Tag Archives: wind turbine

World’s first recyclable wind turbine blade closes the sustainability loop in wind energy

Credit: Pixabay.

While up to 85% of a wind turbine’s parts can be recycled, its blades have remained a constant thorn in the industry’s side. While that remaining 15% might not seem like a big deal, it’s worth remembering that wind turbines are behemoths, whose blades measure at least 40 meters nowadays and can weigh seven tones. We expect thousands of wind turbines to be decommissioned over the next few decades, so that translates to a lot of waste destined for landfills.

Although these blades are non-toxic and, technically speaking, safe for landfills, the lack of recycling options is seen as inherently incompatible with the wind industry’s commitment to sustainability and full circularity.

But all that may change for the better. This week, Siemens Games, one of the world’s leading wind turbine manufacturers, announced “the world’s first recyclable wind turbine blades ready for commercial use offshore,” an exciting move that may finally transition turbines close to 100% sustainability.

The new recyclable wind turbine blades. Credit: Siemens Gamesa.

The company’s product, aptly dubbed RecyclableBlades, measures 81 meters (266 feet) in length and is made of composite lightweight materials cast together with a special resin. Once the blades are ready to be decommissioned at the end of their lifecycle, the resin can be separated from the components thanks to its specially designed chemical structure.

“This mild process protects the properties of the materials in the blade, in contrast to other existing ways of recycling conventional wind turbine blades,” according to a press release from Siemens Gamesa.

The first operating RecyclabeBlades are scheduled to be installed at the Kaski offshore wind power plant in Germany, a joint project with RWE Renewables that is excepted to be completed from 2022 onwards. The first six ReyclableBlades have already been manufactured at a factory in Aalborg, Denmark.

Conventional turbine blades are typically made out of a combination of balsa wood, carbon fiber, and glass, bound together by stiff resin. However, this glue is too powerful for its own good, and separating the components is very costly — to the point that isn’t economically feasible to do so.

Many wind turbines currently operating in Europe and elsewhere across the world are part of the first generation that was installed in the 1990s, and are now nearing the end of their lifetime. By 2030, as many as 6,000 individual wind turbines per year could be decommissioned, resulting in massive blade graveyards.

There’s not all that much we can do about these old blades. In some cases, they can be reused for new projects, but this is only viable for a small fraction of turbines. New technologies, such as those pioneered by Spanish startup Reciclalia, which eliminates organic matter and separates the glass and carbon fibers, are also useful.

By the end of this year, Reciclalia claims it will be able to recycle 1,500 blades a year. That’s actually pretty good, but going forward the next generation of recyclable blades will make this process a lot easier, cheaper, and hopefully cover close to 100% of newly installed wind energy projects.

Once separated from the composite material, the RecyclableBlades components won’t be suitable for new wind turbine blades as they won’t be able to withstand typhoon conditions. Instead, their technical and physical properties will make them suitable for the auto and boat industry, or even for consumer goods.

Based on estimates of new offshore wind projects, Siemens Games expects that more than 200,000 blades could now be recyclable until 2050. Other companies will likely follow suit. Vestas, another leading wind turbine manufacturer, said it aims to produce “zero-waste” turbines by 2040, while GE Renewable Energy recently signed a deal to recycle blades from onshore wind projects in the United States.

How wind turbines work — here’s what you need to know

They look like airplane propellers running circles on the spot, spinning round and round all day long. Wind turbines take the kinetic energy from the wind and use their giant rotors to capture some of it turn it into electricity, and they may play a key role in saving us from catastrophic climate change. Let’s take a closer look at how wind turbines actually work. 

Image credit: Flickr / Richard Edmond

Wind turbines are based on a simple principle, in essence: the wind turns the blades, which causes the axis to rotate, which is attached to a generator, which produces electricity. The stronger the wind, the more electricity is generated. That’s why we usually see industrial-scale wind farms with high towers and large blades across the world: larger blades can gather more power and are more efficient. But while the basic principle is simple, the technology is complex.

Windmills make the world go round

A turbine is a machine that spins around and catches some of the energy passing by. All sorts of machines use turbines, from jet engines to hydroelectric plants. In a wind turbine, the rotor blades are the “turbine” part, similar to airfoil wings on a plane. They have a curved shape and gain kinetic energy (energy of movement) when the wind blows. 

Although we talk about “wind turbines,” the turbine is actually just one part of these machines. For most turbines, another key part is the generator, whose gears convert the relatively slow rotation of the spinning blades into higher-speed motion. So the wind provides the movement and torque and the generator does the rest, being an essential part of all turbines. 

The longer the rotor blades, the more energy they can capture from the wind. The blades multiply the wind’s force like a wheel and axle, so a breeze is often enough to make the blades turn around. Even so, wind turbines don’t generate maximum power most of the time – a deliberate feature of their design to work efficiently in ever-changing winds. 

A typical wind turbine nacelle is 85 meters (280 feet) off the ground, and there’s a good reason for this. Wind travels much faster when it’s clear of any obstructions at ground level. So if a turbine’s rotor blades are high in the air, they can capture much more wind energy than they would lower down — and capturing energy is what wind turbines are all about. 

