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Machynlleth's Centre for Alternative Technology is 40

29 July 2014 Last updated at 19:56 BST

Forty years ago they described themselves as "crazy idealists", but now many of the green energies pioneered by staff at the Centre for Alternative Technology are mainstream.

It was set up by a radical community who launched the Green Movement in Britain in a disused Quarry in Machynlleth, Powys.

Matt Murray reports for BBC Wales Today.