In 2011, the worldwide population exceeded 7 billion. This is well up on the earths population at the beginning of the last century when there were just 1.6 billion people. This rapid rise in human numbers is unprecedented and threatens the very well-being of the planetary systems on which all life depends. As population grows bigger and bigger, there is an increased demand for food, water, housing, and other resources including energy.
The bulk of energy we use comes from non-renewable fossil fuels such as coal, oil or natural gas. We burn these fuels in power stations to make electricity or in combustion engines as transport fuels. The combustion of fossil fuels results to an increased concentration of carbon dioxide in the atmosphere which can then lead to global warming. Much of the easily accessible oil will be gone in 50 years (figure 3) and coal will be scarce in 200 years. As more and more fossil fuels are used those that are the easiest to find will be used up first. As time goes on it will be harder to find new reserves of fuels and the cost of extracting them will increase.
The use of renewable energy sources to provide electricity is rapidly increasing in popularity among proprietors and companies. The increasing use of natural and renewable energy sources is needed to help relieve us of our current dependency on fossil fuels. The significantly high level of fossil fuel products burnt each and every day is polluting of the air and surrounding environments and may also be contributing to climate change.
Renewable energy sources are those that can regenerate in a relatively short time such as solar, hydroelectric, geothermal and wind. All of which harness the earths power without the need to destroy it.
Wind energy, currently the cheapest renewable energy source, involves the generation of electricity from the naturally occurring force of the wind. Sites where there is strong, consistent wind, such as Southern Australia, are the most appropriate locations for wind farms. An excellent wind site is generally considered to deliver average wind speeds larger than 8 metres per second at sea level.
Australia has some of the worlds best wind resources. The total operating wind capacity at the beginning of 2011 was 1991 megawatts. The amount of installed capacity of wind power has increased by an average of 30 per cent a year over the past decade. Wind energy supplies over 5,100 gigawatt hours of electricity annually around 2 per cent of Australias overall electricity needs.
Currently there are 53 operating wind farms in Australia, with a total of 1089 operating turbines. South Australia has the largest installed capacity with around 51 per cent of the nations total wind capacity. In 2010 estimated wind energy generation saved Australia 5,100,000 tonnes of carbon dioxide. That is equivalent to the removal of 1,133,000 cars from our roads. As an additional environmental benefit, no water is needed for wind farm operation.
The use of wind power continues to grow around the world. Global installed capacity at the end of 2010 was almost 194 gigawatts a 22 per cent increase on 2009.
In 2010, around 36 gigawatts of new wind capacity was installed around the world with a value of around $US65 billion.
- China 42,287 MW
- United States 40,180 MW
- Germany 27,214 MW
- Spain 20,676 MW
Wind farms have various societal, commercial, ecological and health implications. The most noticeable impact a wind turbine places upon the people in the surrounding environment is noise pollution. It also has the potential to lower property values within a varying radius of construction. Nina Pierpont, a paediatrician based in New York, conducted a research that suggests that people living close to wind turbines are vulnerable to what she calls Wind Turbine Syndrome (WTS), an illness with symptoms including sleep disorders, heart disease, panic attacks and headaches.
Another disadvantage regarding a wind turbine and its impact on the surrounding environment can be expressed with the term visual impact or visual pollution. Some people believe wind turbines actually look quite nice, yet many people disagree seeing turbines as a scare on the landscape.
Bird deaths are a cause for concern and a key biological issue related to wind turbines. The number of birds that perish at the arms of wind farm sites created an outcry from fishing and wildlife agencies and conservation groups like PETA. On the other hand, several large wind farms have functioned for years with only minor impacts on such wildlife. Also tied in with this matter is the construction of wind turbines. As with many other developments, wind turbines require deep bases, and this has the potential to abolish underground habitations, and disrupt surrounding ones.
