Secondary products Coal Coke Patent Fuel Brown Coal Briquettes Coal Tar Coke oven Gas Gas Works Gas Recovered Gases Other coal products Peat Briquettes Other Peat products Primary Products Hard Coal Anthracite Coking coal Other bituminous coal Brown Coal Lignite Sub-bituminous coal Peat Oil Shale/Oil sands
Measurement units – original/natural units Original or natural units Used at the point of measurement of the fuel flow the units measured should be the best suited to its physical state (solid, liquid or gas) Examples include: Mass units for solid fuels (e.g. kilograms or tons) Volume units for liquids and gases (e.g. litres or cubic metres) Energy units for electricity (e.g. kilowatt-hour) and heat (e,g. calories or joules).
Measurement units – Common units Natural units are often converted to a common unit to enable comparison between fuels, estimating efficiencies etc. Common units are typically this is an energy unit (e.g. megajoule or ton of oil equivalent). Calorific value (heating value) are conversion factors that expresses the heat obtained from one unit of the fuel Example calorific values (CVs) include: gigajoule/tonne (GJ/t) for coal megajoule/cubic metre (MJ/m3) for gas NOTE: Calorific values vary between products and also countries
Net and Gross Calorific values Calorific values may be expressed in gross or net terms. The difference is due to latent heat of vaporization of the water produced during combustion. Net calorific values are typically 5% to 6% less than the gross calorific value for solid and liquid fuels and about 10% less for natural gas.
IRES No specific measurement units are recommended for national data collection (most suitable for the circumstance) However, certain units are recommended for dissemination. In particular, Solid fuels -> Metric Tons Gases -> Terajoules
Calorific values IRES recommends the use of net calorific values (NCV) when expressing the energy content of energy products rather than gross calorific values (GCV) However, where available, countries are strongly encouraged to report both gross and net calorific values IRES 4.36
Default Calorific values Default calorific values only to be used in absence of specific values IRES provides default calorific values in line with those in the 2006 IPCC guidelines
Examples of Net Calorific Values (GJ/Metric ton) Anthracite26.7 Coking coal 28.2 Other bituminous coal25.8 Sub-bituminous coal18.9 Lignite 11.9 Peat 9.76…
Statistical units A statistical unit is an entity about which information is sought and for which statistics are ultimately compiled. It is also the unit at the basis of statistical aggregates IRES recommends the use of establishments and households as statistical units for energy statistics
Data items They reflect data collected from statistical units
Data sources IRES recommends to distinguish, as applicable, at least the three reporters groups: Energy industries Other energy producers Energy consumers IRES 7.18 Statistical units classified according to ISIC rev. 4 and grouped as described in IRES
Data sources Statistical data sources From censuses and/or sample surveys (enterprises surveys, households surveys, mixed-households surveys) IRES recommends that countries make efforts to establish a programme of sample surveys which would satisfy the needs of energy statistics in an integrated way to avoid duplication of work and reduce response burden. IRES 7.38
Data sources Administrative data data created originally for purposes other than the production of statistical data - monitor activities related to production and consumption of energy; - enable regulatory activities and audit actions; - assess outcomes of government policies, programmes and initiatives
Annual Questionnaire Imports Stock changes Non energy use Final Energy Consumption Manufacturing, const. and non-fuel industry Transport Other (Agriculture, Households, etc.) Production Transformation Final consumption Total energy supply Energy industry own use Losses Exports Int. bunkers
Common problems Data on calorific values are often not reported Distinction between international bunkers and (domestic) transport High statistical difference Production of secondary products without input into the transformation Conversion into electricity and heat plants should be looked at in conjunction with the electricity production Energy industry own use and transformation