On and under the surface

TC work supports a wide range of technologies to convert marine energy into electrical energy

By Morand Fachot

As the quest for a greater share of renewables in the global energy mix gathers momentum, marine energy is emerging as a huge and potentially unlimited source of power. IEC TC (Technical Committee) 114: Marine energy, prepares International Standards for this promising sector.

Array of tidal turbines (Photo: Siemens) Array of tidal turbines (Photo: Siemens)

Recent TC for developing technologies

Harnessing marine energy presents particular challenges, which explains why investments in this sector have been relatively modest so far compared to efforts in other renewables.

As oceans represent a huge source of power that can be partly converted into electrical power, the drive to develop existing technologies, or new ones, led to the creation of IEC TC 114 in 2007.

Its title: Marine energy – Wave, tidal and other water current converters, gives a clear indication of its scope, although the TC adds that it is open to "other conversion methods, systems and products". However, it also specifically excludes "tidal barrage and dam installations", which are covered by IEC TC 4: Hydraulic turbines.

TC 114 remit is to prepare International Standards that allow technologies developed for marine energy conversion to evolve beyond early stages of developments, in which they have remained for some 30 years, to reach full commercial deployment.

Wide-ranging tasks

To achieve this objective TC 114 has adopted a structure that brings together 96 experts from 14 Participating countries and 8 Observer countries into 9 PTs (Project Teams) and 3 AHG (ad hoc Groups).

The TC prepares International Standards that aim to address essential aspects of marine energy conversion such as:

  • system definition
  • performance measurement of wave, tidal and water current energy converters
  • resource assessment requirements, design and survivability
  • safety requirements
  • power quality
  • manufacturing and factory testing
  • evaluation and mitigation of environmental impacts

The TC's work so far has led to the publication of three TS (Technical Specifications) that cover terminology, and power performance assessment of wave and tidal energy converters. More are due to be released in the coming months.

Its current work programme includes the preparation of publications that cover Guideline for design assessment of OTEC (Ocean Thermal Energy Conversion) and the assessment of mooring systems for marine energy converters as well as for wave and tidal energy resource assessment and characterization.

Paving the way for large-scale deployment

As marine energy conversion projects now shift from research and prototype schemes to grid-connected commercial deployments, the need for standardization is obvious. International Standards will help reduce the technical and financial risks associated with the wide range of new technologies and enable a quicker adoption of marine energy conversion.

To prepare these Standards TC 114 set up PTs for design, device performance and resources assessment. It also set up a PT for electrical power quality requirement issues to address grid connection and integration, and a PT to move forward on OTEC.

TC 114 is now dealing with the full spectrum of technical issues from scale testing to grid integration.

Since marine energy projects share some technical issues with offshore wind farms on common elements, such as mooring and floating installations, TC 114 is liaising with TC 88: Wind turbines.

The IEC's CAB (Conformity Assessment Board set up WG (Working Group) 15 to develop a Framework for an internationally standardized approach of addressing the conformity assessment needs of the marine energy industry.

Obvious customers for TC 114 Standards are the industry (device and project developers and manufacturers), test centres, certifying bodies and regulators, national and local authorities, and potential investors.

Considering the publications already issued, the projects that have been launched or are near completion it is safe to assume that TC 114 work will give the marine energy industry and utilities all the necessary Standards to manufacture and deploy the best possible systems.

Array of tidal turbines (Photo: Siemens) Array of tidal turbines (Photo: Siemens)
Floating oscillating water column wave energy converter (Photo: Ocean Energy Ltd) Floating oscillating water column wave energy converter (Photo: Ocean Energy Ltd)
AR 1000 tidal turbine being loaded onto a ship (Photo: Atlantis Resources Corporation) AR 1000 tidal turbine being loaded onto a ship (Photo: Atlantis Resources Corporation)