Abstract:With the increasing integration of high-penetration renewable energy, the forecasting of wind and photovoltaic power generation has become increasingly critical. However, the existing wind power prediction methods based on statistics and machine learning have problems such as difficulties in mining complex nonlinear time-series features and insufficient integration of domain knowledge. Currently, large language models (LLMs) have attracted much attention in various fields due to their strong feature extraction capabilities and inherent natural language interaction capabilities. Therefore, a time-series forecasting method based on LLMs for the task of wind and photovoltaic power output prediction is proposed. The main innovations include: Firstly, through domain-supervised fine-tuning, the LLM is adapted to wind and photovoltaic power prediction, which supports natural language instruction inputs and simplifies the integration of domain knowledge. Secondly, a temporal reasoning mechanism is proposed, including cross-modal representation of power time series data and natural language, as well as a causal reasoning method guided by intermediate variables, which enhances the ability of data feature mining and reasoning. The effectiveness of domain-adaptive fine-tuning and temporal reasoning module is verified through experiments, and the proposed method achieves superior performance in both wind and photovoltaic power generation prediction.