– It should be noted that only cumulative energy demand (CED)
approach is broader than NER or EROI boundaries [47]. This is
ascribed to the fact that CED encompasses both the energy used
at the facility and the energy needed for the production of the
required inputs (e.g., chemicals) and the construction of infrastructures and buildings, associated to the total energetic debt of
1 MJ of biofuels [48].
Land-Use Change (LUC): This indicator takes into account the
potential of a given biofuel for area occupation on a yearly basis per
biofuel energy unit (dm
2
.a/MJ). In cases where LUC data are not
available on an annual basis, a single harvest per year will be
assumed [26]. LUC of first generation biofuels is a major concern.
Depending on a number of factors including the original land use,
new land use, and climate, the magnitude of the impact of these
changes is diverse [31]. A major positive aspect of algal fuels is that
fertile cropland would not be necessary. Both direct and indirect
LUC can lead to various environmental impacts. A large number of
different procedures have been introduced and used for direct,
indirect, or combined investigation of LUC. Nevertheless, there
are some guidelines to be taken into consideration regardless of the
methodology used as follows:
1. Use the algae cluster by the IPCC Tier 1. This methodology is
very transparent and widely used at the same time [31]. Given
the latter, the results obtained can be compared with those
reported previously. Using IPCC Tier 1 has also been recommended by the European RED (paragraph 71) [49]. It should
also be noted that this method is also associated with some
oversimplifications. More specifically, it adopts that nitrous
oxides (N 2 O) emissions are solely a function of nitrogen inputs
to the soil and does not account for the carbon fluxes [50].
2. Consider the following according to the IPCC Tier
1 method [49]:
(a) Biomass carbon stock change;
(b) Soil organic carbon stock change; and
(c) Incomplete combustion of biomass and dead organic
matter (DOM) in the initial land-use category before
conversion.
3. It should be noted that all values are taken from the default data
available in the IPCC guidelines, according to the land area
changed, climate, type of vegetation, and many other variables
[49]. Moreover, biomass and organic soil carbon stocks are
estimated before and after land conversion to new uses, and
the summation of these changes is added to the emissions from
incomplete burning of biomass and DOM [31].
Life Cycle Analysis
137
approach is broader than NER or EROI boundaries [47]. This is
ascribed to the fact that CED encompasses both the energy used
at the facility and the energy needed for the production of the
required inputs (e.g., chemicals) and the construction of infrastructures and buildings, associated to the total energetic debt of
1 MJ of biofuels [48].
Land-Use Change (LUC): This indicator takes into account the
potential of a given biofuel for area occupation on a yearly basis per
biofuel energy unit (dm
2
.a/MJ). In cases where LUC data are not
available on an annual basis, a single harvest per year will be
assumed [26]. LUC of first generation biofuels is a major concern.
Depending on a number of factors including the original land use,
new land use, and climate, the magnitude of the impact of these
changes is diverse [31]. A major positive aspect of algal fuels is that
fertile cropland would not be necessary. Both direct and indirect
LUC can lead to various environmental impacts. A large number of
different procedures have been introduced and used for direct,
indirect, or combined investigation of LUC. Nevertheless, there
are some guidelines to be taken into consideration regardless of the
methodology used as follows:
1. Use the algae cluster by the IPCC Tier 1. This methodology is
very transparent and widely used at the same time [31]. Given
the latter, the results obtained can be compared with those
reported previously. Using IPCC Tier 1 has also been recommended by the European RED (paragraph 71) [49]. It should
also be noted that this method is also associated with some
oversimplifications. More specifically, it adopts that nitrous
oxides (N 2 O) emissions are solely a function of nitrogen inputs
to the soil and does not account for the carbon fluxes [50].
2. Consider the following according to the IPCC Tier
1 method [49]:
(a) Biomass carbon stock change;
(b) Soil organic carbon stock change; and
(c) Incomplete combustion of biomass and dead organic
matter (DOM) in the initial land-use category before
conversion.
3. It should be noted that all values are taken from the default data
available in the IPCC guidelines, according to the land area
changed, climate, type of vegetation, and many other variables
[49]. Moreover, biomass and organic soil carbon stocks are
estimated before and after land conversion to new uses, and
the summation of these changes is added to the emissions from
incomplete burning of biomass and DOM [31].
Life Cycle Analysis
137