The MODERATOR project addresses the critical issue of high energy consumption and waste heat in data centers, which in 2024 is accounted for approximately 415 TWh globally, around 1.5% of global electricity usage. Traditional air cooling methods in data centers are not only inefficient but also waste valuable low-grade heat, especially problematic as energy prices rise and energy efficiency becomes a key economic factor, particularly for smaller data centers.
The overall objective of MODERATOR project is the development and demonstration of a fully integrated and modular prototype system that combines immersion cooling with novel and highly efficient long-term heat storage materials and systems. This system aims to recover, store and exploit waste heat from data centers transforming an environmental and economic challenge into an opportunity for sustainable energy reuse.
MODERATOR proposes a game changer shift by replacing conventional air-cooling systems with immersion cooling, where IT components are submerged in dielectric fluids. These fluids offer significantly higher thermal capacities, enabling superior heat removal and reducing the Power Usage Effectiveness (PUE) below 1.1 when the industry average is 1.6. The main innovations of MODERATOR include (i) a novel designed immersion cooling system that enables heat recovery from data centers, (ii) a novel waste heat recovery (WHR) system using phase change materials (PCMs) for efficient low-temperature heat recovery, (iii) a highly efficient multilayer insulation system for thermal energy storage (TES) that uses recycled glass granules and microparticles to minimize heat losses and (iv) the integration of these components into an automated prototype for direct heat utilization and long-term storage. The project also includes horizontal modeling and simulation activities to optimize materials and systems performance, along with robust evaluation and dissemination strategies to maximize exploitation impact. The major outcome of the project is the operation and demonstration of a fully automated integrated prototype combining a 40 kW data center immersion cooling system connected with an associated TES unit for WHR and reuse.
The MODERATOR project has the potential to significantly reduce environmental and economic footprint of data centers. By improving energy efficiency by over 30% through immersion cooling and thermal energy storage, the solution could lead to CO2 savings exceeding 200 million tons per year globally, if deployed widely across the more than 200 GW of installed data center capacity. Economically, individual data centers could save over €1 million annually, with a return of investment in 4-8 years, while enabling additional revenue from electricity sales or heat reuse. The modular, transferable nature of the technology means it can be scaled from small (kW-scale) to large (multi-MW) installations, offering substantial cumulative impact across Europe and beyond, including benefits for low-income communities, SMEs, and the electricity grid. The project is thus highly aligned with the EU Green Deal and Strategic Energy Technology Plan, and can play a pivotal role in accelerating climate neutrality and energy resilience objectives.
