Projects - EPEC S.A.

Synchronization Equipment Adjustment Study

This project, developed by EPEC S.A. members for the later National Energy Control Center (CENCE), now ICE‑DOCSE, focused on determining optimal settings for synchrocheck relays (SC) used in Costa Rica’s national power grid. These devices are critical during switching operations to prevent harmful transients when reconnecting transmission lines.

The report reviews international methodologies and selects the one proposed by Dr. Jan Machowski due to its practicality and reliance on static models rather than dynamic EMTP simulations. It uses four protection‑based criteria to calculate the maximum allowable phase angle difference for safe reconnection.

The selected method was implemented in Python, validated with IEEE 14‑bus cases, and applied to 12 real‑world scenarios using regional system data. Results showed that most synchrochecks could be safely configured with angle thresholds above 15°, although some lines required more restrictive values (e.g., 4.9° for Rio Claro to Progreso tramission line RCL-PRO).

A user‑friendly software tool was developed to automate this methodology, compatible with DOCSE’s simulation tools and designed to export results in Excel format to facilitate analysis.

Contact: Anabelle Zaglul Fiatt – ICE‑DOCSE

Impact of Residential PV Generation in Distribution Grids

This consultancy developed by EPEC S.A. members aimed to analyze the technical, economic, and regulatory conditions for implementing distributed generation (DG) in Costa Rica, especially focused on CNFL (Compañía Nacional de Fuerza y Luz) and other utilities.

Baseline and Technology Analysis: The study reviewed DG programs by ICE CNFL, identifying photovoltaic (solar) as the most viable and widespread technology. Main barriers to DG adoption included technical knowledge gaps, high equipment costs, and limited monitoring infrastructure. Financial and operational impacts on utilities from DG interconnection were minimal at current penetration levels.

Municipal and Cooperative Utilities: These utilities showed limited interest and capacity for DG, citing lack of studies, staff training, and regulatory clarity. While a few had allowed ad‑hoc installations, they generally awaited regulatory guidance (e.g., AR‑NT‑POASEN) before wider adoption.

Market and Potential Assessment: A geographic and customer‑type‑based model estimated high DG potential, especially in wealthier areas like Escazú and Curridabat. Estimated technical potential reached up to 245 GWh/year, or 7.4 % of CNFL’s 2014 sales.

Financial Impact on CNFL: DG leads to reduced income for CNFL due to lower energy sales. However, DG can reduce losses and transmission costs. Financial viability for residential customers is weak under current tariffs, with long payback periods except for large consumers or under ICE’s tariff structure.

Implementation Plan and Tariff Reform Proposals: Recommendations include addressing technical barriers, improving monitoring, and revising tariffs to reflect cost breakdowns. A mixed fixed‑variable tariff is proposed, including demand‑based charges for commercial/industrial clients, and shared peak cost among residential users.

Grid Impact Simulation (Circuit 2203, CNFL): Using OpenDSS, simulations revealed that high DG penetration could cause overvoltage issues in secondary networks, especially beyond 3000–5000 kW of installed capacity. Other risks like imbalance and overloads were found to be minor. Reinforces the need for updated planning and coordination tools rather than blanket capacity limits (e.g., the 15 % feeder cap).

Policy and Regulatory Recommendations: Suggests that ARESEP revise the technical and tariff frameworks to align with the realities of DG. Encourages creation of financial mechanisms to make DG more accessible, particularly for residential users.

The report concludes that distributed generation, especially solar PV, has high potential in Costa Rica but faces technical, economic, and regulatory challenges. A strategic combination of technical planning, capacity building, and fair tariff reform is essential to enable a sustainable and large‑scale adoption of DG in the country.

Contact: Raúl Fernández Vásquez – CNFL

EVs Impact on Distribution Networks of Dominican Republic

As part of a trilateral cooperation project between Germany, Costa Rica, and the Dominican Republic, EPEC S.A. members contributed to a technical study assessing the impacts of electric vehicle (EV) integration into the medium- and low-voltage distribution networks of two major utility companies in the Dominican Republic (EDENORTE, EDESUR).

The project involved the development of geo-referenced electrical network models using Python, QGIS, and OpenDSS, and the simulation of different EV penetration scenarios through time-series power flow analysis .

Using statistical distributions derived from real-world EV usage data in Costa Rica, the study simulated charging behaviors—battery state‑of‑charge, connection time, and charger power levels. These simulations were run using OpenDSS with 15-minute resolution time-series power flow analysis over multiple projected penetration levels (10%, 30%, 50%) through the year 2030. Key technical indicators such as voltage violations (below 0.95 pu), transformer overloads, and conductor ampacity limits were tracked to assess network stress.

