When I heard about the bat mortality rate caused by wind turbines in a recent conversation, I wondered how many bats really die every year by this cause. So, I did some research to find out if wind turbines are sucking the life out of bats.
Are wind turbines sucking the life out of bats? Wind turbines have been proven to be the cause of a large percentage of bat deaths all over the world. In fact, over three-fourths of bats that die every year were killed by wind turbines in one way or another.
There have been multiple rumors about wind turbines being the cause of wildlife deaths, especially smaller flying species like bats that could come in contact with the blades. This subject has not only been a topic of conversation, but there has also been a significant amount of scientific research behind it. So, how many bats really die every year from this cause and how can that be prevented in the future?
Related: The Cost of Harnessing, Transmitting, and Using Wind Energy
How Bats Are Killed By Wind Turbines
The bat mortality rate every year that is caused by wind turbines is shockingly high. With millions of bats suffering from the spinning blades and air pressure surrounding these massive machines, they are responsible for approximately three-fourths of all bat deaths every year. That’s almost one hundred percent of all bats killed everywhere in the entire world every single year.
Part of the reason why bats are affected so negatively by wind turbines is the fact that there are multiple causes of turbine-related deaths that the animals could fall victim to. The first and most obvious cause of death occurs when the bats fly too close to the turbines as they are spinning and get caught up in the blades.
Each blade on a wind turbine is several feet long and extremely heavy in order for the machine to effectively intake the wind’s energy. Since the rotor blades can spin at very high speeds, some reaching almost 200 miles per hour, the impact will cause instant death to the tiny flying animals in most cases.
Alternatively, the bats could not come in direct contact with the turbine blades at all but still suffer serious injury or death as a result. This is directly caused by the levels of turbulence that are created between each of the turbine’s rotor blades. When they spin at a rapid speed in reaction tothe pressure of the wind, the blades begin to rotate at extremely fast speeds.
The air that is being rotated between the blades so quickly causes the entire vicinity of the wind turbine to release significantly higher levels of pressure into the atmosphere around them. As a result, the bats that are flying around the turbines will have trouble breathing in the high pressured air and it will eventually cause their lungs to explode, killing them from the inside out.
Unfortunately, it doesn’t require coming into direct contact with the machines for these small creatures to feel the effects that come with them.
Although these causes of death are widely known among scientists and wind turbine owners, it is very hard to prevent them from occurring for a variety of reasons. First of all, the time frame of the bats’ migrating and mating seasons cannot be controlled, so there is really no way to avoid the high probability of the animals flying through areas full of wind turbines during certain seasons throughout the year.
Additionally, there is virtually no way of regulating when and where the bats fly through the atmosphere in the first place.
What Attracts Bats to Wind Turbines
In addition to the seasons throughout the year in which bats have more of a presence flying through the air, there are certain factors that actually attract the animals toward the wind turbines. Most of the wind turbines that are found all across the world today are painted the exact same color: white.
The color white has been chosen for wind turbines for a wide range of logical reasons including the aesthetic and protective properties it can offer to the large machines. However, this choice of color is not so beneficial to the animals that fly around in the area and frequently fall victim to the fatal machines.
When the sunlight shines down on the wind turbines during the day, the light that is given off is reflected by the light colored paint. The turbines are essentially shining or glowing and stand out against everything else that surrounds them as a result.
This attracts swarms of flying bugs that will either gather in areas as close as they can get to the shiny reflective surface or land on the actual machines. So, how does this affect the bats if there are bugs around the turbines?
Well, since a bat’s diet consists of bugs and their daily flying patterns include hunting for their meals in the air, the bats are also lured closer to the wind turbines. They might land on the turbines before they start spinning or completely disregard the rotating blades as they are pursuing their dinner.
This can be detrimental to them, because when bats are anywhere near these machines they tend to have a high probability of serious injury or death, in one way or another.
The number of bat deaths that occur each year can also damage nearby farms, as bats usually serve as a form of pest control among crops. If the species become extinct in the future, it could be bad news for crop farmers.
Studies showing the relationship between bat mortality and wind turbines
There was a recent study that was performed with the objective of gaining information about the actual death toll of bats around the world that are caused by wind turbines every year. This study took place in the Appalachian Mountain region.
The scientists that took the lead in this study began by observing the local bats in the area and taking notes of their daily patterns and routines. They also took the time to track the exact flying patterns of where the bats flew and when they did it. Throughout the duration of the study, the bat fatalities were recorded and statistics were created from that information.
The results of the investigation concluded that wind turbines actually do account for three-fourths of bat deaths every year. Although there was no exact quantity of bats in the area or knowledge of exactly how many bats exist in the world as a reference point, this study confirmed the increasingly high mortality rates that wind turbines have inflicted on bats for many years.
How wind turbines can improve to harm less bats
In regards to the topic of bat fatalities caused by wind turbines, there have been some helpful ideas proposed by various scientists over the years that could potentially lower the fatality rates caused by these machines.
Since it has been acknowledged that the bright white paint color that coats mostly all of the wind turbines that exist across the globe has inadvertently attracted several bugs toward these areas, there have been recent arguments for painting wind turbines an alternative color instead.
The new paint color would have to be much less reflective and be proven to attract fewer bugs to ultimately keep the bats as far away from danger as possible.
A scientific study was performed specifically to determine which color would be the best replacement for white on wind turbines everywhere. The research began with a series of colored cards that were placed in a row and illuminated by a bright light one by one.
