Did you know wind energy was a form of solar energy? Well, now you do! Wind is the motion of air that results from the sun’s unequal heating of Earth’s surface. In other words, wind energy and the breeze we feel is what becomes of air that travels from the hotter portions of Earth’s surface into the colder regions.
These currents of air are what people ‘harvest’ by the use of wind turbines to produce wind energy or wind power.
To put ‘harvesting’ wind into simpler terms, a wind turbine converts kinetic energy of the wind into mechanical energy. This mechanical energy is then converted to electrical power with the help of a generator. It is then ready for distribution as this electric energy produced from wind goes through transformers and into appliance or equipment circuits.
Mechanical energy produced by the wind turbine doesn’t always need to be converted to electrical energy. It can be immediately utilized in specific tasks such as water pumping in farms.
Wind energy is a pretty neat power source. But there are a number of things to consider about it. It has its advantages and challenges as well as considerations when putting up a wind farm. But with the right circumstances, a wind farm may be able to provide as much as 1000MW to 5000MW of power.
Advantages of Wind Energy
There is no problem in harvesting wind continuously. Unlike its fossil fuel counterparts that run out, wind will have pretty much the same supply of resource in the future as it does now.
Wind power farms are known to generate between 17 and 39 times as much power as they consume, compared to 16 times for nuclear plants and 11 times for coal plants.
Wind energy produces non-polluting electricity. Unlike conventional power plants, wind farms emit little or no air pollutants and greenhouse gases.
In 2014, wind power avoided over 608 million tonnes of CO2 emissions globally. The number of CO2 emissions avoided further increased in 2016 with 637 million tonnes of avoided emissions.
Lower lifetime expenses
Building a wind farm requires a huge initial investment mostly on its machinery and installation. But throughout its lifetime, it costs less than conventional power plants which still includes fuel and operating costs.
Fluctuating fuel costs have no impact on wind power generation costs. It also operates in relatively minimal expenses. According to Lazard, wind costs have fallen 66% since 2009, from $140/MWh to $47/MWh.
Flexibility to demand
Wind energy projects are flexible with regard to an increasing energy demand. When demands increase, single turbines can easily be added to an existing wind farm.
Disadvantages and Challenges of wind energy
Each turbine can generate the same level of noise as a family car travelling at 70 mph. More of the wind is converted in rotational torque and some of it, into acoustic noise.
Most of the turbine noise is masked by the sound of the wind itself, and the turbines run only when the wind blows. In recent years, engineers have made design changes to reduce the noise from wind turbines. Early model turbines are generally noisier than most new and larger models.
Additionally, proper siting and insulating materials can be used to minimize noise impacts.
Avian/ Bat Mortality
Bird and bat deaths are one of the most controversial biological issues related to wind turbines.
Although several large wind facilities have operated for years with only minor impacts on these animals, the deaths of birds and bats at wind farm sites have still raised concerns from fish and wildlife agencies and conservation groups.
Careful site selection is needed to minimize fatalities and in some cases additional research may be needed to address bird and bat impact issues.
Intermittent energy production
Many critics often cite the fact that technologies like wind turbines only produce energy when the wind is blowing. The production of each turbine is dependent whether the wind is blowing hard enough.
It is challenging because intermittent production disrupts conventional methods for planning the daily operation of the electrical grid.
Large wind turbines are unsightly structures and not pleasant or interesting to look at. They disfigure the countryside and are generally ugly.
Even though it’s nice to place wind turbines aesthetically, efficient placing is still priority. Wind turbines are placed where harvesting wind is greatly optimized.
High initial investment and large land area used
Initial investment in building a wind farm is high. Approximately 75% of the total cost of a wind farm is related to upfront costs such as the cost of the turbine, foundation, electrical equipment, grid-connection and so on.
In regards to the land required, not all the land in a wind farm is used. Wind turbines must be spaced approximately 5 to 10 rotor diameters apart, so that they may operate more efficiently and lessen turbulence created by neighboring turbines and obstructions. An 80-meter (262-foot) rotor would need to be about 560 meters — more than a third of a mile — from adjacent turbines.
A rule of thumb is to install a wind turbine 150 meters away from any nearby obstruction, and at a height such that the bottom of the rotor blades will be 9 meters (29.5 feet) above the obstructions, including buildings and trees.
Wind farms aren’t concentrated in land. In fact, offshore wind farms exist. London Array is the largest offshore wind farm located in the outer Thames Estuary more than 20km off the coasts of Kent and Essex.
There are many other concerns for wind energy. But with proper siting and planning, these concerns are outweighed by the advantages it brings. More and more people have been investing in wind and solar technologies in producing electricity. Around 2014, wind energy supplies 3% of global electricity. That number increased to 3.7% in 2015.