Technical Note: Conversion of fuel data to MWh

Transcription

1 Technical Note: Conversion of fuel data to MWh Questions 12.2 and 12.3 of the information request ask for energy and fuel inputs to be reported according to standardized units commonly used for measuring electricity consumption, i.e.: MWh. Energy and fuel inputs mean the energy content of: Fuels before combustion in operations/assets within your reporting boundary; and The amount of purchased energy inputs which include electricity, heat, steam and cooling for use by those operations/assets. Information about how to convert purchased energy inputs (electricity, heat, steam and cooling) to MWh is provided in the guidance for Q12.2. Cooling is included in this list because when cooling services are purchased using a district system, the compressor system that produces the cooling may be driven by either electricity or fossil fuel combustion. This appendix provides guidance on how to convert fuel data to MWh. Fuel can be measured in terms of: Energy content e.g. in kilojoules (kj), British thermal units (Btu) or therms; Volume e.g. in m3 or liters; and Mass e.g. in metric tonnes or short tons. The way in which fuel data may be converted to MWh depends upon whether information about fuel is expressed in terms of energy content, volume or mass and guidance on conversion for each measurement is set out below. For fuel inputs, we ask for the energy content of fuels prior to combustion. Please include in your calculations the energy content of any biomass and self-produced fuels that you use for stationary combustion. Self-produced fuels are fuels produced by assets or activities within your reporting boundary that are combusted for energy generation. This is common in the oil and gas sector, e.g. refinery fuel gas, associated gas, etc. If you have your fuel data in energy units If you have your fuel data in an energy unit, you can convert it to MWh using a conversion tool such as: Additionally, there is a conversion table listed in Appendix E in this guidance document. If your fuel data is in units of volume or mass and you know the energy content of your fuel 1. If your fuel consumption is measured by volume or mass you need to obtain the energy content of the fuel in corresponding units, e.g. kj/liter, kj/m3, kj/metric tonne. This is usually called the calorific value or heating value. It may be obtained from your fuel supplier or you may have your own values generated by your own tests. 2. Multiply the fuel volume or mass by the calorific value (or heating value) in the appropriate units i.e. if the fuel data is in metric tonnes, then the calorific value must be expressed in energy units per metric tonnes. This gives you the energy content of the fuel used. 1

2 3. Take the resulting figure and convert it to MWh using a conversion tool. If your fuel data is in units of volume or mass and you do not know the energy content of the fuel If you cannot obtain a calorific value (or heating value) specific to the fuel you purchase, default heating values may be used. Default heating values are reproduced from the GHG Protocol s stationary combustion Excel spreadsheet 3.1(1). Please note: These default values are meant only to provide guidance for users who are developing their own values. Users are encouraged to develop their own values based on the actual characteristics of the fuel being combusted. The GHG Protocol has produced a new tool version 4.0. Its simpler and clearer user interface means that some reference data such as the figures below are no longer visible. Fuel Type Higher Heating Values (HHV) / Gross Calorific Values (GCV) units TJ/Gg Lower Heating Values (LHV) / Net Calorific Values (NCV) units TJ/Gg Crude oil & derived substances Crude oil Orimulsion Natural Gas Liquids Motor Gasoline Aviation Gasoline Jet Gasoline Jet Kerosene Other Kerosene Shale oil Gas/Diesel oil Residual Fuel oil Liquefied Petroleum Gases Ethane Naphtha Bitumen Lubricants Petroleum coke Refinery feedstocks Refinery Gas Paraffin waxes White Spirit & SBP Other petroleum products

3 Fuel Type Higher Heating Values (HHV) / Gross Calorific Values (GCV) units TJ/Gg Lower Heating Values (LHV) / Net Calorific Values (NCV) units TJ/Gg Coal & derived substances Anthracite Coking coal Other bituminous coal Sub-bituminous coal Lignite Oil shale and tar sands Brown coal briquettes Patent fuel Coke oven coke & lignite coke Gas coke Coal tar Gas works gas Coke oven gas Blast furnace gas Oxygen steel furnace gas Natural gas Natural Gas Nonbiomass waste fuels Municipal wastes (non-biomass fraction) Industrial wastes NA NA Waste oils Peat Peat a Biomass fuels Wood/Wood waste Sulphite lyes (Black liquor) Other primary solid biomass fuels Charcoal Biogasoline Biodiesels Other liquid biofuels Landfill gas b Sludge gas b Other biogas Municipal wastes (biomass fraction)

