Since the Paris Agreement, academics and industry have dedicated efforts to reducing Information and Communications Technology (ICT) greenhouse gas (GHG) emissions. Data centers play a key role in ICT electricity consumption since they are built to run 24/7. One way to reduce these emissions is to switch from brown energy to green energy from renewable sources (RES). However, RES introduce several uncertainties due to their intermittence. This work is part of the Datazero2 Project. This project aims to design a data center powered only by RES production and storage elements. Datazero2's clean-by-design data center requires several decisions at different levels of management. Usually, research works focus on offline decisions (e.g., decisions for the next three days) or online decisions (e.g., decisions in real-time). This work proposes a mix of offline and online decisions producing a reliable and change-aware solution. While the offline focuses on the long-term renewable usage plan, online adapts it according to the power fluctuations. The results demonstrate that this mixed management approximates the planned and real storage levels with a low impact on the Quality of Service (QoS).