Bats About The Wind

Hello everyone!

With Halloween coming, you may be thinking of bats, so this post is about the impacts of wind farms on bats. Bats are affected significantly by wind turbines and many are found dead within wind farms. There are two main causes for bat fatalities and they are collision with the turbines (similar to birds) and barotrauma, which is when body tissue is harmed because of a very fast or very large change in air pressure. It’s kind of like when you’re in the plane and your ears feel blocked and you pop them but way worse for bats.

Bats which roost in trees could be more at risk in wind farms.
Photo by Vlad Kutepov on Unsplash

Bats are found to move towards wind turbines and one possible reason is that turbines look kind of like trees. A large proportion of bats which roost in trees and migrate were found dead in wind farms, which supports this hypothesis. This study found that bats tend are less likely to move towards wind turbines if the blades are spinning quickly and if the wind speed is high. This means that bats are more likely to hit the turbines at low wind speed, so raising the speed at which turbines start generating electricity could help to reduce the number of bat deaths. Turbine blades can also spin even if they aren’t generating energy, so it was found fewer bats died if the blades could be prevented from rotating at very low wind speeds. However, that could be a problem if we want to get as much use of the wind as possible, as lower cut-in speeds would help to increase the clean energy that we could get. On the other hand, since bats are an important part of ecosystems, we shouldn’t treat their deaths at the hands (blades?) of wind turbines lightly. After all, energy which harms animals isn’t clean.

The other reason for bat fatalities is barotrauma, where the bats can get serious internal injuries, especially in their respiratory system, if they fly near the spinning turbine blades. The anatomy of bats causes them to be extra vulnerable to the changes in air pressure, which results in barotrauma being responsible for many bat deaths in wind farms. Unfortunately, I couldn’t find solutions to prevent bats from flying near the blades so this is a big problem. I wonder if building a sort of fence/ cage around a turbine could prevent bats from being near to the turbines without affecting wind collected? Or would bats just fly into the cage and get hurt anyway if they cannot detect the cage? Hopefully, researchers will be able to figure out exactly why bats are attracted to wind turbines and find a way to stop it.

I hope this post has highlighted the dangers that wind farms pose to bats and that maybe someone will be able to figure out a better solution to prevent more bats from dying without affecting our green energy generation.

See you next week!

~Rayzel

The Birds and The Breeze

Hello again dear readers!

For this post, I will be looking into birds and their interactions with wind farms. I have already mentioned some impacts of offshore wind farms on seabirds in my previous post, but I will be looking more into the impacts of onshore wind farms on birds.

Kestrels are one species of bird which are at risk of colliding with wind turbines. Image by Daniel Polák from Pixabay

Other than noise pollution, wind turbines can also cause bird fatalities as the birds can collide with the turbines as they fly. As wind farms are generally established in places far from tall buildings, to take advantage of strong winds, these sites could overlap with the habitats of birds, which could result in a higher probability of collisions. Birds that use air currents to fly are also likely to be found near the wind farms. Collision rates depend on the species of bird, how tall the turbine is, the time of the year and many other factors. Before wind turbines are built, the local species and their flight patterns and behaviour should be factored in to reduce the chances of birds hitting turbines. While there is a wide range of collision rates (it is generally less than 1 collision per turbine in a year, but it really depends on the factors mentioned above), it should still be reduced as far as possible. A few birds per year is still a lot in the long run, so it shouldn’t be dismissed as insignificant.

Another impact of wind farms on birds is that their habitat is reduced, causing them to move away from their original living space. Similar to collision rates, the impact of habitat loss varies with the type of species present near the wind farm. Birds which live in habitats which have seen a lot of human influence are less likely to be affected by the construction of wind farms, while birds which live in more untouched areas are more likely to be displaced. Since birds tend to avoid human developments, the building of wind farms could really affect their populations because of the change or loss of habitat. Currently, there isn’t enough evidence to show that birds can adapt to the change in habitat, so I think that wind farms shouldn’t be built in places where there are many birds present. Maybe more research could be done to find out if birds could adapt to the presence of wind farms, like how the wind turbines in the sea can serve as a new habitat for marine life. I would suggest camouflage but that would cause the problem of collisions to increase if the birds can’t see the turbines, so I can’t think of any solutions other than ruling out bird-rich locations as potential sites for wind farms. (。╯︵╰。)

I hope that this post helps show how our desire to save biodiversity can conflict with our goal of producing cleaner energy.

