"The boost in voltage level will significantly reduce losses and make the wind generation systems more efficient. It also brings lifecycle benefits and cost-efficiency gains," ABB explained.
The transformer can still be installed in a turbine's tower, ABB said.
A first set of five transformers are due to be fitted on MHI Vestas' V164 8.3MW turbines due to be installed at the 41.5MW Blyth demonstrator project off England's north-east coast.
Then, a further 11 transformers will be installed inside the V164 turbines destined for Vattenfall's 92.4MW European Offshore Wind Development Centre (EOWDC) off Scotland's coast.
"The development facilitates the integration of offshore wind energy, bringing clean power to the people and reinforcing our position as a partner of choice for enabling a stronger, smarter and greener grid," said Markus Heimbach, managing firector of ABB's transformers business.