The bottom line is that everything and everybody has an impact on the environment. Regardless of size, energy requirements, output or impacts. There are affects which we might calculate into the model or chose to ignore. Regardless of our choice of action, impacts exist. Wind farms as an alternative energy source is no different. Yes, they appear to be relatively clean and free, with lower impact than the traditional energy sources.
But what is the hidden environmental and social cost of wind power generation? Keep reading to know the answers:
Countries have already made large-scale transition to low carbon emission sources of energy. There are vast swaths of land populated with towering wind turbines that stretch as far as the eye can see. As with every major development, the environmental impact reports and assessments highlight the positive and negative aspects of the new development versus the traditional or standard method of using coal and/or gas to generate power.
Research papers published in the USA have highlighted the land demands of wind and solar power sites within the USA. To meet the energy demands, yes wind and solar are far more favourable in ecological terms. But in mere spatial terms, the amount of land required to generate energy to meet the growing demands far exceeded initial estimates.
Land requirements can be anywhere between five to 20 times the land area initially calculated. These massive or large-scale wind farms could in fact, warm average surface temperatures. It has been estimated that over the continental U.S. the surface temperatures could increase by 0.24 degrees Celsius.
It is now very well understood that low-carbon technologies do have social and environmental impacts. To tackle this issue, estimates and calculations of environmental impact from low-carbon technologies on very expansive areas of land and/or water are required. The burning question is how much land or how much water is required to generate electricity that will meet future energy demands.
According to current thinking (for the past decade) it is considered that wind power generation has been over-estimated as the earlier calculations did include consideration of the interaction between the wind turbines and natural environment. But this interaction between structure and nature was underestimated.
The under-estimation is primarily due to the “wind shadow” created by the wind turbines themselves. This wind shadow effect slows down the turbine blades which reduces the amount of power generated compared to what was originally calculated on the draughting table. This means that turbines need to be spaced further apart to reduce the impact of the wind shadow. The reality is that the energy demands will continue to grow and its not feasible to consider and endless expanse of wind turbines covering the land. Eventually, the interaction and climate impact from wind energy generated power will be less avoidable.
Now that wind-generated and solar-powered electricity plants are up and running, there is real data to analyse and calculate the average power density factor. It appears that wind farms that are more than 5-10 kilometers deep there is major impact on the power density component.
It appears that the average power density of wind-generated electricity plants is lower than the average power density of solar farms. This means that more land is required to achieve the predetermined renewable energy target for any one site. This leaves the climatic impact of ever larger wind farms open for further discussion and calculations.
140MW Windfarm near Tangiers in Morocco
The largest environmental impact will occur during the night when the turbines are actively continuing to mix the atmosphere near the ground with the air aloft when untampered natural environment would experience more still air without the enhanced mixing. Calculations suggest that the surface temperature in the night hours could increase by as much as 1.5 degrees Celsius.
The in-situ measurements have been compared with satellite-observations in various US states and similar temperature increments were observed and/or calculated. These warming effects will be localised depending on the operation size of the wind-power electricity plant. A key factor in these sorts of calculations is whether one is assessing for short term impacts of over a ten-year period or calculations are over a considerably longer period of hundreds of years.
A note to end on that must be considered in this debate is that the direct climate impacts of wind power are instant and immediate, whereas the benefits of reduced emissions accumulate slowly over time.
