- Welcome to Engineering with Rosie.
The idea for today's video came a while back
when my friend Kate, hi Kate,
posted one of my wind energy videos on Facebook
and a friend of hers replied
with a helpful link to an article showing piles
of wind turbine blades being buried in landfill.
So Kate asked me to help her respond to him.
And since I'm obviously a bad friend,
it has taken me about three months to get that response.
But here it is now.
In this video,
I'm going to talk about how long wind turbines last,
how much waste there is at the end of their life,
and how much of that waste can be recycled.
Then I'm going to compare the wind turbine waste
with the waste produced by coal power plants
and the amount of garbage the average person creates
over the lifetime of a wind turbine.
(upbeat music)
There has been a lot of focus
on wind turbines' end of life recently.
You may have seen posts and articles like these popping up
in your social media feeds.
Photos like these raise questions
about whether you can really call wind turbines green,
if they create so much non-recyclable waste.
Does burying tons of fiberglass
at the end of a turbine's life undo all the good work done
by the clean energy generated over its lifetime?
These are completely reasonable questions
and I want to know the answers too.
But one thing that I noticed was
that these questions are always
about wind turbines in isolation.
I didn't see anyone asking how the waste produced
by wind turbines compared to other forms
of electricity generation, or other sources of waste.
So I set out to do a little bit
of what I'm calling investigative engineering.
I was actually really surprised by the results,
and I think that you will be too.
Let's start by talking about the scale of the problem,
how long do wind turbines last,
how much waste do we need to deal with
at the end of their life,
and how much of that waste can be recycled?
Wind turbine lifetimes are most commonly 20 years.
Most of the mass of a wind turbine is metal or concrete,
and can be recycled relatively easily and economically.
It's cheaper for the company responsible
for decommissioning to recycle these materials,
than it is to send them to landfill.
So that's what they do.
Wind turbine blades make
up approximately 10 to 15% of the turbine weight.
And the blades are the only major component
that can't be recycled.
The primary material used to make the blades is fiber glass,
with relatively small amounts of other materials,
like paint, balsa wood, carbon fiber,
some little bits and pieces of other things.
Now, composite materials like fiberglass
and carbon fiber can't be easily
or economically recycled yet.
So, we need to dispose of them in other ways.
Incidentally, this is true for all products made
out of composite materials, not just wind turbine blades.
Wind turbine blades make up only around 5%
of the mass of composite products produced annually.
The construction, transportation, marine
and infrastructure industries all share this problem
of what to do with composite products
at the end of their life.
And in these industries,
it's on a much bigger scale than it is
for wind turbine blades.
But still, the number and the size
of wind turbines installed continues
to increase nearly every year,
meaning that this end of life problem is growing.
For now, the amount of wind turbine blade waste
is relatively small, even if the photos of blades
in landfill look shocking.
The first utility scale wind farms were installed
in the 1990s, and it's only these early farms
that are ready to retire now.
The current figure is probably only a few tens
of thousands of tons per year.
And yeah, okay, perhaps only a few tens
of thousands of tons sounds like a really big number,
but by 2050, the amount of wind turbine blades will be
between 200,000 to 370,000 tons per year, a huge increase.
When it is time for a wind turbine to retire,
you have a few options.
The best thing that you can do is to extend the life
of the turbine.
This might involve repair, refurbishment,
replacing some components.
This can be really economical.
And there are a lot
of these kinds of lifetime extension projects happening
at the moment, which is helping to delay the time
when we start to see really large volumes of blade waste.
But it's only a delay, the turbines won't last forever.
Obviously, eventually, you will need
to decommission each turbine
and do something with its blades.
Now there are four main things that you can do
with them currently, and to be honest,
none of them are really that great.
The first option is landfill, which we've already seen.
You truck the blades to landfill, and you bury them.
It's the cheapest of the options.
The second option is to regrind and reuse.
You chop the blades up,
you separate the materials as much as possible,
and then the resulting low value material can be used
as a filler and combined with other materials
and products like insulation and building panels.
