Upgrading the North-Central Transmission Arteries: Steel Pole Selection Logic Behind a 65-km Line and New Substation

Costa Rica‘s electricity sector is undergoing a grid-centric transformation driven by deeper renewable energy integration, enhanced grid stability requirements, and the rapid electrification of transport and industry. At the heart of this transformation lies a landmark infrastructure project: the North-Central Transmission Infrastructure Upgrade, approved by the Board of Directors of the Instituto Costarricense de Electricidad (ICE).

This project represents not just a significant capital investment, but a clear signal of the technical direction for transmission infrastructure in Costa Rica—and a direct indicator of the steel pole specifications that suppliers must be prepared to meet.

I. Project Overview: Scope, Investment, and Timeline

The North-Central Transmission Infrastructure Project is a strategic initiative aimed at strengthening the national high-voltage grid that supports the National Electric System (SEN). Its core parameters are as follows:

ICE President Marco Acuña described the project as “key to guaranteeing the electricity supply the country needs in the medium and long term, responding to energy demand and strengthening the stability of the National Electricity System (SEN)”.

II. Market Driver: Renewables Integration and Grid Capacity

The project is directly driven by Costa Rica’s rapidly evolving energy mix. ICE plans to add more than 500 megawatts of generation capacity between 2025 and 2028, representing a growth of nearly 14%. This new capacity comes primarily from variable renewable sources such as solar and wind.

Critically, these new renewable plants are being built in Guanacaste and Puntarenas—regions that are geographically distant from major load centers such as the capital, San José. This geographical mismatch creates a clear technical imperative: the existing transmission corridors must be expanded and upgraded to transport clean power efficiently from generation sites to consumption centers. The North-Central Transmission Project directly addresses this gap.

On a broader scale, this project is part of ICE‘s Transmission Expansion Plan (PET) 2024–2034, under which the utility has earmarked USD 1 billion to expand and modernise the national grid. The plan calls for the addition of 674 km of lines and 1,330 MVA of transformer capacity by 2034. The North-Central project represents a foundational component of this decade-long build-out.

III. Technical Challenges: What This Means for Steel Pole Selection

For steel pole suppliers, the North-Central project presents a clear set of technical requirements. Based on the project‘s scope and ICE’s established procurement patterns, the following parameters are critical:

1. Voltage Level Compatibility

Costa Rica‘s national high-voltage network operates at 230 kV and 138 kV. The 65-km line in this project will likely operate at one or both of these voltage levels. Steel poles must be designed to provide sufficient electrical clearance and insulation coordination for these voltage classes—dictating pole height, cross-arm length, and structural configuration.

2. Structural Design Standards

Costa Rica is situated in the Pacific volcanic and seismic belt. Steel pole designs must comply with the Costa Rica Building Code (Reglamento de Construcciones) and the Costa Rica Seismic Code (Código Sísmico de Costa Rica) . Design loads must cover combinations of dead loads, live loads, seismic loads, and wind loads—with wind load estimation based on a 50-year return period.

3. ICE Procurement Specifications

ICE‘s historical tenders provide a clear benchmark for steel pole specifications. For example, ICE tender 2019LA-000020-0000400001 specified: galvanized steel pole of 1 or 2 bodies, 11 m height, 13 cm tip diameter, 350 kgf working load, 8 sides (octagonal). Additional tenders have specified 13 m height poles with 400 kgf working load.

These specifications—octagonal cross-section, galvanized finish, specific height and working load ratings—represent the technical baseline that suppliers must meet for ICE projects.

4. Regional Interconnection Requirements

Beyond domestic needs, the project also aims to optimise international exchange capacity, consolidating Costa Rica‘s position in the Central American Electricity Market (MER). Costa Rica’s grid is interconnected via the SIEPAC transmission system—a 1,793 km, 230 kV regional grid linking six Central American countries. Steel poles deployed on this project must therefore be compatible with regional interconnection standards, not just domestic requirements.

IV. Supplier Considerations: Meeting ICE‘s Technical Threshold

For steel pole manufacturers targeting the Costa Rican market, the North-Central project offers several clear takeaways:

• Octagonal geometry is the established standard. ICE tenders consistently specify 8-sided (octagonal) poles. Suppliers must be equipped to manufacture octagonal cross-sections with consistent dimensional accuracy.

• Galvanized finish is non-negotiable. ICE requires hot-dip galvanizing for all transmission steel poles. Suppliers must have certified galvanizing capabilities and be prepared to provide mill test certificates.

• Height and load ratings vary by application. The 11 m / 350 kgf and 13 m / 400 kgf specifications represent two common configurations. Suppliers should be able to offer multiple height and load combinations to suit different project requirements.

• ICE approval is the gateway. ICE operates Costa Rica‘s entire interconnected transmission system. All steel poles must pass ICE’s technical approval process—suppliers should anticipate rigorous design review and factory inspection.

Summary

The USD 100 million North-Central Transmission Infrastructure Project—with its 65 km of new high-voltage lines, new substation in San Rafael de Alajuela, and expansion of the Garabito substation—represents a defining infrastructure investment for Costa Rica‘s energy future. Driven by the integration of over 500 MW of new renewable capacity in Guanacaste and Puntarenas, this project establishes a clear technical benchmark for transmission steel poles: octagonal geometry, hot-dip galvanized finish, compliance with Costa Rican seismic and building codes, and alignment with ICE’s established procurement specifications. For steel pole suppliers, understanding and meeting these requirements is the essential first step toward participating in Costa Rica‘s decade-long grid modernization program.