Until next time!

~Rayzel

Return to the Sea

Hello again everyone!

Today’s post will be a continuation of last week’s, where I will be looking at other environmental impacts of offshore wind farms.

Building on last weeks post, when I said that seabirds could be more attracted to the turbines because they could find more food there, more prey may be found at the base of the wind turbines as the hard material of the base can become an artificial reef. Fish, mussels and other filter feeders are all examples of animals that may be attracted to the turbine bases. The measures taken to prevent the seabed from eroding around wind turbines, called scour protection, can also help to change the habitat. Placing artificial fronds around the base can help to trap the sediment, but these fronds can act in the same way as seagrass beds, providing a habitat for animals like seahorses and sea dragons who hang on to seagrass to stop themselves from drifting away. However, these could change the local biodiversity drastically as a previously unavailable habitat is suddenly present and ready to be colonised, possibly by invasive species. I think that this could still count as a possible benefit as there is a chance that the fishes attracted could be protected from fishing and maybe experience more population and biomass growth. This could lead to a possible replenishing of fish stocks and also more prey for seabirds like I mentioned last week. Wouldn’t it be great if offshore wind farms could provide clean energy and a new home for marine life? They could be helping the environment in more than one way!

Another possible factor affecting marine biodiversity is the electromagnetic fields that are formed by cables which transport the electricity to land. Animals which use electric or magnetic fields like we use GPS or maps could be affected in their hunting and identifying their position. However, currently, it cannot be concluded if there is a serious impact as there is not enough research or evidence. Still, I think that the cables used should be properly constructed and placed to protect these animals, just in case.  Hopefully, there will be more research or more conclusive evidence found in the future, so that we can be more sure when planning new wind farms!

I hope that these two posts have helped show that the environment can be affected by the presence of offshore wind farms, but depending on the location and how they are built and managed, they should still be able to bring many benefits to us.

Until next time!

~Rayzel

On the Land or On the Sea

Greetings dear readers!

Today, I bring tidings of offshore wind farms and how they impact the environment!

Offshore wind farms have turbines rising out of the sea like giant trees.

Last year, the top three countries with the most wind farms out at sea were namely China, the UK and Germany. China has almost 40% of the global share of offshore wind, which probably contributes greatly to its rapidly increasing wind power capacity. Building wind farms in the water has some benefits such as wind being more available and at higher speeds out at sea, allowing for more electricity to be generated. They also free up land for use since wind turbines need to be at least 7 times the diameter of the rotor apart, causing onshore wind farms to require a significant amount of space. As you can probably guess, these wind farms can also pose threats to the environment, such as emissions from the construction and transportation of the wind turbines as mentioned in my previous post.

Other than greenhouse gas emissions, possible threats to seabirds are an issue as, similar to land wind farms, birds could accidentally hit turbines while flying. However, research has shown that many bird species tend to avoid offshore wind farms. There are some that do fly near or through the wind farms, but there is a very low chance that they will hit the turbines as they fly far away from the turbines. In some cases, birds are attracted to the wind farms as there is more prey available for them there caused by the turbine’s foundation material providing a different habitat for marine life. This could mean that the risk of collisions would increase if the density of seabirds within the wind farm increases, but on the other hand, they could just fly beneath the rotors near the sea. Since the turbines are so tall and there is so much space in between them, I think the birds would be able to catch prey without a high chance of collision with the turbines.

On the topic of marine biodiversity, sea life within and around offshore wind farms could be affected by noise pollution (remember this?). When building the wind farm, ensuring that the wind turbines stay in place through a process called pile-driving generates a large amount of noise which can be heard up to 70km away from the wind farm. This could affect marine mammals including harbour seals, porpoises, dolphins and whales.  However, during the electricity generation phase, noise pollution is unlikely to be harmful to them, which is a relief as their communication will not be covered up. ε-(´・`)

As this post is getting quite long, I will continue to elaborate on the impacts of offshore wind farms in my next post.

See you next time! ( ´ ▽ ` )ノ

~Rayzel

Greenhouse Gas Emissions from Wind Farms

Hello everyone!

