There’s a reason TS Conductor’s Aluminum Encapsulated Carbon Core (AECC) technology has been recognized with prestigious awards from the U.S. Department of Energy, Public Utilities Fortnightly, S&P Global Platts, and Bloomberg NEF. AECC technology delivers the increased capacity and minimal sag of advanced conductors while maintaining the safety, reliability, and ease of installation expected from traditional conductors. This breakthrough performance comes from the modern materials science and practical engineering of three critical components: the pre-tensioned carbon fiber composite core, the aluminum encapsulation protective layer, and the fully-annealed aluminum conducting strands. AECC’s patented design optimizes each element while ensuring they work together as an integrated system.
Modern materials science offers no better solution for overhead conductors than carbon fiber composite. Its exceptional strength-to-weight ratio and near-zero thermal expansion are ideal for this demanding application. The carbon fiber core is both stronger and lighter than steel, allowing us to add significantly more aluminum conducting material while maintaining the same overall weight and tension as traditional conductors. The low thermal expansion allows utilities to increase line capacity by operating at higher temperatures while maintaining required clearances.
While carbon fiber composites offer superior tensile strength, they have a well-known materials science challenge: their compressive strength is only 60-70% of their tensile strength. This becomes critical during installation, where bending forces create compression on the under layer of any bend. We address this through pre-tensioning during manufacturing, which we preserve with our aluminum encapsulation layer. By starting with the core under tension, we offset the compressive stresses that occur during bending, enabling the conductor to handle standard bending radiuses without risk of damage to the composite core.
Our core design also reflects another crucial engineering choice: we avoid the use of glass fiber layers that would compromise performance. Glass fiber’s modulus is only one-third that of carbon fiber – adding it significantly reduces the core’s overall stiffness. This matters because core stiffness directly affects conductor performance, particularly in challenging conditions. Long spans and ice loading create substantial mechanical stress. A lower-modulus core allows greater sag, potentially violating clearance requirements. By avoiding glass fibers, our core delivers consistent performance across all operating conditions.
The seamless aluminum encapsulation layer serves as both protector and enabler of our conductor’s superior performance. During manufacturing, we use this thick aluminum layer to preserve the core’s critical pre-tensioned state. During installation, this same layer acts as a cushion during crimping, allowing the conductor to achieve full compaction with standard compression fittings without risking damage to the composite core. This means utilities can use their existing tools and procedures – no specialized equipment or training required.
The encapsulation layer also provides comprehensive protection against multiple threats to long-term reliability. Its seamless design eliminates the possibility of galvanic corrosion between the carbon core and outer aluminum strands by preventing the moisture and oxygen ingress necessary for this electrochemical reaction. This sealed environment also protects the composite matrix from degradation that can occur when exposed to moisture, oxygen, and other environmental factors. Even in cases where the outer strands become separated, the core remains protected from damaging UV radiation and corona-induced ozone.
This thick, seamless barrier is crucial to the conductor’s longevity. Most alternative designs rely on thin coatings or glass fiber barriers that can wear away or allow moisture penetration over time. Our thick aluminum encapsulation ensures decades of reliable protection while enabling standard installation practices – a key advantage for utilities focused on both performance and practical deployment.
Our conducting strands use fully-annealed aluminum formed into a trapezoidal shape. This configuration allows us to pack more aluminum into the same outer diameter compared to traditional round wire designs, maximizing conductivity. The annealed aluminum provides lower electrical resistance than hard aluminum while enabling high-temperature operation.
When combined with our near-zero thermal expansion carbon core, these strands can operate at high temperatures without the excessive sag that plagues traditional conductors. This allows utilities to substantially increase line capacity while maintaining critical clearances
This integration achieves superior performance across all key metrics while maintaining the built-in safety and reliability of traditional options. The design doubles the capacity of traditional ACSR conductors while reducing line losses by 50%, enabling more efficient power delivery. Minimal thermal sag maintains critical clearances even at high temperatures, allowing utilities to increase capacity without modifying existing structures during reconductoring. For new construction, these characteristics enable longer spans with fewer structures, reducing project costs and environmental impact.