Most wind turbines have a capacity of 2-3 megawatts (MW), which can produce over 6 million kilowatt-hours (kwh) of electricity every year. That’s enough to meet the electricity demand of around 1,500 households. The faster the wind blows, the more electricity is generated – up to a certain level. If the wind is too strong, the turbines will shut down to prevent damage. 

Wind farms are planned to make sure they’re in locations with a reliable amount of wind all year round. This tends to be on the summit of a hilltop with lots of open space around, and in coastal locations. A wind turbine is typically 30-45% efficient – rising to 50% efficient at times of peak wind. If they were 100% efficient, the wind would drop after going through the turbine.

Types of wind turbines

There are two basic types of wind turbines, horizontal-axis and vertical-axis, and the size of the turbine varies widely. The length of the blades is the biggest factor in determining the amount of electricity a wind turbine can generate. While small turbines can generate about 10 KW, the largest one in operation can generate up to 10MW. Even larger ones are currently in development, especially for the offshore. 

Horizontal-axis turbines are the most common by far — these are the wind turbines most of us are familiar with. Most of these turbines have three blades and operate upwind, with the turbine pivoting at the top of the tower so the blades face into the wind.

Meanwhile, vertical-axis turbines are more similar to an eggbeater than to an airplane propeller. They are omnidirectional, which means they don’t have to be adjusted to point into the wind to operate. The blades are attached are the top and bottom of the vertical rotor. As they don’t perform as well as horizontal ones, they are much less common, but they do offer great promise in some situations

Using wind turbines

Land-based wind turbines can be connected to a utility power grid, combined with a photovoltaic system or even be used as stand-alone applications by homeowners and farmers. For utility-scale (megawatt-sized) sources of wind energy, a large number of wind turbines are usually built close together to form a wind plant, also referred to as a wind farm. 

When turbines of any size are installed on the “customer” side of the electric meter, they are called “distributed” wind turbines. Most turbines currently found in distributed applications are small and are used for residential, agricultural, and small industrial applications.

Having a turbine can even give you profits, as you can sell the extra energy that you don’t use (if the national grid allows it). However, installing a wind turbine is generally more complicated than something like a solar panel.

Image credit: Flickr / Paul

Offshore wind energy is a relatively new industry around the world. The turbines tend to be massive, even taller than the Statue of Liberty in some cases. Their components are transported by ships and barges, reducing the logistical challenges of land-based turbines. They can capture powerful ocean winds and generate vast amounts of energy. 

The electricity produced by offshore wind turbines travels back to land through a series of cable systems that are buried in the seafloor. This electricity is channeled through coastal load centers that prioritize where the electricity should go and distributes it into the electrical grid to power homes, schools, and businesses. This makes offshore wind turbines more expensive to install and manage, but they also produce more energy — a common tradeoff.

Advantages and disadvantages of wind turbines

It’s hard to imagine why anyone would object to clean and green wind turbines, especially when compared with dirty coal-fired plants. But they do have some disadvantages that need to be considered carefully.

Firstly, they don’t generate as much power as conventional gas, nuclear, or coal plants. A typical turbine has a maximum power of 2MW, enough to supply 1,000 homes, if it produces energy 30% of the time. The largest offshore wind turbines can make about 13MW as winds are stronger and more persistent at sea, powering about 6,500 homes.This means we would need 1,000 2MW turbines to make as much power as a sizable (2,000MW) nuclear power or fossil fuel station. In practice, as fossil fuel and nuclear power stations produce energy consistently while wind is variable, you would need rather more. Wind power is variable and an efficient power grid needs a predictable supply of power to meet varying demand.

That’s why a mixture of different types of energy would be ideal. Some of these will make power whenever they can, like wind, some will operate continually, like nuclear, some will produce power at peak times, like hydroelectric plants and some will raise or lower the power at short notice, like natural gas. Large, efficient batteries can mend this problem but wind can’t be the only form of energy in the mix. 

Wind turbines also can’t be jammed together. They have to be spaced some distance apart and take up a lot of space. Powering an entire country with wind alone would require covering a vast land area with turbines. Connecting a lot of wind turbines to the power grid can also be much more difficult than just wiring up a single power plant.  

Turbines can also be disturbing to wildlife as they’re quite noisy, they bring humans to the area, and they’re a significant collision risk for birds. The design of most turbines makes them hard to see for birds, promoting impacts. That’s why studies have suggested painting one of the rotor blades in black to help birds see the turbines and avoid collisions.

On the plus side, wind turbines are a leading clean energy source. Once constructed, they don’t generate carbon dioxide emissions, which are causing global warming, or the sulfur dioxide emissions, which cause acid rain. The energy they make is limitless and free over a typical lifetime of 25 years, except for spare parts and maintenance. 

Building them has some environmental impact as the towers and nacelles have metal and concrete foundations to stop them falling over. Recycling wind turbines is notoriously difficult, and acts as a sort of “Achilles heel” of wind energy.

Even so, they have among the lowest carbon dioxide emissions of any form of power generation when looking at their entire operation lifespan. They are also much cheaper in terms of kilowatt-hour of power they produce. 

How big is wind energy now?

