Technology Status - NET Nowak Energie & Technologie AG

germane, and toxic metals like cadmium. However, current control
technologies appear sufficient to manage wastes and emissions in today’s
production facilities. Recycling technologies are being developed for cell
materials. The development of thinner layers and better deposition
processes can make the use of these materials more efficient. The use of
cadmium and other “black list” metals in PV components is controversial,
though there are no indications of immediate risks.
● Energy payback times: As mentioned above, the effective energy
payback time of PV systems depends on the technology used and the type
of application and energy yield in different climates. Although it varies by
type of technology, the payback time is much shorter than the 20-30 year
expected lifetime of a PV system. For crystalline silicon modules, most of
the energy is needed for silicon production, while for thin-film modules
the encapsulation materials (e.g. glass) and processing represent
the largest energy requirements. There remains a large potential for
reducing energy use in production, which will also reduce the inherited
emissions.
● Operation and emissions: PV systems operate virtually without any
harmful emissions. They work silently and do not emit any gases.
Electromagnetic interference may cause technical problems, but it is not
harmful to humans.
● Land use: Large-scale, ground-based PV arrays may become a future issue
where land is scarce. However, small scale PV systems can be easily
integrated into buildings, an advantage in comparison to other power
plants.
Prospects for Solar Photovoltaics
● Cost Reduction Opportunities
Cost reduction has been a key issue for PV, as costs are still relatively high
compared to other types of grid-connected electric technologies. But cost
reductions of BIPV systems have been considerable and average costs have
been reduced by a factor of 2 in each of the last two decades, as depicted in
Figure 22. This trend is likely to continue in the future.
Cost-reduction opportunities for cells and modules are important because
these items are expensive key components of PV systems. Improvements in
cell technology efficiency through R&D are depicted in Figure 23.
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SOLAR PHOTOVOLTAIC POWER
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