water metre).

 Public water distribution network: refers to all installations and equipment of water distribution system, including reservoirs, main and minor water distribution lines and water pump house, all of which belong to the Water and Sewage Company.

 Sewage extension: refers to the part of minor sewage pipelines, including pipes and related accessories, with a profile appropriate to siphon or contractual capacity, which carries joint sewages away from the siphon to the private line or to the public network responsible for collecting sewages.

Public network for collection and transmission of sewage: refers to all installations and equipment, such as main collectors, used for collection and transmission of sewage to water treatment house and pump houses of urban sewage and public side networks, all belonging to the Water and Sewage Company. The network is not responsible for collection, transmission and disposal of rainfall water flowing on passages, flood channels and channels inside and outside cities located in the customers’ estates.

 Nominal capacity (registered nominal capacity): refers to the nominal capacity of a turbine or generator mentioned on a plate attached to it for a specific conditions in horse power or megawatt (Mw).

Actual capacity or actual power (registered power): refers to the maximum amount of electricity that could be generated by a generator or a plant regarding the conditions of installation site (temprature, altitude and other environmental conditions).

Gross production: refers to the amount of electricity generated by a generator or a plant during a certain period which is measured on output series of main or supplementary generators and stated in kilowatt hour (Kwh) or megawatt hour (Mwh).

Net generation: refers to the electricity measured at the point of transmission to the power grid. During a certain period, the net generation may be calculated by subtracting gross internal consumption form the gross generation in the same period.

Other institutions: the institutions which generate electricity for their own consumption and also sell a part of  their production to other institutions but are independent from the Ministry of Energy;  some examples are, Esfahan Steelworks ,     Mobarakeh    Steel      Industries ,

Petrochemical       industries,       Tabriz   Tractor

Industries, and Sarcheshmeh Copper Industries.

 Interconnected network: the collection of production sites and regions of consumption around the country  connected together with a network of transmission lines and high voltage stations. The network lets electricity exchange between the regions covered, and makes the export of electric energy possible.

 Isolated network: refers to a collection of generation and consumption of electricity connected to each other, but not connected to the interconnected network

Load demand: the power consumed during a certain period in a certain part of the network Maximum coincidental load: in a full interconnected electricity system, maximum coincidental load for a day, a week, a month, or a year refers to the sum of load at the peak of consumption in regions in megawatt. Where the interconnected system does not cover the total country, the maximum coincidental load may be calculated by adding up maximum load of interconnected network and load of separate regions in megawatt simultaneously. With regard to the difference between peak hours of consumption in different regions connected to the interconnected network, maximum coincidental load is less than the sum of the maximum loads of the regions.

 Maximum non-coincidental load: the peak of consumption in different regions of the country during a  certain period, which are not necessarily simultaneous.

 Power company:  the companies (Ltd.) which are by law engaged in generation, transmission and  distribution of electricity or in a part of such activities.  The definition  covers  the  water  and

 power organizations as well.

 Power plant: refers to the installation place of generators and related equipment.

Hydroelectric power  plant: a  power   plant   in

which the potential energy of water is used to drive the electricity generator turbine.

Thermal power plant: a power plant in which chemical energy inherent in solid, liquid, gaseous fuels is transformed into electricity. This definition covers nuclear, steam, gas and combined-cycle power plants.

Steam power plant: a kind of power plant in which   the  steam   produced   from  the  thermal

energy in liquid, solid and gas fuels drives the steam turbine to generate electricity.

Gas plant: a type of power plant in which hot gas produced from the thermal energy in gas and liquid fuels drives gas turbine to generate electricity.

Combined-cycle power plant: a kind of power plant in which, in addition to electric energy in gas turbine, the heat in gasses off the gas turbine is used for production of steam using a recycling steam kettle. The steam produced is transformed into electric energy in a steam turbogenerator set.

Diesel power plant: a kind of power plant in which gas or liquid is used in cylinders to transform mechanical energy produced by coupled generator into electric energy.

Internal consumption: refers to the sum of electricity consumed internally by units and for non-technical cases, as well as consumption of lights, etc. in a power plant in a certain period in kilowatt-hour (Kwh).

Losses: refers to the energy lost on transmission and distribution lines in a network or a certain system. Energy lost by transformers is considered as losses of transmission and distribution.

Sale or consumption of electricity: the amount of electricity sold to the consumers for various consumptions.

 

 

 Energy produced by the fuel (thermal value): the amount of heat (kilo calorie or B.T.U) produced through burning of the mass unit of a certain fuel.

 Thermal output: considering that the thermal energy produced by 1 Kwh is equal to 860 kcal, the output of  thermal power plants (thermal output) is calculated through the following formula:

 output(%) = (860/thermal energy consumed for 1 Kwh of power generated) times 100

 Line: the cables installed on poles to transmit the electric power from the production site (power plant) or substation to consumption places in different voltages.

 Power transmission line: a line which transmits  the generated electric power in voltages 230 and  400 Kv.

 Subtransmission line: a line which transmits the produced electric power in voltages 63 and 132 kv.

Electricity customers: natural or legal persons whose specifications are registered by customers division according to the regulation of the power company after submitting the required documents and payment of the related costs, then they are offered a customer number.

Household uses: electricity used by households to operate common electric appliances and for lights in residential units.

Public uses: electricity used for public services.

Agricultural uses: electricity used for pumping surface and underground water or repumping water for production of crops or carrying out agricultural activities. Agricultural activities are defined in ISIC Rev. 3.

Industrial uses: electricity used for doing jobs in establishments engaged in manufacturing and mining activities. Manufacturing and mining activities are defined in ISIC Rev. 3.

 Commercial uses: electricity  used in commercial and  business places.