Energy

Leading the change towards a more sustainable future.

Líneas de Negocio - Energía

Telecommunications

Advanced solutions for a constantly evolving market.

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Special Projects

Transforming major challenges into unique solutions.

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Energy

Líneas de Negocio - Energía

Telecommunications

Special Projects

Welcome to SEMI

Tradition, experience, and future.

Over 100 years driving the electrical and industrial sectors through innovation, excellence, and quality in all our services.

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Key Figures 2025

0M€

Annual Production

Professional Employees

Our Clients

Clients with whom we have shared successes and goals.

Business Lines

Líneas de Negocio - Energía

Energy

The energy sector faces increasingly pressing challenges, such as the need to address growing energy demand driven by consumption in the most prosperous countries and the emerging needs of developing nations.

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Telecommunications

SEMI began its Telecommunications activity in the 1950s, participating in the construction of Television, Telephone, and Radio networks. Today, we have extensive experience in deploying Fiber Optic Networks and Mobile Telephony Networks.

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Líneas de Negocio - Telecomunicaciones
Líneas de Negocio - Telecomunicaciones

Special Projects

Over time, SEMI has excelled in the execution of specialized civil works, with a particular focus on projects for the Armed Forces, industrial facilities, and demolition and dismantling works, among others.

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Featured Projects

Explore our most outstanding projects

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Distribution Networks

High/Medium/Low Voltage Electrical Distribution

Distribution Networks

Maintenance and execution of new works on Medium Voltage (MV), Low Voltage (LV), and Overhead Lines (LAT) distribution networks in the Asturias area.

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225 kV Line Central and Associated Substations in Nouakchott

Transmission Lines

225 kV Line Central and Associated Substations in Nouakchott

Design, supply, and assembly of the 225 kV Central Dual — OMVS line (Nouakchott) and associated electrical substations.

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225 kV Line Central and Associated Substations in Nouakchott

225 kV Line Central and Associated Substations in Nouakchott

Design, supply, and assembly of the 225 kV Central Dual — OMVS line (Nouakchott) and associated electrical substations.

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Live-Line Work in the Province of León

Live-Line Work in the Province of León

Live-Line Work in the Province of León

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Rehabilitation of Distribution Networks

Rehabilitation of Distribution Networks

Replacement and extension of the Medium Voltage (MV) network, installation of transformers, expansion of the Low Voltage (LV) network, and installation of prepaid and postpaid meters.

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Broadband Network in Peru

Broadband Network in Peru

SEMI has participated in the construction of 140 nodes to provide broadband network access in the regions of Cuzco and Ayacucho. The project is part of the strategic initiatives of Peru’s Ministry of Telecommunications, aimed at delivering fiber optic connectivity to rural areas to provide coverage for both individuals and institutions. To date, SEMI is […]

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Distribution Networks

Distribution Networks

Maintenance and execution of new works on Medium Voltage (MV), Low Voltage (LV), and Overhead Lines (LAT) distribution networks in the Asturias area.

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SEMI Around the World

México

Alemania

Francia

República Dominicana

Rumania

El Salvador

España

Panamá

Grecia

Perú

Emiratos Árabes Unidos

Chile

Uruguay

Arabia Saudita


21 September 2026

News

SEMI renews its three Compliance certifications with Bureau Veritas

SEMI has successfully renewed its ISO 37001 (Anti-Bribery Management System), UNE 19601 (Criminal Compliance Management System) and UNE 19603 (Compliance Management System for Competition Law) certifications after successfully completing the audit process carried out by Bureau Veritas. The renewal of these certifications reaffirms the strength of our Compliance model and SEMI’s commitment to ethics, transparency, […]


21 April 2026

News

Safety Awareness and Reflection Sessions

On March 25 and 26, SEMI suspended its activity in Galicia and León to hold awareness and reflection sessions on safety, with a strong focus on prevention and raising awareness. These sessions, held in Ourense and León, were attended by our CEO, Maikel García, as well as Berta Domínguez, HSQ Director, and Julián de Bustos, […]


21 April 2026

News

In line with its commitment to young talent

SEMI is once again taking part in Leoni4, a meeting forum that brings together university students from the Schools of Engineering and companies from the province of León, allowing them to learn first-hand about the companies where they can develop their professional careers.