by Aluminum cable is an electrical cable made with aluminum conductors rather than copper. Aluminum has been used for decades as an electrical conductor but was less common than copper cable until the last 20-30 years. There are several advantages to using aluminum cable including lower material costs and lighter weight.
Material Cost Advantages of Aluminum Cable
One of the biggest benefits of Aluminum Cable is the reduced material cost compared to copper. Aluminum is much more abundant than copper in the Earth’s crust and is therefore significantly less expensive. For the same cross-sectional area, aluminum cable can cost up to 60% less than equivalent copper cable. This cost reduction allows for larger cable to be installed for the same budget on long distribution lines and substations connections. The lower materials cost has helped drive increased adoption of aluminum cable worldwide.
Lighter Weight of Aluminum Cable
Another advantage of aluminum cable is its lighter weight. Aluminum has about one-third the density of copper. For the same conducting capacity, aluminum cable will weigh nearly two-thirds less than a copper cable. This reduced weight is useful for overhead power lines, allowing for longer spans between support structures like utility poles. It also reduces installation and transport costs. The lighter cable are easier to handle and save money on things like equipment requirements and fuel usage during deployment projects.
Higher Ampacity Rating
The lower weight of aluminum enables an increased ampacity rating. Ampacity refers to the maximum current a cable can safely carry before overheating. Because aluminum conductors require less material and have better heat dissipation, aluminum cable are able to handle higher currents than similarly sized copper cable. This increased ampacity means fewer cable may be needed for a given installation, further reducing costs. It also provides reserve capacity to accommodate future load increases without upgrading infrastructure.
Improved Corrosion Resistance
While copper is more conductive, Aluminum Cable forms a thin, resilient oxide layer on its surface that provides good corrosion resistance. This natural oxide layer protects the aluminum from further oxidation and corrosion underground or outdoors. Copper, on the other hand, is more prone to corrosion which can increase resistance over time. The superior corrosion characteristics of aluminum help maintain consistent performance and conductivity longer. Less maintenance and fewer unplanned outages result from corrosion issues with aluminum cable.
Connection Compatibility Concerns
One drawback that previously limited aluminum cable adoption was its incompatibility when connecting to copper busbars or terminals. The different metals can form an electrically resistive galvanic cell if joined directly without proper separation. This can lead to overheating and failure over time. However, connection technologies have been developed to address the issue. Compounds like Noalox are frequently used to coat aluminum strands before terminating connections to prevent reactions. Properly installed and maintained connections with dissimilar metals are now reliable in practice.
Underground Applications
Underground distribution has seen increasing usage of aluminum cable while overhead transmission still relies mostly on copper. Underground cable are insulated and shielded from the elements so corrosion is less of a concern. The material cost savings and lighter weight are therefore attractive advantages of aluminum. It has become the predominant choice for new underground residential distribution (URD) and subdivisions. Underground installation avoids many permitting and right-of-way issues associated with overhead lines as well.
Wider Use in Transmission and Substation Connections
In addition to distribution networks, aluminum cable adoption is growing for transmission systems and substation applications. Larger aluminum conductors offer cost benefits for new high voltage transmission lines. They facilitate upgrade projects when existing lines approach capacity limits. Aluminum cable are also being used more frequently for transformer and generator connections in substations. The improved ampacity helps future-proof electrical infrastructure and allows additional capacity increases without equipment replacements. Overall, aluminum cable performs well and brings economic advantages for utility providers.
Standardization of Aluminum Cable Design
As cable gained traction, standardized cable designs and sizes were developed to facilitate widespread usage. The American Wire Gauge (AWG) and Metric Designators (MD) provide dimensional specifications matching counterpart copper cable. Having consistent aluminum options makes procuring cable easier and allows reuse of pre-existing conduit, ducting and equipment optimized for copper dimensions. Standardization also simplified training, installation practices and safety procedures related to cable handling. This further reduced implementation barriers enabling rapid adoption throughout the electrical industry.
Aluminum cable delivers compelling advantages over traditional copper options. Lower material costs, lighter weight, and higher ampacity ratings enable larger and longer distribution lines or connections for equivalent budgets. Improved corrosion resilience maintains consistent performance longer with less maintenance needs. While historical connection issues posed challenges, modern practices ensure reliable connections between dissimilar metals. Overall, aluminum cable is becoming the cable of choice for new electrical infrastructure projects thanks to its cost-effectiveness and support for greater capacity demands into the future. Continued standardization efforts will sustain widespread usage of this alternative conductor material across power systems globally.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