Last year was the best year in history for the global wind industry with 93 GW of new capacity installed – a 53% year-on-year increase, according to the Global Wind Energy Council (GWEC). Today there’s 743GW of wind power capacity worldwide, helping to avoid 1.1 billion tons of CO2 globally – equivalent to the annual emissions of South America. 

Still, this growth isn’t sufficient to ensure the world becomes carbon neutral by 2050, as agreed in the 2015 Paris Agreement on climate change. The world needs to be installing wind power three times faster over the next decade in order to stay on a net-zero pathway and avoid the worst impacts of climate change, according to GWEC’s estimates. 

Wind power will certainly play a big part in the coming years, as the world says goodbye to fossil fuel energy sources to reduce greenhouse gas emissions. But how big a part will depend on where in the world you are and whether there are better alternatives. In countries with windy weather (so, the vast majority of the world), it will be definitely a strong contender.

Wind turbines act as apex predators in local ecosystems

Wind farms play an essential role in humanity’s mission to transition towards a 100% renewable energy future, but although their impact on the environment is minimal compared to that of fossil fuels, wind turbines are not entirely benign. According to a new study, wind turbines have cascading effects on the food chain and local ecosystems, as if they were the new apex predators in the area.

Image credits: Pixabay.

By now, it’s common knowledge that wind turbines reduce the number of local birds and bats, disrupting their migratory paths. However, the assumption that wind turbines only affect flying species fails to take into account how fewer birds, who are often predators, can change an ecosystem’s dynamic.

Maria Thaker and colleagues at the Indian Institute of Science in Bengaluru surveyed wildlife in India’s Western Ghats, where wind turbines have been functioning for the past two decades. The researchers found that the number of predatory birds, but also the number of predatory attempts (dive attacks), was four times lower in areas with wind farms than in areas without them.

The areas where wind turbines are operational have fewer predatory birds (for example, Buteo, Butastur and Elanus species), which consequently, but have a higher density of lizards, such as Sarada superba. Not only were there more lizards around wind farms, but they also had lower levels of the stress hormone corticosterone, which allowed humans to get closer to the lizards before fleeing — another important clue that the local ecosystem is experiencing less predation.

“We found that densities of the most common lizard species were three times higher in sites with wind turbines compared with those without. We also found strong trait-mediated effects of predator release: lizards at sites with wind turbine not only had lower stress-induced corticosterone levels and anti-predator behavioural responses, but they also had lower body condition and intensity of sexual ornamentation,” wrote the authors in the journal Nature Ecology & Evolution.

Image credits: Indian Institute of Science.

This study suggests that wind turbines act as an additional top level in the food chain, essentially mimicking the effect an apex predator has on the ecosystem.

Close to 17 million hectares of land is currently used for wind energy generation worldwide, with more land coverage to be added as wind energy expands. Thanks to wind energy, communities can enjoy electricity without polluting the atmosphere or contributing to global warming. However, as this study shows, wind turbines can have important disruptive effects on ecosystems, something that should be taken into account when planning their placement.

Does living near wind turbines really affect your health?

Wind turbines are a clean source of energy, excellent for powering many parts of the world. But some people who live close to turbines have complained that wind turbines are affecting their quality of life, citing shadow flicker, audible sounds, and the subaudible sound pressure levels as “annoying.”  Now, a team of researchers from the University of Toronto and Ramboll, an engineering company funding the work, set out to investigate these processes.

The main idea behind turbines is centuries old: exploiting the energy of wind to get something done — whether it’s grinding cereal or producing electricity, the essential principle has remained unchanged. The benefits of harvesting wind energy are evident, but are there any downsides?

For the most part, there’s not much to complain about, but some people are complaining of the noise and rumble created by modern wind turbines. With this in mind, a team of researchers set out re-analyze to data collected for the “Community Noise and Health Study” from May to September 2013 by Statistics Canada, the national statistical office. They focused on noise from wind turbines and produced one of the most thorough studies.

“The Community Noise and Health Study generated data useful for studying the relationship between wind turbine exposures and human health — including annoyance and sleep disturbances,” said Rebecca Barry, an author on the paper. “Their original results examined modeled wind turbine noise based on a variety of factors — source sound power, distance, topography and meteorology, among others.”

Just like the first study, this second analysis found that people who live in areas with higher levels of modeled sound values (40 to 46 decibels or dB) reported more annoyance than respondents in areas with lower levels of modeled sound values (<25 dB). For reference, the urban ambient noise is around 40 dB, and a silent rural area would come in at around 30 dB.

The first study found no connection between the respondents’ quality of life and the proximity to wind turbines. However, this second study reported that survey respondents closer to wind turbines reported lower ratings for their environmental quality of life. However, Barry and her colleagues weren’t able to find out if this happened due to the turbines or if there is a separate, underlying reason. The scientists also didn’t find evidence that wind turbine exposure can affect one’s health.

“Wind turbines might have been placed in locations where residents were already concerned about their environmental quality of life,” said Sandra Sulsky, a researcher from Ramboll. “Also, as is the case with all surveys, the respondents who chose to participate may have viewpoints or experiences that differ from those who chose not to participate. Survey respondents may have participated precisely to express their dissatisfaction, while those who did not participate might not have concerns about the turbines.”

