In power systems, managing excess electrical energy is essential for maintaining stability, protecting equipment, and ensuring efficient operation. While traditional dump loads often rely on bulky resistor banks, flexible heaters can serve as an effective solution to address this issue.
An adaptable alternative, flexible heaters are not only compact and customizable, but they can also help engineers repurpose surplus electrical energy in applications ranging from renewable energy systems to aerospace and industrial equipment.
What Is an Energy Dump?
An energy dump is a method used in electrical systems to dissipate surplus electrical energy that can’t be stored or used immediately. One real-world example of this is regenerative braking on your hybrid or electric vehicle. This concept is particularly relevant in renewable energy systems, such as wind turbines and solar farms, where power generation isn’t always synchronized with demand. Instead of allowing this extra energy to cause voltage spikes or damage equipment, the system diverts it to a dump load.
A dump load is typically a resistive element, like a bank of resistors, that converts excess electrical energy into heat. By doing so, it prevents overload and helps balance the power system. In wind turbines, for example, when generated electricity exceeds consumption, the dump load provides a safe path for this surplus energy, protecting both the turbine and the grid.
Electrical schematic showing several resistive loads.
What makes energy dumps even more valuable is when the excess energy can be put to use, such as heating water, warming enclosures, or simply dissipating heat in a customized form factor- this is where flexible heaters come into play.
What Is a Flexible Heater?
Flexible heaters are fixed resistance circuits made from specialty alloys formed into complex shapes, and then enveloped with high-temperature resilient materials like polyimide or silicone. Many heaters include a rear adhesive, also known as PSA (pressure-sensitive adhesive).
A flexible polyimide heater, also known as a Kapton® heater, is an ultra-thin, fixed-resistance heating element designed to convert electrical energy into heat. Unlike bulky resistor banks, flexible heaters are completely customizable in size, shape, wattage, and voltage requirements.
These heaters consist of a resistive circuit (typically etched foil) laminated between layers of polyimide film.
Polyimide heaters are known for their:
- Minimal thickness, often under 0.2 mm
- Excellent thermal stability
- High reliability in demanding conditions
- Low outgassing properties of polyimide
Ultra-thin polyimide flexible heater with etched foil circuit, ideal for high-reliability, low-outgassing performance in demanding environments.
In addition to polyimide, similar heaters can be constructed using vulcanized silicone elastomer. Instead of a pouch made of polyimide that is laminated together, these are silicone heaters that are vulcanized shut. Both silicone and polyimide heaters can be used as energy dump style heaters.
Flexible silicone heaters are known for their:
- Material resilience
- Temperature uniformity with minimal hotspots
- Ultra-high temperature limits
- Ability to withstand a wide range of input power conditions
Flexible silicone heater rated at 12V, 6W, built for high temperature resilience, uniform heating, and versatile power conditions.
Why Use Flexible Heaters as an Energy Dump?
According to high school physics classes, energy is neither created nor destroyed; it is only changed from one form to another. This fact obviously assumes ignoring entropy losses- but what high school physics course wasn’t riddled with caveats like ignore the effects of friction, etc. In power systems where excess electricity is generated, that energy must go somewhere. A flexible heater can effectively act as an energy dump by converting surplus electrical energy into heat that is safely dissipated into the surrounding environment or used for a secondary purpose.
Unlike traditional resistor banks that can be bulky and rigid, flexible heaters provide a low-profile, lightweight alternative. Most flexible heaters are less than 1mm thick and can be adhered to any flat or curved surface, which can help dissipate heat.
Flexible heaters can replace conventional dump loads in systems that have space constraints or need special mounting considerations. This is especially important for enclosures, moving parts, and other types of sensitive equipment.
Applications of Flexible Heaters as Dump Loads
Aerospace and Space Systems
In aerospace and space applications, flexible heaters shine due to their low outgassing materials (polyimide films and aerospace-grade adhesives) and ability to survive extreme thermal environments.
These heaters are ideal for managing excess energy generated during operations like braking or rotational motion in satellites or spacecraft. Instead of dissipating surplus energy through traditional means, flexible heaters can convert that energy into heat to help maintain thermal balance or prevent condensation in sensitive areas.
Industrial Systems
Industrial equipment often generates excess energy during motion control processes, regenerative braking, or during idling periods of high-powered machinery. Flexible heaters offer a cost-effective, customizable option for managing that surplus energy while serving a functional purpose, such as warming enclosures or preventing condensation in electrical cabinets.
Complete Customization
Their customizable nature means these heaters can be designed to fit into tight spaces or complex geometries, offering targeted heat dissipation exactly where it's needed. It’s not just the shape of the heater that is customizable, but also the wattage and power characteristics. Custom flexible heaters can be designed to a range of power ratings accommodating 5 volts to hundreds of volts.
Beyond their technical merits, flexible heaters provide engineers with a level of design freedom that traditional resistive dump loads can’t match. Whether it’s a non-rectangular footprint, the need for zoned heating, or integration into moving components, flexible heaters allow creative solutions for managing surplus energy without adding bulk or complexity.
Summary
Flexible heaters offer an innovative solution for managing excess electrical energy in modern power systems. Using a flexible heater as an energy dump allows engineers to dual-purpose the dissipation process, converting waste energy into usable heat for processes like warming fluids, enclosures, or critical components.
By converting surplus energy into controlled, useful heat, they provide an alternative to traditional resistor-based dump loads, especially in environments where space, weight, and reliability are critical. Whether used in aerospace systems, industrial equipment, or renewable energy applications, flexible heaters give engineers the ability to design smarter, more adaptable energy management solutions. As power systems continue to evolve, flexible heaters are proving to be a valuable tool in balancing performance, efficiency, and safety.
Key Takeaways
- Flexible Heaters Are an Effective Alternative to Traditional Dump Loads: Instead of relying on bulky resistor banks, engineers can use thin, lightweight flexible heaters to safely convert surplus electrical energy into heat, especially in systems with space or weight constraints.
- They Enable Energy Recovery in Critical Applications: Flexible heaters can dual-purpose the energy dump process, dissipating excess energy while also providing functional heat for enclosures, fluid warming, or condensation prevention, particularly valuable in aerospace and industrial environments.
- Highly Customizable for Complex Designs: Flexible heaters can be tailored in shape, size, wattage, and voltage, allowing them to be integrated into curved surfaces or tight spaces, delivering heat exactly where it’s needed in nontraditional or moving components.
- Engineered for Harsh and High-Reliability Environments: Both polyimide and silicone-based flexible heaters are built to withstand extreme temperatures, offer uniform heating, and exhibit low outgassing properties, making them suitable for high-performance systems like satellites, EVs, and heavy machinery.
- Support Smarter, More Adaptable Energy Management: As power systems become more advanced, flexible heaters offer a scalable and efficient solution for balancing performance, thermal control, and safety, especially in renewable energy, aerospace, and motion control applications.
