The design of long-life, high-efficiency PEM fuel cell power supplies for low power sensor networks. (3rd August 2017)

• Record Type: Journal Article
• Authors: Thangavelautham, Jekanthan; Strawser, Daniel Dewitt; Dubowsky, Steven
• Is Part Of: International journal of hydrogen energy. Volume 42:Number 31(2017)
• Page Start: 20277
• Page End: 20296
• Publication Date: 2017-08-03
• Subjects: PEM -- Power supply -- Degradation -- Sensor networks -- Hydrogen storage; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2017.05.206
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Field sensor networks have important applications in environmental monitoring, wildlife preservation, in disaster monitoring and in border security. The reduced cost of electronics, sensors and actuators make it possible to deploy hundreds if not thousands of these sensor modules. However, power technology has not kept pace. Current power supply technologies such as batteries limit many applications due to their low specific energy. Photovoltaics typically requires large bulky panels and is dependent on varying solar insolation and therefore requires backup power sources. Polymer Electrolyte Membrane (PEM) fuel cells are a promising alternative, because they are clean, quiet and operate at high efficiencies. However, challenges remain in achieving long lives due to factors such as degradation and hydrogen storage. In this work, we devise a framework for designing fuel cells power supplies for field sensor networks. This design framework utilize lithium hydride hydrogen storage technology that offers high energy density of up to 5000 Wh/kg. Using this design framework, we identify operating conditions to maximize the life of the power supply, meet the required power output and minimize fuel consumption. We devise a series of controllers to achieve this capability and demonstrate it using a bench-top experiment that operated for 5000 h. The laboratory experiments point towards a pathway to demonstrate these fuel cell power supplies in the field. Our studies show that the proposed PEM fuel cell hybrid system fueled using lithium hydride offers at least a 3 fold reduction in mass compared to state-of-the-art batteries and 3-5 fold reduction in mass compared to current fuel cell technologies. Highlights: PEM Power Supply design framework for field sensor networks. Design framework accounts for fuel cell degradations and includes a control approach to maximize fuel cell life by minimizing degradation. Technology utilizes Lithium hydride hydrogen storage technology with 5, 000 Wh/kg specific energy. Benchtop laboratory experiments performed and demonstrated operating for 5, 000 hours. Applications in environmental monitoring, security, disaster monitoring, agriculture and exploration.