Energy Meteorology for the Evaluation of Solar Farm Thermal Impacts on Desert Habitats

Abstract

This work addresses challenges and opportunities in the evaluation of solar power plant impacts, with a particular focus on thermal effects of solar plants on the environment and vice-versa. Large-scale solar power plants are often sited in arid or desert habitats, which tend to include fauna and flora that are highly sensitive to changes in temperature and humidity. Our understanding of both shortwave (solar) and longwave (terrestrial) radiation processes in solar power plants is complete enough to render the modeling of radiation fluxes with high confidence for most applications. In contrast to radiation, the convective environment in large-scale solar power plants is much more difficult to characterize. Wind direction, wind speed, turbulence intensity, dust concentration, ground condition, panel configuration density, orientation and distribution throughout the solar field, all affect the local environment, the balance between radiation and convection, and in turn, the performance and thermal impact of solar power plants. Because the temperatures of the two sides of photovoltaic (PV) panels depend on detailed convection–radiation balances, the uncertainty associated with convection affects the heat and mass transfer balances as well. Those balances are critically important in estimating the thermal impact of large-scale solar farms on local habitats. Here we discuss outstanding issues related with these transfer processes for utility-scale solar generation and highlight potential pathways to gain useful knowledge about the convective environment directly from solar farms under operating conditions.

摘要

本项工作涉及太阳能发电厂影响评估方面的挑战和机遇, 特别侧重于太阳能发电厂对环境的热效应以及环境对电站的反作用. 大型太阳能发电厂通常位于干旱或沙漠地区, 这些地区的动植物对温度和湿度变化高度敏感. 我们对太阳能发电厂中短波和长波辐射过程的了解已经非常全面, 足以使辐射通量的建模在大多数应用中具有很高的可信度. 然而, 与辐射相比, 大规模太阳能发电厂中的对流环境更难以描述. 风向、风速、湍流强度、沙尘浓度、地面状况、电池板配置密度、朝向以及在整个太阳能场的分布, 都会影响当地环境、辐射与对流之间的平衡, 进而影响太阳能电站的性能和热影响. 由于光伏电池板两侧的温度依赖于精细的对流-辐射平衡, 因此与对流相关的不确定性也会影响传热和传质平衡. 这些平衡对于估算大规模太阳能发电厂对当地生存环境的热影响至关重要. 本文讨论了这些传递过程在大型太阳能发电中的关键问题, 并强调了从实际运行的太阳能发电厂中直接获取对流环境有用信息的潜在途径.