Over the past four years, the International Electrotechnical Commission (IEC) has been undertaking a major revision to IEC 61400-2. The 61400 is a set of design requirements made to ensure that wind turbines are appropriately engineered against damage from hazards within the planned lifetime. The standard concerns most aspects of the product life; with the 61400-2 referring specifically to the safety philosophy, quality assurance, and engineering integrity and specifies requirements for the safety of Small Wind Turbines (SWTs). This includes the design, installation, maintenance and operation under specified external conditions.
The four year long modification process has gone through the IEC committees, which include over 40 representatives of global small wind manufacturers and Certification Bodies. The revision has incorporated many of the lessons learnt as a consequence of operating the MCS/BWEA scheme and standards.
The corresponding MCS document (MCS 006) has been updated and will be published at the same time as IEC 61400-2. The most substantial change to MCS 006 will be the scope. Previously the scope was limited to 50kW with a swept area of 200m2. Once the new standard is published the limitation of 200m2 will be removed in order to provide clarity around the different boundaries and bring it in line with the international standard. This has been done by allowing certification either via the Renewable UK (RUK) standard (i.e. reliant on the IEC 61400-2 small wind standard), or via IEC 61400-1 (the large wind standard, which has no lower limit) plus adding in the other requirements of the RUK and IEC 61400-2 standards (e.g. requiring acoustic and power performance testing, giving guidance on variants, etc).
Alongside the imminent updates to the small wind standards, MCS has recently started to develop a medium wind standard which will be based on the underlying IEC 61400 standards. The majority of the work to date has been completed by a sub group of the IEC TC 88 (MT01). MCS will look to incorporate this work into a formal MCS standard in the near future. The scope of the medium wind standard will cover turbines from 100kW-500kW in size. A suggested implementation date for this new standard is spring 2014.