Mynydd Maen Wind Farm is actually positioned north of Mynydd Maen (Stoney Mountain), on Mynydd Twyn-Glas (Blue Hill Mountain?); although the boundary between the two is vague!
It is a beautiful place, have a look at the photos and the description on this website.  https://www.thewildlifeoculus.com/2020/06/birding-on-slopes-of-mynydd-twyn-glas.html 

Also see Wikipedia

https://en.wikipedia.org/wiki/Mynydd_Twyn-glas

A poem by Jimhl

The mountain top concerned is an environmentaly sensitive upland peat plateau and many acres of this peat and associated habit and species will have to be removed to build 8km of roads and vast concrete turbine bases.

The land belongs to The Llanover Estate and Pontypool Park Estate but it is managed and used by commoners who are represented by the Mynydd Maen Amalgamated Commoners Association.

Local ladies used to visit the mountain in summer to pick wimberries; other plant species include gorse, heather, and of course grass. There is also bracken, an invasive species, but that is mainly on the slopes, not the proposed site of the wind farm.

A local bird watcher has recorded the following species on the plateau

• Stonechat
• Linnet
• Lesser Redpoll
• Goldfinch
• Bull Finch
• Dunnock
• Blackbird
• Song Thrush
• Jackdaw
• Carrion Crow
• Magpie
• Raven
• Collared Dove
• Woodpigeon
• Willow Warbler
• Meadow Pipit
• Skylark
• Wheatear
• Reed Bunting
• Herring Gull
• Lesser Black Backed Gull
• Buzzard
• Cuckoo
• Robin
• Starling
• House Martin
• Swallow
• Pied Wagtail
• House Sparrow
• Great Tit
• Buzzard
• Wren
• Chaffinch
• Chiff Chaff

Our mountain is a beautiful place, very important for the well-being of local people.