Case Study: Designing SOFCs Into An Offgrid Power System

Electronic warfare (EW) is pervasive in modern battlespaces, so how can we ensure that missions remain flexible and successful when a single, all-encompassing solution to GPS and GNSS interference does not currently exist?

“Even the quest for a silver bullet to solve the problem of GPS interference is a flawed concept,” says Allen Gardner, Chief Technology Officer at Edge Autonomy, a leading provider and OEM of autonomous uncrewed aircraft systems, advanced optics, and resilient energy solutions.

“The more effective tactic is to have the capacity to quickly incorporate new innovations to augment your solution. “As new technology emerges, you integrate. As the adversary changes, you adapt.”

The Increasing Rise of Interference

The deliberate jamming of Global Navigation Satellite Systems (GNSS)—when a competing signal broadcasts “noise” that overpowers the GNSS/GPS signal, rendering it unusable—is a routine challenge to military and commercial operations alike.

While slightly more difficult to execute, signal spoofing—when an adversary broadcasts on the same signal to confuse data, resulting in inaccurate positioning or time—is no less threatening to mission success.

Both spoofing and jamming are on the rise – in both battle zones and commercial aviation – and must be actively addressed to maintain an upper hand and ensure that aircraft and weapons are not compromised.

The electronic warfare market had an estimated value of $18.45B in 2024 and is expected to reach $27.35B by 2031¹. With EW strategies presenting a constant threat—one capable of immense financial and strategic damage—it is critical that we explore a wide range of options to keep this threat at bay.

Electronic Warfare and Real-World Implications

From Finland to Poland to Turkey – and of course in the Ukraine conflict – Eastern Europe has seen GNSS and GPS interference become a significant disruptor.

Russian jamming of satellite-guided weapons has had a significant impact on Ukraine’s ability to defend its territory, decreasing the effectiveness of existing solutions and sending military officials on a renewed hunt for newer and more sophisticated technology².

“When you’re facing an adversary who will stop at nothing to interfere with your mission and endanger the men and women defending freedom on the front lines it is imperative that we bring every available resource into play to protect our allies, whether they are foreign or domestic,” says Tuna Djemil, Vice President of Business Development & Strategy for Edge Autonomy. “The battlefield is constantly evolving, which means we innovate in step with real-world mission needs.”

Adaptation and Integration at the Speed of the Modern Battlefield

As geopolitical crises escalate, so will the complications caused by GPS/GNSS interference. Emerging drone warfare will perpetuate jamming and spoofing attacks as uncrewed aircraft and autonomous vehicles play an increasingly central role in current conflicts.

Despite the lack of a silver bullet solution to GPS/GNSS interference, defending military operations while increasing mission flexibility in the face of mounting EW is possible. How can the U.S. military, NATO, and other allies maintain an edge over insidious adversaries?

Rapid adaptation is a must as we confront the widespread EW threats that exist in today’s battlespaces. By developing new technologies that are not dependent on GPS/GNSS – including solutions that utilize position, navigation, and timing (PNT) – we can stay ahead of nefarious spoofing and jamming techniques.

Beyond GPS: Advances in Position, Navigation, and Timing for Maximum UAS Flexibility

PNT technologies serve to augment and complement GPS and range from self-contained navigation techniques to radar sensing to advanced tracking solutions through Artificial Intelligence to front-end cyber solutions and beyond.

“The key is flexibility,” explains Djemil. “This interference game of cat-and-mouse calls for the ability to quickly pivot existing technology, adapt new technology, and keep your finger on the pulse of how to combine the two in order to thwart our adversaries.”

Modularity to Meet Mission Needs

Why is adaptability so critical to advanced navigation systems capable of withstanding the constant threat of GPS/GNSS interference? While several reliable defenses do exist for the UAS and their navigation, none are effective in every circumstance or environment. Adapting a modular open systems approach (MOSA) means that rather than relying on a single technology, users can augment and build upon the base system over time as new technologies become available.

The most EW-resilient UAS will be aircraft capable of seamlessly integrating the new and ever-evolving defensive technologies that arise to counter debilitating attacks. Advanced platforms like a PNT fusion engine ensure accuracy by combining data from multiple sensors for reliable, robust, and accurate position and time determination, even in environments where GPS signals may be either interfered with or unavailable.

