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Maesgwyn wind farm construction

Client: Pennant Walters

Value: £5 million


  • Former opencast Mine
  • Significant Remediation required to stabilise ground
  • 14 Km of access roads
  • 12 km of Cable trenching
  • 13 Masts
  • 17m2 Octagonal Bases requiring 300M3 Concrete.


The Maesgwyn Wind Farm started life as an opencast mine, having been loosely backfilled and partly remediated with conifers and associated flora, it had been used for a variety of Motorsport activities. The challenge facing Walters Group was to stabilise the loose ground enough to support the considerable bulk and lateral stresses of thirteen, 80m tall (to the hub) wind turbines. The resulting electricity would then need to be fed into the national grid via a substation with associated cabling and infrastructure. Significant environmental planning considerations would also need to be met both during construction and in day to day use. Throughout the construction, the site would need to be in almost continual use as a motorsport testing and event venue.


Using our considerable experience in land remediation and stabilisation, we undertook to fulfil the contract and satisfy all the stringent planning requirements. Sub-consultants were employed included geotechnical, geo-environmental, structural, landscaping, archaeological and ecological consultants, however all earthworks modelling and access track alignment was undertaken by the Walters in house design team. To make access easier for the heavy plant (our own) required to transport and install the turbines, we constructed 14km of new and improved access roads through the forestry. Crane platforms (crucial for safe lifting into position) and solid concrete bases were poured and stabilised. A further 12km of hidden cable was trenched and buried on site, leading to a specially constructed substation, largely hidden from public sight by the landscape. Throughout the process the land was able (with the use of diversions and relocations) to be used by the BMW off Road Skills Academy and various World Rally teams and manufacturers for testing. Local traffic and residents were largely unaffected due to excellent management of heavy plant movements and sensitive timing

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