Page 244 - Materials Chemistry, Second Edition

Comparing Various Indicators for the LCA 233

Fig. 12 EI 99 results for PV in Belgium (BE) and Spain (ES) with assumed lifetimes of 20 or 30
years, compared with gas and coal (based on data from Ecoinvent v2.0)

Generally speaking, resource depletion is the most important contributor to the
overall environmental impact score, except for hard coal electricity generation,
where impact on human health is more important.
The Individualist (I,I) prefers natural gas and puts a high weight on the resource
depletion related to the production of PV systems. Not surprisingly, as the indi-
vidualist is very much concerned with human health, the score related to human
health impact for coal is very high since the burning coal is related to unhealthy
emissions. The results in the Hierarchist (H,A) and Egalitarian (E,E) views are
rather similar, with the exception of the impact score for hard coal. Coal will only
become scarce in the very long term; this could explain the relatively high impact
according to the Egalitarian view since it is more considered about long term
effects (see Table 3). Notice that coal generally has the highest impact score, even
higher than Individualists’ estimate for PV systems, assuming the latter are
installed in sunny regions.
The view of the Hierarchist and the Egalitarian is very clear; they prefer PV
systems as electricity sources instead of fossil-based electricity production.
According to these two perspectives, the overall score for PV is many times smaller
compared with natural gas or coal. The score for gas is much higher here, since fossil
fuel depletion is considered to have an unfavorable impact on future generations’
ability to obtain sufficient amounts of natural gas with a reasonable effort.
In a recent article by Martínez et al. (2009a), an EI 99 score of about 0.001
points is assigned to 1 kWh of wind energy from a 2 MW turbine in Spain. This is
about 3 times lower than the score we found for PV systems in the most optimistic
case (0.003 eco points, high solar irradiation, and a 30 years life expectance) using
the Hierarchist perspective. According to our results, PV systems have good
properties, but according to Martínez et al. (2009a), the use of wind turbines has
less environmental impact. Unfortunately, only one perspective was used by
Martínez et al. (2009a), the impact of different perspectives was not analyzed.
Jungbluth (2005) has also compared the LCA results from PV systems with
those of wind, hydro, biomass and gas plants (and others). In his paper, the EI 99