I couldn’t come up with a fun title for today’s post, so I hope you are not too disappointed by this boring thing! I’ll try my best to make my next post title more interesting to match with the rest and hopefully, this will be the anomaly (⁀ᗢ⁀).

Now, on to the real issue! Today, I will be focusing on the amount of greenhouse gas produced by the wind energy industry. I know what you’re thinking, isn’t wind energy supposed to be cleaner? It is, but that doesn’t mean that it produces zero emissions. Making the wind turbines, bringing them to the farms and the upkeep of the turbines are all included in the calculation of total emissions when scientists make what is called a Life Cycle Assessment. I think this is important as it would give a more well-rounded idea on how clean the entire operation is, rather than just one component aka the generation of energy part.

While there is some variability in emissions calculations due to assumptions made when information is not easily obtained, it is generally concluded that onshore wind farms produce less greenhouse gas than offshore wind farms. This is likely because more structural support is needed for the wind farms to be built at sea. Other reasons for the difference in results from different sources are the differences in turbine power output and the method of calculation. This source states that wind farms on land produce 0.082kg of carbon dioxide for every 1 megajoule of energy generated, while wind farms out at sea emit 0.130kg of carbon dioxide. Using the same example as my first post, one 3-room HDB flat in 2018 would produce 77.3096kg of carbon dioxide and equivalents per month if they used onshore wind. This is still way less than the current emissions for natural gas use (approximately 34,230kg for a 3-room HDB flat per month (o_O)), but it is not insignificant. Still, using wind energy could cut greenhouse gas emissions by a lot so countries should consider using wind power more if possible.

The moving of the wind turbines to the farms, the production of making the components of turbines and getting rid of spoilt turbines are the biggest source of emissions for wind turbine production, while there are negligible emissions when the turbines are collecting energy. On the bright side, most of a turbine can be recycled or used to build new turbines after it is no longer usable. One suggested solution is to build the factories where the turbines are made near to their operation site to reduce gas produced from logistics. Logically though, if wind farms are spread out around the country, I think that it would be hard and expensive to construct so many different factories. Also, wouldn’t building more factories produce more greenhouse gas emissions since materials are needed to construct them?

I hope that you now know more about greenhouse gases produced by wind energy generation and realise that although it is a greener energy source, the life cycle of a wind farm does emit greenhouse gases.

See you next week!

~Rayzel

The Blades on the Turbine Go Whirr

Salutations dear readers!

Today, I will be looking at the sustainability of wind energy. Wind energy is renewable and isn’t as taxing on the environment as say, fossil fuels, but there are still environmental problems associated with wind farms. Noise pollution is one issue and it is the focus of today’s post.

 

Wind turbines produce noise as both the machinery working and the spinning of the blades caused by the wind makes sounds. This sound is at a very low frequency (this means that it sounds deep, also, pitch is another word to describe frequency), but we can still hear it. Currently, the noise from the machinery is minimised due to improvement in turbine design which helps to block the sound, so the main noise issue is the sound the blades make when the wind blows past them. 

 

People are concerned as there are studies that show that this sound irritates people and could cause health issues such as sleep loss. However, studies on turbine related health issues can be contested as there is no hard evidence that their self-reported health problems were caused by the noise from wind turbines. Instead, they could be just blaming all their problems on the turbines because they were already prejudiced towards turbines. Besides, people are exposed to low-frequency sound even in places with no wind turbines. The wind blowing, the sound of my fan spinning as I write this and the noise of vehicles moving on the road are just some examples of sources of low-frequency sound in our everyday lives. As you can see, wind turbine noise is probably not the main cause of these issues.

 

Noise from wind farms could also affect animals living near them as animals might tend to stay away from wind farms because of the noise. On the other hand, some animals do frequent wind farms, which may be related to noise as well.  I will be looking into the impacts of wind farms on animals in later posts, so be sure to stick around if you’re interested in that!

 

Lastly, I’ll leave you with this fun video where the sound level produced by wind farms is compared with the sound in other areas.

See you next time!

~Rayzel

Turbine or not turbine

Hello and welcome back!

Today’s post is about how wind turbines work. The first obvious question is: What is a wind turbine? Is it the same as a windmill?

