Published: December 17, 2015

ocean energy


Although most technologies are still at pilot stage; with “oceans of energy” out there, this renewable resource cannot be ignored. Tractebel Engineering’s involvement goes deep, helping to engineer pilot projects, and via the European Technology and Innovation Platform (ETIP) Ocean, chaired by one of our own marine energy experts.


In recent years experts have been closely following, and auditing, technological developments in Ocean Energy in which 4 key technologies, drawing on different aspects of ocean energy potential, are leading developments. Read more.


In the interest of raising support at European level for the ongoing development of this clean energy sector, representing both Tractebel Engineering and the Division Research and Technologies (DRT) of its holding Group ENGIE, Fiona Buckley chairs the collaborative European Technology and Innovation Platform (ETIP) Ocean – leading to increased awareness and essential grants needed for the industry to take ocean energy forward as a viable energy alternative. Read more.


Pilot projects are underway in several countries in Europe and worldwide – with many on the brink of moving forward from single small test model to full-scale models and even arrays (several machines connected to the grid).  A number of our specialists have assisted with the engineering studies. Read more.




The world’s oceans offer many “free-fuelled” kinetic, thermal and chemical energy opportunities through; the movement of tides and currents, wave oscillation, temperature variations and salinity. Potentially accessible to a third of the world’s population, this bounty of contained energy, noted for many years, but less developed than other renewables (wind and solar), is now getting the attention it deserves. Development is focussed on 4 different modes of ocean energy capture:

Ocean Energy


1. TIDAL: Following on from developments in wind power, Tidal Energy Converter (TEC) technology is based on the principle of using tide movements and ocean currents to turn turbines to produce electricity. The concept can be down-scaled to canals and rivers.

 TECs are the most advanced Ocean Energy technologies. Multiple designs for tidal turbines have been developed around the world. To date no one technology has emerged as a leader but there is a convergence in 3-bladed vertical turbines. Nevertheless, several other different designs exist: vertical and horizontal axis turbines, bi-directional turbines, multiple blade turbines, open-ring turbines, semi-floating turbines etc.  The first foreseen plants in Europe, MeyGen (UK) and Raz-Blanchard (FR) will both deploy 3-bladed vertical TEC’s (in total from 3 different manufacturers).

2. WAVE: Using oscillation of the ocean surface, the main idea is to have a floating, hinged device which is worked by the swell of the waves – the up-down differential working the hinges creating hydraulic power used drive a hydraulic motor which turns the generator. Other hinged devices work with sea surge and concepts where waves are used to fill reservoirs which drain via a turbine fitted outlet are also under consideration.

A concept starting from scratch, technology is still very developmental. Floating devices of many shapes and sizes are being tested. An ongoing challenge has been to design first small prototypes able to survive extreme wave conditions for long enough for developers to determine their long-term feasibility – as always, costs of building prototype models, and storm damage forcing regular returns to the drawing board, are prohibitive.

3. OTEC: Ocean Thermal Energy Conversion generates electricity through conventional heat exchange; exchanging heat from shallow sun-warmed water from the ocean surface with extremely cold water from the deep ocean.

Ocean Thermal Energy Conversion is not a new concept or technology, but its use on such a large scale is. Today’s technological developments primarily concern pipe strength. Projects have been achieved in Honolulu and Sea Water Air Conditioning feasibility is being considered in places like Reunion Island and Tahiti and a project is already underway in Marseille.

4. SALINITY GRADIENT: Electrochemical processes aim to capture the natural energy gained in mixing saltwater and fresh water. Two methods under study are reverse electrodialysis and pressure retarded osmosis. Pressure retarded osmosis is leading the way in Europe utilising a process where fresh water and pressurised seawater fill tanks separated by a semi-permeable membrane. As fresh water molecules pass to the seawater side, both the volume and head pressure of the sea/brackish water increases to a point where it is discharged with force through a turbine.

Although it has been discussed since the 1970’s, actual research into Salinity Gradient concepts has only been quite recent. A first pressure retarded osmosis prototype is already operational in Norway.





TP Ocean is one of several European Technical and Innovation Platforms (ETIP); falling under the category of energy, with direct advisory responsibility to the EU Director Generals of Research and Technology Development (DG RTD) and Energy (DG Ener).


