Sustainability Report - Bank Sarasin-Alpen

Solar Energy 2005
WEEE directive
The WEEE directive (waste of electric and electronic equipment) makes it compulsory
for the industry to take back used electronics products.
At present PV modules are explicitly excluded. But solar-powered calculators,
clocks, etc. already fall under the directive. It is quite feasible that the legal situation
could change once photovoltaics develop from a niche product into a massproduced
technology.
Initial initiatives are already under way for the recycling of solar modules.
Deutsche Solar has set up a recycling plant and feeds the recovered solar-grade
silicon back into its production process. Although the procedure for recycling wafers
is rather laborious, it makes both environmental and financial sense because
of the high manufacturing costs and the general shortage of raw material.
Fragments of cells cannot be worked up directly into wafers, but first have to be
melted and formed into silicon ingots. This leads to high energy consumption
and substantial material loss. On the other hand, the recycled wafers can now
also be produced in bigger dimensions.
First Solar also takes back its CIS cells. However, this company uses the harmful
substance cadmium, and its public reputation is therefore more vulnerable.
A “green industry” such as photovoltaics would do well to proactively engage
with these problems. Only if the industry takes the initiative itself in organising
the return and disposal of its products will it be able to avoid the WEEE being
extended to PV components as the quantities of materials it uses continue to
grow in future.
RoHS directive
Sustainability also an issue
in the IEA-PVPS
PV components are not currently affected by the EU’s RoHS directive (restriction
of the use of certain hazardous substances). As of 1 July 2006 lead, mercury,
cadmium, hexavalent chromium and other substances can basically no longer be
used in the manufacture of electrical and electronic equipment. The plan to ban
lead in particular presents a challenge to the solar industry. Traditionally solder
containing lead has almost always been used to join together the individual PV
cells. But lead-free products are already available. Schott Solar uses solder
made of 96.5% tin and 3.5% silver; the percentage of lead is tiny and complies
with RoHS requirements. Crystalline modules produced by Mitsubishi Electric
have been lead-free since 2003, according to company information. The RoHS
directive presents a special challenge for manufacturers of thin-film modules
based on cadmium telluride (CdTe). They will need to be granted a special exemption
from the RoHS rules.
At the 20th European Photovoltaics Conference in Barcelona the IEA-PVPS 9 organised
a workshop on the topic of sustainability. Experts from the fields of environmental
audit, recycling, product return systems and legislative bodies discussed
the status quo. The results of the workshops reveal a common
awareness of the issues and the need for further research into this area, as well
as improved technical conditions.
9
www.iea-shc.org
Dezember 2005 30