Life Cycle Assessment of a Model Parabolic Trough Concentrating Solar Power Plant With Thermal Energy Storage

Abstract

This study evaluates the environmental impacts of a hypothetical 103 megawatt, parabolic trough, wet-cooled concentrating solar power (CSP) plant in the U.S. Southwest with 6.3 hours of thermal energy storage by means of a hybrid life cycle assessment. Life cycle greenhouse gas emissions, cumulative energy demand, and water consumption associated with the manufacture, construction, operation, dismantling, and disposal of the power plant are evaluated and disaggregated by major systems and components. The reference CSP plant emits 26 g CO2eq per kWh of electrical output across its life cycle, cumulatively demands 0.43 MJeq/kWh of energy, and consumes 4.7 L/kWh of water. The majority of water is consumed by the power block for evaporative cooling. Sensitivity analyses are performed on several key assumptions and design elements: the configuration of the thermal energy storage system (i.e., thermocline), the heat transfer fluid, the nitrate salts, the cooling system type (i.e., dry-cooled) and the energy required for construction and end-of-life dismantling. Our base case results are robust to alternative assumptions regarding the heat transfer fluid and energy required for construction and dismantling; however, the total life cycle impacts are strongly influenced by the type of cooling system and nitrate salts employed.