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6. Comparing systems and market demands
general issues
certification
financing schemes,
subsidy issues
awareness
technical issues
reliability issues (e.g. stagnation temperature resistance)
efficiency issues (optics, heat transfer, temperature effect on PV)
integration issues
aesthetics
plug-and-play PVT
design tools
combined PVT & PV systems
combined PVT & heat pump
combined PVT & solar cooling
Table 12. Priority issues
for PVT market introduction
in which electricity is used to drive the pump
while the thermal yield is used for heating
the inlet water. It is an important asset that
such systems can be manufactured as plug-
and-play stand-alone systems. Attention
should again be paid to the issues of reliabil-
ity and theft.
Commercial stand-alone
Professional stand-alone applications may be
campgrounds or mountain huts. This sector will
have the same demands as consumers, but the
constraints are less severe. Initial cost will be less
problematic and load patterns may be much more
regular, although still showing a strong seasonal
peak. This will increase the economy of these
systems. Also here, PVT systems for water puri-
fication may be an interesting niche market in
island applications or arid areas.
Hot water systems will be more suitable than for
autonomous consumers, while the technical prob-
lems are reduced, due to professional installa-
tion, easing the use of glycol systems.
Agricultural application
Drying with solar energy mainly in the agricul-
tural sector might become an interesting market.
Especially in regions with no electricity supply,
drying combined with PV electricity production
might become a further promising niche of PVT
applications.
Hay drying with solar air collectors was already
done some decades ago, however, the market
penetration was very weak. In any case, the total
potential of this market segment seems to be quite
modest.
The main function of the PV will then be to drive
the fan, which limits the required PV area rela-
tive to the required solar thermal area. Whether
glazed or unglazed systems will be used depends
on the temperature level required, but for many
applications, unglazed will be the most appro-
priate. The increased electrical yield due to the
cooling of the PV may allow a smaller PV area,
increasing the profitability of the system as com-
pared to separate PV and solar thermal.
Conclusion
Based on the promising markets for PVT and the
appropriate market-system combinations, a
number of issues were identified as priority
issues for the market introduction of PVT. An
overview is presented in table 12, while an
action plan for these issues will be defined in
chapter 7.
Photo: Grammer Solar
Photo: Grammer Solar
PVT Roadmap.p65
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