Nant Helen opencast coalmine at Abercraf is Celtic Energy's largest operational site, with an annual output of around 400,000 tonnes of coal and reserves of around three million tonnes. All mined coal is transported directly to the nearby processing and distribution centre at Onllwyn (nprn 306037). The site is projected to continue coaling until 2014 and will be restored mainly to upland common.
(Source: Celtic Energy)
B.A.Malaws, RCAHMW, 07 May 2010.