Windmills can look very picturesque and are tourist attractions in the Netherlands.

 

Well… no. As the name implies, windmills are structures which capture wind energy to perform actions such as making flour from grain (which is what mills do) or to draw water. On the other hand, wind turbines collect wind energy and convert it into electricity. This electricity is then funnelled to where it is needed, which includes homes, schools, street lights (in some countries) etc. In simpler words, windmills use wind energy directly while wind turbines turn wind energy into electricity for use elsewhere. 

This is a wind turbine I saw on my trip to Taipei a few years ago.

Next, how does a wind turbine work? When the wind blows, it causes the rotor blades of the wind turbine to spin, like when you blow on a toy pinwheel (this brings back childhood memories (◡‿◡✿)). This causes the turbine to gain kinetic energy from the wind. A generator then converts the kinetic energy into electricity. Click here for a cool animation on how turbines work.

 

Horizontal-axis (these are the ones we normally see on wind farms) and vertical-axis turbines are the two broad categories of wind turbines, which each have different pros and cons. Some sites abbreviated them as HAWT and VAWT 🤣, but I find it too funny so I won’t be using them. Horizontal-axis wind turbines need the wind to blow from the correct direction to where it’s facing to get the maximum energy possible, while vertical-axis turbines can capture wind blowing from any direction. Vertical-axis turbines also produce less noise than horizontal-axis turbines, which is a plus if the wind turbines are installed near residential areas. However, some vertical-axis turbine designs are less efficient and generate less electricity for the same amount of wind energy than horizontal-axis turbines.

 

Generally, wind farms have horizontal-axis turbines, probably because they are ‘easier’ to understand and are what people tend to think of when wind turbines are mentioned (practically all free stock images of wind turbines are horizontal-axis turbines and the rest are windmills 😒). Actually, the designs of vertical-axis turbines are less complicated, but the problem is that less research goes into improving them and is instead more focused on horizontal-axis turbines. I think that they should look more into using vertical-axis turbines as they are more adaptable than horizontal-axis turbines. While horizontal-axis turbines can change direction to better face the wind flow, the adaptations can cause the blades to crack from stress caused by the spinning of the turbine back and forth, which means that maintenance costs will likely be higher in the long run. 

 

I hope that you now have a better idea of what wind turbines are and do! If you have any doubts, feel free to ask them in the comments below.

 

Until next time!

Rayzel☘

I Can Show You The World (Of Wind Energy)

Hello and welcome, dear readers, to my blog!

My name is Rayzel and I am a year 1 Environmental Studies student, intending to specialise in Environmental Biology. I love reading, tea and listening to music… which pretty much explains my sedentary lifestyle. For someone studying the environment, I sure love staying indoors! o(^▽^)o

 

This is from when I went to Jeju Mazeland 🙂

I’m not sure when my love for the environment began, but I do think it was because I found one of my mum’s guidebooks to the wayside trees of Singapore (It’s really interesting and you can see it here). I would spend ages poring over it. My mum also has guidebooks to other native flora and fauna of Singapore, but this was the one that really held my interest. When I went out, I would examine the trees at the roadside and try to identify them based on what I read. My favourites included the yellow flame of the forest, the golden shower tree and the entire section on palm trees.

At the end of JC,  I didn’t have a clear idea of which course to study because I didn’t have a really strong passion for anything. Then, I decided on Environmental Studies because it seemed interesting and hope that my studies can help me to do my part for the environment in the future.

In this blog, I hope to open your eyes to the splendid world of wind energy. With some help from Dr Coleman (Thank you!), I narrowed down the scope of my previously-too-broad theme idea to the sustainability of wind energy. Did you know that in 2019, global wind power capacity was 651 Gigawatts(GW)? This is equivalent to 268 212 utility-scale wind turbines which could power about 2.5 million 3-room HDB flats! As you can see, wind energy can provide a significant amount of electricity, but there are also challenges being faced on the road to increasing wind power capacity. I hope that you have time to spare as I take you on this magic carpet ride to gain a deeper understanding of wind energy!

“A whole new world
(Don’t you dare close your eyes)
A hundred thousand things to see
(Hold your breath; it gets better)”

~Disney’s Aladdin

Until next time!

Rayzel☘

Skip to toolbar