Technology Status - NET Nowak Energie & Technologie AG

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● Thermal Storage
Like hybridisation, thermal storage improves the dispatchability and
marketability of solar-thermal power plants, allowing them to deliver
electricity on demand, independent of the solar cycle. Storage not only
allows high-value dispatch of power, but can decrease costs by permitting
the use of smaller turbines.
The most advanced thermal storage techniques have been applied to power
tower technology. The lessons learned from Solar Two (a 10 MW solar power
demonstration project in the Mojave Desert, California) are being applied to
the first commercial molten-salt power plant, Solar Tres (SIII), a 15 MW
demonstration project in Spain. Other advanced thermal storage
technologies will be explored in future demonstration plants.
There is no thermal storage option for current trough technology. SEGS plants
meet dispatchability needs with natural gas-fired boilers. A molten-salt plant
similar to the one used in Solar Two, but for lower temperatures, deserves
evaluation. Dish/engine system technology does not offer thermal storage
capacity. Other options, such as battery storage, are possible but expensive.
Dish/engine systems are ideal for grid-connected applications, and may be
more useful for stand-alone applications with the addition of storage.
● Costs
Investment and electricity generation costs depend on a multitude of factors
related to technology (e.g. system performance, component size, power
cycle, dispatchability), local logistics (e.g. plant size, location, irradiation,
land cost, water availability) and market circumstances (e.g. manufacturing
volume, project financing, taxation).
Investment Costs
Table 19 gives an overview of emerging CSP technology costs at high
radiation levels (>1,700 kWh/m2 ). Only the parabolic trough costs have been
proven through commercialisation. The costs for power tower technology
and dish/engine systems are based upon pilot or demonstration plants and
thus need confirmation. Costs are listed for the next systems to be deployed
and do not represent future costs which are expected to be much lower.
Differences in the investment and generation costs for CSP systems can be
explained by their different maturities and by the different technological
approaches each uses. Different approaches imply different efficiency rates
and different investment structures. Figure 31 shows the relative costs of
parabolic trough and power tower plants. The most significant difference is
CONCENTRATING SOLAR POWER X4