Being able to quantify energy production losses in photovoltaic (PV) systems is important in order to reduce the risk associated with investing in PV. Two such loss components are degradation rates and soiling losses. However, in systems where both these phenomena exist, quantifying them is not straightforward because of their combined effect on the power output. In this article, we propose an algorithm that iteratively decomposes a performance index time series of a PV system into a soiling component, a degradation component, and a seasonal component. This makes it possible to simultaneously estimate soiling losses and degradation rates of PV systems. Bootstrapping is used to estimate confidence intervals so that both data uncertainty and model uncertainty is taken into account. Based on simulated data we show that this method makes more accurate estimates of soiling losses and degradation rates than relevant state-of-the-art methods.

中文翻译：

---

光伏系统退化和污染损失的联合估计

能够量化光伏 (PV) 系统中的能源生产损失对于降低与光伏投资相关的风险非常重要。两个这样的损失分量是降解率和污染损失。然而，在存在这两种现象的系统中，由于它们对功率输出的综合影响，量化它们并不简单。在本文中，我们提出了一种算法，将光伏系统的性能指标时间序列迭代分解为污染分量、退化分量和季节性分量。这使得同时估计光伏系统的污染损失和退化率成为可能。Bootstrapping 用于估计置信区间，以便同时考虑数据不确定性和模型不确定性。