Battling The Blaze: An interview with HoZe Solutions' Martin Hofmann

Hoze Solutions is dedicated to tackling the two primary challenges posed by wildfires: effective water usage and risk mitigation. With rising global temperatures and growing water scarcity, the demand for a more sustainable approach to firefighting is pivotal. The Papageno system is designed to optimize water consumption, making it possible to combat fires in remote, water-scarce areas while reducing environmental impact. Moreover, its autonomous systems enhance safety for firefighters and residents, ushering in a new era of firefighting technology.

Amidst the escalating influence of climate change on wildfires, we sat down with the co-founder of Hoze Solutions to delve deeper into their innovative firefighting solutions and their mission to transform the landscape of fire protection.

Martin: The hose is designed to distribute water over a long distance, one module covering 800 meters, so that the crew of a single fire truck can treat a fire front from a safe distance. The system is left running to allow practitioners to move out of the danger zone. This contrasts with the current use of water where hoses are used to treat point-like burning vegetation exposing practitioners to heat, flames, and smoke.

The hose is fitted with nozzles at regular intervals. The nozzles themselves have been optimized to wet the immediate surroundings with a spray and the vegetation further away by emitting a mist, which is drift-prone and will, by design, always wet the vegetation in the path of the fire. The water consumption is relatively low per unit of time, allowing a standard fire truck with a 3000 liter water reservoir to operate the system with a refill from another truck occurring every 10-15 minutes.

The operating principle is twofold: to wet the vegetation ahead of the fire to avoid that vegetation to reach the combustion temperature of roughly 200°C - this is a much more efficient approach from a thermodynamic point of view than to spray water on something that is already burning at temperatures above 800°C. Then to replace hot dry air with wet cold air which gets sucked in as the heat of the fire draws in surrounding air even against prevailing wind directions.

We have tested the system with a series of field tests establishing a rough scaling law of water volume (linearly proportional to the running time) as a function of fireline intensity. Given a certain topography and weather pattern, the fire intensity will depend on vegetation parameters such as vegetation density, type and dryness. We can evaluate those in advance (using satellite imagery and UAVs) and then give an informed answer as to how long the system needs to run depending on the vegetation.

Being firefighters, we always build in safety layers and see one predominant use for the system: transforming paths and roads into effective fire breaks.

Every time you see a wildfire jump a road, it is essentially jumping over an insufficiently large and completely inert fire break. With our system installed along that road, it becomes a highly potent and wet fire break with a controlled humid and cool atmosphere. To contain a wind-driven fire with flame heights of 8 meters and more we estimate the required running time to be 45 minutes.

So essentially, the fire service needs to be able to foresee where the fire will be in an hour's time, identify a road or path parallel to the fire front, and install our system along that line. Such estimations are already made today and will improve in the future with improved propagation models. In fact, the tactics resemble the operating mode of aerial means. Except that our system is much safer to use thanks to the unmanned operations run at night and under strong winds and comes at only a fraction of the costs (airplanes cost roughly €15000/hour to keep in the air).

Martin: For now it is purely water. We are planning to test the use of retardant - typically in a scenario where we would secure an evacuation route - and the use of surfactant to alter the wetting pattern.

Martin: : Yes, the University of Coimbra oversaw a series of three field tests, with the latest reaching fireline intensities of 2500 kW/m and corresponding flame heights of over 8 meters. These intensities are way above safety thresholds for ground-based tools used today, such as water hoses connected to a fire truck.

Martin: With the option of the water tank being a foldable water tank, reducing weight and space requirements, we can transform vehicles like an all-wheel drive Mercedes Sprinter or Iveco Daily into a bespoke vehicle to be used as a system carrier. Similarly, the hose segments needed are shorter than standard hose lengths. We can therefore upcycle damaged hose lengths into our system.

Martin: Summers will more and more come with droughts and reduced availability of water as an extinguishing agent. Despite this, fire services lack rough guides as to how much water is needed to contain an advancing firefront, leading to inefficient water usage. This will obviously vary with the specific fire, but we believe that our scaling law can be a good starting point to optimize water usage. With this in mind, our system has been designed to be operational in areas where water reservoirs are already built in fire-prone areas, as is done in France, Spain, Portugal, Greece, etc .. Water reservoirs of several thousand liters of water are maintained at strategic locations. Our Papageno system then allows for the most controlled distribution of that water along strategic lines. (I have attached an illustration showing the wetting pattern obtained with our system and an aerial view of a field test)

Martin: The system has been used operationally during prescribed burns in Portugal in March 2023. We see this as an important use case next to the containment of fire fronts during the fire season. Portugal and other countries have a legal obligation to carry out prescribed burns. Using our system as a means to secure flanks and anchor points can help agencies burn faster to reach their targets and avoid major catastrophes.

Martin: We foresee the use of seasonal installation around assets in the wildland urban interface - such as agricultural land, tourism, or energy and transport infrastructure such as energy plants, power lines, and airports. The deployment in the agricultural sector can be aided by the fact that the system could then be used for other duties during the year.

Martin: We are planning a roadshow next year, with already fixedly planned dates, such as January in southern France, March in Portugal, and June in Germany. We are looking for further demonstrations all over Europe and are building on our network in five further countries with dates to be confirmed in Spain, Greece, the UK, Sweden, and Switzerland.

Martin: We are so far bootstrapped with occasional financing support such as the WIPANO scheme covering 50% of patent-related costs. We are raising 800,000 Euros to finance our roadshow and are looking for public funding and equity financing from business angels and family offices.