Design of solar fields for Concentrated Solar Power plants considering operation & maintenance activities

Properly sizing the solar field in Concentrated Solar Power (CSP) plants is crucial for their economic performance. Current techniques overlook operation and maintenance (O&M) costs which can significantly affect the levelized cost of electricity (LCOE), and fail to incorporate key O&M-related productivity losses, such as heliostat failures and soiling, within their productivity models. This study presents an approach for designing the solar power plant including O&M costs for heliostats repair and cleaning, concurrently identifying the optimal deployment of cleaning resources. The developed methodology is applied for a modular solar tower plant in Mount Isa, Australia, where the solar field size that minimizes the LCOE is identified, simultaneously optimizing the power block (PB) and the thermal energy storage (TES) capacity. The outcomes of the analysis show that including O&M expenses due to heliostats repair and cleaning leads to a larger solar field: the optimal design for the LCOE scenario features a 22 % oversize. This configuration is paired with a PB of 32 MW and a TES of 1326 MW h-14.5 h, significantly smaller than the 56 MW, 2320 MW h-14.5 h reference. In the grid-driven scenario, the optimal solar field is also oversized by 22 %, with a PB of 56 MW matching the reference size, and a smaller 1520 MW h-9.5 h TES. This methodology emphasizes the impact of O&M activities on plant design, alongside the influence of turbine operation.