Cogeneration¶

Scope¶

The module is designed to hold functions that are helpful when modeling components that generate more than one type of output.

Concept¶

Currently there are three different methods that can be used to allocate the emissions to the two outputs of a unit that produces electricity and heat.

IEA method

$EM_{el} = EM \cdot \frac{\eta_{el}}{\eta_{el} + \eta_{th}}$ ,

$EM_{th} = EM \cdot \frac{\eta_{th}}{\eta_{el} + \eta_{th}}$ .

Efficiency method

$EM_{el} = EM \cdot \frac{\eta_{th}}{\eta_{el} + \eta_{th}}$ ,

$EM_{th} = EM \cdot \frac{\eta_{el}}{\eta_{el} + \eta_{th}}$ .

Finnish method

$EM_{el} = EM \cdot (1-PEE)\frac{\eta_{el}}{\eta_{el,REF}}$ ,

$EM_{th} = EM \cdot (1-PEE)\frac{\eta_{th}}{\eta_{th,REF}}$ ,

with

$PEE = 1 - \frac{1}{\frac{\eta_{th}}{\eta_{th,ref}}+\frac{\eta_{el}}{\eta_{el,ref}}}$ .

Reference: Mauch, W., Corradini, R., Wiesmeyer, K., Schwentzek, M. (2010). Allokationsmethoden für spezifische CO2-Emissionen von Strom und Waerme aus KWK-Anlagen. Energiewirtschaftliche Tagesfragen, 55(9), 12–14.

Usage¶

em_el, em_heat = allocate_emissions(
        total_emissions=200,  # in CO2 equivalents
        eta_el=0.3,
        eta_th=0.5,
        method=method,
        eta_el_ref=0.525,
        eta_th_ref=0.82
)

Fig. 1: The above figure illustrates the allocation of emissions using the different allocation methods.