Technology Status - NET Nowak Energie & Technologie AG

from USD 10 to 18 per W. Off-grid systems greater than 1 kW show slightly less
variation and lower costs. This wide range is probably due to country and
project-specific factors, especially the required storage capacity. For example,
in the US Southwest, DC systems with four to five days of storage capacity can
be installed. A local retailer can profitably install a simple system with PV
arrays, mounting hardware, charge controller and a lead-acid, deep-cycle
battery bank for USD 10-13 per W. In a moderate climate, an AC system with
ten days of storage capacity, a stand-alone inverter and ground-mounted
hardware can be installed for USD 13-17 per W. High-reliability systems for
industrial uses in moderate climates with 20 days of storage, all-weather
mounts, battery enclosures and system controllers cost at least USD 20 per W.
Generation Costs
Investment costs are one of most important factors determining the cost of
the electricity generated from PV installations. Operation and maintenance
costs are relatively low, typically between 1% and 3% of investment costs, and
the lifetime of PV modules is 20 to 30 years. However, inverters and batteries
have to be replaced every five to ten years, more frequently in hot climates.
While “harmonised” investment costs (same components and systems in
different areas) are relatively similar, kWh costs depend greatly on the solar
irradiation level. Electrical output is roughly proportional to the incident light
reaching the active area. Hence, an efficient PV system receiving 1,100 kWh of
solar irradiation per year and per square meter may produce 110 kWh of
electricity per year and per square meter in most areas of Germany. The same
system receiving 1,900 kWh of solar irradiation per year and per square meter
may produce 190 kWh of electricity per year and per square meter in some
areas of California. The electricity costs 40% less in the second case, where
irradiation is about 70% greater. Electricity output also depends on other
factors like operating temperature, reflectivity and share of diffuse light.
Based on system investment and annual electrical output (but ignoring other
factors such as risk and the environment), generation costs can be estimated
for a range of applications (see Figure 19). Today’s lowest generation costs
(20 to 30 USD cents per kWh) occur with installations having low investment
costs (around USD 4,500) and high energy output (over 1,500 kWh per kW
per year). In the best locations, these costs can fall below 20 USD cents per
kWh over the lifetime of the system.
Cost-competitiveness is greatest where high solar irradiation coincides with
daily (peak) power demand. In Japan, a system cost level of USD 3,000 is
projected to be reached in four to six years.
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