Environmental impacts of wind power
Positive environmental impacts
Wind power requires no fuel and does not pollute the air, water or soil. Carbon dioxide emissions for wind power are approximately 10 g/kWh, emitted principally during construction, assembly, transportation and maintenance [1].
Wind power emits approximately 10 g / kWh of carbon dioxide and is mainly generated by the construction, transport and maintenance of wind turbines [1]. Depending on the way it is calculated, the wind turbine returns energy in its manufacture, transport, construction, operation and disassembly, in less than a year, even less than half a year.
The main positive environmental impact of wind energy is the reduction in overall energy system carbon and particle emissions. The size of this reduction depends on which other forms of energy generation are replaced by wind power. If wind power replaced coal fired power stations, the reduction in carbon emissions would be of the order of 800-900 gCO2/kWh. This is roughly the same reducing effect of wind power on greenhouse gas emissions as seen in Denmark, where there is a lot of coal-fired electricity production.
In Finland the majority of consumed electricity is produced using natural gas, hydroelectric and nuclear power, all of which produce less greenhouse gas emissions than coal-fired power stations. When wind power produces 10% of total Nordic electricity consumption, very little nuclear or hydroelectric production will have been replaced.
Given the structure of electricity generation in Finland, the initial effects of wind power on greenhouse gas emissions would be in the region of 700 gCO2/kWh. Once wind power accounts for over 10% of consumed electricity, the reducing effect on emissions would be 600 gCO2/kWh. When coal and natural gas fired power stations are completely replaced by wind power, the overall reducing effect on electricity generation emissions will be 300 gCO2/kWh [2,3].
Negative environmental impacts
As with all forms of energy production, wind power also has some negative environmental impacts. These environmental impacts can be divided into those caused during construction, during operation and during decommissioning.
The nature of the environmental impacts and in particular their severity is dependent on a number of factors, such as the size and method of implementation, the conditions on the site and competing land use. When wind power is constructed in an existing industrial setting, the environmental impacts (not including visual impacts) are indistinguishable from those of the existing industrial activities. However, if wind power is to be installed in sensitive natural areas (e.g. mountain crests or outer archipelago), a detailed environmental impact assessment is required. It is recommended that wind power is not built in the most sensitive areas.
With regard to landscape change, beauty is in the eye of the beholder: some consider the change in the landscape to be positive, others consider it negative.
Sources:
1. Arvensen A, et al, 2009. Extended life-cycle assessment for offshore wind power. Seminar presentation, European offshore wind conference, 15.9.2009.
2. Soimakallio, S, Savolainen I. (eds.), Technology and Climate Change CLIMTECH 1999-2002, Technology
Programme Report 14/2002 Final Report, TEKES, Helsinki 2002
3. Holttinen, H, Tuhkanen, S, 2004. The effect of wind power on CO2 abatement in the Nordic Countries, Energy Policy Vol 32/14 pp 1639-1652.