The Greenhouse Gas Protocol Initiative: Allocation of Emissions from a Combined Heat and Power Plant
The Greenhouse Gas Protocol tool for allocation of GHG emissions from a combined heat and power (CHP) plant is a free Excel spreadsheet calculator designed to determine the GHG emissions attributable to the purchase or sale of energy from a CHP plant. CHP systems produce multiple forms of energy (e.g., steam and electricity) from one fuel supply. This tool allocates GHG emissions to a CHP plant's separate energy streams by determining the GHG emission factor associated with each stream.
The methodologies embedded in the tool are based on the Greenhouse Gas Protocol developed by the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD). Emissions from a CHP plant may be scope 1, 2, or 3, depending on the energy stream and the relationship of the reporting organization to the CHP plant (for instance, if a community is purchasing steam or electricity from a CHP plant, it should report these emissions as scope 2). This calculator can be used to develop a GHG emissions baseline specifically for a community's purchase or sale of energy from a CHP plant.
Inputs and Outputs
Inputs include: The user must input the total direct emissions from a CHP plant; the steam output from the plant; and the electricity output from the plant. The user should also input the assumed efficiency of steam and electricity combustion (defaults are provided in the tool).
Outputs include: The tool outputs the emissions from a CHP associated specifically with steam production; the emissions associated specifically with electricity production; and the respective emissions factors for steam and electricity.
The GHG Protocol tool for allocation of emissions from a combined heat and power (CHP) plant can be used in conjuction with other WRI tools (e.g., the GHG Protocol tools for stationary combustion and purchased electricity), or generally whenever the required data is known. The tool is accompanied by a detailed guidance document, Allocation of GHG Emissions from a Combined Heat and Power (CHP) plant. This document provides instructions on using the tool, examples, and guidance on determining when it is appropriate for an organization to allocate emissions from a CHP plant.
This tool represents one of the Greenhouse Gas Protocol Initiative's several cross-sector spreadsheets that can be used separately or in conjunction to develop a GHG inventory of various emissions sources within a community. Separate calculators are available for emissions from purchased electricity, stationary combustion, mobile combustion, refrigeration and air conditioning equipment, and several industrial sectors.