Powerful and quick as the wind

Wind power is set to gather more pace with the growing reliance on renewable energies

By Morand Fachot

As countries throughout the world try to increase the share of renewable energies (REs) in their electricity generation portfolio, wind power has surfaced as the most cost-effective and fastest-growing new RE sources in recent decades. Standardization work by IEC Technical Committee (TC) 88: Wind turbines, has made this expansion possible.

London Array offshore wind farm Offshore wind farm installation (Photo: London Array Ltd)

Wind blowing coal away – in the long term

Environmental concerns are driving governments throughout the world to curb the use of fossil fuels. Particular efforts to achieve this focus on the use of REs in the electricity generating sector, which is a major producer of CO2 and other greenhouse gases.

RE, in the form of hydropower, has long played a major role in electricity production. It is now being complemented by “new”, non-hydro RE sources, with wind power having emerged as the most cost-effective to date. This has been driving its rapid growth since its introduction as an electricity-generating alternative in the late 1990s.

Installed wind power capacity increased from 17,4 GW in 2000 to 369,6 GW in 2014, an average compound annual growth rate of 24,4% per year, according to Global Wind Energy Council (GWEC) data.

This trend is set to continue as wind power is seen as offering the greatest potential for growth in the renewable energies’ domain. In its World Energy Outlook 2014 the International Energy Agency (IEA), forecasts that cumulative capacity addition of wind power will represent nearly 50% of new RE sources addition between 2014 and 2040.

The IEA sees REs (including hydropower) overtake coal around 2035 as the leading source of electricity generation.

TC work driving wind success

Extensive work by IEC TC 88 experts paved the way for the launch of wind power and has underpinned its growth since it was rolled out.

TC 88 was created in 1987, quite a few years before wind power became a major source of electrical energy at the global level.

Its scope, last formulated in 2002, is to prepare International Standards for wind turbines that "address design requirements, engineering integrity, measurement techniques and test procedures. Their purpose is to provide a basis for design, quality assurance and certification. The standards are concerned with all subsystems of wind turbines, such as mechanical and internal electrical systems, support structures and control and protection systems".

TC 88 International Standards, developed by over 580 experts, have made it possible to manufacture better wind turbines and to extend the scope of their installation to encompass diverse and more challenging environments. The TC is preparing up-to-date International Standards, exploring new applications and making improvements to existing systems.

Complex TC structure

Experts from 38 countries (26 Participating and 12 Observer countries) take part in TC 88 work which is constantly expanding to include all elements of wind turbine installation. The multiplicity and complexity of this task has led to a TC structure that includes three Working Groups (WGs), six Project Teams (PTs), nine Maintenance Teams (MTs), two Joint Working Groups (JWGs) and an ad hoc Group on terminology.

WG 3 is tasked with developing an International Standard on the design requirements for offshore wind turbines. These have specifications that differ from those of their onshore equivalents and wave loading represents an additional category that is required.

The WG 15 remit is to assess wind resource, energy yield and site suitability input conditions for wind power plants.

WG 27 defines standard dynamic electrical simulation models for wind turbines and wind farms. The models will be used in power system and grid stability analyses.

PTs prepare International Standards for wind turbine installations and aspects that are not yet covered by their own specific standards. These include, among others, design requirements for floating offshore wind turbines, which present particular constraints, for rotor blades and for wind turbine towers and foundations. The MTs are tasked with updating existing International Standards and projects.

JWG 1 brings together experts from IEC TC 88 and from the International Organization for Standardization (ISO) TC 60: Gears. JWG 1 developed IEC 61400-4:2012, Design requirements for wind turbine gearboxes.

Experts from IEC TC 88 and TC 57: Power systems management and associated information exchange, work together within JWG 25 to "develop standards for monitoring and control systems and associated information exchange for wind power plants".

More wind on the horizon, offshore

The prospects for wind power are very positive: the IEA forecasts that installed onshore and offshore capacity will exceed 1 300 GW in 2040, with onshore capacity making up 85% of the total (against 98% in 2011). This expansion will require additional International Standards to cover new areas as well as an update of existing ones to support technical developments in the sector.

As of early June 2015, TC 88 had issued 26 publications, that include International Standards and Technical Specifications in the IEC 61400 series, available as an Online Collection from the IEC Webstore.

The rapid expansion of new RE sources led to the decision taken by IEC Conformity Assessment Board (CAB) to create of IECRE, the IEC System for Certification to Standards Relating to Equipment for Use in Renewable Energy Applications, at its June 2013 meeting. IECRE covers three Sectors, wind, solar PV (photovoltaic) and marine energy.

IEC International Standards for the wind turbine industry ensure that wind systems and installations meet the latest technical requirements. For installers, utilities and other users, they guarantee that the equipment they acquire and install is as safe, reliable and efficient as possible. They also ensure that the wind turbine industry will continue to prosper and make an ever larger contribution to electricity generation.

London Array offshore wind farm Offshore wind farm installation (Photo: London Array Ltd)
offshore wind farm Offshore wind turbines are expected to provide 15% of total wind energy by 2040
Siemens nacelle Assembled wind turbine drivetrain, generator and power unit being installed into a nacelle (Siemens press picture)