What can't be used in this way, still has to go to landfill.
The third option is cement kiln,
where the blade material is ground
and heated and used in cement.
And it actually reduces the carbon dioxide emissions
by about 16% compared to standard cement.
This is the process preferred in Germany
where sending blades to the landfill is prohibited.
The fourth option is paralysis
where you heat the composite material at high temperature
and recover the fibers.
But it hasn't been commercialized yet
for wind turbine blades.
Researchers are working on promising technology
that will allow this on a large scale
for wind turbine blades.
It should be ready within a few years,
and I'm actually going to be talking
with the lead researcher on that project.
So keep an eye out for that video coming up.
The upshot is that for now,
the cheapest option is to send blades to landfill.
So where that's allowed, that's what happens.
But you know what?
Talking about wind turbine waste
on its own seems a bit strange to me.
When I seen this issue discussed in the media,
it's always talking about wind turbines in isolation.
Waste from wind turbines is a problem,
but the choice isn't between wind turbines and nothing.
If we stop installing wind turbines,
but don't reduce our electricity usage,
then we'll need to add another form of generation instead.
It could be coal, oil, gas, nuclear, hydro, solar,
any of these alternatives has associated waste,
but to be able to make meaningful comparisons
across the different sources,
we really need to do a few calculations.
To keep things relatively simple,
I just crunched the numbers on coal.
I chose coal because it's currently the main source
of electricity generation in Australia, where I'm from,
and also in many other parts of the world for now.
I'm also going to compare the amount of waste produced
from wind and coal electricity,
to the amount of municipal garbage produced,
so that we can get a sense of perspective for the problem.
This isn't going to be a detailed lifecycle analysis.
That is incredibly complex and it's beyond the scope
of what I can achieve in a weekly video.
Here, I'm going to compare only the solid waste
from coal power plant operation and end of life waste
from wind turbines with municipal waste.
There's also waste from upstream processes,
for all of these, and I haven't included any of that,
just so I can keep the amount of research
and calculations manageable.
I will put a link to an article that I wrote
that has all of the sources and the assumptions,
so you can follow that.
And if you think that I missed something important out,
then let me know in the comments.
A wind turbine lasts about 20 years
and has on average 10 tons
of blade material per megawatt of turbine capacity.
Over its lifetime, a one megawatt turbine would produce
about 61,000 megawatt hours of electricity,
assuming a 35% capacity factor.
So that is about 160 grams
of solid waste per megawatt hour of wind energy.
In 2010, Australians used on average 2,691 kilowatts
of electricity in their homes.
So, in 20 years, the average Australian
will use 54 megawatt hours of electricity
in their home, making their share
of solid wind turbine waste nine kilograms.
That's nine kilograms of wind turbine waste
for 20 years worth of one person's electricity usage.
In the U.S., they use 4,517 kilowatt hours
per person per year, which gives them a 15 kilogram share
of wind turbine waste over 20 years.
In Germany, it's a bit less,
as they only use 1,731 kilowatt hours per year,
giving them a 5.6 kilogram share of wind turbine waste
for 20 years worth of electricity.
So my mountain bike is German,
and it has more composite materials in it,
than a German's share of wind turbine waste
over 20 years of electricity use.
So I guess I should be more concerned about my biking habit,
than my wind energy habit.
Now let's compare that with
if the electricity had been generated
from coal power plant instead of from a wind turbine.
When coal burns, it produces ash,
84 kilograms per megawatt hours.
About 64% of the ash is reused
in other products like cement,
but the remainder goes to landfill.
And it's not inert like a wind turbine blade.
It contains varying amounts of toxic chemicals.
If the electricity comes from coal instead of wind,
then the amount of solid waste produced
by 20 years worth of electricity is 1,600 kilos
for an Australian, a thousand kilos for a German,
and 2,700 kilos for the average U.S. resident.
So this means that the amount of solid waste
from one megawatt hour of coal electricity is
about 200 times more than the amount
of waste from one megawatt hour of wind electricity.