As each colored card displayed its reflection into the air, the number of flying bugs that flew toward it was recorded. The results of the entire study showed that the color purple was the least attractive color in the eyes of the flying bugs out of all other options.
As a result, there have been multiple debates between scientists since this information was discovered, rooting for wind turbines to have a paint makeover and become purple.
However, there are just as many people who are against this adjustment due to the aesthetic properties of purple turbines in nature as well as the potential damage that could be done to the inside of the turbines if the sunlight is not correctly averted away from the machines.
An additional way to prevent bat fatalities by wind turbine throughout each year is to simply turn off the machines during certain seasons when the bats will most likely be flying through the area. The most common migration seasons for bats is around the fall season when there are very small amounts of wind in the atmosphere anyway.
Many scientists that are interested in protecting wildlife have argued that there is virtually no reason for the turbines to remain functioning throughout the entire year, especially during a season where there is barely enough wind to harness and convert.
Some people would argue that the use of electricity in an entire region couldn’t just stop to protect the bats, however, this practice actually would not affect the energy supply and demand as much as you would think.
Thanks to new technology that allows wind turbines to compress the excess energy provided by the wind in order to save it for later use, additional energy supply could be harvested throughout all of the other seasons to supplement for the times the wind turbines are not functioning.
On the other hand, wind turbines could still be left on during bat migration seasons, but just turned off purposely during their frequent flying times.
Other scientific studies that were conducted around the relationship of bat fatalities and wind turbines tested how effective certain methods of protecting bats would really be. In response to the idea of putting a stop to wind turbine rotation in the event of low wind speeds and seasons where there is not much wind in the atmosphere, to begin with.
They set out to validate and prove the point that holding the blades of wind turbines in one place more frequently would cut down on the majority of injury and death that bats endure when they inevitably come in contact with the powerful machines.
The conclusion of this specific study was that all bat deaths could be reduced by up to 90 percent if this plan were to go into effect all over the world. This theory had its fair share of opposition, with the popular argument that this would cause a large amount of energy loss.
However, it was further proven throughout the duration of the study that this claim is actually false.
The effects of wind turbines on other flying animals
Wind turbines have also been known to have adverse effects on other species of wildlife besides just bats. Along with the study that was conducted in the Appalachian Mountains in regards to the bat death statistics in the area, there have been numerous scientific studies that focused on the fatalities of birds when they come in contact with the machines.
Similar to the bats’ cause of death, there have been frequent reports of birds flying through areas with heavy wind turbine presences and getting caught up in the spinning blades. In a 2014 study, it was concluded that there were almost half a million bird deaths that occurred each year due to wind turbine blades alone.
Sadly, many people in the wind industry will argue that wind turbines do not account for nearly as many bird deaths as other more common causes of death that they can run into in more populated areas.
To wrap this up, it can be concluded that wind turbines do cause a lot of harm to bats and various other species of flying animals. While most of these negative effects cannot be controlled or avoided, there is an equal amount of helpful suggestions that could potentially reduce the wildlife fatalities that are caused by the blades of wind turbines every year.
Related Questions
What effects do wind turbines have on other animals and livestock?
Although there have been many stories told by farmers over the years about the animals on their farms reacting strangely after the appearance of wind turbines in close proximity to the area, there has been no actual scientific evidence to back these theories.
However, there are published books that describe various accounts of these events all over the world, including Wind Turbine Syndrome by Nina Pierpont. Some of the stories that are told in this book include chickens laying eggs with no shells and horses miscarrying or not being able to feed their children.
An additional claim came from a farmer in Taiwan, who discovered over 400 of his goats lying dead in the grass following the construction of a nearby wind turbine farm. Since the goats had been behaving normally before the wind turbines had appeared adjacent to his animals, it was only right for the farmer to assume that they caused the accident.
He had also reported strange behavior among the goats in the short time leading up to their deaths after the turbines had already been installed.
Do wind turbines have any other adverse effects on the environment?
Since wind energy is a natural and renewable resource, there are very little known adverse effects that wind turbines have on the environment around them. Although many people claim that the buzzing noise let out by the large machines can send harmful rays out into the atmosphere potentially harming the people and animals in its path, there is no scientific evidence of these stories being true either.
There is one more common belief about the waste that wind turbines have the potential to produce. This only applies to wind turbines that are constructed with rare earth materials that are usually mined in and imported from China.
Although there are no visible and immediate effects on the environment directly in the location of the wind turbine, Chinese cities are suffering from intense pollution and gigantic lakes of toxic waste.
Luckily, most wind turbines do not use these toxic materials within them. It was reported that only 2 percent of all wind turbines on the earth have a presence of these rare earth materials.
How Fast Can Wind Turbine Blades Actually Spin?
The blades of a wind turbine react to the pressure that is applied by the current wind speeds and rotate accordingly. Depending on the size of each individual wind turbine, some of them have the ability to reach a maximum speed of up to 180 miles per hour.
The average residential wind turbine, however, will most likely reach maximum speeds anywhere from 50 to 100 miles per hour. These speeds are determined by the minimum and maximum speed thresholds that are programmed into every wind turbine at the time they are constructed and installed.
These limits are put into place for maximum efficiency of the machine as well as to protect the parts of the turbine and prevent any unnecessary damage.
Learn More
If you’re serious about learning more about wind energy, I recommend the Wind Energy Handbook on Amazon. This book is great for both students and professionals, and it holds invaluable information on the subject of wind power.