IN Brief:
- Jones Bros has been appointed principal contractor on a £46.5m package within the £100m-plus Carno III wind farm.
- Works include turbine foundations, a new substation, 20km of underground grid cable, and nearly 9km of upgraded or new access tracks.
- Construction is under way, with completion expected in autumn 2027 and substantial Welsh supply chain participation planned.
Jones Bros Civil Engineering UK has been appointed principal contractor on a £46.5m infrastructure package for the Carno III Wind Farm in Powys, covering civil engineering, grid, access, and enabling works on the 10-turbine project.
Carno 3 LLP, a joint venture between Amegni Renewables and Gresham House, is developing the 45MW scheme at a total cost of more than £100m. Construction is under way, with completion expected in autumn 2027 and the wind farm forecast to generate electricity equivalent to the annual consumption of around 46,000 homes.
The Jones Bros package extends beyond turbine foundations. The contractor will install around 20km of underground cable between Welshpool substation and a connection point south of Abermule, strengthening part of SP Energy Networks’ existing 132kV network in mid Wales and providing the route needed to export generation from the site.
On the wind farm itself, the company will construct turbine foundations, a new substation and control building, associated cabling, and the access infrastructure needed for heavy construction and turbine deliveries. More than 4.4km of existing tracks will be upgraded, with another 4.7km of new tracks built across the site.
Existing highways will also require modification for abnormal-load movements. Wind farm construction places unusually demanding loads on local roads and site access because blades, tower sections, nacelles, cranes, concrete, reinforcement, and electrical equipment have to arrive in a sequence that matches foundation and erection programmes.
The project therefore combines several civil-engineering disciplines within one principal contract. Earthworks, roads, reinforced-concrete foundations, drainage, buried cables, substation infrastructure, and highway interfaces must progress in a coordinated sequence rather than as isolated packages.
Rhys Roberts, senior contract manager at Jones Bros, said the award is “our highest value wind farm contract in Wales to date”. The contractor also worked on Carno II in 2009, giving the latest scheme a direct connection with earlier phases of wind development in the area.
The programme comes after a relatively quiet period for major onshore wind construction in mid Wales. Garreg Lwyd, between Llandrindod Wells and Newtown, entered operation in 2017, while Carno III is expected to be the first significant new wind development in the region for almost a decade.
Once the third project is operational, the three locally operated Carno wind farms are expected to comprise 78 turbines with combined installed capacity close to 100MW. The development also carries a community benefit programme and a substantial commitment to Welsh procurement.
More than £50m of contracts across the wider Carno III development have been awarded to Welsh businesses and individuals, according to the project team. Jones Bros has said it intends to use regional suppliers where practical, while its own project workforce is expected to reach about 90 people, including apprentices.
Environmental measures sit alongside the main construction scope. More than 350 hectares of habitat enhancement and peat restoration are included within the wider development, together with improvements to the local public rights of way network. Those commitments affect haul routes, drainage, reinstatement, earthworks, and the timing of activity through sensitive areas.
The underground grid connection is one of the most substantial elements. Twenty kilometres of cable requires excavation, cable installation, crossings, backfilling, testing, and reinstatement over a route that extends well beyond the turbine site itself.
That work illustrates the growing importance of off-site infrastructure in renewable energy construction. A generating asset can be physically complete but unable to export power without the cable, substation, protection, and network works needed to connect it into an existing electricity system.
The scale of the grid package also affects construction logistics. Cable drums, jointing operations, temporary access, traffic management, and testing have to be coordinated with the wind farm programme so that energisation does not become a late-stage bottleneck after civil works on the main site are complete.
Jones Bros brings a large directly operated plant fleet and experience across renewables, highways, reservoirs, coastal protection, and remediation to the project. Carno III will draw on several of those disciplines at once, combining remote site earthworks with highway interfaces and high-voltage infrastructure.
The programme now runs through the remaining construction seasons towards the autumn 2027 completion target. Before then, the project team must complete the underground connection, prepare almost nine kilometres of new or upgraded site access, construct the turbine foundations, and bring the substation infrastructure through testing and commissioning.
The size of the civils package shows how much construction sits behind a 45MW onshore wind scheme before turbine erection is complete. The visible machines will eventually dominate the site, but roads, concrete, cable routes, drainage, and grid infrastructure will determine whether they can be delivered and connected on programme.