And that doesn't even account for all
of the waste from a coal power plant.
In a coal power plant, there's also scrubber slurry
and polluted wastewater.
There's of course end of life waste
from the coal power plant equipment,
and there are gas emissions.
There's carbon dioxide, which we're all well aware of
and its effect on the earth's climate.
And there's also particulate pollution,
which is the cause of millions
of premature deaths per year worldwide.
So even though I work in the wind industry,
I was surprised by these results.
I was expecting the amount
of waste from wind turbine blades to be more than it is
from other sources of electricity generation,
just purely because that's
what I've seen reported in the media.
Even though there is so much waste associated
with coal power plants, because the ash is produced
and disposed of continuously onsite,
there isn't a single event
at the end of 20 years where it's transported to landfill
for us to see and be shocked by.
So now let's move
to the final comparison with municipal garbage.
The average Australian generates 560 kilos
of municipal waste each year,
it's 630 kilos in Germany and 740 kilos in the U.S.
So between 10 and 15 tons total
in the 20 year period, we're basing our comparison on.
Some of this is recycled.
The official figures are 55% recycling rate in Australia,
60% in Germany and 35% in the U.S.
Not all of the municipal waste designated
for recycling is actually recycled though.
A lot of it is unsorted or it's contaminated,
or just simply too low value to have any economical use,
and so it ends up in landfill.
But that's a sidetrack I don't really wanna go down today,
it could be a topic for another video perhaps.
So I'm gonna assume that all of the waste
that we put in recycling actually gets recycled,
and that means that we have between five and 10 tons
of non-recycled municipal waste per person over 20 years.
So let's compare that to the amount
of waste produced by electricity generation
from wind or coal.
The amount of non recycled municipal solid waste is three
to five times more than from coal,
and over 500 times more than from wind.
And, like coal, municipal waste contains toxic chemicals
and it releases greenhouse gas emissions as it decomposes.
Now, of course, I already knew
that we produce way too much garbage
as part of our modern lifestyle,
but the scale of it hadn't really hit me until now
when I make the comparison.
Okay, I know there are a lot of numbers
in the previous section,
so I wanna state this as simply as possible,
if an individual Australian gets all
of their household electricity from wind energy,
over 20 years, their share of non-recyclable waste
will be nine kilograms.
That same mass of solid waste is produced
by one person's share of coal fired power plant in 40 days,
and it's just 13 days of municipal waste for one person.
The U.S. figures are similar, and in Germany,
due to their lower electricity usage
but higher garbage production, it takes only eight days
for one person's share of municipal waste to be the same
as 20 years of waste from their share of wind energy.
To sum up, waste associated
with non-recyclable wind turbine blades is a problem,
We need to find better solutions
so that we don't have to continue to put them in landfill.
But compared to waste from other sources,
waste from wind turbines is actually very small.
And it's certainly not a reason to turn back to coal energy.
You'd get a lot more waste that way.
Coal power plants create vastly more waste
that goes to landfill, and it's also toxic.
It has associated gas waste, including carbon dioxide
and particulates that harm human health.
But when you're just talking about the mass is bigger
than either coal or wind electricity is municipal waste.
This is a problem, that by mass,
is more than 500 times greater than wind turbine waste.
So, let's tackle the problem of wind turbine waste,
that's important, but without taking the focus
off the more important issues
of reducing coal usage and reducing municipal waste.
So thank you for watching today.
And I hope that I've been able to give you a little bit
of perspective on the wind turbine waste issue,
relative to other waste problems
that we have to deal with as a society.
Now, if you didn't understand something
or I thought I explained something badly
or you disagree with some of my assumptions or methodology,
then please let me know in the comments
and make sure that you keep an eye out
for upcoming videos on this topic
of wind turbine blade reuse and recycling.
And if you would like to see more videos like this,
then please remember to like and subscribe
and share with your friends.
I'll see you next time.
(upbeat music)