This isn’t the first study to assess the potential health impact of wind turbines — but studies generally report no reason to worry. In 2015, a study in Australia found that infrasound generated by wind turbines is less loud than the infrasound created by a human heartbeat. A subsequent study found that the so-called “wind turbine syndrome” (allegedly caused by long-term exposure to wind turbines) is essentially an imagined condition.

The evidence is not exactly clear, and it’s notoriously difficult to prove that something doesn’t happen. For now, most evidence seems to indicate that wind turbines are completely safe. However, it’s important to continue assessing any potential health risks, researchers said.

“Measuring the population’s perceptions and concerns before and after turbine installation may help to clarify what effects — if any — exposure to wind turbines may have on quality of life,” Sulsky said.

The article, “Using residential proximity to wind turbines as an alternative exposure method to investigate the association between wind turbines and human health,” is authored by Rebecca Barry, Sandra I. Sulsky and Nancy Kreiger. The article will appear in The Journal of the Acoustical Society of America June 5, 2018, (10.1121/1.5039840).

 

 

wind farm offshore

We could power the whole of human civilization with wind turbines in the open sea

Floating wind farms could prove more lucrative than land-based turbines whose ‘sweetest’ real estate is becoming increasingly filled. A new study suggests that offshore wind turbines could provide up to three times more power than terrestrial wind farms of the same size.

wind farm offshore

Credit: Pixabay.

Where the wind blows

More than 54 GW of clean renewable wind power was installed across the global market in 2016, marking a year-by-year growth in global wind energy of 12.6% and reaching a total of 486.8 GW.

“Wind power is now successfully competing with heavily subsidized incumbents across the globe, building new industries, creating hundreds of thousands of jobs and leading the way towards a clean energy future,” said GWEC Secretary General Steve Sawyer.

“We are well into a period of disruptive change, moving away from power systems centered on a few large, polluting plants towards markets increasingly dominated by a range of widely distributed renewable energy sources. We need to get to a zero emissions power system well before 2050 if we are to meet our climate change and development goals.”

Some countries have a much larger share of wind energy in their grid than others, for obvious geographical reasons. Uruguay, Portugal, and Ireland can boast over 20% for example, while Denmark gets a whopping 40% of its power from wind turbines.

The problem with wind, however, is that you eventually run out of it. As silly as that might sound, this is a real issue. Not only are the best spots, the ones with the amplest wind, taken in much of the Western World, but current turbines also deplete the strength of wind gusts downstream from them. The effect is called “wind shadow” and its impact is proving to be more of a nuisance than predicted. For instance, if a turbine absorbs half of the energy from a wind gust, then the turbines in the second row will get only a quarter of that initial wind energy, and so on.

Scientists at the Carnegie Institution for Science in Palo Alto, California, suggest that maybe it’s time to start looking elsewhere before we lose the precious momentum in installing wind capacity. According to their investigation, based on the latest climate models, turbines placed in the North Atlantic could produce three times as much power as existing terrestrial turbines in Kansas over the same area.

In the open sea, wind currents are about 70% stronger than on land. Wintertime low-pressure systems are mainly driving these amplified winds by mixing the energy from the faster, upper-level winds down to the surface of the ocean. Offshore turbines, of course, get wind-shadowed as well but they make up for it because wind replenishes its energy in the open sea. In other words, the upper limit of wind energy that you can capture in this conditions is much higher than on land.

“We found that giant ocean-based wind farms are able to tap into the energy of the winds throughout much of the atmosphere, whereas wind farms onshore remain constrained by the near-surface wind resources,” said Carnegie’s Anna Possner, one of the lead authors of the new study.

Were we to power the whole of the U.S. or China with terrestrial turbines, a project that would require about 6 terawatts annually, even covering much of central U.S. would be insufficient. In the North Atlantic, however, you’d only need to cover the ocean over an area three times smaller than on land to get the same results. The study published in the Proceedings of the National Academy of Sciences estimates that powering humanity’s energy needs entirely from wind is possible with an installation covering 3 million square kilometers of ocean. Yes, that’s a huge area — larger than Greenland or about the size of India. In fact, we sure wouldn’t want to do it at this scale, since these many turbines could actually heavily influence the climate. The researchers estimate that the planetary-scale effects would be far-reaching, potentially cooling parts of the Arctic by as much as 13 degrees Celsius.

“While no commercial-scale deep water wind farms yet exist, our results suggest that such technologies, if they became technically and economically feasible, could potentially provide civilization-scale power,” the authors noted in their paper.

We do not have the resources to undertake such a project at this scale, but the crux of this study is that there’s a huge energy potential waiting to be tapped in the open ocean. As terrestrial wind turbines become more and more inefficient as we occupy the best spots, it’s refreshing to learn that there is still much energy we can harness by delving into the open seas.

“In the long term, I think offshore wind is a lot more robust an investment. I think the wind field is likely to be more reliable and predictable. It certainly has a greater energy density, a significantly higher energy density,” said Dr. Harvey Seim, a professor and chairman of the department of marine sciences at UNC-Chapel Hill, who was not involved in the present study. “But there is a big capital investment that has to be factored into all that. However, if it’s managed properly, it should be recouped by the facility over the long term.”

