Boost Commercial UAV Flight Times With Hydrogen Fuel Cell Technology

Drones (or UAVs) are transforming operations in a number of industries, including infrastructure inspection, agriculture, search and rescue, mining, and more. Commercial drone operators have three distinct power solutions to choose from: lithium batteries, internal combustion engines, or hydrogen fuel cells. But which technology can truly deliver the most cost-efficient (hence profitable) performance?

This article explores how hydrogen fuel cells can solve many of the shortcomings of batteries, with none of the noise, pollution and reliability issues of internal combustion engines. We’ll also introduce Ballard’s new complete commercial fuel cell drone solution, the FCair™ family, and share what we’re doing to make fuel cell technology more accessible for drone operators than ever before.

What are the challenges of using battery power? Today’s small to mid-scale electric drones are powered by batteries. While batteries cost far less than any alternative solutions, they’re quite costly—in terms of total cost of ownership and practicality on the job—because of restrictions in flight time and battery management issues.

Low flight times reduce efficiency.  Flight time for battery-powered drones is very low, typically in the 15-45 minute range. This restricts their potential applications. On a typical working day, battery powered drones spend less than half of their time in the air, as operators swap out batteries and deal with other logistical issues associated with battery powered flight. To put it another way, more than half of the drone’s working potential is lost, which is bad for operational costs and profits.

Battery life is another challenge: a drone battery’s typical service life is six months (with daily use). So every six months, operators must source new, expensive, batteries to replace the old ones.

Shipping and handling involves complicated logistics. A typical drone requires two lithium batteries that weigh four to five pounds each. In the field, an operator needs enough replacements on hand to keep the drone in the air long enough to fulfill its mission.

Then there’s the question of transporting a drone—and its complement of batteries—to the job.

Batteries are restricted on most commercial airlines. Many operators are forced to ship the batteries separately, via ground transport, which often requires paperwork and certifications, and is slow and costly process.

Maintaining a battery storage and charging facility is labor-intensive. A professional drone operator needs to seriously consider the infrastructure of battery recharging, storage and management. There needs to be adequate charging for enough batteries to keep drones in the air long enough to complete their designated tasks. Then there’s the need to store a complete kit of batteries in a safe, dry location. Not to mention the need for a tracking system to ensure the timely replacement of aging batteries. As an operator’s fleet grows, battery management becomes increasingly complex and cumbersome.

What about internal combustion engines?  Most larger drones are powered by internal combustion (IC) engines. While internal combustion engines are
well known and understood, so are the many problems they represent:

- high maintenance costs (labor, parts, and the need to have spares and tools on site)
- pollution from gasoline engines (which is far worse with smaller engines) for film use, image quality is affected by engine vibration
- engine noise restricts usefulness:
     not appropriate for surveillance
     interferes with sound recording

Additionally, the total cost of ownership for IC powered drones can be surprisingly high. Typical engines require an overhaul after only 200 to 300 cycles, or 600 to 800 working hours. That level of service means a frequent need for spares and qualified service staff.

For longer flying times and simpler logistics: Hydrogen fuel cells are the solution. Like batteries, fuel cells are a source of DC power, and are clean and quiet. Unlike batteries, their power comes from converting a fuel—hydrogen—into energy. Unlike batteries they provide greater power output for longer. For drone operators, using fuel cells means more flying time.

Fuel cells by the numbers:
     triple the energy density of batteries
     2-3 times longer flying time

In a multi-rotor drone, where a battery might last 20 minutes, a fuel cell would last 90 minutes or longer. In a fixed-wing drone, where a battery might run for four hours, a fuel cell could last 12-15 hours.

Why choose hydrogen fuel cells?

- Clean electric power: hydrogen fuels are emission-free in operation.
They can be zero-emission across the supply chain, if the hydrogen is generated from renewable energy.
- Quiet in operation: A fuel cell drone is as quiet and vibration-free as a battery-powered drone, making it useful for filming, surveillance and other vibration and noise-sensitive applications.
- Logistically easier: Fuel cell drones require no battery spares/storage/recharging etc.
- Reliable and durable: Fuel cell maintenance is far less than internal combustion engines or battery power. Minor maintenance is required after 1000 to 1200 hours in service, and after 2000 hours the fuel cell is replaced.

The initial purchase price of batteries is lower—but when the total operating costs are considered, the economic picture changes.  Drones—both multi-rotor style and fixed wing—continue to prove their worth in myriad applications in many industries. But they continue to come up against the limitations of current power technologies.  Internal combustion engines are polluting, noisy, and service-intensive. Battery-powered electric drones are quiet and effective, but flying times are short, and battery recharging and management is a headache.

Fuel cell powered electric drones are clean and quiet, with higher system durability than other options. Fuel cells are logistically less demanding than batteries, and have a far longer flight time. Longer flight time means operators can improve efficiencies and significantly reduce costs.