The transformer has been purpose-built by Areva T&D and is filled with its Envirotemp FR3 fluid, supplied by Cooper Power Systems, to replace mineral oil.

The new oil is biodegradable, less flammable and is reputed to extend the life of the transformer.

EDF Energy will be working with the University of Manchester and Areva T&D to compare the performance of the vege transformer with a second transformer filled with mineral oil. The transformer, which will contain 30,000 litres of the fluid, is due to be installed on the network in 2007.