Towards the stand-alone operation of data centers with free cooling and optimally sized hybrid renewable power generation and energy storage

Recent increases in the global demand for IT services have increased the power consumption, total ownership costs and environmental footprint of data centers. Recent efforts to reduce these effects have focused on either their cooling systems, or their power systems. In this paper, we have developed an integrated approach to minimize the total power demand of data centers, whilst their reliance on power imported from the grid is minimized. First, the power demand of data center has been reduced utilizing various air-side economizer-based cooling systems. Since the effectiveness of economizers significantly depends on the local weather conditions, 42 stations in major cities across the world have been considered. A more than 80% reduction in total cooling power consumption is achieved by using the most appropriate air-side economizer at each location. Second, the reliance of data centers on power imported from the grid is minimized utilizing on-site hybrid renewable power generation and energy storage. The on-site renewable power generation and capacity factors have been calculated for 1 MW wind and solar renewable power plants to identify the location with the highest renewable power generation capability. The optimal size of a hybrid renewable power plant, and associated battery energy storage system, is also determined for each data center using linear programming to minimize total levelized costs. Finally, the optimal location for constructing and operating the most energy efficient, cost-effective and sustainable data center has been identified by calculating its level of independence from the power grid. It is found that the level of grid independence increases as we move away from the equator, for example more than 50% grid independence can be achieved at Regina station located in Canada.