Photovoltaic Power Generation - Renewable Energy: Technology, Economics and Environment - page 290

to different investments for plants of the same capacity due to different technical
solutions available on the market with different costs.
With increasing capacities of the photovoltaic power station specific power
production costs are further reduced, however, the decrease is considerably lower.
For a 2,000 kW photovoltaic power plant mean power production costs vary be-
tween approximately 0.25 and 0.40 €/kWh under the circumstances discussed
above (Site 1). For even higher installed electrical capacities a further reduction of
only a few percent can be expected. The partly tremendously lower specific power
production costs of photovoltaic power plants in comparison to roof-mounted
solar systems are primarily attributable to lower specific overall investment costs,
generally higher mean annual inverter efficiencies as well as the optimum inclina-
tion and orientation that can be assumed for ground-mounted plants. Thanks to the
latter two reasons, an increased number of full-load hours can be achieved at the
same site.

0.60

Depreciation period
20 a = 10 0 %
Overall investment
78 k€ = 100 %

0.55

0.50

Operation costs
800 €/a = 1 00 %
Full load hours
800 h /a = 100 %

0.45

0.40

Interest rate
4.5 % = 10 0 %

0.35

0.30

0.25

70 80 90 100 110 120 130

Fig. 6.33 Parameter variation of the main influencing variables on the specific power pro-
duction costs of the 20 kW photovoltaic multi-crystalline generator at Site 1 indicated in
Tables 6.3 and 6.4

Parameter variation in %

Yet, in particular cases and under different site conditions, power production
costs may differ tremendously from the magnitudes indicated in Table 6.4. To
estimate the impact of such influences on the power production costs, Fig. 6.33
illustrates a sensitivity analysis of predominant parameters within a variation of
+/-30 %, using the example of the 20 kW photovoltaic system at Site 1 based on
multi-crystalline modules taken from Table 6.4. Thus, besides plant investment
costs, the number of full-load hours calculated on the basis of the system utilisa-
tion ratio and the effective radiated solar energy within the course of a year and
the site conditions, has the most important impact on the power production costs.
As a consequence, the costs of photovoltaic power generation can be noticeably
decreased by a reduced investment volume, e.g. due to more cost-efficient cell
manufacturing methods or enhanced plant efficiency, for instance, achieved by