The contract will require Siemens to supply, install and commission 54 units of SWT-3.2-101 direct drive wind turbine at the Clyde wind farm, whose current capacity is 350MW with 152 operational turbines.

Siemens will start delivering and installing the turbines in June 2016.

The turbines, each with a capacity of 3.2MW and a 101m rotor diameter, will increase energy output and provide the Clyde wind farm with the latest direct drive technology, Siemens said.

Construction of the extension to the Clyde wind farm commenced in July this year, with planned completion in June 2017.

During the construction period, the project is expected to create 500 local jobs.

Siemens wind power and renewables division onshore CEO Thomas Richterich said: "We are very pleased to continue the long and successful relationship with our customer SSE in an important project like the Clyde Extension.

"Our direct drive units improve performance, reliability and maintainability. We see this innovation in our products as a stable basis for further collaboration with experienced customers like SSE."

Siemens will also provide long-term service for the new Clyde extension project.

SSE submitted the application for Clyde Wind Farm extension to Scottish Ministers in October 2011.

Later in 2012, SSE submitted an addendum to the proposal by reducing the number of turbines to 54 from the proposed 57 and maximum capacity to 162MW from 171MW.

SSE also reduced the tip height of ten turbines in response to landscape and visual comments raised by Scottish Natural Heritage and Scottish Borders Council during the application consultation period.

Image: Siemens will start delivering and installing the turbines in June 2016. Photo: © Siemens AG.