Mesh network powered by trees detects fire dangers
The U.S. Forest Service and the Bureau of Land Management have tested a wireless environmental-monitoring system used to help first responders prepare for wildfires and disastrous events. The pilot test and system installation demonstrated Voltree Power‘s remote sensing and mesh technology, as well as its integration with existing remote automated weather stations (RAWS) network that transmits air temperature, humidity and diagnostic data using a preexisting satellite infrastructure, said the company’s CEO Stella Karavas.
The system uses a series of climate sensors and a mesh network, so first responders can receive environmental data that can stave off large-scale events, Karavas said. The Early Wildfire Alert Network (EWAN) consists of thousands of humidity and temperature sensor nodes distributed over remote forestland. Each node contains a wireless transceiver using the IEEE 802.15.4 wireless personal area networks protocol that enables EWAN to communicate the onset of wildfires, as well as to monitor forest conditions constantly for accurate, day-to-day, fire hazards she said.
Karavas said that while most of the technology behind EWAN is inexpensive and has been available off-the-shelf for several years, the necessity of constantly replacing batteries at remote locations has kept “smart dust” or mesh-network solutions to forestland monitoring from being implemented in the past. The company solved the problem of battery replacement by developing a small electricity generation system that harvests metabolic energy from the forest trees themselves and converts it to useable electricity. She explained that a bio-energy converter has been integrated into a power module that does not depend on wind, light, heat gradients or mechanical movement and is environmentally benign to produce and run. It is weather resistant, leaves no heat signature and is about the size of a small pack of gum.
“It parasitically harvests metabolic energy from any large plant without harming it,” Karavas said. “The useful lifetime of the device is only limited by the lifetime of the host.”
Voltree’s wireless mesh network transmits data signals from one unit to another until they reach a Vaisala-built central monitoring station. These stations subsequently provide a satellite microwave uplink connection that lets the collected information to be shared with numerous government agencies and many other users worldwide, Karavas said
“Our solution for remote forest monitoring provides a reliable and cost-effective method of collecting microclimate, ‘under-the-forest-canopy’ weather data that will serve as a valuable tool for weather and climate modeling as well as climate change research. This predictive approach will enable strategic resource allocation and prioritization,” she said. “Hence by better pre-positioning resources the government land agencies can maximize public and firefighter safety as well as reduce losses and lower costs.”