EN15804 Indicator Materials for Energy Recovery and Exported Energy

Question

Hello, I just reviewed the results of a LCA of a construction product according to EN15804 (with the Ecoinvent 15804 Add-on database). I wondered why the results for the indicator "Materials for Energy Recovery" and "Exported Energy" are 0. Most of the products components are incinerated in the disposal phase. I assumed that this indicator includes the mass of product that gets incinerated or respectively the energy that is produced by incineration.

Then i read the documentation to the 15804 Add-on database. There you state that there are no flows that meet the requirements of the indicator in the database. 

Why do incineration processes not count towards that indicator? Because from my understanding "Materials for energy recovery" includes all material flows that provide energy after for example: incineration. 

I also found some sources that say you should include incineration processes in that indicator (How to calculate EN 15804:A2 indicators in desktop SimaPro). 

There it says for materials for energy recovery: "Tracking in the Network the quantities that leave the boundaries of the system and go to incineration with energy recovery. If you consider incineration within your boundaries, then you should declare Exported Energy and not MER." 

and for exported Energy: "In the incineration of waste, there is description in ecoinvent which lists the amount of electricity and heat generated from the incineration process. So, the characterization factors for each incineration process were simply the actual amounts of electricity (EEE) and heat (EET) that were generated for a particular incineration process. So, these values have to be entered manually.

Can you please explain why you dont include waste incineration processes in these indicators and what your sources for your approach are? 

Best Regards Nils 

Answer 1

Dear Nils,

It is true that EEE and EET could be added by tracking the output of all "market for electricity, for reuse in municipal waste incineration only" and "market for heat, for reuse in municipal waste incineration only". Some of this burden-free energy is re-used in incineration and some of this energy is fed into a generic market.

We have included the indicator and the corresponding amounts for EET and EEE in our soon upcoming release of the new EN15804-addon based on ecoinvent 3.10. In general, the exported energy can be found from energy that has empty providers (burden-free energy) and this corresponds to some energy flows from incineration processes.

All these flows are typically named "... for reuse in municipal waste incineration only" and that's why they were not found/declared as exported energy in our previous versions.

Comments

I think you can also count each total of the different waste flows going to incineration manually and multiply it with the corresponding kWh/kg or MJ/kg in the incineration description.

But I'm not sure if this leads to an overestimated value since it is not tracking the real amounts in the product system exported (energy supplied to a market that can feed the incineration or the generic electricity/heat markets).

The empty processes that yield electricity and heat for re-use in incineration are actually the activities "producing" the exported energy from incineration out of nothing (empty cut-off activities).