A Self-Powered Sentinel

Massachusetts-based Voltree Power is currently developing a network of sensor nodes that will monitor forest conditions and immediately alert users to wildfires. The system, the Early Wildfire Alert Network (EWAN), resembles other efforts to create decentralized monitoring networks. The network tracks humidity, air temperature, and other factors, sending the data via wireless transceivers to centralized processing centers or sending up red flags when wildfires appear, and has been designed to integrate seamlessly into the Department of the Interior’s Remote Automated Weather Stations system. EWAN’s power source, however, makes the project unique. Rather than relying on battery-operated sensors and transceivers, Voltree is working to perfect a method of harvesting energy from the trees themselves.

EWAN uses the small (usually 50-200 mV) current created by a pH imbalance between the tree and surrounding soil to power the system. The converter that powers each unit is fairly small (”about the size of a pack of gum”) and allows each sensor to operate for the lifetime of its arboreal host.

While Voltree’s pilot project focuses on wildfire monitoring and prevention, the company hopes to find broader uses for this type of self-powered, decentralized monitoring network.  Researchers could easily use the system to monitor fragile ecosystems or gauge agricultural conditions, and Voltree has started exploring applications that would incoroprate similar monitoring networks into border security.