“The communication has been very good with Firth. We did ask that they work with another local supplier for this project due to the sheer volume required at times. It isn’t always easy and to their credit they have communicated and worked very well with them. Our site managers Simon Brew and James Kemp have worked closely with Firth and have said they have been impressed everyone has worked together to keep the project on track. In days gone by people could work long days on projects like this but with wellbeing at the forefront of our minds, having two concrete suppliers was probably the only way it would have worked. Firth’s ability to be flexible and to chop and change things around has been really appreciated by us and United Civil.”
Firth Taupo pulls out the stops at Tauhara
Principal: Contact Energy
Customer: Naylor Love
Customer: United Civil
Project: Tauhara Geothermal Power Station
Location: Taupo
Product: Firth Certified Concrete
Construction of Contact Energy’s latest geothermal power station Tauhara began in early 2021 and has seen Firth included on the list of main suppliers to the project, with concrete a key material in its construction.
Supplying large amounts of concrete to geothermal power stations in the North Island is nothing new for Firth with the connection to the construction of geothermal power sites beginning in 2007 with concrete supply to ‘Kawerau’, then the construction of ‘Nga Awa Purua’ at Rotokawa, Contact Energy’s ‘Te Mihi’ in 2013 and ‘Ngatamariki’ Geothermal field about 17kms north-east of Taupo a year later.
Firth’s expertise, comprehensive network and ability to manage large projects has been called on by main contractors Naylor Love and United Civil to assist with the supply of specialist mixes to Tauhara.
“Naylor Love is the contractor building the Power Station and United Civil are doing the civil works for the Steamfield Project, both of which make up the complete Tauhara Power Station project,” explains Greg Blank, Sales Manager (Waikato) for Firth. “We have partnered with another local supplier for some of the larger pours as they have been between 500 and 900m3.”
With approximately 25,000m3 of concrete required by Firth, pours started in November 2021. “Most of the mixes are low shrink which contain flyash to help control temperature build-up in the thick slabs,” adds Greg. “The mixes also require a certain Microstrain as determined by the engineers for the project.”
Geoff Baume, Compliance Manager for Naylor Love says that they have been on site since the middle of 2021. “We have been working with Firth for concrete supply from the beginning and things have gone very well. With Taupo being a relatively small place there is limited capacity for concrete supply. We know the amount of concrete requested from them, in amongst their everyday work and in what has also been a busy time for residential construction, has been a big ask but Firth has managed this situation extremely well.”
Geoff says that for one large pour in particular the concrete had to be batched at the same plant, a requirement of the engineers, to ensure consistency and that it would cure at the same rate. “Trucks were called in from other areas and suppliers, but Firth managed that very large pour out of their plant.”
“I also have to mention that Firth is technically very strong. Seeing the quality of the product regularly produced by them has meant that I have confidence that everything is correct. It’s a huge weight off my shoulders. For that reason I have also used them for the temperature monitoring process. I have been able to rely on them as they have demonstrated throughout the project.”
Jacob Dunn, Construction Manager for United Civil talks about their side of the project. “We started on site at the end of November 2021 and more or less started straight into the concrete construction side of things, so we have worked with Firth from the beginning. We have completed eight very large pours in excess of 700m3 with one at 840m3, which was batched by Firth.
“I have done a lot with both suppliers in the past and both have both done really well in terms of coming together and delivering the project. I do think Firth has produced a very high level of service throughout the project and consistently high-quality concrete which makes placing it that much easier.”
“From my perspective the team at Firth Taupo, headed by Mike Smart, with Sarah Dickenson and Tony Matangi has been outstanding. They really deserve acknowledgment as it’s been a huge demand on them and their plant. They have really stepped up and the service has been second to none. The product has also been of a consistently high standard as per the mix designs. I personally want to thank them for their efforts.”
With between four and 12 months of work left on site for both United Civil and Naylor Love, both men say they are pleased with progress.
“My aim is to walk away with everyone being proud of this job and for me to know there aren’t any bodies buried anywhere or that there was more we could have done,” adds Geoff. “The plant will be here for a while, so we want to do our best and produce our best.”
Facts and figures about Tauhara:
- Tauhara is Contact’s sixth geothermal power plant and is a 168MW geothermal steam turbine power station.
- The Tauhara power station is situated just off Broadlands Road east of Taupō.
- Tauhara will operate 24/7 and is not reliant on the wind blowing or the sun shining to generate power.
- Tauhara will produce 1,420 GWh of electricity per year, which is around 3.5% of NZ’s electricity and enough for 200,000 households.
- Tauhara is expected to displace 500,000 tonnes per year of carbon emissions as fossil fuel generation is shut down. This is equivalent to removing over 220,000 petrol cars from New Zealand roads.
- Tauhara power station will be Contact’s sixth geothermal power station in the Central North Island adding to their existing over 80% renewable portfolio.
- Contact’s geothermal plants already supply 8% of New Zealand’s electricity and this will increase to 11.5% once Tauhara is built.
Why now?
New Zealand is in the early stages of a decades-long transformation from reliance on fossil fuels to renewable electricity. Building Tauhara will be key in delivering on New Zealand’s Zero Carbon 2050 ambitions and updated 2030 targets. 2021 saw a drastic increase in coal use to meet electricity demand. Geothermal will play a crucial role in New Zealand’s transition away from fossil fuels.