Comprehensive transferability assessment of short-term cross-building-energy prediction using deep adversarial network transfer learning

Data-driven models are widely used for building-energy predictions (BEP). In practice, these models may fail when the available data on the target building is insufficient. Transfer learning (TL), where useful knowledge from information-rich source buildings with sufficient data is learned to enhance the prediction of information-poor buildings with data shortages, can address the problem of poor prediction performance caused by insufficient data. However, an important issue is finding suitable information-rich buildings to maximize the advantages of TL in cross- BEP. To address this issue, this study explored the selection of source buildings from three perspectives: building-energy data similarity between source and target buildings, building information characteristics, and the volume of training data. The impact of these three factors on the performance improvement of cross- BEP was assessed in a data-centric manner. Based on our previous studies, we selected a deep adversarial neural network (DANN) as the TL strategy for cross- BEP and systematically investigated the performance improvement and transferability of DANN from multiple perspectives of both post-hoc and ex-ante analysis. The Building Data Genome Project datasets were used for validation. Thirty-six buildings of six types and 180 source-target building pairs were considered. Our results demonstrated that DANN could effectively improve model performance by 40-90% and 20%-80% compared to non-optimized LSTM and parameter-optimized LSTM. When the same type and location source-target building pairs were only considered, the DTW index showed a relative strong negative linear correlation with the DANN prediction performance improvement, and the goodness of fitting is around 0.80. For building energy data within one year considered, DANN should be trained using no less than 6-month source domain data and no more than 4-week target domain data to improve transferability and reduce the cross-building energy prediction error.