News, Events and Culture

Largest solar farm in New Zealand to be built in Palmerston North

Friday December 20 2013

A 100 kilowatt solar photovoltaic (PV) farm will be installed on the rooftop of Palmerston North City Council’s Central Administration Building and the city’s Convention Centre.

Solar hot water panels

Powersmart NZ Ltd of Tauranga won a competitive tender to build the solar farm - which will be the largest in the country.

Palmerston North Mayor Jono Naylor says Palmerston North is committed to being a sustainable city and he's pleased to see this project come a step closer to fruition.

"Last year we converted the Council's main office building to solar heated hot water and we installed solar energy panels on the roof of Council's depot at Manawaroa Street. These projects alongside many others including an LED street light trial and free tertiary student bus travel demonstrate Palmerston North's commitment to creating a sustainable future."

Energy officer John Debney says that the $215,350 project involves installing 400 photovoltaic solar panels on the roof of the Central Administration Building (CAB) and the Convention Centre. The solar panels work by converting sunlight into electricity. As the sunlight hits the silicon cells in the panels, an electric current is generated. The electricity generated by the solar panels is a direct current (DC) voltage and each panel has a positive and negative lead. The panels are all wired together and connected to an inverter which turns the electricity into alternating current (AC) which we use in the building.

John Debney says the solar farm will go some way towards meeting the Council's electricity needs and most of the electricity will be used on site, to reduce the amount of electricity imported into the building from the supply grid. The CAB building uses approximately 1,100,000kWh of electricity per year. The solar farm will reduce this by about 10%. Last year the electricity costs at the CAB building were $173,000.

The modelling by Powersmart shows the farm will generate approximately 118,000kWh per year. There should also be a reduction in electricity demand charges as Council will be using less electricity from the network during times of peak demand. However, he says, we won't know the total savings until this time next year because the demand charges for electricity stay on the bill for one year.

John Debney says the solar farm project is very exciting. "We're fairly confident of how successful it will be given our experience with the solar electricity system at Council's Esplanade Depot at Manawaroa St."

That site has used 4,550kWh from the grid since March this year, and in that time exported 3,270kWh back to the grid. This represents about 72% of the electricity imported to site being sent back to the grid. During the day the complex is using electricity generated on site by the solar panels resulting in further savings. "That project was designed to be able to generate as much electricity as it uses and we appear to have achieved this goal."

Construction will begin in mid February and is expected to take about three weeks to complete.