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Meridian’s latest wind farm, Te Uku near Raglan, reached its first stage of construction in what is a model of community involvement and, despite difficult construction conditions, is ahead of schedule. By Alan Titchall.
“We toyed with the idea having our project office on site, but there were a number of reasons why we have set it up in Raglan,” says Meridian’s Te Uku project manager, Robert Batters. “The community was very keen to see us here for the obvious economic benefits, from leasing property to buying goods and services from local retailers – re-fuelling of vehicles at the local gas station, and they do a great pie on a cold day.” Putting value back into the community is a top priority for this project on all levels. “Where practical we have engaged the services of local contractors. While we still have procurement policies that we must adhere to being an SOE, using local contractors makes good commercial sense and, at the same time, you get buy-in from the community.” The office takes up the entire second floor of 5 Wainui Rd to accommodate every major contractor on the Te Uku wind farm project, including the civil contractors, Hicks and Spartan JV, Siemens who are providing and installing the turbines, and NZ Cranes who will erect the turbine components. “We refer to our partners as ‘our construction team’ as we work collaboratively together and under one roof,” says Batters.
“The approach has cost benefits through providing an effective way of communicating and making decisions very quickly. Because of the project’s timeframe, construction decisions had to be made quickly - we just didn’t have a week to think about things.” Proof of that theory is the fact that civil works, after starting late last year, had completed 23 kilometres of roading and 23 of the 28 turbine foundations by July this year. The project completion date is now tracking four to six weeks ahead of plan, with the farm now scheduled to be fully operational by the end of March 2011. In an arrangement that departed from the construction approach taken in Meridian’s other wind farms, the developers chose two smaller-sized civil contractors to undertake the civil works, Hick and Spartan JV who formed a joint venture for the project, rather than one of the five big contractors who dominate most large projects in this country. “We felt Hicks/Spartan JV offered us a lot in terms of the practical experience their people would bring to the job. Plus they allow us to run a very flat management structure between my role as project manager and the guys on the tools who in some cases are the owners of their business.” Construction challengesAlthough it features only 28 turbines, the wind farm site covers over 55 square kilometres at heights of over 400 metres above sea level, and is a working sheep and cattle farm. The name, Te Uku, is also a reference to the region’s red clay, which turns dangerously slippery when wet. These local soils created problems from an environmental perspective and the logistics of building 23 kilometres of road through steep grades and ravines over a short construction window.
“It only needs to get a little water on it and it turns into a slippery slush, so erosion and sediment control was a key environmental management focus from the start, as was managing the very dangerous working conditions, particularly at the start of the project.”
Unique partnershipTe Uku is the first wind farm in this country built under a partnership between a state-owned power generator and retailer and a community-trust owned electricity distribution company. Under an agreement between the two companies, Meridian will build and operate the turbines and own the electricity generated, while WEL Networks will own and manage the electrical lines and substation within the wind farm as well as the 26 kilometre-long, 33kV high voltage lines that connect the farm into the WEL Network at its Te Kowhai and Whatawhata sub stations. Owned by a community trust, WEL Networks operates a distribution system in the Waikato that connects 80,000 customers to the national grid. It was WEL that applied to Waikato District Council for the original wind farm consent in June 2008. Appeals were settled through successful mediation without proceeding to an Environment Court hearing and the project had only one turbine to relocate during the process – one from the site’s northern end, which is visible to SH23. “It was the first time Meridian has entered into such an alliance with a local lines company, which provides a lot of value for the local community and also brings local expertise to the job,” says Batters.
