Grantee Research Project Results
Final Report: Ultralow Power Sensor Package for Ground Level Air Pollution Levels from Wildland Fires
EPA Contract Number: 68HERC20C0053Title: Ultralow Power Sensor Package for Ground Level Air Pollution Levels from Wildland Fires
Investigators: Findlay, Melvin
Small Business: KWJ Engineering, Inc.
EPA Contact: Richards, April
Phase: II
Project Period: June 1, 2020 through May 31, 2022
Project Amount: $300,000
RFA: Small Business Innovation Research (SBIR) - Phase II (2020) Recipients Lists
Research Category: Small Business Innovation Research (SBIR)
Description:
Stakeholders, including governments, citizens, and businesses need to be able to detect and monitor wildfires to minimize occurrence, damage, and loss of life. The hypothesis proven herein is that wildfires produce changes in air quality that can be measured by low cost IoT enabled pollutant sensors. even while the fire is small and in a startup phase This work provides a feasible path for using tiny low-cost air quality sensors for wildfire detection and monitoring. The KWJ team led a study that developed integrated affordable sensor networks that reliably measure air pollutants, including particulates, carbon monoxide, nitrogen dioxide, and carbon dioxide, over the wide range of concentrations expected downwind of wildland fires. In Phase II, KWJ integrated low-cost gas sensors with a particle sensor into a single, <8oz module with the target dimensions of approximately 4"x5"x1" (10x12.5x2.5cm). Operating on battery power with inputs for operation/charging via solar cells or local power, and interfaced to a wireless communication board, these low-cost, configurable modules can be deployed in a variety of ways: 1) worn by personnel, 2) packaged in weather-proof cases, attached to tripods or other stationary items, or 3) mobile monitors deployed on vehicles and drones. Additionally, we found that with optional DC or solar power, the AQ [air quality] monitor could be permanently deployed in remote locations to monitor AQ and alert downwind areas of pollution hazards from wildfires.
Summary/Accomplishments (Outputs/Outcomes):
During this SBIR project evaluations, KWJ built and then calibrated low-cost sensors in the laboratory against existing standards to determine the sensitivity, selectivity, and response time of an AQ monitor for wildfires made from low-cost sensors. KWJ then tested the AQ sensors in modules against several simulated wildfire emissions in the Missoula, MT test facility and also deployed sensor arrays locally in CA during wildfire season to obtain filed measurements.
Of the sensors evaluated, SPEC Sensors miniature printed gas sensor for NO2 and O3 are comparable in performance to the currently used larger and more costly gas sensors. The SPEC CO and SO2 sensors were improved to obtain sub-ppm resolution and lower temperature coefficients that were correctable. Commercial low-cost CO2 and particle sensors were adequate to characterize AQ emission from wildfires with good correlation to reference methods. In Phase II we conducted additional laboratory evaluations of the SPEC CO and SO2 sensors, confirming the improvements in temperature coefficient (effect of temperature on baseline) and lower detection limit. We assembled a set of R&D prototype WildFire Air Quality Monitors (WFAQM) and conducted several months of testing outdoors in the California Bay Area, alongside a 3rd party benchmark.
Conclusions:
Our testing shows the low cost SPEC CO sensor combined with particulate sensing and/or CO2 sensors provide a clear indication of an emerging fire. The CO sensor is preferable over CO2 due to faster response and quicker differentiation from ambient levels of the gasses. Other gases are also emitted during biomass combustion, but levels are much lower and not as quickly discernable from ambient fluctuations. VOC data was also collected with low-cost HMOS VOC and amperometric CH2O sensors during the combustion lab tests. This data from these sensors may offer additional insight into the combustion source.
In the field, we envision multiple low-power CO sensors will be operated continuously to provide redundancy and the best reliability. Advanced operating algorithms can be deployed to improve power consumption and accuracy. In this way, a low cost, low power, long lifetime sensor array can be deployed for early warning of wildfires and pollution monitoring for impacted populations.
In summary, the work herein suggests some very practical next steps for EPA and its stakeholders for protection of communities from wildfire damages. It has been shown that a low cost sensor node [just CO and particles] was able to track the smoke-fire events and report values comparable to the nearby EPA stations even when the sensors were 1.5 and 4 miles away. This suggests that the density of sites to protect a populated area need not be immensely dense. For example, a suite of monitors 1 mile apart could, in principle, protect an area 100x100 sq miles at an estimated cost of $1M [10,000 nodes of $100 each; costs could go lower with mass production]! The area of greater Sacramento, CA is about 100 sq.mi. and Santa Rosa, CA is 41.5 sq.mi. with populations of 2.4M and 167K, respectively. Even if only 1 fire in 10 years is averted [or warned in its startup stage so as to be mitigated] by such a deployed system, the lives saved and property loss averted would clearly pay for the system many times over. This work strongly advocates for EPA and its partners to perform test deployments of grids of various density low cost sensors in various terrain to understand how, in practice, to address protection of communities from wildfires using AQ monitors alone and in combination with satellite images.
As a result of this SBIR, the following commercial activity now exists. The sensors used herein are now commercially available from SPEC Sensors, LLC. Monitoring systems are being offered by several vendors. KWJ is offering commercial and OEM AQ monitors. Alternative electronics for low cost sensors that bypasses supply chain issues are available from KWJ and thousands are planned for shipment in 2022 and 2023. Other paths to market are being developed based on the sensor work performed herein, including distributing high performance sensor modules on Digi-Key.
Journal Articles:
No journal articles submitted with this report: View all 5 publications for this projectSBIR Phase I:
Ultralow Power Sensor Package for Ground Level Air Pollution Levels fromWildland Fires | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.