Located 1 kilometre north of St. Stephen-in-Brannel, the Trethosa Solar Farm is constructed on sloping fields, with careful consideration for its neighbouring archaeological environment, which was deliberately omitted from the project. A large area to the north of the site is still under active exploration for China clay, while there is an abandoned mica lagoon to the east. A geophysical survey of the site had identified a probable Iron Age-Romano-British barrow, at least two roundhouses, and several linear features. As a result, a no-build area was designated over the most archaeologically sensitive section in the northern end of the site.

The solar farm was constructed in 2016 and has been operating since.