Page 245 - Materials Chemistry, Second Edition

234 R. Laleman et al.

Fig. 13 Mineral ore depletion 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)

perspective is compared with other indicators, such as the GWP, the ‘‘ecological
scarcity 97’’ Index and the CED nonren . He finds that PV has a better profile
compared with natural gas when using EI 99, GWP, and CED nonren methods, the
score for scarcity is, however, similar. When compared to the other renewables,
PV had the worst score for all the selected LCIA methods.

5.4.2 Mineral Extraction for 1 kWh of Electricity

The total amount of minerals needed for the production of a 3 kWp PV system is
relatively high (Table 5). If the data from table 5 is divided by the total amount of
electricity produced, the ‘‘per kWh mineral use’’ is obtained. In Fig. 13, this is
compared with the ‘‘per kWh mineral use’’ of other technologies. The results from
the Ecoinvent database (v2.0) show that the amount of copper and aluminum ore
extraction is much higher for PV-electricity, compared with the fossil-based
technologies. This clearly indicates that PV has a big impact on mineral depletion,
compared with the other technologies, especially for the more expensive metals
like copper (Cu) and aluminum (Al). The results for iron depletion (Fe), on the
other hand, are similar to the results for gas and coal.
When comparing Figs. 13 and 12, it is clear that, according to the Individualist,
the energy technologies that are very mineral-intensive (such as PV) have a high
environmental impact. Technologies that need very small amounts of minerals,
such as gas, have the lowest score. Despite the fact that most of the metals are
considered to be recyclable, the impact of PV systems on mineral depletion is not
to be ignored. Our results indicate that about 2 grams of iron ore and 1.5 grams of
aluminum ore (Bauxite) are needed for the production of 1 kWh of PV electricity.
An article by Pehnt (Pehnt 2006) mentions comparable figures of 3.3 g of iron ore
and 1.2 grams of Bauxite. If PV systems are to become a major contributor to the
electricity supply, an efficient recycling program would be advisable. Fortunately,
this issue is receiving increasing attention. 8

8
For more information see http://www.pvcycle.org/.