Economic allocation calculations

Post Reply
abenoist
Posts: 2
Joined: 09 Apr 2015 17:37

Economic allocation calculations

Post by abenoist » 09 Apr 2015 17:58

Dear all,

First, thanks a lot for this open LCA software!

I had some issues with economic allocation calculations and I think it may be a bug. I found the same thing in the comprehensive user manual (1.2, March 2015) and in the software.
Page 34 and Figure 37, there is an example of economic allocation. A CHP process (Combined Heat & Power) produces 2 MJ electricity and 1 MJ heat. Market values are 0.79 €/MJ of electricity, and 0.36 €/MJ of heat. My own calculation for allocation factors would be, for electricity for instance:

Electricity allocation factor = (Economic benefit from electricity) / (Total economic benefit) = 2 MJ * 0.79 €/MJ / (2 * 0.79 + 1 * 0.36) = 81%.

openLCA finds an allocation factor of 47%, and I think it comes from the calculation : (2 MJ / 0.79 €/MJ) / (2/0.79 + 1/0.36) = 48%. Meaning that the higher the market value, the lower the allocation factor. The same problem occurs in the software itself with other examples.

Thank you

Best regards

aciroth
Posts: 750
Joined: 09 May 2010 23:28

Re: Economic allocation calculations

Post by aciroth » 10 Apr 2015 11:08

Hi, you are right this is indeed a bug. We convert to the reference property straight away here and do not take into account that costs are not the reference property. Will be fixed with the next beta release!
Thanks again, best wishes,
Andreas

abenoist
Posts: 2
Joined: 09 Apr 2015 17:37

Re: Economic allocation calculations

Post by abenoist » 10 Apr 2015 12:33

Perfect! Thanks again for openLCA!

Post Reply

Who is online

Users browsing this forum: No registered users and 10 guests