A wind farm or a single turbine can feed electricity into the national grid, so long as the grid connection complies with technical and safety requirements. The national grid carries electricity at very high voltages, with a network of transformers to ‘step down’ the voltage until it reaches 230-240 Volts for domestic supply. Exporting power to the grid will involve making a connection at an appropriate voltage.

The power from a variable source, such as the wind, will tend to fluctuate. These fluctuations need to be moderated electronically so that the exported electricity matches the grid. Both the voltage and the frequency of the current need to conform, for the very good reason that many electrical appliances would be damaged otherwise (230/240 Volts at a frequency of 50 Hertz is the UK standard for domestic supply).

The technical issues around grid connection need to be discussed with the appropriate network operator. Compliance with the relevant Engineering Recommendation is a legal requirement and is a job for a qualified engineer.