Abstract The challenge of predicting photovoltaic power (PV) output is addressed in this paper, with a particular focus on enhancing prediction accuracy. A novel multi-scale prediction method for PV output is introduced, based on the integration of Generative Adversarial Networks (GANs) with the Informer model. The study’s content revolves around the leveraging of GANs for feature extraction and the development of the GAN-Informer model to forecast PV power outputs in national grid systems. Empirical investigations were conducted to validate the superior performance of the model. The outcomes reveal that the GAN-Informer model excels in ultra-short-term predictions, achieving the highest accuracy at a 15-minute scale with a mean squared error predominantly below 0.05, and a 1-hour prediction accuracy of 0.9728. These findings significantly contribute to improving PV energy utilization efficiency and promoting sustainable development.