Energy Balances and Electricity Profiles - Concepts and definitions
The methodology and format of the energy balances presented in the Energy Balances and Electricity Profiles follow the guidelines provided in the UN publications: Concepts and methods in Energy Statistics, with special reference to Energy Accounts and Balances and Energy Statistics: A Manual for Developing Countries.
| DESCRIPTION OF THE ROWS OF THE ENERGY BALANCE
of primary energy (row 1): Primary
energy refers to energy sources as found in their natural state (as opposed
to derived or secondary energy, which is the result of the transformation
of primary or secondary sources). Production of primary energy refers to the quantity
of fuels which are extracted or produced, calculated after any operation
for removal of inert matter. In general, production includes the quantities
consumed by the producer in the production process (e.g. for heating or
operation of equipment or auxiliaries) as well as supplies to other producers
of energy for transformation or other uses. Data on the production of hard coal and lignite refer to coal after washing and screening
for the removal of inorganic matter. Production of natural gas liquids
is shown together with the production of crude petroleum. Data
for natural gas refer to dry marketable production measured after
purification and extraction of natural gas liquids and sulphur. Extraction
losses and the amounts that have been reinjected, flared, and vented are
excluded. Production includes quantities used within the natural gas
industry, in gas extraction, pipeline systems and processing plants. Production
of primary electricity refers to gross production of electrical
energy of nuclear, hydro, geothermal, wind, tide, wave and solar origin.
Biomass production includes only that portion used for fuel purposes.
(row 2) and exports (row 3) refer to the amount of fuels obtained
from or supplied to other countries. Fuels in transit are excluded.
Imports and exports of crude petroleum also include imports and exports
of feedstocks, unrefined and semi-refined oils and components derived
from crude petroleum. In the energy balance format, imports are positive
numbers, and exports are negative numbers and carry a negative sign (-).
bunkers (row 4) refer to the amounts of fuels delivered to
ocean-going ships or aircraft of all flags engaged in international traffic.
Consumption by ships engaged in transport in inland and coastal waters,
or by aircraft engaged in domestic flights, is not included. The minus
sign is used for entries under this item.
changes (row 5) (at producers, importers and industrial consumers)
refer to the difference between the amounts of fuels in stocks at the
beginning and end of the year. A positive number indicates a reduction
in stocks and thus an increase in available energy; the negative sign
(-) indicates a net increase in stocks and thus a decrease in energy available
energy requirements (row 6) is computed as: production
(row 1) + imports (row 2) - exports (row 3) - bunkers (row 4) - stock
changes (row 5).
converted (row 7) shows the net input of primary and derived
energy into the conversion or transformation process for the purpose of
obtaining other derived products, and the net output of the derived energy.
Inputs carry a minus sign, and outputs, which relate to gross production,
are shown as positive numbers. Row 7 represents the sum of items from
row 8 to row 16.
by the energy sector (row 18) comprises the consumption of
fuels and electricity used by the energy producing industries, e.g. for
heating, lighting, and operation of all equipment used in the extraction
process, for traction and distribution. It includes the quantities consumed
in compression stations and pumping stations of oil and gas pipelines,
as well as the station use and loss of electric power plants (including
electricity used for pumping at pumped storage installations). The minus
sign is used for entries under this item.
in transport and distribution (row 19) refer to the losses
of fuels and electrical energy, which occur outside the utilities or plants
before reaching the final consumer. The losses carry a minus sign.
for non-energy uses (row 20) refers to the quantity of energy products
consumed as raw materials in the chemical, petrochemical and other industries,
not in order to produce energy. The minus sign is used for entries under
differences (row 21) in the energy balance are calculated
as follows: total energy requirements (row 6) +/- energy
converted (row 7) +/- net transfers (row 17) - consumption by the energy
sector (row 18) - losses in transport and distribution (row 19) - consumption
for non-energy uses (row 20) - final consumption (row 22).
consumption (row 22) refers to the consumption of primary and
derived energy by industry and construction, by transport and by households,
agriculture and other consumers.
by industry and construction (row 23) is broken down into the
iron and steel industry, the chemical industry and other industries and
construction. Consumption in the chemical industry refers to use as fuel
only. Fuels consumed by the energy sector, and all inputs into energy
conversion, such as fuels used by industrial/self producers of thermal
electricity, are excluded.
by transport (row 27) includes all fuels consumed by road traffic,
by ships engaged in transport in inland and coastal waters and aircraft
engaged in domestic flights, and by railways. Fuels consumed by agricultural
equipment are included in agricultural consumption.
| DESCRIPTION OF THE COLUMNS OF THE ENERGY BALANCE
Hard coal, lignite and peat (column 1)
coal - Coal that has a high degree of coalification with
a gross calorific value above 23,865 KJ/kg (5,700 kcal/kg) on an ash-free
but moist basis, and a mean random reflectance of vitrinite of at least
0.6. Slurries, middlings and other low-grade coal products, which cannot
be classified according to the type of coal from which they are obtained,
are included under hard coal. There are two sub-categories of hard coal:
(i) coking coal and (ii) other bituminous coal and anthracite (also known
as steam coal). Coking coal is a hard coal with a quality that allows
the production of coke suitable to support a blast furnace charge. Steam
coal is coal used for steam raising and space heating purposes and includes
all anthracite coals and bituminous coals not classified as coking coal.
