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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Agenor Photovoltaic Project

Photovoltaic Plants

Agenor Photovoltaic Project

Execution of the EPC contract for the Agenor photovoltaic park with a total capacity of 50 MW.

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DAS System Installation in Stadiums and Special Environments

DAS

DAS System Installation in Stadiums and Special Environments

SEMI has carried out the installation of DAS systems to provide mobile network coverage in the Camp Nou, Mestalla, and Riazor stadiums. These installations involved deploying small-sized antennas distributed throughout various areas of the stadiums, with coaxial feeder lines converging into multiple equipment rooms (Base Stations) strategically located within the facilities.Transmission to these equipment rooms […]

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Broadband Network in Peru

Broadband Network in Peru

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

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Demolish NSGA Facility

Demolish NSGA Facility

Demolición de 8 Edificios y sus Vías de Acceso, incluso desmantelamiento de las instalaciones y equipos con recuperación de materiales. Posteriormente el reacondicionamiento paisajístico de toda la zona tratada.

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PE Pecasa

PE Pecasa

Execution of the Balance of Plant (BOP) under a turnkey project for the 50 MW Pecasa Wind Farm, featuring 25 SG wind turbines of 2 MW each. The project included the construction of a new 33/128 kV substation and a 128 kV overhead transmission line (OHL).

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FTTH and FTTN Network Deployment

FTTH and FTTN Network Deployment

SEMI has been involved in the deployment of FTTH networks, with over 100,000 homes passed, and FTTN links, with more than 3,000 connected nodes. These projects add to SEMI’s extensive experience in the deployment and maintenance of fixed networks, both for operators and carriers, as well as utilities, in aerial and underground environments.

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“Cruce de Cabral” Project

“Cruce de Cabral” Project

The Cruce de Cabral project involves the construction and expansion of 3 Electrical Substations located in the southern region of the Dominican Republic:

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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 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.


18 February 2026

News

SEMI participates in the recovery of the electrical grid in Portugal after storm Kristin

From SEMI, we have traveled to our neighboring Portugal to collaborate in the recovery work of the E-REDES distribution network, affected by storm Kristin. The Northwest Electricity Delegation team has been in charge of carrying out this deployment, thus reinforcing our presence and operational capacity at a particularly complex time. Our commitment and vocation for […]