Latest / Internet of Things with Fexingo: Connected Devices, Sensors, and Industrial IoT / How IoT Sensors Are Monitoring Landfill Methane Emissions
Transcript
- Lucas: Landfills are the third-largest source of human-caused methane in the United States. They emit about 110 million metric tons of CO₂ equivalent every year, according to the latest EPA inventory. Luna: And methane is something like 80 times more potent than CO₂ over a 20-year period. So even small leaks matter. Lucas: Exactly. And for decades, landfill operators have relied on monthly walkaround inspections with handheld gas detectors. You walk the perimeter, you poke probes into the ground, you take a reading. It's slow, it's labor-intensive, and it misses a lot. Luna: How much does it miss? Do we have data on that? Lucas: A 2023 study by the Environmental Defense Fund deployed aircraft-mounted sensors over 250 landfills and found that measured methane emissions were, on average, about 1.4 times higher than what operators reported. So the gap is significant, and regulators are starting to pay attention. Luna: That's where IoT comes in, I'm guessing. Lucas: Yeah. A startup called Sensoneo — based in Slovakia, but they've deployed in a dozen countries — has been putting low-cost fixed sensors on landfill surfaces. These are non-dispersive infrared sensors, or NDIR, tuned specifically to methane's absorption band at 3.3 micrometers. Luna: NDIR — that's the same basic technology used in many home CO₂ monitors, right? But tuned to a different wavelength. Lucas: Same principle. An infrared light source shines through a gas sample, and a detector measures how much light gets absorbed at the target wavelength. Methane absorbs strongly at 3.3 microns, so if the signal drops, you know methane is present. Luna: And the key advance here is cost? Lucas: Exactly. In 2016, a single methane sensor with data logging cost around $800. Today, Sensoneo's units are about $140 each. That changes the economics. A landfill that covers 100 acres can now afford to deploy 40 or 50 sensors instead of two or three. Luna: So what does a real deployment look like? Can we pick one? Lucas: Sure. There's a municipal landfill in central Ohio that partnered with Sensoneo in early 2025. They installed 42 sensors across a 90-acre active cell. The sensors are mounted on short posts about three feet above the ground, spaced roughly 200 feet apart. They transmit methane concentration, barometric pressure, and temperature every 15 minutes over a low-power wide-area network. Luna: LoRaWAN? Lucas: Yes, LoRaWAN. The data goes to a cloud dashboard. And within the first month, the system flagged a persistent hotspot near the northeastern corner of the cell — readings consistently above 500 parts per million, while the rest of the site was below 10. Luna: Had the monthly walkaround caught it? Lucas: No. The operator's handheld readings from that area were sporadic — sometimes high, sometimes not — because the leak was intermittent, driven by barometric pressure changes. The sensors caught the pattern that handheld spot checks missed. Luna: So the continuous data gives you a time series, not just a snapshot. Lucas: Right. And that changes how you prioritize repairs. Instead of sending a crew out to check every potential spot, you can say: 'The northeast corner has been above 500 ppm for six of the last seven days, mostly during falling pressure. Let's dig there first.' Luna: How accurate are these $140 sensors compared to the $10,000 reference-grade instruments? Lucas: It's a fair question. Sensoneo publishes a spec sheet showing accuracy within plus or minus 15 percent of reading for concentrations between 10 and 10,000 ppm. That's not lab-grade, but it's good enough for leak detection and for regulatory reporting under the EPA's updated Greenhouse Gas Reporting Program. Luna: The EPA updated its rules in 2024, right? For municipal solid waste landfills? Lucas: Yes. The new rule, which took effect in January 2026, requires landfills above a certain size threshold to monitor methane emissions continuously — not just monthly. The EPA explicitly references 'continuous monitoring systems' as an acceptable technology. That's a direct regulatory driver for IoT adoption. Luna: So it's not just that the sensors got cheaper. The regulation changed, and now there's a compliance need. Lucas: Exactly. And the economics work out. A 42-sensor system costs about $6,000 in hardware, plus installation and connectivity. One avoided EPA violation — which can be $50,000 or more — pays for it many times over. Luna: Are there any downsides? Sensor drift, calibration drift, maintenance? Lucas: NDIR sensors do drift over time — typically by a few percent per year. Sensoneo recommends annual recalibration. The sensors are modular, so you swap the sensor head rather than replacing the whole unit. The bigger challenge is data reliability in harsh conditions: rain, snow, temperature swings from minus 20 to plus 40 Celsius. Luna: Has that been an issue in practice? Lucas: In the Ohio deployment, they lost about 3 percent of readings during a two-week cold snap in January 2026, when temperatures dropped to minus 15 Fahrenheit. The batteries — lithium thionyl chloride cells — held up, but the sensor optics iced over temporarily. Sensoneo added a hydrophobic vent in the next hardware revision. Luna: So it's an iterative process. Deploy, learn, fix, redeploy. Lucas: That's the story of industrial IoT in a nutshell. And the potential scale here is huge. There are roughly 2,000 active municipal landfills in the US alone. If even half adopt continuous monitoring, that's hundreds of thousands of sensors. Luna: And the data from those sensors could feed into a national methane inventory that's actually accurate, instead of the modeled estimates we rely on now. Lucas: Right. And that's the bigger picture. IoT turns a historically invisible problem into a measurable, manageable one. It doesn't solve methane emissions by itself, but it gives operators and regulators the information they need to act. Luna: And if today's conversation gave you something useful to think about, it's worth noting that listener support is what keeps this show going, ad-free and independent. You can find us at buy me a coffee dot com slash fexingo. Lucas: Yeah. Even a small contribution helps cover the infrastructure that makes episodes like this possible. And we genuinely appreciate it. Luna: So back to the landfill example — what's next for the Ohio site? Are they planning to expand the sensor network? Lucas: They are. Based on the first six months of data, the operator is adding 20 more sensors to cover a second cell that's scheduled to open later this year. They're also experimenting with connecting the sensor data directly to their gas collection system controls, so that when methane spikes, the system automatically adjusts the vacuum pressure on the extraction wells. Luna: That's a closed-loop control system. IoT not just monitoring, but acting. Lucas: Exactly. And that's where the real value is. Monitoring tells you what's happening. Control lets you fix it in real time. That's the next frontier for industrial IoT — not just sensing, but actuating. Luna: It's a good reminder that sensors are only half the story. The other half is what you do with the data. Lucas: Right. And in the case of methane, the payoff is both financial and environmental. Fewer leaks means lower emissions, better compliance, and less wasted gas — gas that can be captured and sold or used to generate electricity. Luna: So it's a triple win. Lucas: It is. And it's happening right now, one sensor at a time, at landfills across the country. The technology is mature, the costs are down, and the regulatory pressure is real. I think we'll look back at this moment as the point where continuous methane monitoring became standard practice. Luna: I hope so. Thanks, Lucas. Lucas: Thanks, Luna.