- One of the two sub-categories of brown coal. Brown coal
is coal with a low degree of coalification which retained the anatomical
structure of the vegetable matter from which it was formed. It has a
mean random reflectance of vitrinite of less than 0.6, provided that the
gross calorific value (on a moist ash-free basis) is less than 23,865
KJ/kg (5,700 kcal/kg). Brown coal comprises: (i) lignite - non-agglomerating
coals with a gross calorific value less than 17,435 KJ/kg (4,165 kcal/kg)
and greater than 31 per cent volatile matter on a dry mineral matter free
basis and (ii) sub-bituminous coal - non-agglomerating coals with a gross
calorific value between 17,435 KJ/kg (4,165 kcal/kg) and 23,865 KJ/kg
(5,700 kcal/kg) containing more than 31 per cent volatile matter on a
dry mineral matter free basis.
- A solid fuel formed from the partial decomposition
of dead vegetation under conditions of high humidity and limited air access
(initial stage of coalification). Only peat used as fuel is included. Its principal use is as a household fuel.
Briquettes and cokes (column 2)
fuel (hard coal briquettes) - A
composition fuel manufactured from coal fines by shaping with the addition
of a binding agent (pitch).
briquettes - A composition fuel manufactured from lignite. The lignite is crushed, dried and molded under high pressure into an even-shaped
briquette without the addition of binders.
- The solid residue obtained from coal or lignite by
heating it to a high temperature in the absence or near absence of air.
It is high in carbon and low in moisture and volatile matter. Several
categories are distinguished:
Coke-oven coke - The solid product obtained from
carbonization of coal, principally coking coal, at high temperature.
Coke-oven coke is also called metallurgical coke and is used mainly in
the iron and steel industry. Semi-coke, the solid product obtained from
carbonization of coal at low temperature, is included with coke-oven coke. It is used mainly as a domestic fuel.
Gas coke - A by-product of coal used for the production
of gas works gas in gasworks. Gas coke is mainly used as a domestic fuel.
Brown coal coke - A solid product obtained from carbonization of brown
Crude oil and natural gas liquids (NGL)
Crude oil - A mineral oil consisting of a mixture of hydrocarbons of natural origin,
yellow to black in color, of variable density and viscosity. Data in
this category also includes lease or field condensate (separator liquids)
which is recovered from gaseous hydrocarbons in lease separation facilities,
as well as synthetic crude oil, mineral oils extracted from bituminous
minerals such as shales and bituminous sand, and oils from coal liquefaction.
Light petroleum products (column 4)
gasolene - Light hydrocarbon oil for use in internal
combustion engines such as motor vehicles, excluding aircraft. It distills
between 35oC and 200oC, and is treated to reach
a sufficiently high octane number of generally between 80 and 100 RON. Treatment may be by reforming, blending with an aromatic fraction, or
the addition of benzole or other additives (such as tetraethyl lead).
gasolene - Light spirit extracted from wet natural gas,
often in association with crude petroleum. It is used as a petroleum
refinery and petrochemical plant input and is also used directly for blending
with motor spirit without further processing.
fuel - Consists of gasolene-type jet fuel and kerosene-type
jet fuel - All light hydrocarbon oils for use in aviation
gas-turbine engines. It distills between 100oC and 250oC
with at least 20% of volume distilling at 143oC. It is obtained
by blending kerosene and gasolene or naphtha in such a way that the aromatic
content does not exceed 25% in volume. Additives are included to reduce
the freezing point to -58oC or lower, and to keep the
Reid vapour pressure between 0.14 and 0.21 kg/cm2.
- Medium oil distilling between 150oC and
300oC; at least 65% of volume distills at 250oC. Its specific gravity is roughly 0.80 and its flash point is above 38oC.
It is used as an illuminant and as a fuel in certain types of spark-ignition
engines, such as those used for agricultural tractors and stationary engines. Other names for this product are burning oil, vaporizing oil, power kerosene
and illuminating oil.
Heavy petroleum products (column 5)
products are defined here as products obtained by the distillation
of crude petroleum at temperatures above 350oC, and which have
a specific gravity higher than 0.83. Products which are not used for
energy purposes, such as insulating oils, lubricants, paraffin wax, bitumen
and petroleum coke, are excluded. Heavy products comprise:
- Viscous, liquid hydrocarbons rich in paraffin waxes, distilling
between 380oC and 500șC, obtained by vacuum distillation of
oil residues from atmospheric distillation. Additives may be included
to alter their characteristics. Their main characteristics are: a flash
point greater than 125șC; a pour point between -25oC and +5șC
depending on the grade; a strong acid number (normally 0.5 mg/g); an ash
content less than or equal to 0.3%; and a water content less than or equal
to 0.2%. Included are cutting oils, white oils, insulating oils, spindle
oils and lubricating greases.
