The country's largest solar farm is to be built at Marsden Pt after Refining NZ decided to go ahead with the $37m project.

The solar farm will cover 31ha and is intended to reduce the cost of electricity for Refining NZ's operations at the Marsden Pt Refinery.

The solar farm will supply 26.7 MW - about 10 per cent of the refinery's electricity needs. The project was mooted earlier this year but has just received the approval of its board.

Chief executive Mike Fuge said the farm would also reduce carbon emissions and improve its edge against larger international competitors.


"Tapping into solar generated electricity is expected to shave around $3-4 million from our annual grid electricity bill and will reduce the CO2 emissions associated with the refining operation by a further 18,000 tonnes per year."

Construction is aimed to be complete by December 2020.