Yet these performance gains don’t come at the expense of safety or reliability. The conductor works with standard installation methods and tools, requiring no specialized training or handling procedures. Its robust design inherently protects against common failure modes – the protected core eliminates environmental degradation, the pre-tensioned design prevents installation damage, and the encapsulated construction ensures compatibility with industry-standard hardware. This means utilities can confidently deploy advanced conductor technology without compromising their rigorous safety and reliability standards.
While TS Conductor represents the next generation of advanced conductor technology, our innovation builds upon proven industrial processes and materials that have demonstrated their reliability over many decades. Since our commercial deployment in 2016, utilities around the world have embraced our technology, recognizing its performance advantages and familiar installation characteristics.
Our conductor technology integrates three mature industrial processes, each with decades of proven performance:
The composite core manufacturing process dates back to the 1950s. This pultrusion technology has been continuously refined over 75 years, creating a robust and well-understood manufacturing method.
Carbon fiber composites entered military aerospace applications in the early 1970s before expanding into commercial aviation. This half-century of demanding aerospace applications has thoroughly validated the material’s performance characteristics and long-term reliability.
The annealed aluminum we use has been serving the utility industry since the 1970s in ACSS conductors. This extensive field experience provides confidence in the material’s long-term performance under real-world conditions.
TS Conductor’s innovation lies in how we combine proven technologies in a novel way. Each component of our solution rests on established manufacturing processes and material platforms that have been validated through decades of industrial use.
This foundation of proven technologies allows us to deliver innovation without the uncertainties typically associated with new materials or processes. Our customers can be confident that the core elements of our technology have been thoroughly validated through decades of real-world application across multiple industries.
Rather than asking utilities to take a leap of faith on unproven technology, we offer a solution that builds upon their existing knowledge and experience. The result is a conductor that delivers superior performance while maintaining the reliability and familiarity that utilities require.
In addition to the main conductor evolution story presented elsewhere, several alternative technologies emerged along the way. Understanding why these alternatives achieved limited success provides valuable insights into the practical requirements for transmission conductor design.
Gap type conductors attempted to manage thermal sag by creating space between the core and outer conductor strands. While this approach effectively lowered the thermal knee point, it introduced significant practical challenges. Installation proved extremely difficult, and repairs were virtually impossible since core breakage would result in retraction from the break point.
Perhaps most problematically, the grease used in the gap design often leaked onto the conductor surface, creating a hydrophobic condition. In high-temperature conditions, this grease could drip onto vehicles and buildings below the line, creating environmental and public relations issues.
INVAR steel conductors leveraged the material’s low coefficient of thermal expansion to address sag concerns. However, several fundamental limitations prevented widespread adoption. The magnetic properties of INVAR steel significantly increased inductive impedance, complicating circuit design. Its relatively low strength necessitated pairing with high-temperature aluminum alloys that exhibited poor electrical conductivity, resulting in higher line losses compared to ACSR.
The combination of high material costs and poor electrical performance has limited INVAR conductor adoption—it has never been used in the U.S. transmission grid.
Recent multi-strand composite core designs, such as those using seven smaller composite strands instead of a single core, have generated interest based on a perceived redundancy advantage. This perception, however, is incorrect. A core with four broken strands out of seven provides no more residual strength than a monolithic core with equivalent damage—both have lost the same percentage of their load-bearing capacity.
The multi-strand design actually worsens the fundamental compression failure vulnerability of unidirectional composites. During bending, the strands furthest from the neutral axis experience higher compression stress than an equivalent monolithic core, increasing the risk of failure.
Installation presents additional challenges. Achieving proper crimping force becomes a delicate balance—too little pressure leaves the center strands loose, while too much risks crushing the composite strands at their contact points. These practical issues, combined with higher manufacturing costs from producing and assembling multiple small strands, have limited the success of this approach.
These alternative technologies demonstrate that successful conductor design must balance theoretical performance advantages against practical considerations of installation, maintenance, and long-term reliability. Solutions that appear promising in the laboratory may prove impractical in real-world utility operations.
