Electricity production from wind, solar and other renewable resources has increased significantly in recent years to meet the renewable portfolio standards (RPS) targets (20%) imposed by 31 states in the United States. Stationary energy storage systems, as the bridge to integrate variable renewables into the power grid, are in growing demand. However, battery systems raise significant reliability and safety concerns, preventing widespread deployment.
Inaccurate monitoring of batteries can lead to potential problems in safety, reliability, and efficiency. For example, inaccurate battery charge level estimation may lead to underutilization of existing charge or hazardous situations due to the battery overcharge; poor estimation of battery health may also cause system shutdown if the battery cell dies unexpectedly.
ECE Professor Mo-Yuen Chow is finding solutions to these problems with research funded by the National Science Foundation (NSF) Partnerships for Innovation (PFI) program. His project will build a prototype of a smart battery gauge for stationary storage of renewable energy resources. His work will focus on translating a novel smart battery gauge technology (Figure 1) developed by the Advanced Diagnosis, Automation, and Control Laboratory (ADAC Lab) at North Carolina State University, from research innovation towards commercial application.
The existing battery monitoring technologies usually lack accuracy because of their outdated models, unreliable energy consumption and battery degradation predictions. The Smart Battery Gauge technology outperforms the existing solutions with three salient features:
1) Accurate battery charge level estimation using adaptive battery model parameters,
2) Accurate battery remaining useful life estimation using adaptive model predictive approach; and
3) Flexible battery monitoring using a configurable battery model.
Fig. 1. The Structure of the Smart Battery Gauge Technology
This project will result in a software prototype of the Smart Battery Gauge technology to demonstrate its real-time performance and its flexible customization for multiple different battery chemistries. The market-leading monitoring and prediction accuracy of this technology will provide power systems management and operations with the advantages of improved energy storage system efficiency, reliability, cost-effectiveness, longer lifespan, and reduced capital and operation/maintenance costs.
This Smart Battery Gauge technology will propel the emerging renewable energy market forward by providing a more reliable and safe energy storage system. It will improve the efficiency of smart grid and reduce greenhouse gas emissions, and thus contribute to the U.S. government’s long term clean energy goal (80% renewables).
Furthermore, this technology has commercial impacts well beyond the renewable energy industry. The current global battery market is $89B and is expected to reach $132B by 2016. Successful demonstration of the Smart Battery Gauge technology in the renewable energy industry will attract attention from other industries using batteries, such as data centers, electric vehicles, and mobile devices, including laptops and cell phones.