Wood Pellet Manufacturing – Taupō
Wood pellet manufacturer, Nature’s Flame, taps into Contact Energy’s Tauhara geothermal industrial heat supply, enabling them to dry 150,000 tonnes of pellets per annum, which are then used in assisting both Fonterra and Open Country Dairy to decarbonise parts of their dairy processing operations. Annual GHG (greenhouse gas) emissions reductions of 84,000 tonnes are achieved at the Fonterra Te Awamutu site and 35,000 tonnes at Open Country’s Waharoa site.
Kiln Drying Timber – Kawerau, Taupō, Ohaaki
Carter Holt Harvey (Kawerau), Sequal Lumber (Kawerau), Tenon (Taupō) and Ohaaki Thermal Kilns (Ohaaki) using geothermal energy in kiln drying timber. The Kawerau operations use geothermal steam, the Taupō operation uses two phase geothermal fluid and the Ohaaki operation geothermal water.
Tissue Paper Manufacturing - Kawerau
Tissue and toilet paper manufacturer Essity, at Kawerau, made headlines when it switched its tissue manufacturing processes to geothermal in 2010. This dramatically reduced the company’s carbon emissions (a reduction of 17,000 tonnes per annum), as well as increased the reliability of their manufacturing processes. Essity is in the process of converting one of two of its paper machines, KPM3, completely to geothermal. This $15.5 million project is a first for the world and will further reduce the site carbon emissions by 6400 tonnes per annum. The Government Investment in Decarbonising Industry fund supported the project with a grant of $1.65 million.
Tūaropaki - Mokai
Tūaropaki Trust is an Ahu Whenua trust is involved in business ventures at Mokai, centred on sustainability and the circular economy. The geothermal resource is tapped into not just for generating electricity, but also industrial scale geoheat supplied to the Gourmet Mokai greenhouses and used to create process steam for the Miraka milk processing facility.
Tnue - Taupō
Total Nutrient Use Efficiency (Tnue) is the first tenant in the He Ahi Eco-Industrial Park, Taupō, with the facilities completed at the end of 2023 and production scheduled to commence in February 2024. Tnue, part financed (37%) by NZ Green Investment Finance Limited produces specialist fertiliser, with the geoheat being used in the manufacture of the control release membrane on the granules. The controlled release improves environmental outcomes by increasing the nutrient use, with more nitrogen being taken up by the plants and less nitrogen leached to the ground water.
Wai Ariki Hot Springs and Spa - Rotorua
The Wai Ariki Hot Springs and Spa is a NZD 60 Million Ngāti Whakaue venture that uses geothermal energy to heat the pools and the facility. With the entrance guarded by six statues of Ngāti Whakaue tīpuna, Wai Ariki is uniquely built on Ngāti Whakaue culture, healing practices and manaakitanga (hospitality). There are a range of bathing and spa experiences, such as Wai Whakaora (Restorative Journey) and Te Āhuru Mōwai (The Sanctuary).
Baywave Aquatic and Leisure Centre - Mount Maunganui
The Baywave TECT Aquatic and Leisure Centre in Mount Manganui, with the biggest wave pool in New Zealand, uses low temperature geothermal water from beneath the site to heat the pools and other water facilities. Consents allow the take of up to ~30MWth of heat.
Arts Centre - Christchurch
The Christchurch Art Centre uses 13oC aquifer water from ~130m below the site with the temperatures augmented with heat pumps supplying up to 2.4 MWth to the buildings on site. This energy system was retrofitted as part of the refurbishment undertaken after the 2011 Christchurch earthquake. This poster provides more detail, whilst this paper covering the project was presented at the 2020 World Geothermal Congress.
He Ahi Eco-Industrial Park - Taupō
The He Ahi Eco-Industrial Park under development by Te Pae o Waimihia with Contact Energy supplying geothermal energy opens up the opportunity for geoheat supply to small and medium sized enterprises who up to now have been unable to access geothermal heat because of the high hurdle of the entry capital required. The 45 hectare site north east of Taupō has ~40 sites, half of which can be supplied with geoheat operates on contract leasing for the facilities, with geothermal energy purchased through a separate supply contract.
International Case Studies
Further examples of geoheat uses can found in these case studies from the International Energy Agency (IEA) Geothermal.