Medgrid is a European initiative with the mission of exploring the feasibility of a 1,000 MW HVDC transmission project connecting North Africa to Europe. The link is approximately 600 km long in the Mediterranean Sea.
Due to the deep waters encountered in much of this region, power transmission cables will need to be laid deeper than ever attempted before, potentially to 2,500 m. The working group “Technology” at MEDGRID has identified this particular topic as a crucial area for investigation and is keen to engage with a broad cross-section of the industrial community so as to find out more.
Medgrid has commissioned a consortium of leading engineering consultants, led by CESI in association with Parsons Brinckerhoff and Intertek to undertake a feasibility study aimed at achieving data on the expected context of development of the project, bringing answers on technology and cables limits, laying methods, maintenance, costs and planning, for a generic technical feasibility of a submarine cable system with length and depth indicated above.
The main focus of study activities was on the four subject areas, namely: design and technology, installation, operation and maintenance, economic and contractual issues.
What we have done
In general, the study was given a general and high level approach so as to allow the findings to be applied throughout the Mediterranean.
To this purpose, a feasibility study was developed aimed at identifying the environmental, functional, construction, installation and testing context in which a 1000 MW, 600 km long HVDC submarine cable system envisaged to connect North Africa and Europe may develop. The scope of the system includes the submarine power cable(s), optical fibre cable and their associated accessories.
As the cable route is expected to reach unusual depths, up to some 2500m, special care was required to investigate the possible choices in terms of design concepts, technology availability, construction capability and laying methods. This is from the context of what is expected to be made available by the “market” for the implementation of the required cable functionalities in time for commissioning such a new ‘product’ for two time scenarios: Target Years 2015-2020 or 2030.
Contributions from related industries such as offshore exploration and production, telecommunications, submersible remote operated vehicle or materials science were asked to serve as validation for the consultants’ analysis.
That was accomplished through the participation in a dedicated consultation process.
As a general conclusion, the study has shown that the installation of power cables in deep waters (2,500 m water depth) is possible with some modification to current installation methods and innovative application of vessels and equipment from both the power cable and oil & gas industries.
MEDGRID aims to provide content that is relevant and ultimately of practical value to all stakeholders including the supply chain.