Central American Power Market Integration Accelerates: How the SIEPAC Interconnection Drives Steel Pole Demand in Costa Rica
The Central American Electrical Interconnection System (SIEPAC) is one of the most ambitious energy infrastructure projects in Latin America. First envisioned in 1987, SIEPAC links the power grids of six Central American countries—Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, and Panama—through a 230 kV transmission line spanning approximately 1,800 kilometres. Today, the system operates with an interchange capacity of approximately 600 MW per direction, with plans underway to increase capacity further through additional circuits.
For transmission steel pole suppliers, SIEPAC represents a sustained, multi-country procurement pipeline. Costa Rica, as a core node of this interconnection, is at the centre of both regional integration efforts and domestic grid expansion—driving consistent demand for steel transmission poles that meet stringent technical specifications.
I. SIEPAC: The Regional Backbone
The SIEPAC transmission line runs from Guatemala to Panama, crossing six national borders and serving approximately 37 million consumers. The system is operated by Empresa Propietaria de la Red (EPR) , a regional entity established in 1998 and headquartered in San José, Costa Rica. EPR is owned 75% by the six Central American public utilities and transmission companies—including Costa Rica's ICE and CNFL—with the remaining 25% held by private investors.
The project has been supported by major multilateral financiers. The Inter-American Development Bank (IDB) has backed 12 SIEPAC-related projects worth a total of US$253.5 million—nearly 53% of the total investment in the interconnection. Regional energy transactions have grown substantially, increasing from 700 GWh in 2013 to 3,100 GWh in 2022, with more than 300 participating agents.
II. The Second Circuit: Expanding Regional Capacity
SIEPAC was originally built with provision for a second circuit, and that expansion is now underway. The SIEPAC Second Circuit project involves the construction of additional 230 kV transmission capacity across key segments:
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La Virgen (Nicaragua) – Fortuna (Costa Rica): A second circuit on the Nicaragua-Costa Rica interconnection
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Agua Caliente (Honduras) – Sandino (Nicaragua): A second circuit on the Honduras-Nicaragua interconnection
The project has secured financing of US$37.2 million** from the Central American Bank for Economic Integration (CABEI), with total project costs estimated at **US$46.4 million. This expansion will increase power exchange capacity between Honduras, Nicaragua, and Costa Rica by 300 MW.
For steel pole suppliers, this expansion translates directly into procurement opportunities. The second circuit requires new transmission line construction across 301.8 kilometres at 230 kV, including substation expansions at Agua Caliente (Honduras), Sandino and La Virgen (Nicaragua), and Fortuna (Costa Rica) . Each segment of this multinational line requires steel poles and towers that meet EPR's regional technical standards.
III. Costa Rica's Domestic Grid: The $1 Billion Modernization Program
Beyond SIEPAC, Costa Rica is executing its own ambitious grid modernization. ICE has announced a $1 billion investment plan spanning 2025 to 2034 under its Transmission Expansion Plan (PET) 2024–2034. The plan focuses on upgrading high-voltage lines at 230 kV and 138 kV, constructing new substations, and expanding existing transmission capacity.
Costa Rica's current transmission network comprises 76 substations and nearly 3,000 kilometres of high-voltage lines. Under the PET, energy transfer capacity is expected to increase by 11%, rising from 12,552 MVA in December 2024 to 13,932 MVA by December 2034.
The interconnection between domestic expansion and regional integration is direct. ICE's North-Central Transmission Infrastructure Project—a $100 million, 65 km high-voltage line with a new substation in San Rafael de Alajuela and expansion of the Garabito substation—is explicitly designed to "optimise the international exchange capacity, consolidating Costa Rica's position in the Central American Electricity Market".
IV. What This Means for Steel Pole Specifications
The combination of SIEPAC expansion and domestic grid modernization establishes clear technical requirements for steel poles in the Costa Rican market:
Voltage Class. SIEPAC operates at 230 kV, while Costa Rica's domestic high-voltage network operates at both 230 kV and 138 kV. Steel poles must be designed for both voltage classes, with electrical clearances and insulation coordination appropriate to each.
Structural Design. Costa Rica's location in the Pacific volcanic and seismic belt requires compliance with the Costa Rica Building Code and Costa Rica Seismic Code (CSCR 2010) . Design loads must cover combinations of dead loads, live loads, seismic loads, and wind loads.
Galvanized Finish. All transmission steel poles must be hot-dip galvanized to withstand Costa Rica's tropical climate and coastal salt-spray exposure. Compliance with ASTM A123 or equivalent is the industry standard.
ICE Procurement Specifications. ICE's tenders consistently specify octagonal (8-sided) galvanized steel poles, with configurations including 11 m height / 350 kgf working load and 13 m height / 400 kgf working load, with 13 cm tip diameter.
V. Market Opportunity for Steel Pole Suppliers
The convergence of SIEPAC expansion and domestic grid modernization creates a sustained procurement environment:
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SIEPAC Second Circuit requires new poles and towers across 301.8 km of 230 kV line
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ICE's $1 billion PET 2024–2034 will continue generating steel pole demand for the next decade
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Regional energy transactions grew from 700 GWh to 3,100 GWh between 2013 and 2022, demonstrating the market's vitality
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The Third SIEPAC Protocol is under discussion to modernise regional governance and attract private investment
For suppliers, the path to participation is clear: octagonal geometry, hot-dip galvanized finish, compliance with Costa Rican seismic and building codes, and alignment with ICE's established procurement specifications. The SIEPAC interconnection is not just a regional infrastructure achievement—it is a sustained driver of transmission steel pole demand across Central America, with Costa Rica at its core.
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