How an 'electronic nose' could help fight wildfires

In the summer of 2021, wildfires caused a "disaster without precedence" in the Italian island of Sardinia, burning over 28,000 hectares (69,000 acres) of land and displacing thousands from their homes.

Almost half of the affected land burned in a single catastrophic fire that affected the Montiferru region, near the island's western coast. Now, Montiferru is one of a dozen forest areas across the world that are testing out a new "ultra-early" warning system for wildfires, developed by a German startup called Dryad — after the nymphs of Greek mythology that live in symbiosis with trees.

Preventing even a fraction of wildfires from developing would have sweeping benefits. Climate change is making wildfires more intense, and the number of extreme wildfire events is projected to increase up to 14% by 2030.

Apart from the billions of dollars of damage they cause, the particles and chemicals they produce are strong pollutants and in 2021, wildfires released a record 1.76 billion metric tons of carbon in the atmosphere — equivalent to more than double Germany's yearly CO2 emissions.

Existing early warning systems are based on visual detection of smoke, either through satellite imaging, cameras on the ground or human observers. But these systems are too slow, according to Dryad's co-founder and CEO, Carsten Brinkschulte.

"In order to generate smoke that rises above the tree canopy and can be seen from a distance of, say, 10 to 20 miles, the underlying fire has to be substantially big — you might already have half a football pitch on fire underneath. Then, if you add the time for firefighters to arrive at the scene, it may have become too big to be extinguished at all."

Dryad, which has raised €13.9 million (about $12.2 million), aims to reduce the detection time of wildfires and catch them at the smoldering phase — when there is not yet an open flame —usually within the first 60 minutes.

To do so, the company has designed a solar-powered sensor fitted with a gas detector. "It can detect hydrogen, carbon monoxide and volatile organic compounds — it can basically smell the fire," says Brinkschulte. "Think of it like an electronic nose that you attach to a tree."

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Once the sensor detects a fire, it sends out a signal over a wireless network using a built-in antenna. The signal is then relayed to more complex devices and transmitted to the internet by satellite and 4G. Finally, the information is sent to the forest managers.

"We also send out an alert and we can interface directly with the local fire brigade's IT systems. What you get is an alarm with the exact GPS coordinates of the sensor that picked up the fire," says Brinkschulte.

The sensors sell for €48 ($49) each. Dryad, which has a team of about 30, sells the hardware and also offers an annual subscription model — priced at 15% of the total hardware cost — that includes maintenance and support. Its main clients are municipalities and private forests, as well as electricity companies and railroads, whose equipment is often the source of fires.

So far, the startup has installed 300 sensors across a dozen test deployments in Germany, Greece, Spain, Portugal, Turkey, the United States and South Korea, as well as Montiferru in Italy. Brinkschulte says that these trial runs only require a handful of sensors because the fires are started intentionally, to show forest managers how the system works.

"We have been testing the Dryad system in a forest area of around 50 hectares (124 acres), which was particularly badly affected by arson," says Philipp Nahrstedt, who manages a forest of 62,000 hectares in the central-eastern German state of Saxony-Anhalt.

"We set a forest fire and within 14 minutes it was detected by the sensors. This detection time was phenomenal and showed how much potential the Dryad system has," he adds.

Dryad is now looking to ramp up production of the sensors, with a plan to make 10,000 units in the coming months and 230,000 next year.

"We’ll go into the millions over time," says Brinkschulte, adding that Dryad's goal is to have 120 million of them deployed by 2030. That, he says, would be able to save 3.9 million hectares of forest from burning — about 40% of the land area burned globally by wildfires in 2021 — and prevent 1.7 billion metric tons of CO2 from reaching the atmosphere.