New Zealand’s Might River Power has announced the completion of the world’s largest binary geothermal power plant. The company has dubbed the complex, new geothermal project “a significant strategic milestone”. It now operates five geothermal plants, which account for about 10% of New Zealand’s total electricity generation annually.
The new 100 megawatt Ngatamariki Geothermal Power Station is the third to be commissioned in the past five years, and is located near Taupo in New Zealand’s North Island (or Te Ika-a-Maui). The project developer, Ormat, has said that Ngatamariki is the largest singular binary power plant ever built. In the plant, geothermal fluid in fed to energy converters at a temperature of 193 degrees celsius. The process allows for 100% of the geothermal fluid to be reinjected with no water consumption, which minimizes the environmental impact, and there is no depletion of the underground reservoir.
The company has invested $75 million in exploration, and more than 10 years developing partnerships, before they knew they had a viable project. Nearly half a billion dollars in overall capital was committed to the project. However, the company says this will result in “low-cost renewables production”, which is expected to “drive improved profitability” over the long-term by displacing competitors’ higher cost fossil fuel production.
Might River Power’s CEO Doug Heffernan has said that overall, the company’s geothermal generation assets are saving New Zealand over 3 million tonnes of carbon emissions per year, by displacing coal-fired power generation. Although New Zealand already generates a large percentage (over 70%) of its electricity from renewable sources, it has recently been announced that a second coal-fired unit in Huntly will be withdrawn from production.
However, it has to be said that not all of the new energy resource development the New Zealand is renewable. In a move that seems contrary to the goal of decreasing emissions from fossil fuels, the New Zealand government is currently opening up land and sea for new oil and gas drilling, as well as seabed mining.