Siemens Energy To Deliver Transformers To Seagreen Offshore Wind Farm In Scotland

Siemens Energy has been selected by MHI Vestas Offshore Wind (MHI Vestas) to deliver 114 low-loss 66-kV distribution transformers for the Seagreen Offshore Wind Farm in Scotland. 

With an installed capacity of 1,075 MW, the wind farm is forecast to provide low-carbon energy for around 1.3 million homes.

The fluid immersed distribution transformers will complement 114 MHI Vestas’ 10-MW turbines that the company will deliver to the wind farm located 27 km from the Angus coastline in Scotland. The low-loss distribution transformers were designed to meet high efficiency requirements. The transformer voltage class of up to 72.5 kV will enable larger power capacities, such as provided by MHI Vestas’ 10-MW offshore wind turbines, while keeping energy losses low.

After commissioning, the distribution transformers will transform the voltage from the low voltage of produced electricity to the medium voltage level of 66 kV needed to feed the offshore transmission substation before going to mainland with an even higher voltage.

It is anticipated that the Seagreen Offshore Wind Farm will be operational by 2022/2023.

“Siemens Energy worked closely together with us to develop a customized design transformer that perfectly fits our demands for an energy efficient solution with minimum footprint,” Robert Slettenhaar, vice president, head of Procurement and Category Management at MHI Vestas Offshore Wind, said in the Dec. 1, 2020, statement, in part.

Beatrix Natter, executive vice president, Transmission at Siemens Energy, said in the statement, in part, that the project “is forecast to offset 1.6 million tonnes of carbon emissions per year and will significantly contribute to reach the UK’s net zero emissions targets.”

The solution has been designed for MHI Vestas’ needs for a lightweight and compact solution that passes through the opening in the tower base without disassembly. To combine the compactness with challenging and diverging efficiency requirements, a newly developed core design, an innovative cooling solution, as well as a highly efficient winding arrangement were implemented. The transformers will be filled with safe and biodegradable ester insulation fluid as an environmentally friendly and operationally safe alternative to conventional mineral oil. The transformers have been vibration tested to ensure they reliably cope with the highly demanding service conditions and strong vibration typical for wind power applications. In addition, a short circuit test was conducted to ensure the transformers can withstand potential short circuits.