scope:

Purpose, scope, boundaries In energy economy, emissions are commonly related to the exhaust of power stations or CHP plants (see VDI 4660 Part 1). For environmental and energy policy decision-making, as well as for consumers, it is often more instructive to relate emissions to those forms of energy which are targets of the respective energy conversion process. In the following these forms of energy are referred to as target energies (electricity , useful heat, etc.).

Emissions related to target energy are emissions which result from the conversion of primary energy (energy sources such as coal, natural gas or biomass) to target energy divided by the energy produced during the same time period and under the same operating conditions.

Emissions related to target energy are plant-specific emissions which have to be determined from measurements or from emission data of Part 1 of this guideline VDI 4660 and additional measurements of power or additional efficiency data. In order to perform comparisons as unambiguous as possible be-tween the data of different forms of target energy related emissions and different energy conversion systems and processes, boundaries for energy-balance and ambient conditions must be fixed in addition to the procedure recommended in Part 1. In the case of energy conversion plants producing more than one form of target energy (e.g. power plant with a backpressure steam turbine where both electricity and useful heat are produced), it is also necessary to agree on how the emissions are to be allocated to the target energies.

Throughout the following considerations the terms "target energy" and "target (power) output" refer to net target energy and net target output. This is the desired energy or power produced by the energy conversion plant, minus all of the energy or power required for plant operation including auxiliary power taken from the grid.

No upstream or downstream energy-conversion chains are taken into account in this guideline. The procedure for converting specific emissions into emissions related to target energy is described below. For this, the following cases must be distinguished:

• Conversion of emissions related to fuel energy into emissions related to target energy using efficiency data
• Allocation of emissions according to the various forms of target energies from cogeneration