Wind Energy
New Zealand is fortunate to have excellent wind energy resources, some of which are some of the best locations in the world for wind energy farms. Nationwide, the potential capacity factors for potential locations with the capability to build wind power plants range from approximately 35% to 45%. Taking a typical example with a 40% net capacity factor, statistically speaking, this means that only 40% of the installed wind turbine's production capacity can provide reliable output in a year.
Due to the intermittent nature of natural wind, the actual power generation capacity varies from 0% to 100% of the installed capacity, which is subject to the erratic behavior of wind energy. For several wind farms, local differences in wind speed patterns generally provide some generation capacity. Although the cost of installed capacity of wind power stations is decreasing and is similar to that of current coal-fired power generation (in yuan/MW), the cost of truly safe power generation capacity is very high.
Compared to a solid energy coal-fired power station, a 150 MW coal-fired power station is expected to have a net capacity factor of 90%, resulting in an annual power generation of 1,182,600 MWh (90% net capacity factor x 8760 hours/year x 150 MW). For a wind farm to provide comparable stable production capacity, the installed size of the wind farm would require 337.5 MW (1,182,600 MWh/8760 hours/year/40% net capacity factor). The true cost of a stable wind power plant compared to a coal-fired power plant is therefore 2.25 times the actual installed capacity (337.5 MW wind / 150 MW coal). A typical wind farm has a production capacity of about 15 megawatts per square kilometer. This would require 2,250 hectares of suitable windswept ridges. That is equivalent to a ridge zone of 1 kilometer wide and 22.5 kilometers long. Although this sounds like a lot of land, the impact of wind farms on continuously used land is minimal, because wind turbines, roads and transmission lines occupy only 2% of the total land. Approximately 45 hectares. The aforementioned solid energy coal-fired power station will occupy a 60-hectare land, 1/3 of which will be used to store coal fuel and power station equipment. The remaining land is mainly used for greening, providing a green buffer zone to the public.
Wind energy generation also has its opponents, with some projects such as Awhitu (Manuaka Heads, Auckland) Quartz Hill (Makara, Wellington) and Baring Head (Wellington) failing due to a lack of resource support. Fortunately, perceived issues such as visual, aesthetic and noise issues have not prevented wind energy projects from continuing to develop, such as the Te Apiti and Manawatu wind farms.
There are some studies on the impact of large-scale wind power plants on local climate, and the conclusions are somewhat confusing. Some increase rainfall, some reduce rainfall, and some increase temperature., there is cooling, so the conclusion is not yet certain.
This is related to the basis for comparison of current research methods. After all, there are too many factors that affect climate, and it is difficult to completely exclude other influences. Therefore, the comparison results are difficult to be reliable, and they will also be different from those in different places. The climate environment is related.
The main factors that affect rainfall are the water content of the clouds and temperature changes. If the water content is high enough, the clouds are thick enough and there are changes in temperature, rainfall will occur. The most basic principle of wind power generation is that a conductor cuts a magnetic field to generate current (that is, magnetism generates electricity), and the mechanical energy generated by the wind pushing the windmill is converted into electrical energy.