Mixing Offline and Online Electrical Decisions in Data Centers Powered by Renewable Sources

Abstract

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-bydesign 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).

Assessing Power Needs to Run a Workload with Quality of Service on Green Datacenters

“…In [8], the authors develop a complementary approach to ours. An online module is based on offline decisions, adapting them to real-time events via different compensation policies, to stay as close to the offline plan.…”

“…This plan is made for how the machine will be switched-on and off based on the negotiated power profile. It is sent to an online module, which applies it and adapts it to events, due to the uncertainty of the plan [8]. Since the negotiation process is interactive, this computation must last a reasonable time [24].…”