4 Table 1 Source: 2006 IPCC Guidelines for National Greenhouse Gas Inventories. The IPCC values were originally on a NCV (LHV) basis and have been converted to a GCV (HHV) basis. They have been published by the World Resources Institute/World Business Council for Sustainable Development in their stationary combustion calculation tool version 3.1(1) *Value can be significantly affected by moisture content of fuel **Value can be significantly affected by fraction of air, CO2, and moisture in gas. Please note that the heating values in Table 1 are given in units of TJ/Gg, where the prefixes T and G stand for tera and giga and correspond respectively to multiplication factors of 1012 and 109. When using the tabulated values for heating values, please ensure that your fuel use figures are in the correct units. If your fuel measurements are in units of mass 1. If your figures are already in metric units of mass, convert them to Gg or Giga grams. The online converter has a webpage that can be used to convert between different metric units. The website can also be used to convert to Gg if your figures are in other units of mass e.g. short tons and pounds. 2. Select the appropriate default calorific value (or heating value) from Table 1 above and multiply it by your mass figure in Gg. The resulting figure will be in TJ. 3. Convert to MWh using the online converter. If your fuel measurements are in units of volume 1. If your fuels are gases or liquids and are in units of volume, convert to units of mass. To do this, organizations will need to know the density of the fuel. Organizations are encouraged to develop their own values based on the actual characteristics of the fuel being combusted. However, if you do not have density data specific to your fuel, you could use default density values from Table 2 below which was sourced from the GHG Protocol stationary combustion spreadsheet version 3.1(1). Multiply the units of volume by the appropriate density values from Table 2 below to convert them to units of mass. Check that you are using the appropriate conversion factors i.e. if your data is in cubic feet do not use the conversion factor for cubic meters; use the conversion factor for cubic feet. 2. Convert the data into Gg or Giga grams. The online converter has a webpage that can be used to convert between different metric units. The conversion calculator can also be used to convert to Gg if your figures are in other units of mass e.g. short tons and pounds. 3. Select the appropriate default calorific value (or heating value) from Table 1 above and multiply it by your mass figure in Gg. The resulting figure will be in TJ. 4. Convert to MWh using the online converter. 4

5 Gaseous (kg/m 3 ) a,b Liquid (kg/l) b Gaseous (lb/ft 3 ) a,b Liquid (lb/gal) b Fuel Type Range Typical Range Typical Range Typical Range Typical Coal-based fuels Anthracite coal Bituminous coal Sub-bituminous coal Lignite coal Coal coke Patent fuel BKB Natural gas-based fuels c Natural gas Natural gas (dry) Methane Ethane Propane Butane Isobutane n-butane Natural gas liquids (LNG) Petroleum-based fuels Crude oil Motor gasoline / petrol Aviation gasoline Distillate Oil Distillate fuel oil No Distillate fuel oil No Distillate fuel oil No Residual Oil Residual fuel oil No Residual fuel oil No Jet kerosene Kerosene (other) Petroleum Coke LPG Naphtha Asphalt / bitumen Pitch Lubricants Waxes 5

6 Gaseous (kg/m 3 ) a,b Liquid (kg/l) b Gaseous (lb/ft 3 ) a,b Liquid (lb/gal) b Fuel Type Range Typical Range Typical Range Typical Range Typical Shale oil (liquid) Oil shale Other Fuels Peat Waste plastics Tar Waste tire derived fuels Biomass Wood (dry) Wood (wet) Fuelwood (approx. 20% moisture) Black liquor Landfill gas Waste water treatment biogas Biodiesel Turpentine Vegetable oils Table 2 Source: World Resources Institute/World Business Council for Sustainable Development stationary combustion calculation tool version 3.3(1) a. Density values are highly sensitive to changes in temperature and pressure. Values indicated are based on room temperature and standard atmospheric pressure. b. Dry unless otherwise noted. c. At room temperature and standard atmospheric pressure. Reference: Typical values are based on a compilation of commonly accepted sources such as US DOE/EIA, national inventory reports to the UNFCCC and other sources. 6