Sodium Sulfur Battery Energy Storage And Its Potential To Enable Further Integration of Wind

Posted: July 7, 2010 - 05:10 / Xcel Energy / Reports
Xcel Energy is conducting the Wind-to-Battery (W2B) Project to evaluate the overall 
effectiveness of sodium sulfur (NaS) battery technology in regards to its ability to facilitate the integration of wind energy onto the grid. As part of this demonstration project, Xcel Energy is investigating the ability of the technology to provide system benefits, the cost-effectiveness of the storage device, and methods and procedures to evaluate other types of energy storage technologies in the future. Through this small-scale demonstration project, Xcel Energy can evaluate energy storage technology at a modest level of investment and customer impact. By doing so, the company will promote the future deployment of only proven technologies that meet or exceed cost, reliability, and environmental requirements. 

This report summarizes the primary testing phase of the project, which consisted of a technical evaluation of the battery-based Distributed Energy Storage System (DESS) and grid-related performance data under multiple modes of operation. Project analysts have completed initial testing of the DESS for all modes of operation and collected system performance data accordingly. From preliminary analyses of the data, Xcel Energy has assessed the effectiveness of the technology for each mode of operation and gained a better understanding of the general operating characteristics of the technology. Overall, the battery met expectations by performing successfully in all modes tested. However, project analysts still recommend additional testing to better understand the capabilities and limitations of the storage device.