This is how you install the most powerful wind turbine in the world

Enercon‘s E-126 turbine towers 125 meters high and can generate a staggering 7.58 MW of electricity. As of 2012, 147 such turbines have been installed all over the world. This video shows the non-trivial process required to install and operate an E-126 turbine — the most powerful in the world.

To counter the huge forces exerted by the turbine’s blades, the E-126 needs a solid, 2,500-tonnes foundation. Though very expensive, priced at $12 million without installing costs, large turbines are considered more cost-effective, if the wind conditions are ripe of course. You’d need to install three turbines to get the same output, which means you need more crew members and more labour in the foundation and installing work. Manufacturing per unit KW is also cheaper.

Because it’s so big, the E126 only turns 12 times per minute — ample time for birds to dodge the revolving blades. Birds killed by wind turbines are a big concern, but not with the E126. Even one single E126 can provide enough power to meet the needs of an entire small town. Engineering at its finest!

These wind turbines harness oscillations made by vortices instead of rotary movement. Image: Vortex Bladeless

Are these joint-shaped turbines the future of wind power?

These wind turbines harness oscillations made by vortices  instead of rotary movement. Image: Vortex Bladeless

These wind turbines harness oscillations made by vortices instead of rotary movement. Image: Vortex Bladeless

A Spanish startup called Vortex Bladeless has been receiving a lot hype recently once it unveiled a prototype for a bladeless wind turbine. Like conventional pin-wheel turbines, their turbine also works by harnessing the kinetic energy of the wind. However, instead of moving blades which in turn rotate a shaft connected to a generator, the “asparagus” turbine uses a magnets to transform oscillating movements into electricity. It’s a radical idea, one that might forever change the scenery most of you have already become used to – huge parks of windmills, which personally I’m rather fond of. So far, the engineers behind the project have been rather secretive and the only things we know about the Vortex Mini (the first commercial turbine of this kind set to come out next year) is what has been disclosed by the company. They’re boasting an impressive performance – to the point that it might be feasible to forego pin-wheel turbines altogether in favor of the Vortex – but until we seen some independent assessments I believe skepticism is warranted.

How it works

vertex turbine

A prototype of the bladeless turbine. Image: Vertex Bladeless

The elongated cone is entirely made up of fiberglass and carbon fiber, making it very lightweight. This is essential to the Spanish engineers’ design, and I’ll explain later. When the wind hits the turbine, vortices are made synchronously along the entirety of the mast, making it oscillate. At the base of the cone, there are two repelling magnets. When the mast moves one way, the magnet pushes it in the opposite direction, and so on making the whole turbine swirl. These oscillations are then picked up by an alternator in the base of the device that converts the mechanical movement into electricity. The more vibrations, the better and this is why they made it lightweight.

Why should we care

vortex bladeless

Engineers assembling the prototype. Image: Vortex Bladeless

Let’s talk about some numbers now. According to Vortex Bladeless, the energy made by its turbines costs around 40 percent less than energy made from wind turbines that are operating today. The company claims the savings come from manufacturing (one turbine costs 51% less to make than a conventional turbine) and maintenance, since there are no rotating blades and downtime should be a lot lower. However, Vortex turbine captures 30 percent less energy than conventional wind turbines. No problem, there’s more space to put more Vortex turbines in the same land occupied by a conventional turbine (the blades are huge, mind you). That’s a bit all there is as far as numbers go, but Vortex does list a number of advantages in its name: It’s less expensive to manufacture, totally silent, and safer for birds. According to a 2013 study, wind turbines kill 600,000 birds each year.

While innovative, harnessing oscillations instead of rotary motion is no new idea. As Kcet points out, the Solar Energy Research lnstitute (SERI – now the National Renewable Energy Laboratory) studied the technology for the Department of Energy in 1983. Their verdict wasn’t a favorable one, since they found the powerful swirling oscillations caused significant stresses on both the vane and on the foundation keeping the vane upright. In Vortex’s defense, this was more than 30 years ago and technology has gone a long way. And again, we know next to nothing about the Vortex to comment too much in this respect. I guess, we’ll have to take their word for it – for now.

According to Wired,  Vortex raised $1 million from private capital and government funding in Spain, and company is also seeking funding in the United States. The first test run will be a scaled down product –  a 9-foot, 100-watt turbine – which will be installed in developing countries. The  41-foot Vortex Mini is expected to become available for order next year.

Iowa State students from the College of Engineering's Summer Program for Enhancing Engineering Development (SPEED) program pose near wind turbines and meteorological towers on an Iowa windfarm. Photo: IOWA EPSCOR

Wind turbines help crops grow better

It amazes me when I hear people say they’re against wind turbines because … wait for it… they’re ugly. If you think the same, please get a look at this. Others hate them because they have this misguided impression they’re noisy. Well, modern turbines at least are quieter than a heartbeat. If you really want to make a case against wind turbines, you could argue  they’re bad for wildlife and you’d be right. Birds, bats and other winged creatures are sometimes attracted by the turbines or get slashed when these are in the way of their migration patterns. This is why I believe turbines should be built only in those areas where there is minimal interference with wildlife. They’ll always be downsides to any technology or infrastructure development, but when you draw the line we must be objective whether or not the benefits tip the scales. There’s also another added benefit to turbines you likely never heard about: they help crops grow faster and better when they’re placed on farmland.