Results showed that under high EV penetration, the most critical issues were low voltage conditions and transformer overloads—particularly at night when most charging occurs. The study proposed and tested several mitigation strategies, including dynamic demand control schemes and local power factor correction via EV chargers.

A disconnection-based demand management strategy, which prioritized users with the lowest battery charge, was found effective in eliminating transformer overloads and reducing voltage issues. In parallel, injecting reactive power locally at the EV charger terminals proved highly effective in improving voltage profiles without requiring major infrastructure investments.

To complement operational mitigation, a methodology for network reinforcement planning was developed. It quantified the investment required to eliminate overloading issues entirely and produced investment‑risk trade‑off curves. These tools enable utilities to prioritize investments based on their desired level of risk exposure. Notably, the analysis revealed that most of the reinforcement cost would be concentrated in transformer replacements rather than conductor upgrades.

Overall, the study provided a detailed and adaptable modeling framework for utilities to evaluate and prepare for the growing demand of electric mobility. The findings emphasize the importance of strategic planning, flexible control mechanisms, and targeted infrastructure reinforcement to ensure reliable and efficient integration of EVs into the distribution grid. The outputs of this work are expected to directly inform the national roadmap for EV infrastructure deployment in the Dominican Republic.

Contact: Nataly Montezuma – Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH

Connection of Industrial Facility with DG to Transmission

Industrial de Oleaginosas Americanas S.A. (INOLASA) proposed a direct interconnection to Costa Rica’s national transmission grid at the Barranca substation (138 kV). The project included the development of a 2.3 km underground medium-voltage line and installation of a new transformer, enabling the integration of INOLASA’s biomass-based generation units (1 MW and 4 MW) into the transmission system.

EPEC S.A. was commissioned to conduct a comprehensive interconnection study, following the technical standards and regulatory requirements of the Costa Rican power sector. The analysis included:

Load Flow Simulations to evaluate voltage profiles and loading conditions of transmission lines and transformers under various demand scenarios and contingencies.

Short‑Circuit Analysis to determine the impact of the project on fault levels and equipment protection coordination.

Transient Stability Studies to ensure that the system and the embedded generators remain dynamically stable during disturbances.

All studies were performed using advanced simulation tools tailored to the TSO

Requirements, incorporating detailed electrical models of the proposed equipment and existing infrastructure. Historical demand data and system configurations were taken into account to reflect realistic operating conditions.

The simulations and the analysis demonstrated that the project does not introduce adverse effects on voltage levels, line or transformer loading, or system stability. Minor increases in fault levels were observed but remain within acceptable limits. Overall, the project was found to be technically compatible with the transmission network under all evaluated conditions.

Contact: Jose Pablo Alvarado – INOLASA

Design and economics of EV fast charger corridors in Ecuador

The project was framed within the technical and institutional support provided by the Inter-American Development Bank (BID) and the Ministry of Transportation and Public Works (MTOP) of Ecuador, aiming to promote electromobility as part of the country’s decarbonization commitments. EPEC S.A. colaboradores contributed significantly through their technical and strategic expertise. The work focused on analyzing the existing conditions and developing a national-level plan for electric vehicle (EV) infrastructure deployment, considering international experiences and local regulatory frameworks. This initiative aligns with Ecuador’s National Determined Contributions (NDCs) and long-term plans to reduce emissions, incorporating lessons from Costa Rica, China, and Germany, among others.

GIS-Based Location Methodology: The technical component led by EPEC S.A. included the development of a GIS-based computational tool in Python to determine optimal locations for public EV charging stations. This tool integrated diverse geospatial layers—such as road networks, bus routes, medium-voltage three-phase grids, traffic patterns, topography, and environmental risks—to identify strategic sites. Simulations were conducted using energy consumption models for EVs (like the Nissan Leaf and EBUSCO 2.2 buses), incorporating variables like elevation profiles and vehicle mass. The methodology ensured national coverage by 2040 with 10,000 EVs projected by 2025, requiring over $1.6 billion in phased infrastructure investments.

