The first stage of Top Energy’s Ngawha geothermal power station development was commissioned in 1998, with two generators having a combined output of 10MW. Once stage one was operational, further scientific investigation showed that the Ngawha plant could be expanded without affecting the geothermal field reservoir pressure.

In 2003, Top Energy began the second stage of the Ngawha power station development, which was commissioned in late 2008. The project cost $77 million and provided an additional 15MW of electricity generation capacity to the Ngawha plant.

Today, the Ngawha geothermal power stations have a total generation capacity of 25MW. Electricity produced by the Ngawha plant is fed into Top Energy’s electricity distribution network and then into Transpower’s national transmission grid via Top Energy’s sub-station near Kaikohe.

The construction of two new power stations at Top Energy’s Ngawha geothermal power site will be the third stage of development (i.e. stage three).