Interview: Atir’s opposing blades direct to turn the tides

Atir floating tidal platform deployed for trials in Galicia (Photo: Magallanes Renovables)

 
Tidal Energy Today has talked to Alejandro Marques de Magallanes, General Director of the Spanish tidal energy developer Magallanes Renovables, to get an update on the most recent activities related to the development of the floating tidal energy platform named Atir.

Magallanes Renovables’ tidal energy generating platform on the first sight strongly resembles an ordinary ship.

Alejandro Marques de Magallanes (Photo: Magallanes Renovables)

However, hidden from the view below the surface of the water, the platform will soon receive its distinguishing mark – the power generating equipment, whose tidal turbine blades span 19 meters in diameter and bring the platform’s power generating capacity to 2MW.

The Atir device is currently anchored in Ria de Vigo estuary, located in the Spanish region of Galicia, where it will be fitted with two-side oriented turbine blades at the end of September to expand the scope of trials underway since July 2017.

The 2MW platform is being developed as part of the Ocean 2G project, which involves an international group of companies and organizations, who jointly aim to validate and pre-certify Magallanes’ second generation tidal solution to accelerate its commercial uptake.

One of the partners in the project is the European Marine Energy Centre (EMEC), located in Orkney in Scotland, where Magallanes plans to probe its Atir platform in real sea conditions in 2018.

Mr. Alejandro Marques de Magallanes can you explain in more detail how Magallanes Renovables’ floating tidal stream technology works?

Atir tidal platform scheme (Image: Magallanes Renovables)

Our Atir platform is based on a combination of existing technologies in the wind power sector and the marine industry. This has enabled the development of the first easy-to-moor floating platform with an engine room. Our technology also takes advantage of a pitch control system for the blades in order to achieve the maximum performance during tidal stream energy capture.

The platform has a rated power of up to 2 MW – this capacity is reached by means of two rotors, 19 meters in diameter, placed opposite each other at a depth of 15 meters.

The rotors are counter-rotating, to make the most of the existing potential energy. The system will deliver the electricity from the transformer output by means of a fast connection on the deck of the Atir platform.

Can you offer us more information about the development of the Atir prototype device?

Since 2006, when we began with this research project, the main objective was to efficiently obtain energy from the sea. All related tasks, trials – and even failures – which have been carried out so far, were aimed at developing this full-scale platform. But that is not the end of the project; this platform will let us validate all systems comprising the device and will serve as a model for the design of a commercial floating platform.

Atir platform can be divided into in three blocks. The upper block, which is the most visible one of the floating platform, is 45 meters long and has a beam of 6 meters. In this upper block the engine room is located, as well as the control system, communication and safety equipment. This block has also been designed for accommodating the converters and transformers, necessary for delivering electric power.

Below the upper block it can be found what we call the mast. It is a 12-meter-high structure which fixes the higher block to the lower block. The mast works as the keel in a ship, at the same time it allows for access of people and the movement of equipment to the nacelle. Finally, the lower block or nacelle, is 16 meters long and has a diameter of 3 metres. In this block generators, gearboxes and pitch control systems are housed.

The device was deployed for initial trials at Vigo estuary this summer. Can you tell us more about the performance of the device during testing?

We are now undertaking anchoring tests and once completed we will be ready for starting towing tests. In those tests we will obtain the first results about the behavior of the device with regard to power generation and, above all, in terms of operational security. The objective is to verify all aspects of the platform on the operations.

The tests undertaken in the 1:10 scale model have enabled us to obtain satisfactory results in terms of performance during generation, but trials in the full-scale Atir platform will be those which will allow us to get useful results for the optimization of the platform.


(Photos by Magallanes Renovables)

Can you give us an estimate on the date of Atir’s deployment at EMEC in Scotland, and what will be the purpose of the trials there?

For the time being we are involved in the design of the mooring system and we have engaged an international team in it. Atir can’t be deployed in Scotland yet, since such design has not been finished. The aim of the trials at the EMEC is to analyse the behavior of the platform under real conditions and to collect data about power generation, from a quantity and quality point of view.

What distinguishes the 2MW Atir platform from other floating tidal solutions with the same capacity already introduced by other developers?

The main advantages of Atir platform lie in the following aspects. On the one hand, the implementation of a pitch control system for the blades, which allows their rotation in such a way that they can always operate at the optimal generation point. In this way, it is also possible to regulate power generation and, above all, respond in emergency situations.

On the other hand, there is an engine room, which enables all maintenance works being done quickly and with neither special equipment nor unconventional vessels, making it even possible the replacement of most critical machinery, such as generators.

Finally, the control system of the platform, which facilitates an intelligent management of the platform from a control center onshore; this also grants the operation and maintenance of the platform in such a way that its safety, as well as the safety of adjacent devices, is ensured during the generation mode.

Can you tell us more about plans for further advancement of Magallanes Renovables’ technology, and the markets targeted for its tidal platforms?

The development of Magallanes Renovables’ Atir platform entails equipment which requires continuous innovation. At present, we are totally focused on Ocean 2G project but, understandably, all needs arising from the project are analysed as possible lines of future development.

Our technology can operate at depths up to 100 meters. Therefore, we expect that we could adapt to any site which had an attractive power generation potential.

How do you predict tidal energy sector will develop in the future, and what needs to be done to accelerate its growth?

That’s a difficult question. At this moment, the market needs a product, and we – the stakeholders – are trying to develop the best technology.

Once this way of generating energy is found, we will be in the position of assessing both the economic optimization and the energy demand which allow the market to grow interestingly.


Interview prepared by Amir Garanovic