Unlike most other generation technologies, wind turbines do not use combustion to generate electricity, and hence dont produce air emissions. The only potentially toxic or hazardous materials are relatively small amounts of lubricating oils and hydraulic and insulating fluids. Therefore, contamination of surface or ground water or soils is highly unlikely. The primary health and safety considerations are related to the movement of the fan blades and the presence of industrial equipment in areas possibly accessible to the community. A supplementary concern associated with wind turbines is potential interference with radar and telecommunication facilities. And like all electrical generating facilities, wind generators produce electric and magnetic fields.
One of the limitations of wind power is that consistent wind is needed for continuous power generation. If wind speed decreases, the turbine lingers and less electricity is generated.
Even though wind power has minor disadvantages it is still an excellent alternative to fossil fuels. Wind power produces no pollution that can contaminate the environment, since no chemical processes take place, unlike in burning of fossil fuels, in wind power generation, there are no harmful by-product left over. Also, since wind power is a renewable source of energy, it will always be available for use and the world will never run out of it. Wind farms can also be built off-shore. Farming and grazing can still take place on land occupied by wind turbines which can help in the production of biofuels. By using renewable energy sources such as wind power were able to make the remaining oil, gas and coal supplies last longer.
The initial investment of wind turbines can be expensive, yet it is capable of paying for themselves over the years of operation. Government grants are also available to households and businesses switching to renewable energy system.
The current and prospective policy environments within which a wind farm is operating are central to the effectiveness and competitiveness with which it operates. Direct support through subsidisation or favourable tax policies or indirect support for renewables from costs imposed on greenhouse gas emissions will enhance the competitiveness of wind energy. In Australia growth of wind energy is favoured by the Renewable Energy Target, proposed reductions in carbon emissions and the new proposed carbon tax.
The Renewable Energy Target (RET) scheme was implemented by the Government in August 2009. RET is designed to deliver on the Governments commitment to ensure that 20 per cent of Australias electricity supply will come from renewable resources by 2020. In ten years time the amount of electricity coming from sources like solar, wind and geothermal will be around the same as all of Australias current household electricity use.
The carbon tax has had an adverse effect on the growth of wind energy. The Carbon tax taxes sources which emit carbon dioxide. Carbon taxes address a negative externality. Externalities arise when an individual production or consumption activity imposes costs or benefits on others. By placing a cost on these negative externalities the underlying purpose of a carbon tax is to reduce emissions of carbon dioxide and thereby slow global warming. It will be executed by taxing the burning of fossil fuels like coal, petroleum products such as petrol and aviation fuel, and natural gas like CSGin proportion to how much carbon they add to the atmosphere.
Other current management policy of wind farms is identifying suitable locations for wind energy facilities, it should not lead to unacceptable impacts on critical environmental, cultural or landscape values.
Although wind farms have quite significant negative impacts on the surrounding environment, I would still support the increased use of wind power, as long as wind farms are sited, designed and managed so they do not harm birds and their habitats.
The wind industry and government agencies should sponsor research into collisions, relevant bird and bat behaviour, mitigation measures, and appropriate study design protocols. In addition, project developers should be required to collect data through monitoring efforts at existing and proposed wind energy sites. Careful site selection is needed to minimize fatalities and in some cases additional research may be needed to address bird and bat impact issues. Landscape and cultural heritage values of the land should be considered also when identifying suitable sites for wind energy. It is recommended that wind turbines should be built at least 2 kilometers (a little over a mile) away from peoples homes
Government agencies should also sponsor medical research into the illness called Wind Turbine Syndrome. Project developers should be required to collect data through monitoring people living at close proximity to wind turbines.
Other improvements can also be made to address issues concerning wind power generation/wind farms such as the government continuing to provide sponsorship in investing more into wind farms and continuing to provide incentives and rebates to encourage individual households to invest in wind energy and other renewable energy resource.
A new way to cater for the increased demand of energy can be ecologically sustainable, and that is generating renewable clean energy from the wind.