ecoinvent Forum Archive

HI,

I am working on a project of electricity production from biomass. The renewability analysis in terms of exergy consumption should be compared with the national electricity market. Since in my study heat is cogenerated and delivered to a nearby factory, a certain amount of natural gas is avoided. For the sake of proper comparison, I would like to know whether heat and the relative avoided resources are accounted in the national electricity market (high or medium voltage), since CHP systems are included in the electricity mix. And in case the avoided resources consumptions are accounted, are they considered as negative values?

Dear User,

In ecoinvent CHP systems are modelled in a way that the reference product is heat and electricity is produced as a by-product. How electricity is further burdened depends on the used system model. More information on system models and how they handle by-products can be found here. In the allocation system models (cut-off and APOS) this means the impacts of the CHP plant are allocated according to exergy and price (see Data quality Guidelines for ecoinvent 3). In consequential (substitutional system model), CHP is not part of the electricity mix so there is no need for accounting for avoided resources.

Best regards,

Johannes Müller, Junior Data Analyst, ecoinvent Association