Business and Economic Framework: EPEC S.A. colaboradores also contributed to the economic analysis and business model evaluation, comparing international models from the U.S., China, Norway, Chile, and Colombia. Two tailored models were proposed for Ecuador: one with public ownership (via electric distribution utilities) and another with private operators. A Microsoft Excel tool was built to simulate financial outcomes under pessimistic, base, and optimistic scenarios, analyzing factors such as subsidies, tax exemptions, investment costs, and usage projections. Both models showed viability under base and optimistic conditions at a 20-year horizon, while the pessimistic scenario required stronger fiscal incentives.

Strategic Roadmap for Implementation: The final section of the report presented the ENIRRVEE roadmap (Estrategia Nacional de Implementación de Red de Recarga de Vehículos Eléctricos del Ecuador), structured into three phases: 2025—2026 (planning and regulatory setup), 2026–2030 (initial deployment and evaluation), and 2030–2040 (expansion and optimization). The roadmap emphasized institutional coordination, public-private partnerships, education, and user behavior regulation (e.g., charging time limits beyond 80 %). Key milestones include the launch of a unified management platform, a national network of 500 fast chargers, and at least 10 high-capacity corridors integrated with mass tranfer.

The project represents a pioneering effort in Latin America to integrate technical, economic, and policy frameworks for electromobility. It provides Ecuador with a clear and actionable path to achieve its zero-emission transportation goals. The combination of robust geospatial analytics, realistic financial modeling, and phased policy actions positions the country to meet both environmental and mobility targets. EPEC S.A.’s colaboradores’ interdisciplinary approach and the tools developed throughout this project leave a lasting foundation for future implementation and replication in similar contexts.

Contact: Veronica Briceño – MTOP

PV + BESS + Hydro + Diesel Microgrid in Coco’s Island

The Parque Nacional Isla del Coco (PNIC), located approximately 550 kilometers off the Pacific coast of Costa Rica, is a UNESCO World Heritage site known for its rich marine biodiversity and critical conservation role in the Eastern Tropical Pacific. Due to its remote location, the park requires self-sustaining infrastructure, including its own electrical systems. EPEC S.A. provided technical services to support the modernization of this electrical infrastructure through a series of three integrated projects commissioned by the Fundación Amigos Isla del Coco (FAICO).

The first project, executed in 2023 by EPEC S.A. collaborators in collaboration with the University of Costa Rica, involved a comprehensive diagnostic and modernization study of the PNIC’s electrical system. The study assessed the operational state of existing generation sources, including hydroelectric, diesel, and photovoltaic systems, and proposed measures to improve reliability and sustainability. Field visits revealed critical degradation in components due to saline exposure and outlined a path for integrating the site’s isolated microgrids. The report emphasized opportunities for enhancing redundancy and scaling up demand support using renewable sources while avoiding excessive capital investments.

The second phase entailed the development of technical specifications, construction plans, and a full set of terms of reference for the execution of the proposed works. This included architectural and civil modifications, selection criteria for materials, installation methodologies, and environmental compliance standards. Detailed technical components covered battery energy storage, PV generation, hybrid system integration, monitoring, and grounding schemes. An implementation schedule was defined along with the project budget. EPEC S.A.’s role extended to designing this robust framework, ensuring compliance with Costa Rica’s electrical code (NEC 2020), and coordinating stakeholder engagement including FAICO and SINAC.

Finally, the third project consisted of technical supervision during the construction and commissioning stages of the electrical microgrid reinforcement. EPEC S.A. was responsible for overseeing adherence to specifications, validating the quality of materials and workmanship, and ensuring timely and compliant execution of all project elements. The company was tasked with issuing progress inspection reports, including at 50% and final delivery stages, and managing the approval of disbursements according to measurable milestones. This supervisory role ensured that the project met the environmental, technical, and operational standards expected for such a critical conservation infrastructure.

Contact: Gabriel Rodríguez – FAICO

Normalized catalog for distribution system construction

This project consisted in a normalization of the constructive practices for distribution system projects of all 7 distribution utilities in Costa Rica. The Regulatory Authority of Public Services in Costa Rica (ARESEP) fixes the energy tariffs that utilities charge to customers, based on their operational costs. Part of those costs are the construction of distribution system projects.

The collaborators of EPEC S.A. worked along with the University of Costa Rica in order to build a list with the most complete constructive units (lines, transformers, protection devices, poles, voltage regulators, amongst others), which ARESEP uses to guide the cost revision for the tariffs.

Along with the 800+ pages catalog and the 600+ possible materials, a computational tool was created to facilitate cost calculation process, which output the list of materials, along with man and machine hours for each project.

Contact: Edgar Cubero – ARESEP