Connecting to nature

Tags: renewable energy connector cable ethernet SubConn GreenLink engineering junction box NEXUS optolink mulitiplexer

With a European deadline of 2020 by which 20% of power must be from renewable sources, the race is on to find the best ways of transferring energy from nature to man. Behind the highly sophisticated designs lies a wealth of equally technologically advanced infrastructure designed to transfer the gathered energy offshore to the power grid onshore. And whilst some of the technology is very new, a great deal of the infrastructure technology is based on tried and tested systems and decades of experience.

For underwater experts, the MacArtney Underwater Technology Group, the renewable energy sector is a natural progression. The group has been actively working with renewable energy projects since 2000. Much of the existing product range can be directly transferred to the offshore renewable energy market, others have been further developed, whilst some are completely new designs, tailor made for a particular purpose, project or customer.

Connecting moving systems to static cables

Designs for channelling wave, tidal or offshore wind movement vary greatly from producer to producer. Each has their different challenges to solve. One thing they do share is the fundamental challenge of reliably transferring the collected power to the mainland.

Gathering energy is just part of the equation. The range and variation in designs for harnessing the natural power of water and offshore wind movement is enormous, and devices work in vastly different ways from underwater turbines to floating anchored windmills to large sausage like devices gathering wave energy.

Common to them all, however, is that they need to transfer dynamic energy into energy that can be transferred onshore. This connection must also be able to withstand enormous loads in the harsh underwater environment.

MacArtney has developed a number of underwater connector systems designed to link the moving system with the static power cable. At one end, the connector bears the movement associated with the system, and at the other it connects to the large, less flexible high power cable linking it to the mainland power grid. The systems are also designed for split-phase installation, where cable is laid out ready on site and the system installed at a later date.

Transferring energy and essential data

Renewable energy projects often involve more than one piece of equipment installed offshore. Each collecting a certain amount of water movement power, the energy that is transferred into electricity needs to be gathered in offshore junction boxes to ensure that power is sufficiently high to prevent power loss during transfer. These junction boxes need to be able to gather very high voltages, yet be sturdy and watertight enough to survive in the offshore environment.

MacArtney has already supplied a number of tailor made junction boxes designed to just that. From more simple junction boxes to vastly complex junction box systems, they are designed to be impervious to water. The company has also designed cable arrays that connect a host of systems to power collecting points ready for transfer to the large onshore cables.

Their range of SubConn® connectors, medium and low power cables, terminations and penetrators are ideal for transferring power and data for renewable energy systems, and have already proven to be reliable in thirty years of offshore use. Specially developed, sophisticated high power connectors and penetrators have also been developed; some at the design stage include connectors rated for up to 11kV and new deep water penetrators that have a unique water block feature that can function for several months even if water has ingressed.

Keeping an eye on what’s happening below the water

Essential operational and surveillance data need to be continually sent from renewable energy systems on or under the water to onshore data systems. MacArtney cables, connectors – including the new Ethernet connector range - and multiplexers are already showing their worth, gathering and sending data vital in this development stage. They also connect control systems to valves, relays, navigational systems and a whole host of systems. The company has also supplied sonars and underwater cameras that check how equipment is faring in the harsh environment.

New areas for some, tried and tested territory for others

For companies like the MacArtney Underwater Technology Group, transferring offshore power onshore is nothing new. The technology used here and being further developed is based on decades of experience in servicing the offshore oil industry and providing deep water infrastructure. The technology may be slightly different, but the challenges posed by the underwater environment remain the same.

“Our range of products and wealth of experience is ideally suited to this new branch, and we are of course focussing our energy on remaining at the cutting edge of this new use for underwater technology.”

Advice can be crucial for finding the right solution

“We have been working with renewable energy for several years and customer are increasingly turning to us for advice as well as supply,” explains Niels Erik Hedeager, CEO for MacArtney A/S
“When all else is experimental, it can pay to rely on trusted technology.”

MacArtney A/S 30 years of experience in underwater technology solutions have specialist knowledge that is essential for providing reliable advice and tested technologies and products. Tailor made solutions can be made based on existing products, reducing lead time and ensuring optimal pricing.

Secrecy is paramount

Renewable energy is still in its comparative infancy and it has yet to be seen which designs will prove to be profitable and viable. Designs are still being tried and tested, and at this crucial stage confidentiality and secrecy are paramount. While many MacArtney designs are standard and have been around for decades, many other designs are technologically ground-breaking and made in close cooperation – often tailor made for a particular customer. Each project is treated with the utmost confidentiality.

MacArtney supply

MacArtney has already supplied or quoted the following products and systems, and offers expert advice and project management for all offshore renewable energy projects: Interconnectivity systems including special cable terminations and IL connectors, bend limiting and restrictor devices, SubConn® harnesses, “Optolink” fibre optic connectors, wet mate connectors, cables, LV and MV penetrators, special junction boxes, sensor systems including navigation, cameras and f/o structural strain measurement, rotary products for turbine axis and vertical power swivel, multiplexers, “Didson” – Dual Frequency Identification Sonar systems, environmental systems, and control systems.