79% of New Zealand's electricity generation now comes from renewable sources (hydro, geothermal, wind, wood). Graphic by PM Bendall, data from NZ Herald.
New Zealand is a pioneer and a leader in geothermal power technology. The world's second large-scale plant was opened in Wairakei in 1958 (the first was in Italy in 1911). Much research and development was performed there over the decades that followed, and today New Zealand has four additional plants operating of similar size to Wairakei (100-160MW), plus half a dozen more in the 25-80 MW range. Together these contributed 16.3% of the electricity generated during the past 12 months.
According to NZ Herald this week, Energy Minister Simon Bridges says:
"I'm very excited about geothermal It's the single area where New Zealand has most expertise in the world and I have the view that companies with some help from government should be doing more to leverageAccording to Wikipedia, New Zealand is one of only a small number of countries with numerous geothermal fields that could be developed. Most fields are located in the Taupo Volcanic Zone, but there are also fields in Northland, Hauraki Plains, Bay of Plenty, and in the South Island along fault lines. By the 1980s, some 129 fields had been mapped, and it is possible more will be located that do not have surface expression. Wikipedia also says:," he said.
Many applications of geothermal energy in New Zealand reinject the cooled steam/fluid back into the underground fields, to extend or infinitely use the fields as power sources.While geothermal power is thus considered a renewable energy source, it is not a zero-emission source. This is because some greenhouse gases are released during the process of extracting the fluids and extracting the heat to generate electricity, so geothermal is considered a low-emission energy source. Primarily, these gases are carbon dioxide (CO2), with lesser amounts of (stinky) hydrogen sulphide and methane. Comparing geothermal with other methods of generation using here, according to NZ Geothermal Association the average grams of CO2 released per kiloWatt hour of electricity generated by the seven major plants is 100 g/kWh. Compare this with combined cycle natural gas plants emitting 400 g/kWh, and with coal and oil plants emitting 900-1,000 g/kWh. In summary, geothermal emits one quarter of gas, and just one tenth of coal. For Segway PT owners who want to charge their machines as greenly as possible, plugging it in for recharging overnight (after 11pm or so) is the time of the day when almost all electricity is being generated from renewable sources.