Why is there a big jump in water scarcity from Ecoivent 3.5 to 3.6 using AWARE for electricity production (BG)?

Question

Why are the impact factors for water (AWARE) so different from Ecoinvent 3.5 to 3.6 in EF Methods (adapted)? This results in Ecoinvent 3.6 having an extremely high water scarcity burden due to electricity use in AWARE. 

Ecoinvent 3.6:

 

Whereas in Ecoinvent 3.5, the impact factors even out (it would be 42.95 m3 depriv/m3 and -42.95 m3 depriv/m3)

Many thanks in advance

Sophie

Answer 1

Hi Sophie,

Take a look at the elementary flows in the processes for hydropower generation and how they're included in the impact assessment method as you have it installed in openLCA. For a hydro-power process (see pic), In this example, if there were no regional specificity to the characterisation factors, then the IA method should be set up so that the water emitted has negative characterisation factor of -1 to balance the +1 CF associated with the incoming water. If there is a net impact for this process, then something's awry. Perhaps because of the regonal-weighting now applied to some flows and not others? 

Good luck,

Chris Foster

Comments

I use ILCD 2.0