Iowa State students from the College of Engineering's Summer Program for Enhancing Engineering Development (SPEED) program pose near wind turbines and meteorological towers on an Iowa windfarm. Photo: IOWA EPSCOR

Iowa State students from the College of Engineering’s Summer Program for Enhancing Engineering Development (SPEED) program pose near wind turbines and meteorological towers on an Iowa windfarm. Photo: IOWA EPSCOR

At Iowa State University, the new Wind Energy Student Organization started its first presentation with a talk by adviser Dr. Gene Takle, who’s been studying the effects of wind turbines on climate and wind turbulence.

“One of the effects of turbines is they stir the air, so the crop, the corn canopy itself is drawing down the carbon dioxide level in that part of the atmosphere so within the crop it’s getting lower and lower, so the extra turbulence brings down this higher CO2 air from above and promoting more photosynthesis within the crop during the daytime period. So it’s a good thing and it looks like the turbines from our measurements are actually having a beneficial effect,” Tackle said.

Besides this, the wind turbines also  increase nighttime temperatures, decreased daytime temperatures, and enhanced evaporation. On the downside, the turbulence also increase respiration. Wind turbines are also great for the local economy, since farmers get a new revenue stream from leasing their lands.

“Wind turbines represent an alternative income stream for farmers. Farmers are in a very volatile economy, there’s up years, there’s down years. The turbines provide the same lease amount every year. So it provides some stable income, which is often valued by farmers. They don’t take very much land out of production and from what we’ve shown, they don’t have any negative impact on their farming operation. Possibly even a positive impact,” according to Tackle.

The state of Iowa has seen massive developments in wind power recently. Nearly $10 billion have been invested thus far, and another $10 billion are slated for the next five years. According to the Office of Energy Efficiency and Renewable Energy, by 2030, lease payments will generate well over $600 million for landowners in rural areas in the U.S.

 

New Silent Wind Tree Turbines Make Energy Production Beautiful

Among the more common arguments against wind turbines you usually have noise and ugliness. Personally, I really don’t find wind turbines ugly and studies have found that generally wind turbines are very quiet but hey – this is the general perception. For these reasons, French engineers have spent three years developing beautiful and quiet urban versions of wind turbines – the results can be seen below.

The Wind Tree is the brainchild of Jérôme Michaud-Larivière, founder of the New Wind company.

“The idea came to me in a square where I saw the leaves tremble when there was not a breath of air.”, he said. He went on to hypothesize that the energy “had to come from somewhere and be translatable into watts.”

The company will install a Wind Tree prototype at the Place de la Concorde in Paris in March 2015 in a proof of concept which will also raise awareness about generating renewable energy, especially in an urban setting.

As for the technical capabilities of the Wind Trees, with 72 artificial leaves serving as micro-turbines spinning on a vertical axis, the device will capture energy from winds with speeds as low as 2 meters / second. This means that they’ll be active more than 280 days of the year, with a predicted power output of 3.1 kW. The units will cost around £23,000 and can be linked together. The idea is that since they look so artistic, they could be used as street art, while also generating energy. The steel tree stands 11 m (36 ft) tall and measures 8 m (26 ft) in diameter and the operation is completely silent. New Wind also believe that the trees could be hooked up to buildings via the main switchboard or connected to the grid with an inverter.

Will this trees make it big, or will it be yet another nice but ineffective design? I guess we’ll start finding our in March.

All images via arbre a vent

altaeros_wind_turbine

World’s first airborne wind farm feeds energy to remote Alaska

altaeros_wind_turbine

(C) Altaeros

Floating wind farms may seem like something out of a science fiction novel, but a MIT start-up called  Altaeros Energies just unveiled an  enormous helium-filled wind turbine which will hover 1,000 feet above ground for 18 months. The turbine, called Altaeros BAT, is a part of a pilot program aimed at demonstrating that airborne wind turbines are feasible.

A wind turbine is most efficient when its blades hit an optimal wind speed. The higher you go above ground, the more powerful the winds are, so naturally wind turbine design has evolved to accommodate ever higher altitudes. The current  record holder for the highest wind turbine is the Vestas V164-8.0-MW, however the Altaeros BAT will be over 275 feet taller than that.

[READ] Wind turbines are quieter than a heartbeat, study finds

The BAT will be deployed in rural Alaska, in an area where the energy market is primarily being served by  remote power and microgrids. The BAT aims to bring low cost, renewable energy to the region’s energy market, worth $17 billion which is primarily served by bulky, expensive and CO2 generating diesel generators.

“We are pleased to work with the Alaska Energy Authority and TDX Power to deploy our flexible, low cost power solution for remote communities,” stated Ben Glass, Altaeros Chief Executive Officer told ZME Science. “The project will generate enough energy to power over a dozen homes. The BAT can be transported and setup without the need for large cranes, towers, or underground foundations that have hampered past wind projects.”

