Revisiting Field Layout Designs for Large STE Tower Plants.

Solar Thermal Electricity (STE/CSP) Tower Plants suffer a reduction on the solar field efficiency when their size increases. As plant-size is an important driver for the reduction of generation costs of STE plants - due to the relative impact of the power block and the O&M costs - plant-size could be a big disadvantage for tower plants. To cope with this issue a new rationale is proposed for designing the new generation of large tower plants. This paper demonstrates the performance benefits of the multitower approach, with single storage and power block and with northern fields versus large surrounded type; all at different latitudes and different atmospheric transmittance conditions. Field sizes of 50 MW equivalent - for plants with medium storage - appears to be a kind of standard for locations with relatively clear atmosphere while, in hazy locations, smaller sizes around 30 MW should be preferred. Besides the efficiency advantages, standardizing the designs and making them modular could also contribute to reduction of soft costs for this technology. As the improvement achieved in the solar field seems to offset the investment of an additional but smaller tower and receiver, the multitower approach might lead to a certain cost reduction of STE tower plants. [ABSTRACT FROM AUTHOR]