Windenergy in New Zealand (written by Thomas Ackerman)

During 1996 New Zealand's first wind farm (Hau-Nui) comprising of 7 Enercon E40 machines totaling a capacity of 3.5 MW, was commissioned by local power company Wairarapa Electricity. The wind farm adds to the existing Electricity Corporation of New Zealand (ECNZ) owned Vestas V27 and various smaller turbines owned by other parties, bringing the total grid connected installed wind turbine capacity in New Zealand to close to 4 MW.

Due to the strong equinoctial winds, the wind turbines installed in New Zealand to date enjoy capacity factors ranging from 46% to 52%. Availabilities of turbines installed to date have been high at 95% or greater. Research work performed by wind power consultants DesignPower, have however revealed that the large amount of time spent during strong wind conditions could cause significant production loss due to frequent shut-downs in high wind speeds. The amount of energy loss would depend on the type of control system employed by an installed wind turbine.

Commercial interest in wind farming is steadily increasing as wind energy becomes competitive in a fully deregulated market. During 1996 Resource Consents for a wind farm of 137 turbines, and for a prototype Diffuser Augmented Wind Turbine (DAWT) were also obtained. A resource consent application for a 12 MW wind farm at Baring Head near Wellington was however turned down.

Resource consent applications for a further 85 MW of installed capacity are expected to be submitted by various parties during 1997, on sites with average annual wind speeds of approximately 10 m/s. The high wind speeds are expected to make wind farms developed on these sites economically attractive. Further wind sites totaling up to 600 MW of installed capacity are currently being investigated.

In New Zealand the majority of electricity is produced by hydro power stations with an installed capacity of approximately 4,800 MW. The remainder of electricity is produced by thermal power stations which together have an installed capacity of approximately 2,600 MW.

2. GOVERNMENT PROGRAMMES

The government's over all energy policy for energy is to ensure the continuing availability of energy services at the lowest cost to the economy as a whole, consistent with sustainable development.

Direct government funding is not available for the development of renewable energy, however the Energy Efficiency and Conservation Authority (EECA) was set up in 1992 by the government with the aim of promoting the uptake of energy efficiency, conservation and renewable energy. EECA's primary function is the dissemination of information on potential energy sources and their application.

EECA, with the help of the newly formed New Zealand Wind Energy Association, will soon be applying for a more accurate depreciation rate from the Inland Revenue Department (IRD) which will hopefully improve wind farm economics.

In the R&D area, the government will contribute NZD 660,000 (~USD 470,000) to wind energy related work through its Public Good Science Funding.

3. MANUFACTURING INDUSTRY

A New Zealand company "Wind Torque Limited" plans to begin production of a two bladed, teetering hub turbine which incorporates a "Torque Limiting Gearbox" to allow variable speed operation.

A demonstration "Diffuser Augmented Wind Turbine" (DAWT) has been developed and was installed in February to March 1997.

A low cost vertical axis wind turbine is being developed privately with the aim of producing a low cost turbine for developing countries. The machine is variable speed with a direct drive, and makes use of extruded aluminium parts. The developer is Owen Williams.

Local industry has the expertise to manufacture turbine towers, which was proven recently with the construction of seven towers for the newly commissioned Hau-Nui wind farm.

Interest has been expressed in the manufacture of wind turbine blades from the local fiberglass industry. Experience already exists in high technology, industrial applications.

4. ECONOMICS

On October the 1st 1996, New Zealand opened a deregulated wholesale electricity market. Wind power therefore competes directly with other forms of generation. Wholesale power prices can vary between 0.02 NZD/kWh to 0.11 NZD/kWh, however the overall average of the wholesale electricity price for October and November 1996 was approximately 0.04 NZD/kWh. Extra charges are applied to the wholesale price for transportation of electricity. The open electricity market therefore provides a natural incentive to produce electricity close to load sources which can allow electricity transportation charges to be avoided, and so increases the worth of electricity.

Wind farms constructed at the best sites in New Zealand are believed to produce electricity at a cost of between 0.055 NZD/kWh and 0.075 NZD/kWh given current wind turbine prices.

5. MARKET DEVELOPMENT

The commissioning of New Zealand's first wind farm will allow concerned parties to experience an operational wind farm first hand. It is believed that this will help to alleviate perceived negative effects of wind farms.

Recently the New Zealand Wind Energy Association (NZWEA) was formed which comprises of members from all parts of the wind power industry. The NZWEA's mission statement is "To promote the uptake of New Zealand's abundant wind resource as a reliable, sustainable and clean energy source".

6. GOVERNMENT SPONSORED R,D&D PROGRAMMES

The New Zealand government is funding wind power related research work through the Public Good Science Fund. Wind power consultants DesignPower have been funded by the government to revise the procedures for the prediction of energy produced by wind turbines erected in New Zealand's high wind speed conditions. A significant amount of energy can be lost due to high wind speed shut downs if wind turbines do not include appropriate control algorithms.