Altaeros designed the BAT by adapting existing technology from aerostats, the industrial cousins of blimps which have lifted heavy communication equipment into the stratosphere for decades. Aerostats are already a proven concepts, rated to survive hurricane-level winds, and the BAT is designed to work similarly.  In 2013, Altaeros successfully tested a BAT prototype in 45 mph winds and at a height of 500 feet at its test site in Maine.

Its inflatable shell is packed with helium, while high strength tethers hold the BAT steady and send electricity down to the ground. Besides generating power, these floating power plants can provide data coverage, cell service and local weather data and can be deployed in harsh weather conditions, so they serve multiple purposes.

The project costs $1.3 million and is partially financed by the Alaska Energy Authority’s Emerging Energy Technology Fund. It will be definitely interesting to see how it fairs and whether or not it makes economic sense to deploy these elsewhere where they might be needed.

Wind Turbines are quieter than a heartbeat, study finds

Among the criticism that wind energy gets, one main idea some people complain about is that wind turbines are noisy; some people have even went as far as to claim that even though most of the created noise is way below the range of human hearing (infrasounds), it can cause health problems, including heart issues and vertigo. Now, a study conducted by acoustical experts from Australia has shown that this idea is nothing more than pseudo science mumbo jumbo.

Picture Source.

Picture Source.

The Association of Australian Acoustical consultants found that that infrasound generated by wind turbines is less loud than the infrasound created by a human heartbeat. Even though the noise increases as the wind speed increases, you’re never going to hear it – it will always be masked by the natural noise of the wind as it passes through the environment. The acoustic engineers showed that “those investigations conclude that infrasound levels adjacent to wind farms are below the threshold of perception and below currently accepted limits set for infrasound.”

So even though the created noise is relative, people are subjected to far more significant sources of noise every day in every urban environment – the sound of cars, aircraft, wind, and waves – all do much more noise than wind turbines, and all are still in the tolerated limits.

“Our environment has lots of infrasound already in it, the levels generated by wind farms from our point of view are quite low in comparison and they’re no higher than what is already out there in the natural environment. … People themselves generate infrasound through things like their own heartbeat, through breathing and these levels of infrasound can be substantially higher than an external noise source.”

So why did people believe that it was the turbines causing them harm? Some even went to the doctors reporting symptomes of what came to be called “Wind Turbine Syndrome”. As it turns out, they were simply suffering from a nocebo (the negative, opposite of a placebo); people simply think they hear sounds which will make them sick, and they suggestion themselves into becoming sick. The human mind is a wonderful place.

Picture Source

Picture Source

timbertower wooden wind turbine

First wooden wind turbine installed in Germany is a lot more eco-friendly

timbertower wooden wind turbineAs of 2010 wind power amounted to 2.5% of the world’s energy production with an estimated 25% increase in quota each year. Yes, eolian  power is one of the cleanest forms of energy production, but like any other renewable sources, its no entirely all green. During a wind power turbine’s manufacturing hundreds of tons of steel are used, which translates in an enormous energy consumption. A German engineering company identified this issue and built a 100 meter tall, 1.5-MW timber wind turbine in Hannover, Germany.

The higher a turbine stands, the more energy it can pull since winds are stronger with altitude. However this also means that more and more materials and energy needs to be invested in a turbine, increasing its carbon footprint. Steel is the main component, but it becomes incrementally inefficient with rising heights. Wood on the other hand is a lot cheaper, has a stable market, a longer service life and can be easily recycled when discontinued.

“The TimberTower is a milestone on the way to green energy production because we use 99 per cent renewable resources,” says TimberTower managing director Holger Giebel.

With this in mind the company built the TimberTower. Standing at 100 metres high, the wooden turbine required about 300 fewer tons of sheet steel to build than a traditional turbine. The way these turbines are built and assembled also constitutes a significant advantage over steel turbines.

TimberTurbine wood wind turbine

The assembly first starts off with the layering of the foundation, which can be flat or deep depending on the ground.  The laminated timber panels and surface components are then simply glued. All components are manufactured off-site and transported in 12 m (40 ft) containers for on-site assembly into a hollow octagonal tower. The finished prototype tower measures 100 m (328 ft) high, integrates a ladder and lift system, and is topped off with a Vensys 77 wind turbine. The turbine has a rotor diameter of 77 m (252.6 ft), weighs almost 100 tons (91 tonnes) and generates 1,500 kW of electricity.

“Onshore steel masts can only reach a maximum height of about 110 metres,” says Giebel. “That’s because the base of a 110-metre mast has to be 4.2 metres in diameter, and that’s the maximum size that can pass under road bridges in Germany and elsewhere. That doesn’t apply to a mast made of wood, which is assembled on the construction site, thus saving in addition enormous transportation costs.”

In addition to the standard octagonal cross section, the hollow body can also be constructed with a hexagonal or dodecagonal cross section.

The finished structure extremely resembles the convention steel turbine being  slim and tapering off upward.  The tower is fire proof and  has a guaranteed service life of 40 years. The company claims that the TimberTower saves about 300 tons (272 tonnes) of sheet steel and, thanks to a treatment process that consumes less energy – about 400 tons (363 tonnes) of CO2.

