Energy

Mercury awarded Higgins the ECI civil works contract for the first stage of its $115 million Kaiwera Downs wind farm in the Southland region in September 2022.

Built 15km southeast of Gore, stage one of Kaiwera Downs wind farm consists of 10 wind turbines that generates a combined average of 148 GWh in renewable power each year – enough to power more than 20,000 homes or 66,000 electric vehicles – helping to increase the proportion of electricity generated in New Zealand from renewable sources.

Kaiwera Downs is the sixth wind farm project undertaken by Higgins, along with five of New Zealand’s largest wind farm projects including Mercury’s Waipipi, Meridian’s Te Apiti, West Wind and Mill Creek, and Trustpower’s Tararua T3. These projects, combined, have seen Higgins involved in the construction of 50% of New Zealand’s total 1045MW of wind energy production.  

The broad scope of work included delivery of core services to lay foundations for 10 wind turbines as well as road access to and around the site.

As lead contractor, Higgins was supported by our Fletcher family of brands including Brian Perry Civil for site work, ground improvements and turbine foundations and Firth Industries as the concrete provider. 

Civil works were completed in May and the wind farm opened a year from groundbreaking – under budget and to schedule.

As the market leader in wind farm ‘civil balance of plant’ (CBoP) projects in New Zealand, Higgins brought its extensive experience to deliver a highly successful CBoP contract for our valued customer Tilt Renewables.

Starting in October 2019, Waipipi generated first power with the first turbines brought online, exporting renewable electricity to the Transpower national electricity network in November 2020. The assembly and commissioning of the remaining turbines continues. All civil works have been completed apart from ongoing maintenance works. Restorative topsoiling of the completed construction areas and native planting along the Waipipi stream banks also continues.

Higgins leveraged the Fletcher supply chain for significant scope across the project including drainage materials from Humes, aggregates from Winstones, concrete from Firth, Golden Bay Cement, steel reinforcing from Fletcher Reo and ground improvements from Brian Perry Civil.

Melbourne-based Tilt Renewables expects Waipipi will generate about 455 GWh a year. That’s enough clean energy each year to power about 70,000 homes and save the emissions of roughly 350,000 tonnes of carbon. This is the equivalent of removing about 70,000 cars from our roads.

The project involved: upgrade of 4.5km of road between SH3 and the Dryden Road site entrance, establishment of the site compound and site facilities, construction of an onsite access track network of more than 20km, ground improvement at all 31 turbine locations, foundation construction at all 31 turbine locations, installation of the underground electrical cabling and fibre to all turbine sites, connection of the underground electrical cabling to the assembled turbine, construction of the onsite substation including installation of the main transformer, 31 turbines pre-assembly, 20 turbines full assembly, and 16 turbines operational.

Higgins was the head civil contractor for Meridian Energy’s 26 turbine Mill Creek Wind Farm.

Using a collaborative delivery model, Meridian and Higgins work together to drive opportunities, innovation and smart construction methodology to deliver the Wind Farm Civil works project. 

As head civil works contractor, Higgins was responsible for delivering across the breadth of the civil works encompassing access roading, bulk earthworks, pavement construction, trenching cabling, tower foundations, and associated drainage and structures. The programme for the 800,000m3 of earthworks with associated environmental management and full compliance was substantially completed by November 2013. That's a great achievement for a winter programme.

The civil works for pavement works, trenching and cabling, and foundation construction works progressed over three separable portions for the 26-turbine base and were all delivered on time. The works included 20km of roading, 12km of cabling, 10,000m3 of concrete and 1,300 tonnes of steel for the foundations.

Meridian Energy’s Project West Wind saw the construction of 62 wind turbines at Terawhiti Station and Makara Farm west of Wellington.

This was the third Wind Farm project successfully undertaken by the Higgins Projects team.  Civil construction of wind farms involves a unique set of environmental challenges and the harsh and isolated location of Project Westwind was no different.  The success of the project shows the strength of the Higgins specialist knowledge and the commitment and 'can do' attitude of the Higgins teams.

The completion of the Manapouri Power Station in 1972 was hailed as one of the greatest engineering feats this country had seen. Over eight  yeards, 1800 men had worked to drill and blast the 10-kilometre tailrace tunnel through the hard granite of the Fiordland mountains from the power station at Lake Manapouri to Doubtful Sound.

Shortly after commissioning, it became clear that the power station was only operating at 85% capacity. Friction between the water and the walls of the tailrace tunnel were causing a loss of hydraulic head and, with it, productivity.

To allow the water to flow through the power station more quickly and increase hydraulic head, Meridian engaged the Fletcher Dillingham Ilbau consortium to construct a second tail race tunnel.

Although a modern tunnel boring machine (TBM) replaced the drill and blast methodology of the 1960’s, constructing the second tunnel was no less challenging. Fiordland National Park is a UN World Heritage Site, and therefore treading lightly in the pristine natural habitat was essential.

A bespoke TBM, specifically designed for the hard rock environment, was used to construct the 10km long, 10-metre wide (about the width of a two lane road) tunnel. Muck from the tunnelling operation was placed on top of spoil from the original tunnel excavation, and the area extensively planted to return it to its natural state. 

The new tunnel created enough energy to supply another 64,000 homes – or a town the size of Rotorua - without using an additional drop of water.

The backbone of our national grid is a system of HVDC cables which connect the electricity networks of the North and South Islands. Travelling 610km from Lake Benmore on the Waitaki River to Oteranga Bay, near Wellington, the cables supply North Island homes with cheap power from the South Island’s hydroelectric power schemes.

Arguably the most integral piece of cable is the 40km section that carries power under the turbulent waters of the Cook Strait. We played a key role in both the laying of the original cable in the sixties, and the new cables twenty five years later. 

When the original cable was laid in 1964, we constructed sealing end-supports, protection for jointing and joint pits on the shoreline at Oteranga Bay (North Island) and Fighting Bay (South Island). 

By the late eighties, New Zealand’s growing population and increasing demand for electricity prompted Transpower to upgrade the inter-island link. Brian Perry Civil was engaged as part of a subcontract to the Alcatel STK/ABB Cables AB Consortium to undertake all shore-based works and the maritime assistance associated withthe laying of three new 350 KV DC power cables and two fibre optic cables across the Cook Strait, and new cable terminal stations at Fighting Bay and Oteranga Bay. In joint venture with Wendell Offshore Services, Brian Perry Civil’s work scope included land route preparation including trenching, bedding and backfilling; landing cables on shore at both ends and winching into the terminal buildings; maritime assistance during cable laying and beach landings including standby tug support to the cable laying vessel, ROV assistance and diving support: burial of cables into the seabed within 200m of MHWM by underwater jetting; assistance with electrical termination of cable; and, installation of additional cable protection at suspensions, cross-overs and in surf zones.