- Solid or viscous hydrocarbon with a colloidal structure,
brown or black in color, which is obtained as a residue by vacuum distillation
of oil residues from atmospheric distillation. It is sometimes soluble
in carbon bisulphite, non-volatile, thermoplastic (generally between
150oC and 200oC), often with insulating and adhesive
properties. It is used mainly in road construction. Natural asphalt
waxes - Saturated aliphatic hydrocarbons obtained as
residues extracted when dewaxing lubricant oils, with a crystalline structure
with C greater than 12. Their main characteristics are as follows: they
are colorless, in most cases odorless and translucent; they have a melting
point above 45oC, a specific gravity of 0.76 to 0.78 at 80oC,
and a kinematic viscosity between 3.7 and 5.5 cSt at 99oC.
These waxes are used for candle manufacture, polishes and waterproofing
of containers, wrappings, etc.
coke - A shiny, black solid residue obtained by cracking and
carbonization in furnaces. It consists mainly of carbon (90 to 95%) and
generally burns without leaving any ash. It is used mainly in metallurgical
processes. It excludes those solid residues obtained from carbonization
petroleum products - Products of petroleum origin (including
partially refined products) not otherwise specified.
Natural Gas Liquids (not elsewhere specified) - LPG or Plant condensate is treated as natural gas liquid
Liquefied and other petroleum gases (column 7)
gas - Gases consisting mainly of methane occurring naturally
in underground deposits. It includes both non‑associated gas (originating
from fields producing only hydrocarbons in gaseous form) and associated
gas (originating from fields producing both liquid and gaseous hydrocarbons),
as well as methane recovered from coal mines and sewage gas. Production
of natural gas refers to dry marketable production, measured after purification
and extraction of natural gas liquids and sulphur. Extraction losses
and the amounts that have been reinjected, flared, and vented are excluded
from the data on production.
Derived gases (column
gas - Gas produced by public utilities or private plants
whose main activity is the production, transport and distribution of such
gas. It includes gas produced by carbonization, by total gasification
with or without enrichment with oil products, by cracking of natural gas,
and by reforming or mixing gases.
Coke-oven gas - By-product of the carbonization process in the production of coke
in coke ovens.
Blast furnace gas - By-product in blast furnaces recovered on leaving the furnace.
(column 10 and electricity profiles)
Production refers to gross production, which includes the consumption by station
auxiliaries and any losses in the transformers that are considered integral
parts of the station. Included also is total electric energy produced
by pumping installations without deduction of electric energy absorbed
utilities (electricity profiles) - Undertakings whose
essential purpose is the production, transmission and distribution of
electric energy, primarily for use by the public. These may be private
companies, co-operative organizations, local or regional authorities,
nationalized undertakings or governmental organizations.
Primary biomass energy (column 11)
- All wood in the rough used for fuel purposes. Production
data include the portion used for charcoal production, using a factor
of 6 to convert from a weight basis (metric tons) to the volumetric equivalent
(cubic metres) of charcoal.
- The cellulosic residue left after sugar is extracted
from sugar cane. It is often used as a fuel within the sugar milling
wastes - Excreta of cattle, horses, pigs, poultry etc., and
(in principle) excreta of humans, used as a fuel.
wastes - Mainly crop residues (cereal straw from maize, wheat,
paddy rice, etc.) and food processing wastes (rice hulls, coconut husks,
ground‑nut shells, etc.) used for fuel. Bagasse is excluded.
Municipal wastes - Consist of products that are
combusted directly to produce heat and/or power and
comprise wastes produced by the residential,
commercial and public services sectors that are collected
by local authorities for disposal in a central location.
Hospital waste is included in this category.
wastes - Consist of solid and liquid
products other than solid biomass and animal products
mentioned above (e.g. tires) combusted directly, usually
in specialised plants, to produce heat and/or power.
- Ethanol (ethyl alcohol) and methanol (methyl alcohol)
for use as a fuel. Ethanol can be produced from sugar, starch and cellulose
and is used mainly in transport (on its own or blended with gasolene). Methanol can be produced from wood, crop residues, grass, and the like,
and can be used in internal combustion engines.
- A by-product of the fermentation of biomass,
principally animal wastes, by bacteria. It consists mainly of methane
gas and carbon dioxide.
Derived biomass energy (column 12)
- The solid residue, consisting mainly of carbon, obtained
by the destructive distillation of wood in the absence of air.
Other energy sources (column 13)
- Heat obtained from (a) combined heat and power (CHP)
plants generating electricity and useful heat in a single installation;
(b) district heating (DH) plants and (c) nuclear power plants and geothermal
sources. The heat may be in the form of steam, hot water or hot air.
(column 14) - Summation of column 1 through column 13.
United Nations Statistics Division - Environment Statistics