Embracing the community
“The group keeps the local Raglan community informed about project progress while also providing a forum for any issues to be raised, discussed and resolved.” This group meets every two months and will continue to meet for two to three years after wind farm construction is complete. At the end of the day it is also the local community that will reap the benefits of the wind farm, says Batters. “For those living in Raglan who are familiar with the challenges the local lines company has in terms of security of supply, this will have a major impact in terms of reinforcing electricity supply to the Raglan area.” The single circuit running out to Raglan has always been problematic and Te Uku effectively brought forward the Western network investment upgrade that WEL Networks was intending to make by about a decade. The next major project as part of this upgrade is the construction of a substation in Raglan and an upgrade of the Te Uku substation. “And as the region grows, more of the wind farm’s generation will be used by customers connected to the local network.” The resource
Through its 2.3MW Siemens’ turbines Te Uku will generate 64.4 megawatts, enough power to provide the average annual needs of around 30,000 homes. Through today’s electronic management the site will be maintained for just 92 days of the year on average and the rest of the time the wind farm will be able to be controlled by Meridian from Twizel in the South Island, or from Denmark by Siemens. Te Uku will be Meridian’s sixth wind farm after Te Apiti, White Hill in Mossburn near Invercargill (a similar site in number of turbines), West Wind near Wellington (at 55 square kilometres it similar site in terms of area), Wattle Point (in Australia) and a three turbine farm at Scott Base in Antarctica. Te Uku is fed by a prevailing south-westerly wind that whistles up Aotea Harbour before hitting Mt Karioi and is channelled straight up a valley and across the wind farm. Te Uku is a class 2 site with a mean wind speed of 8.2 metres per second, not quite as windy as West Wind which is a class 1 site with winds of 10 metres a second. Four years of wind data used in the micro-positioning of the turbines also proved that a longer blade at 49 metres, compared with the 40 metre blades used at West Wind, would increase generation. The turbine selection together with the wind speed distribution at Te Uku results in a wind farm capacity factor of 43 percent, significantly greater than the world average. The blades installed on the turbines at Te Uku are the longest of any turbine used in New Zealand.
Consents allowed for access road 10-metres wide, but the final design reduced road widths to a maximum of six metres, substantially reducing bulk earthworks and civil construction costs. The road width is usually dictated by the size of the crane needed to erect and maintain the turbines, however the developers are going to use a narrow ‘wheeled’ crane as opposed to a tracked crane. “This has allowed us to optimise the road design which has had a huge impact on reducing bulk earthworks, the amount of aggregate required and minimised the impact on the environment,” says project manager Robert Batters. The Siemens turbine towers (in three sections), blades and components are due to be transported from Auckland in September, with the last turbine due to be erected in February 2011. EnvironmentThe Te Uku wind farm site is one of the biggest projects Environment Waikato has ever worked on. Local soil conditions were the main concern for Environment Waikato and the reason for constringent erosion and sediment controls being included in the project’s consent conditions. “Erosion sediment control was a key focus from the start,” says Meridian project manager Robert Batters. Some 160 structures and 30 sediment ponds were constructed to mitigate the impact of bulk earthworks and stop sediment from these works entering the local waterways. These ponds had to be maintained in at times atrocious weather conditions that saw the site closed down three times, he adds. Exposed soils have been hydro-seeded and covered with hay to stimulate grass growth to control erosion and Meridian is in the process of planting 40,000 native plants over a total of 4.56 hectares to help to improve water quality downstream. Many of the key streams on this site feed straight back into Bridal Falls, the most visited Department of Conservation site in the Waikato and run-off from the surrounding area has long tainted the river feeding the falls. “The falls features a sad sign explaining why the water is the colour it is. It would be great for the local community if they can pull that sign down and I think we have contributed towards that mission.”
Energy NZ Vol.4 No.5 September-October 2010 |
Meridian’s wind farm project office is located upstairs above a smart bunch of retail shops in Raglan’s village-like retail centre.
“This makes sure we are communicating effectively and making decisions quickly as a team. The ‘one team’ concept is something people talk about, particularly during the tender phase of a project, but doesn’t often eventuate, but here it does.
“The soil conditions at this site are some of the most challenging our contractors have ever had to work with,” says Meridian’s Te Uku project manager, Robert Batters.
Born and bred in the Waikato, Batters rarely mentions the Te Uku project without a reference to the local communities that surround it, be it the four landowners who now have better farm access and supplementary incomes, or the community liaison group, made up of locals, including Iwi, school principals, council representatives and community leaders.
When completed, Te Uku will operate as a 28 turbine wind farm on private land on the Wharauroa Plateau, about 30 kilometres west of Hamilton, and southeast and inland of Raglan above the community of Te Mata.
The 28, 80-metre towers sit on reinforced concrete ‘gravity’ foundations that are up to 18 metres wide and 2.25 metre deep. The alternative was to use pile foundations, but the site features too many boulders (some the size of a large car) thrown out by nearby Mt Karioi in its violent past.