As with all ETIPs, the TP Ocean is a voluntary and transparent collaboration of involved industrial partners and stakeholders created in 2014. Recognised by the European Commission as key actors in driving innovation, knowledge transfer and European competitiveness, it develops research and innovation agendas for action at EU and national level to be supported by both private and public funding. It mobilises stakeholders to deliver on agreed priorities and share information across the EU. Working together, platform members also help deliver solutions to key challenges.

“What we are ultimately doing is facilitating the transmission of messages between industry and the European Commission, ministers and member states, around what is needed to facilitate Ocean Energy to create a functioning and fully contributing new renewable energy sector. We also participate in a lot of conferences to share what is being done by the platform and communicate to the energy market in general on both political and technological exchanges and the potential that Ocean Energy holds for different players.”

Fiona Buckley – Vice President Business Development Power & Gas – Tractebel Engineering.



1. STRATEGIC RESEARCH AGENDA: compiling information on the strategic pathway; defining research priorities for the next 5 – 10 years and establishing industry consensus and credibility, to develop the sector through the efficient, strategic use of public RD&I funding – leading towards commercialisation.

2. HORIZON 2020: working as an advisory body to the European Commission on research priorities for the bi-annual Horizon 2020 work programme – outlining future calls for proposals.

3. OCEAN ENERGY ROAD MAP: the production of a strategic roadmap by the end of 2016 for the commercialisation of this sector. The roadmap is being produced through a Forum, reporting to the DG MARE   (The Directorate-General for Maritime Affairs and Fisheries), with 3 work streams: Technology, Finance and Environment & Consenting – with tasks and feedback split between experts coming from the TP Ocean’s 250 stakeholders. Tractebel Engineering’s input is valued in guiding the Forum and work streams.

“The challenge for all first movers in a new sector is it is a big investment with no clear timeline as to when you will get it back. Our work in the TP Ocean is going a long way to answer that question for stakeholders. Progress is being made all the time – particularly now the TP Ocean has the attention and interest of the European Commission, which has dedicated 63€Million (2014-2016) for Ocean Energy development. In support of ENGIE, which embraces energy transition in its strategy, and all of our other clients with ocean energy interests, we are committed to being an effective partner in the process of moving forward.”

Fiona Buckley – Vice President Business Development Power & Gas – Tractebel Engineering.



Drawing on expertise and experience gained in many years involvement in off-shore wind projects regarding; underwater foundations, off-shore grid connections, connectivity of machine arrays as well as project management, contracting, audits, levelised cost of energy studies, Tractebel Engineering is involved in many ocean energy pilot projects at different pilot phases. Typical projects include:


Pilot Project Raz-Blanchard


Pre-feasibility study, technical audit and foundation design assistance on a project testing a small array of one type of turbine devices to investigate installation and to assess how devices interact and feed energy into the grid – ahead of potentially up-scaling to a larger pilot project.


Pre-feasibility study and measurement campaign to develop a tidal/wave park in Latin America. Selection of potential sites based on wave, tidal and bathymetrical data; energy yield assessment; grid connection and accessibility to the site. Calculating energy production for devices still under development and ranking the sites for each potential technology.


Feasibility studies looking at the future potential integration of tidal energy arrays within an offshore wind farm.


Feasibility, modelling, bathymetric survey, dredging and anchoring studies etc. with marine engineering subsidiary IMDC, investigating Ocean Thermal Energy Conversion projects to deliver Sea Water Air-Conditioning to Papeete’s Hospital – Tahiti and major public buildings in St Denis – Reunion Island.


Discover more about Tractebel Engineering’s work in ocean energy and other renewable energies:

Group power

Within the ENGIE Group, Tractebel Engineering is often called on by the Group’s Division Research and Technologies (DRT) to follow, investigate and support new technologies supporting renewable energies and energy transition. It’s a win-win situation as early involvement in new sectors gains us, as engineers, technological insights we are able to share with all of our clients.

Floating wind

Although not classed as Ocean Energy, Floating Wind prototypes are also being developed with a view to taking advantage of close to the shore, deep water areas available for wind farms. Yet another technology our experts follow and support.

More information

Fiona Buckley – Vice President Business Development Power & Gas – Tractebel Engineering / Chair – TP Ocean (Sponsored by DRT – ENGIE)

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