Spanish Consortium to Advance Floating HVDC Converter Stations

Spanish engineering and technology group SENER is leading a multi-partner research and development programme named CONECCMAR — an acronym for CONexión Eléctrica en Corriente Continua MARina (Marine Direct Current Electrical Connection) — aimed at advancing the next generation of offshore HVDC grid infrastructure in Europe.

The consortium comprises SENER alongside Seaplace, the Instituto de Investigación Tecnológica of Universidad Pontificia Comillas, CoreMarine, Deep Insight Blue, and Ravenwits. An advisory board made up of Acciona Energía, Naturgy, and Navantia Seanergies will provide industrial guidance to align the programme's technical developments with current and future challenges in the energy sector. Spanish grid operator Redeia has also expressed its interest in the project through a letter of support.

CONECCMAR is structured around three primary lines of applied research over a two-year period. The first focuses on advanced floating HVDC substations based on next-generation concepts. The second addresses compliant fixed structures adapted for deep-water applications. The third targets hybrid multi-terminal offshore HVDC interconnection nodes. Together, these workstreams are intended to establish the technical and functional foundations for offshore electrical technologies capable of operating in highly demanding marine environments.

The proposed solutions are designed to support the integration of both fixed-foundation and floating offshore wind farms through combined HVAC and HVDC transmission systems. The hybrid interconnection nodes are intended to enable a single offshore node to simultaneously handle renewable energy export and transnational electrical interconnection, improving grid resilience and flexibility.

The project is co-financed by the Community of Madrid through its CTVI programme and the European Regional Development Fund (FEDER), under a scheme supporting strategic public-private R&D cooperation in consortia.

SENER, a Basque engineering group, has been active in the offshore wind and floating substation space through a number of related initiatives, including the ECOFOSS floating marine substation prototype developed with Navantia Seanergies, and the HiveWind semi-submersible floating wind platform developed with Nervión-Naval Offshore.

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