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Continuing on with our discussion on wind turbines, today I will go into why they are so difficult to recycle when past their cost-effective life. As you may remember, we already covered how many there are, how large they are, what their cost is, how long it takes for them to pay for themselves, and how they produce electricity as cheaply as coal and gas fired plants.
As previously discussed, wind turbines are good for the environment as they generate clean and renewable power. Unfortunately, though, when their blades reach the end of their lives, the current options on what to do with them — burning or landfilling — aren’t so good. And there are a lot of blades that are no longer useful.
How long do the blades last? Again, it is shorter than I had imagined. I found the design life of a good quality modern wind turbine is about 20 years. However, it was noted that, “Depending on how windy and turbulent the site is, the turbine could last for 25 years or even longer, though as with anything mechanical, the maintenance costs will increase as it gets older.”
Unfortunately, many of these blades are now landfilled or cut up for fuel. A spokesperson for the industry noted they can be crushed and burned in cement kilns, offsetting the need for fossil fuels. That’s one solution, but the problem of what to do with these no longer cost-effective blades starts at the end of their life. As these blades can be 150 feet long or longer and weight up to 8 tons each, they are not simple to handle. And when they are removed from the towers, their owners desire them to be removed quickly. Because of their size, the blades generally need to be cut up on-site so they’ll fit on standard sized trucks.
What seems to be the problem with recycling them? Good question. But the answer isn’t so simple.
Generally, fiberglass blades are made of a glass fiber-thermoset composite. It’s a special composition to give them strength and make them longer lasting. In addition, they can also contain a core of PS foam, polyurethane foam or balsa wood to reduce weight and alter stiffness. Unfortunately, unlike thermoplastics, thermosets are permanently cured and can’t simply be remelted and molded. However, one company, Global Fiberglass Solutions (GFS), a Washington statebased company is hoping to recycle the blades into pellets and boards.
It has developed and is enlarging a plant in Sweetwater, Texas to recycle fiberglass from these wind turbine blades. It is the first company in our country to commercially recycle these fiberglass wind turbine blades. With the great number of these blades needing to be recycled, let’s hope other companies will follow suit.
In its operation, we find a mechanical breakdown process is used to size reduce the blades. This grinding of the material is difficult as first. The metal bolts and fasteners must be removed with magnetic separation equipment. Gravity separators and air classification separators then are used to sort shredded pieces by size.
Here we are again at the length of these articles which I try to stick to so as not to take up too much of your time. And I’m still not finished so I will have to conclude this series with one more.
Till next week, do have a great one...
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Ollie is a local citizen concerned with the environment and helping others. A retired Air Force fighter and instructor pilot, he is a graduate of Leadership San Marcos and received his degrees at Texas State University where he worked on staff before totally retiring. For questions or comments, he invites you to call him at 512-353-7432.
