normalized or not-normalized impact categories results
could be performed [29].
3. Application of weighting in cut-off quantification: For quantification of the achieved completeness/cut-off, the normalized
results for the different impact categories may be weighted
across the indicators [51].
4. It should be noted that if weighting is intended, normally
normalized LCIA results of algal fuels are multiplied by a
separate weighting factor for each impact category to obtain
“weighted LCIA results” [55].
5. It should be noted that weighted results of algal fuels can be
summed up across the impact categories or areas of
protection [56].
6. It should also be noted that weighting of algal fuels shall not be
used in studies leading to comparative statements planned for
public disclosure [57].
7. It should be noted that the selection of weighting factors
essentially includes value choices [58].
6.4 LCIA in
Comparative Studies
of Algal Fuels
In comparative LCA studies focusing on the type of algae fuel
produced, an impact assessment must be performed as well in
order to calculate the final LCIA results. The interpretation
phase, as well as the conclusions and recommendations, must be
based on the outcome of the LCIA results [29].
7 Interpretation
When interpreting algal fuels, the following guidelines should be
taken into account:
1. Identify the significant issues in algal fuels production or use
chain. Those include key processes, parameters, assumptions,
and elementary flows [59].
2. Evaluate these issues in terms of their sensitivity or influence on
the overall LCA results in algal fuels production or use
chain [60].
(a) It should be noted that this includes an evaluation of the
completeness and consistency of the significant issues in
the LCI/LCA of algal fuels production or use chain.
3. Use the outcomes of the evaluation in drawing conclusions and
offering recommendations from the LCA of algal fuels production chain. It should be noted that if comparison of two or
more algal fuels production or use chain systems is intended,
further considerations should be included in the interpretation.
Life Cycle Analysis
139
could be performed [29].
3. Application of weighting in cut-off quantification: For quantification of the achieved completeness/cut-off, the normalized
results for the different impact categories may be weighted
across the indicators [51].
4. It should be noted that if weighting is intended, normally
normalized LCIA results of algal fuels are multiplied by a
separate weighting factor for each impact category to obtain
“weighted LCIA results” [55].
5. It should be noted that weighted results of algal fuels can be
summed up across the impact categories or areas of
protection [56].
6. It should also be noted that weighting of algal fuels shall not be
used in studies leading to comparative statements planned for
public disclosure [57].
7. It should be noted that the selection of weighting factors
essentially includes value choices [58].
6.4 LCIA in
Comparative Studies
of Algal Fuels
In comparative LCA studies focusing on the type of algae fuel
produced, an impact assessment must be performed as well in
order to calculate the final LCIA results. The interpretation
phase, as well as the conclusions and recommendations, must be
based on the outcome of the LCIA results [29].
7 Interpretation
When interpreting algal fuels, the following guidelines should be
taken into account:
1. Identify the significant issues in algal fuels production or use
chain. Those include key processes, parameters, assumptions,
and elementary flows [59].
2. Evaluate these issues in terms of their sensitivity or influence on
the overall LCA results in algal fuels production or use
chain [60].
(a) It should be noted that this includes an evaluation of the
completeness and consistency of the significant issues in
the LCI/LCA of algal fuels production or use chain.
3. Use the outcomes of the evaluation in drawing conclusions and
offering recommendations from the LCA of algal fuels production chain. It should be noted that if comparison of two or
more algal fuels production or use chain systems is intended,
further considerations should be included in the interpretation.
Life Cycle Analysis
139