whats the difference between pterm and pem

However, current power supplies typically depend on rechargeable battery technology and in rare instances, primary non-rechargeable batteries. Significant advancements have been made in the miniaturization of electronic devices, sensors, actuators and radios. A key to making these sensor systems practical and ready for wide-scale use is the need for high-energy power supplies. To be practical, once deployed, field sensor network modules need to operate unattended, ideally for years. Using this footage, it is possible to determine where the object will land and impact the ground and determine its origin/source. For this, a camera is mounted to a robotic telescope that scans and tracks incoming objects of interest. There is an ever-growing need to continuously monitor incoming objects from space, including spacecraft debris re-entering the earth’s atmosphere and meteors. For security applications, several hundreds or thousands of modules might be deployed over large areas, including border regions and wirelessly report their data to a base-station.Īnother new emerging application is Space Situational Awareness (SSA). There are similar needs to monitor high-security facilities for intruders. In the field of security, field sensor networks have important applications in securing borders, by providing continuous monitoring of border regions including above, below and at ground, for illegal entry, smuggling of people, goods and controlled substances ( Figure 1, right). They are playing a critical part in continuous observation with emerging applications in border security (right) and space situational awareness.įield sensor networks have important applications in the emerging field of precision agriculture ( Figure 1), where hundreds or thousands of sensors provide periodic monitoring of soil humidity, plant growth, health, and soil nutrition to provide accurate predictions for harvest, enable healthier, higher return on crops and mitigate plant diseases and loses. The results of the study show that the PEM hybrid system fueled using lithium hydride offers a three- to fivefold reduction in mass compared to state-of-the-art batteries.įield sensor networks have important applications in environmental monitoring and precision agriculture including monitoring of water, air and soil health (left). Lithium hydride in combination with fuel-cell wastewater or ambient humidity can achieve fuel specific energy of 5000 Wh/kg. The aim is to achieve long operational lives by controlling degradation and utilizing high-energy density fuels such as lithium hydride to produce hydrogen. In this chapter, we present a design framework for high-energy fuel cell power supplies applied to field sensor networks.

However, challenges remain in achieving long lives due to catalyst degradation and hydrogen storage.

Polymer electrolyte membrane (PEM) fuel cells are a promising alternative, because they are clean, quiet, and operate at high efficiencies. Photovoltaics require large, bulky panels and are impacted by daily and seasonal variation in solar insolation that requires coupling to a backup power source. A promising alternative is photovoltaics. Batteries limit potential applications due to their low specific energy. Networks of field sensors have emerging applications in environmental monitoring, in disaster monitoring, security, and agriculture. The rapid miniaturization of electronics, sensors, and actuators has reduced the cost of field sensor networks and enabled more functionality in ever smaller packages.

Whats the difference between pterm and pem