For over a century, ACSR (Aluminum Conductor Steel Reinforced) has remained the standard overhead conductor technology. While several innovations have emerged to address ACSR’s limitations, none achieved widespread adoption until now. Each new generation of technology solved specific problems but introduced new challenges that prevented mainstream use. Understanding this evolution reveals why TS Conductor’s AECC technology represents the first viable alternative to ACSR in over 100 years.
ACSR technology, invented in 1908, combines a galvanized steel core with hard-drawn aluminum outer strands. This design emerged from the materials limitations of its era. The steel was not strong enough, requiring strength contribution from hard aluminum strands to obtain adequate conductor strength.
This created an inherent temperature limitation: at temperatures above 93°C (the annealing temperature), the hard-drawn aluminum permanently converts to its softer, annealed state. This metallurgical change causes permanent loss of tensile strength, leading to increased conductor sag and reduced line clearances. This temperature ceiling effectively limited current-carrying capacity, prompting the search for high-temperature alternatives.
ACSS technology emerged in the 1970s, leveraging advances in the steel industry that enabled the use of higher-strength steel cores. These cores, available with various protective coatings to prevent corrosion, allowed the conductor design to fully support mechanical loads using annealed aluminum strands instead of hard-drawn aluminum. This eliminated ACSR’s 93°C temperature limitation and increased capacity.
However, this solution to the temperature problem created a new challenge: excessive thermal sag. The steel core’s high coefficient of thermal expansion meant that as temperatures increased, the conductor experienced substantial sagging. To maintain required clearances, utilities needed taller structures and stronger supports. Increased structure costs limited ACSS adoption primarily to special applications where increased capacity justified the additional investment.
This limitation sparked the search for conductor technologies that could deliver both high-temperature operation and low thermal sag.
The 1990s saw the emergence of composite core conductors designed to address thermal sag through the use of advanced materials. These conductors replaced steel cores with engineered composites made from ceramic or carbon fibers. The composite cores provided both high strength and low thermal expansion, enabling high-temperature operation without excessive sag.
However, these first-generation advanced conductors never achieved widespread adoption. They gained a reputation for being delicate and difficult to work with, requiring specialized installation procedures and equipment. Utilities were concerned about the risk of conductor damage during installation and long-term reliability issues. When combined with significantly higher costs compared to traditional conductors, these factors limited their use primarily to niche applications where their unique properties justified the additional expense and complexity.
The industry clearly needed a solution that could deliver advanced conductor performance while maintaining the safety and reliability of traditional conductors.
AECC (Aluminum Encapsulated Carbon Core) technology represents a natural evolution that combines advanced conductor performance with traditional conductor safety and reliability. The design uses a pre-tensioned carbon fiber core protected by an aluminum encapsulation layer, paired with annealed aluminum outer strands. This configuration delivers 2-3 times the capacity of ACSR using the same structures, with half the line losses, while maintaining low thermal sag at high operating temperatures. The ability to achieve this increased capacity without structure modifications or replacements provides utilities with a cost-effective path to grid modernization.
The pre-tensioned core provides inherent resistance to compression failures during bending, while the aluminum encapsulation serves multiple functions: protecting the core from environmental exposure, providing mechanical cushioning during installation, and preventing moisture or oxygen from reaching the carbon fiber. This allows the use of standard compression fittings, dead ends, and splices – eliminating the need for specialized hardware or installation procedures.
AECC maintains complete compatibility with traditional installation methods. Line crews can use their standard tools and familiar techniques, requiring no specialized training or equipment. The robust design tolerates normal handling practices while providing protection against moisture, UV degradation, oxidation, and extreme weather events throughout the conductor’s service life.
AECC technology represents the first viable alternative to ACSR in over a century because it delivers superior performance through modern materials science while maintaining compatibility with standard installation practices and ensuring long-term reliability through core protection. This combination of advantages, without corresponding disadvantages, positions AECC to become the new standard for grid modernization.