“When a UAS can combine multiple GPS-denied technologies so that the strength of one overcomes the weaknesses of another, what you get is an adaptable and uniquely robust solution,” Gardner explains.

Edge Autonomy’s Battle Proven Stalker UAS

Rather than rely on a single technology, Edge Autonomy’s Stalker uncrewed system can fly in GPS/GNSS-denied environments by employing a PNT fusion engine that interfaces with multiple technologies (both current and future), uniting them in a navigation solution that provides the warfighter with the data needed to make decisions quickly and accurately to meet mission needs even in a rapidly changing environment.

The modular architecture of the Stalker design provides the agility needed to pivot quickly, advancing the mission no matter the circumstance.

“Intentional awareness of real-world adversarial threats uniquely positions us to come alongside our customers,” says Joshua Stinson, Chief Growth Officer at Edge Autonomy. “We designed the Stalker with maximum flexibility in mind, knowing that the ability to integrate new technologies and adapt to emerging threats, especially when it comes to electronic warfare, is vital for mission success in today’s dynamic environments.”

Learn more about the battle proven Stalker, and how a modular open systems approach can positively impact positioning, navigation, and timing – even under contested or austere circumstances:

¹https://www.coherentmarketinsights.com/industry-reports/electronic-warfare-market

²https://www.stripes.com/theaters/europe/2024-05-24/russian-jamming-high-tech-weapons-ukraine-13964032.html

The northern border in Washington State is so mountainous that cellular reception is not available, and many satellite phones do not work. For the USDA Forest Service, rangers have to rely on radio repeaters to maintain vital communication — especially during emergencies. As shared in this interview with Stacy Griffith, the Alaska Region Radio Manager, the issue was finding an offgrid power solution to keep the small 100W radio stations powered, regardless of weather conditions.

The Problem:
At these offgrid and high-altitude locations, equipment and fuel must be airlifted, which is expensive. The agencies were spending thousands of dollars just on maintaining the radio repeaters. And the solar arrays frequently lost power due to harsh weather and low sunlight — compromising critical communications.

The Forest Service needed to install a dependable backup power source, but several common solutions failed to meet their needs. Wind is typically used to backup solar arrays, but it was not viable because extreme winter weather would cause the turbines to ice over and stop working. A thermoelectric generator (TEG) is another common backup source, but high fuel needs and inefficiency in extreme cold temperatures took it out of consideration. And airlifting hydrogen to power a Proton-Exchange Membrane Fuel Cell (PEM) was not a viable option.

The Solution
The Forest Service redesigned the entire power system for their radio repeaters to include a Performer Series P250i Solid Oxide Fuel Cell to supplement the solar array during times of low sunlight.

Benefits of Designing Performer Series P250i SOFC Into A Power System:

Performance in extreme weather
Ability to customize
Flexible voltage
250 cycles
Remote monitoring
Fuel efficiency
Low maintenance needs
Reliable 250W output

While other technologies fail in extreme cold, P250i excels because it is engineered to store, start and operate in temperatures from -40°C to 50°C. It produces no liquid water and is constructed of heat-resistant ceramic tubes that will not freeze. So the radio stations will stay up even in the harshest weather.

Plus, the system is unique in the market because it’s specifically designed as a battery tender to cycle up to 250 times. And engineered with automation features, it is easier to control remotely than other backup technologies.

Results
40 radio repeater sites now include a Performer Series P250i as part of the power system. None of the sites have lost power due to the SOFC.

Due to the high efficiency of P250i, the agency does just 10 helicopter refueling visits per year. That is spread across 40 sites in their sector, which spans 308 miles or 46,000 sq mi.
$3,000 is the average fuel cost per year for all 40 sites combined — compared to the same fuel cost to power just one radio site using other technologies.
The minimal noise signature of P250i keeps the agency compliant with their mandate to minimize environmental impact.
Adaptive Energy customized the P250i enclosure to fit into existing buildings. It features custom brackets and venting created exclusively for this use case.
Other federal agencies seek the guidance of Forest Service on designing efficient power systems for offgrid sites that experience harsh weather.
Due to its power output relative to size, fuel efficiency and flexible voltage options, P250i offered the reliable backup Forest Service needed to keep their critical communications infrastructure running. Learn more about our work with Forest Service in this interview.