The number of wind and solar farms must double by 2050 if New Zealand is to meet its carbon reduction targets, and farmers could be beneficiaries.
Major electricity generation companies are committing billions of dollars to renewable solar, wind and geothermal energy, with forecasts of wind-generated energy increasing from 6% in 2021 to between 20% and 34% in 2035, and solar from 1% to 6% over the same period.
Energy company Mercury said $10.2 billion investment in renewable energy generation and a further $30bn in transmission and distribution is required this decade alone to meet those goals.
“There is more than enough renewable energy generation in the project pipeline to achieve the BCG’s [consulting group] roadmap of 98% renewable generation by 2030,” it said.
Meridian Energy alone needs to invest in 20 new projects by 2030 to retain its status of generating 30% of NZ’s energy.
The NZ Wind Energy Association said growth and expansion have been rapid. Between 2019 and 2023, completed wind projects increased capacity from 690MW to 1265MW, taking wind’s share of generation from 6% to more than 10%.
It has attracted new entrants to the sector, along with interest in establishing offshore wind farms off the Taranaki and Waikato coasts.
Rebecca Knott, Meridian’s head of renewable development, said the company will commission seven projects by 2030. Each takes at least three years of planning and consenting.
Wind is the cheapest to construct followed by solar then hydro and she said finding suitable locations is a mix of in-house research and approaches by landowners offering potential sites that are either very windy or exposed to the sun for solar.
Access to the grid is central to viability but that usually means the vicinity is close to populated areas which can lead to some public resistance.
Contact Energy’s proposed 50-turbine wind farm at Slopedown in Southland has attracted opposition from some locals concerned it will destroy the Catlins landscape.
A turbine blade is unloaded at Meridian Energy’s Harapaki wind farm in Hawke’s Bay.
Another factor is the volume of civil works required such as roading, which can be significant for accessing wind farm sites.
Knott said often wind farms straddle one or more farms so agreement from multiple landowners can be needed, but once constructed 95% of the land area can be grazed.
To be economic, a solar farm needs to be a minimum of 100ha and once built can be grazed by sheep.
Knotts said wind turbines and solar panels last for 20-30 years and provide farmers with an additional source of income and have been used to help meet a farm’s nitrogen and phosphate restrictions.
Energy generators either buy or lease land for solar farms or pay landowners a base annual rate per megawatt generated for wind.
Other payment options allow landowners to share in years when generation is high.
When buying or leasing land, Knott said Meridian pays the same as the next best alternative land use.
At the end of a wind or solar farm’s lifespan, the project can be decommissioned, upgraded and re-powered.
Matthew Cleland, Contact Energy’s head of wind and solar, said demand for renewable energy is growing as industries such as dairy and meat processors move away from using fossil fuels.
Contact is also investing in grid batteries, complexes the size of a rugby field in which energy is stored when generation is in abundance to meet demand when the wind doesn’t blow or sun doesn’t shine.
These need to be built adjacent to transmission lines and substations.
Cleland said new energy sources will be a mix of wind, solar and geothermal due to the high cost and lack of suitable sites for hydro.
Mercury opened the first stage of its Kaiwera Downs wind farm near Gore this week and is considering adding a second stage.
Portfolio manager Phil Gibson said the 10 turbine site will generate 43MW, enough energy to power over 20,000 households or 66,000 electric vehicles. The second stage will take it to 228MW.
Gibson said Mercury expects to commit $1 billion in the coming year to renewable generation development which will be constructed over the next three years.
Examples of wind and solar farms recently commissioned or planned include:
• A 41-turbine, $448 million Harapaki Wind Farm on the Maungaharuru Range between Napier and Taupō.
• Proposed 50-turbine wind farm, Wyndham, Southland.
• Two geothermal projects in Taupō.
• 300,000 solar panel farm on 300ha next to Christchurch Airport.
• 220ha solar farm on the Kaipara Coast, Auckland.
Genesis Energy and FRV Australia.
• 90ha solar farm at Lauriston, Canterbury.
• Three solar farms in Manawatū, Waikato and Hawke’s Bay covering 740ha.
• Recently commissioned a 10-turbine wind farm at Kaiwera Downs, Southland.
• Proposed 19-turbine Kaiwaikawe wind farm, Northland.
Pioneer Energy and Manawa Energy
• Proposed 70-turbine wind farm at Kaihiku, South Otago.
• 135,000 solar farm, Marlborough.
• Three wind farms proposed at Huntly and near Whanganui.