Wind energy is one of the major renewable energy sources with a huge potential. It is estimated to play a key role in reducing our dependence of fossil fuels for power generation. In recent years, wind energy sector has witnessed a rapid growth, underpinned by technological advancements.
Wind turbine manufacturers are rolling out new designs to increase energy output from wind farms with reduced costs. Offshore wind power sector is also witnessing a fast growth due to technological innovations.
In its Global Wind Report: Annual Market Update report, the Global Wind Energy Council (GWEC) said that cumulative global wind power capacity grew by 12.6% to reach a total of 486.8 GW in 2016. The cumulative installed capacity is expected to reach more than 800 GW by the end of 2021.
Here are the pros and cons of wind energy:
Renewable: As it generates power from wind, the energy is classified as a renewable source. It does not have constraints compared to power generation from finite fossil fuel reserves. As wind is naturally occurring source of energy, there are no limitations to harness power from wind. The energy production from wind may last for eternity as long as there is availability of wind.
Image: Wind power plants in Xinjiang, China. Photo courtesy of Chris Lim from East Coast/Wikipedia.
Clean power: As wind power generation emits no harmful gases into the atmosphere, it is an environmentally friendly energy source. Compared to coal power plants and other traditional power generation sources, wind energy generation does not lead to releases of methane and carbon dioxide, which are greenhouse gases responsible for global warming. However, the manufacturing, transportation and installation of wind turbines cause slight pollution to the environment.
Cost effective: As operational costs involved in maintaining wind power plants are low, after the erection of wind turbines, they are considered to be cost effective. Further, wind power installations occupy less space compared other modes of power generation, bringing in increased operational efficiencies. Wind farms can also be built on agricultural lands, without causing any interruption to cultivation activities. However, maintenance of wind turbines may vary, as some need frequent checks.
Huge potential: Wind energy has seen a massive growth over the past ten years, occupying a significant share in the global renewable energy generation. Wind power generation is also getting cheaper with new strides in technology. Besides, there is growing policy support for the wind power industry, offering scope for further expansion of wind energy generation. Policy incentives for wind power generation are attractive in some countries. A study by the International Renewable Energy Agency (IRENA) showed that China, Germany, India and the US accounted for almost three-quarters of new wind energy capacity of 51GW in 2016.
Image: The MHI Vestas-built offshore wind turbine. Photo: courtesy of MHI Vestas Offshore Wind.
Drawbacks of wind energy:
Unpredictability: As it is difficult to predict the occurrence of winds, there may be fluctuations in power generated by wind farms. Wind turbines often operate at less half of their capacity due to unreliable winds. Sometimes, wind farms will not be able to generate any power if the weather conditions are not suitable for turbine rotations. In addition, wind turbine may get damaged in case of powerful winds, causing an obstruction to electricity generation.
Site suitability constraints: Wind power can only be generated in locations where winds blow at high speed. Limited availability of such sites has remained as a major constraint in the development of wind power projects. Urban places may not provide suitable conditions for construction of wind power projects. The limitations have restricted the growth of wind power projects worldwide. However, recent innovations in design and turbine technology for wind power are expected to offer a potential to increase the installed capacity of wind farms plants.
High capex: Compared to other forms of renewable energy like solar, wind power projects need huge capital expenditure. As the wind farms are mostly located in remote areas, new high-voltage transmission lines need to be constructed to supply power generated by those facilities to households in the residential areas. So, additional costs need to be incurred to build those lines, which increase the overall capital expenditure involved to develop a wind farm. In case of offshore wind energy, submarine cables are required to bring the generated power to electricity grids. As installation of such cables involves considerable costs, the development of an offshore wind farm requires huge investment.
Environmental effects: Though wind power facilities emit no pollutants, there are some effects on the environment that result from operating them. A rotating wind turbine can lead to death of flying creatures like birds, if there is direct collusion. Some environments have severely criticized the damage caused by the wind farm to the wildlife. Besides, noise created by the rotating wind turbine can be a severe problem to the people living in the vicinity of wind farms. However, in case of offshore wind, there is no noise pollution. Wind turbine companies have rolled new designs that generate low noise.
Visual impact: As wind turbines are usually located in open places, the high visibility of turbines is found to cause an aesthetic impact to the landscape. However, aesthetic issues can be avoided by making proper siting decisions. To partially avert visual impacts, siting of fewer turbines in a particular location is one of the techniques that have been advised by experts. Using of new larger and more efficient turbine designs can also address the issue.