credit for "cleaner" electricity

[Phil]

Dear all,
My problem is about emission credit for cleaner electricity:

I use a fuel cell (FC) for supplying a single family home (SFH) with heat (e.g. 17,000  MJ/a) and electricity (e.g. 14,000 MJ/a).
However, since the electricity demand of the SFH is only 13,000 MJ/a the FC actually, produce more electricity than needed. Hence, the SFH exports electricity to the grid.

I like to compare the “Life Cycle Impacts” per year of supply of heat and electricity by a FC compared to the supply by a system consisting of a “conventional gas condensing boiler” plus “electricity from the grid” (e.g. using the ENTSO-E electricity mix).

I would like to account for the fact that emission per kWh electricity surplus produced by the FC are lower than the emission per kWh using the ENTSO-E electricity mix.

Hence, I would like to give an emission credit to the “Life Cycle Impacts” per year of the FC. This corresponds to "the emission per kWh electricity using the ENTSO-E electricity mix" times "the electricity exported by the SFH".

Is there an elegant way to include this in an Umberto model?

Thank you and best regards,
Phil

[Genisto]

Dear Phil,

In order to include the credit for the amount of FC electricity, that is exported to the grid, into your model you only need to insert the production of ENTSO-Electricity mix with a negative coefficient into your Umberto model/process specification.

Imagining you only have one process for the FC specification you add the pre-chain or a dataset for the production of the ENTSO-E electricity mix but instead of using a positive input coefficient (e.g. 1000 kWh) you use a negative coefficient (e.g. -1000 kWh). This will bring a credit for the “saved” amount of 1000 kWh ENTSO-E electricity mix and corresponds to “the emission per kWh electricity using ENTSO-E electricity mix” times “the electricity exported by the SFH”

Please keep in mind that you may have to adjust the coefficient in order to correctly implement it into your model depending on the actual specification you have chosen. Also pay attention to the right allocation when having multiple products. Finally, you need to be clear in your communication about the overall impact of the FC and the credit you take for the exported electricity.

Best regards

[Phil]

Thank you very much! Now, that I how to do it... it is obvious 

I have to use negative value of the exported electricity on the input side of my house!

Regards,
Phil