Small scale wind power: Impacts on nature and people
17 May 2012 | Fact sheet
Are you planning to fund, build or manage a wind power project? Have you considered the environmental, social and economic issues this can raise? Are you prepared to manage these issues?
Pacific Energy Projects: Impacts on nature and people
TYPICAL WIND POWER PROJECTS
Wind power uses turbines to convert kinetic energy from moving air into electrical energy. A consistent breeze is best for a reliable electricity supply, while intermittent breezes and gusts are less effective. Like most renewable energy, wind power is intermittent power.
Household wind power – these are small turbines (usually 1kW or less), mounted on existing buildings. They are raised on towers somewhat taller than the typical TV antenna, strength requiring suitably strong buildings and attachments. Batteries for storage complete the system.
Commercial wind power – large turbines can be over 100m high, with a capacity of 1 MW or more. Each turbine independently aligns with the wind direction, and has its own transformer. Together, these turbines form a wind farm, and must be located away from ‘roughness’, features that disrupt airflow.
WIND POWER PROJECT DEVELOPMENT
The best time to build positive outcomes and avoid negative impacts is during development and design. The best projects will weigh up the available wind resources, local environmental concerns, equipment options, and placement of individual turbines. For example, larger turbines, with taller towers and longer blades, have higher output, but need higher average wind speeds. Involving neighbours, and placing the wind turbines, are the two biggest factors in determining the social and environmental impacts.
The location determines the power output, the need for clearing, and the wider area of people and ecosystems affected. Sufficient knowledge and good planning is therefore essential.
Wind turbines are used globally, powered by clean energy with no wastes or air pollutants. The energy used to produce a wind turbine is quickly ‘paid back’, typically in under a year. Turbines can be a hazard to birds, bats, and even aviation if tall enough. In addition to the wind turbines and foundations, wind farms can require supplementary development such as access tracks and distribution networks, which must also be considered.
Wind power often affects a wide area. Consultation with stakeholders in the area is important to address potential concerns over noise and visual impacts. Modern turbines are quiet, but it is best to deal with this perception at an early stage. Design, size and maintenance of turbines all influence their impact. Where the blades cut through the line of sight of communications channels, they may interfere with radio, TV and other transmissions. As with other renewable energy technologies, wind power provides electricity to households and communities. This can enable lighting and productive activities in the evening, as well as improving quality of life. The technology is similar to other motor systems, requiring care, maintenance, and the associated skills and money. Failing to save money for maintenance and battery replacement can cause the system to fail giving a negative perception of the technology.
Increasing the number of wind turbines in an area can raises other issues. While a single turbine may be barely noticeable, many turbines can be a nuisance. As wind passes over the turbines, the interrupted flow is unsuitable for other turbines, an effect called ‘milling’. More turbines also increases the area of interference with bat and bird flight paths, and the likelihood of overlapping with telecommunications channels. Assessing a wind farm considers the turbines collectively, but for many small turbines good policies are essential.
Further information on additional resources can be found on the PDF available for download.