Meanwhile, a 140-metre tower is also in development. The extra height should allow the turbine to generate between 30 and 40 per cent more electricity than on a conventional mast, while construction cost would be 20 per cent lower.

via ZeitNews

Coal energy slowly becoming more expensive than wind

I recently came across a great article written in the Washington Post which really gives some insight about the economics behind wind power and coal power.

A new dawn for wind power…

If you happen to listen to the more politicized or economic discussions, you’ll probably notice that the ball is thrown into the field of natural gas: many believe that low fortune of coal companies is caused by the low costs of natural gas, which convinced many industries to opt for them, but that’s not entirely true: the cost of mining coal has been going up. Why is this happening? I mean, the US are often regarded as the Saudi Arabia of coal, with resources enough to last another 200 years. The answer lies in the increased costs of transportation, explosives and wages, but most of all, it lies in geology. Whenever a resource is tapped, the easiest access, richest areas are always explored first. Now, despite the massive resources the US and many countries still have, it will be quite hard to extract them, which means more costs, and less profit; the “easy” coal has run out.

While coal power is in its twilight

But then again, on the other side of the coin lies wind power; according to the American Wind Energy Association, the costs of wind energy were 10 times higher in 1980 than they are now. More efficient, better technologies are alwasy appearing to lower the costs, and there is no “easy” wind or “hard” wind. Being a renewable energy, you can access a great area indefinitely. At the moment, a lot depends on local subsidies, taxing, etc, but we are definitely nearing a point where the costs of wind and coal will be pretty much equivalent – and that will definitely be a game changer.

NREL energy

US electricity demand could be 80% supplied by renewable sources by 2050

NREL energyAccording to a recently publicized rapport by the  Department of Energy’s National Renewable Energy Laboratory (NREL), renewable energy sources could account for as much as 80% of the US’s electricity demand by 2050. The rapport signals the various difficulties that need to be overcome to reach this goal, and note that while 80% might be very challenging to reach, a 50% reach is highly possible.

The major players in the renewable energy game of 2050 will be  wind, photovoltaics, and biomass power plants. Surprisingly, hydropower, which is the current dominant renewable energy source in the US, will amount to a smaller proportion in the future.  Increased offshore wind and biomass power plants is where the Department of Energy is currently seeking to invest, and hopefully reach its ambitious 80% renewable energy covered demand.

The US has made significant efforts in increasing the renewable energy stake, and in 2010 renewable energy actually surpassed nuclear energy in provided electricity. Still, the nation is still lagging pretty far behind, compared to other countries’ efforts. Currently, Germany has 17 GW of solar PV installed, versus less than 4 GW in the US – even though the US covers a much larger surface. Scotland has over 31% of its current electricity demand covered by renewable energy, and, along with Denmark, plans to reach 100% by 2050.

The study notes that 439 gigawatts of wind capacity will be required in 2050 for the U.S. to be adequately supplied by renewables. Only 50 gigawatts are currently installed, meaning if the US is keen on reaching its goal, it needs to develop 10 gigawatts per year for almost 40 years, or install ~3,000 wind turbines per year.

“Annual renewable capacity additions that enable high renewable generation are consistent with current global production capacities but are significantly higher than recent U.S. annual capacity additions for the technologies considered,” said the study. “No insurmountable long-term constraints to renewable electricity technology manufacturing capacity, materials supply, or labor availability were identified.”

Whether the Department of Energy can back its claims and walk the talk, it remains to be seen. What’s pretty certain is that fossil fuel monopoly is shacking more nervously by the day.

source: IEEE

Green reasons to be cheerful

brown lester

Lester Brown is “one of the world’s most influential thinkers”, according to the Washington Post, and the Calcutta refers to him as “the guru of the environmental movement”. He has been trying to analyze problems and also trying to find solutions to these problems. Books such as Seeds of Change (1970) and Who will Feed China? (1995) may have not forseen exactly how things will happen, but the issues he treats are very important, especially in these times.An advocate of wind and solar power since the days when most saw them as hopelessly fringe, he believes the following years will be very important in leaning the balance towards a healthy green economy and industry. He also says this movement will start from America, as Europe still relies heavily on oil and coal. Despite the fact that he says carbon capture and storage attempts are highly unefficient, he is still optimistic, but not just as optimistic as Al Gore.

“We’ve just seen the first big win in the fight to stabilise the world’s climate. It’s just possible that by the end of 2008 we’ll have something approaching a de facto moratorium on new coal plants in the US. We’ve crossed a tipping point on this issue, and it’s amazing how fast it has happened. This could be the first big win in the effort to stabilise the earth’s climate.”

Also, wind will be massive according to him. The Texan sized ambition for wind turbines is just another step in achieving this goal. He points out something that is important, despite the fact that many people don’t admit it; wind turbines and other green initiatives exist not because of environmentalism, but because of economics. “Governor Parry isn’t an environmentalist. He’s doing this because it makes economic sense. So is [Texan oilman] T Boone Pickens. He’s put $10 billion in a 4,000MW wind farm in the Texas panhandle.”