Maximizing Grid Capacity: Strategies for a Sustainable Future

Steel-core conductors are popular due to their performance and cost-efficiency. As the demand for increased electrical grid capacity grows, partly due to rapid advancements in renewable energy, grid operators face the challenge of delivering more power while balancing sustainability and cost-effectiveness. Selecting the right conductor is essential.

Different conductor types serve specific needs, much like various tools in a toolbox. Aluminum Conductor Steel Reinforced (ACSR) conductors are the industry standard because they offer a combination of low cost, durability, and flexibility. Advanced Aluminum Conductor Steel Supported (ACSS) conductors further enhance the capacity of steel-core conductors.

Composite core conductors, offered by several providers, claim to be essential for a sustainable, resilient, and efficient grid. These conductors benefit from a higher strength-to-weight ratio and reduced thermal expansion, which minimizes thermal sag.

This can be particularly advantageous in situations where controlling sag is critical. However, the overall savings from reduced sag often do not outweigh the total project costs. To evaluate these claims, we have compared conductors with advanced steel cores to the latest carbon fiber composite (CFC) core conductors. Do CFC-reinforced or supported conductors truly outperform the advanced ACSS steel-core conductors?

Resiliency can be seen as the combination of two attributes: survivability after extreme weather events or hostile acts, and the time and expense required to restore service following damage from an extreme event.

Sustainability is defined by Merriam Webster: “of, relating to, or being a method of harvesting or using a resource so that the resource is not depleted or permanently damaged.” When ranking sustainability, we consider criteria such as resource depletion, monetary cost, and resource recovery by recycling. Cost can also be grouped under sustainability because money is a resource that can be put to beneficial use elsewhere. In this discussion, cost is covered as a separate criterion under the quantitative analysis.

Capacity is the electrical load, in amperes, at the manufacturer-recommended maximum operating temperature. The values used in this paper come from opensource literature with standard default values for ambient temperature, wind speed, and solar heat gain.

Cost encompasses the total lifetime cost of the transmission line for land usage, materials, installation, operation (including the cost of line losses), maintenance, repair, and decommissioning costs. For this paper, we have only focused on the first cost. Analyzing the true total cost can be done only on a project-specific basis.

Steel cores increase electrical grid capacity primarily through their structural benefits, which enhance the performance of conductors in high-demand situations. Here’s how they contribute to greater grid capacity:

1. Strength and Durability: Steel cores provide the necessary tensile strength to support conductors over long distances and in challenging conditions. This increased strength allows for the use of conductors with higher current-carrying capacities without risking mechanical failure. As a result, the grid can handle higher loads without compromising safety or reliability.
2. Higher Current Carrying Capacity: By reinforcing conductors with steel cores, it becomes possible to increase the current-carrying capacity of the conductors. This means that the same physical space can carry more electricity, thus boosting the grid’s overall capacity.
3. Enhanced Conductor Performance: Steel cores enable the use of larger diameter conductors or more conductive materials, which can reduce electrical resistance and improve efficiency. This means that more power can be transmitted with lower energy losses, contributing to a more effective grid.
4. Greater Span Lengths: The strength provided by steel cores allows conductors to span longer distances between towers or poles. This reduces the need for frequent support structures and can lead to more efficient grid layout and reduced infrastructure costs.
5. Thermal Performance: While steel cores themselves do not directly affect thermal performance, they support conductors that can handle higher temperatures without excessive sagging. This helps maintain conductor performance during periods of high demand, which is critical for ensuring reliable power delivery.

In summary, steel cores contribute to increased grid capacity by enabling conductors to handle higher currents, span greater distances, and operate more efficiently, all of which help to meet the growing demands of modern electrical grids.