Physics.
World. Hello and welcome to the Physics World Stories Podcast.
I'm Andrew G. Lester. In this episode,
we're gonna hear about some fascinating technologies,
which are hopefully building towards our carbon neutral future,
or at least the one that we're being promised later in the podcast,
we'll hear about how Tidal stream energy might join the energy mix in a
considerable way relatively soon. But first,
we'll go to the European Space Agency,
where the Solaris project is looking at using solar energy
from space right here on earth. Here's Nicole Kaplan.
I am an exploration scientist at the European Space Agency based in Nord Vike,
uh, on the coast of the Netherlands, um, which is nice and sunny today,
but it's not always sunny. See, I'm jumping straight into the topic.
Oh.
Well, yeah. So tell me what it's, tell me, tell it's Solaris, right?
Which to me sounds like a rather wonderful old Russian sci-fi film.
You, you are not wrong, um,
in thinking that it's related to sci-fi because the original concepts,
um, were indeed, um, sci-fi. So Solaris, uh,
in essence is space-based solar power that is, uh,
beaming energy wirelessly, um,
from the sun to solar panels in orbit
to a receiving station on earth through the form of
microwaves, converting that energy into usable power, um,
for the grid for people like you and me and everybody else. The,
I the idea itself has been around, um, for, yeah, I think just over,
over a century. I think the earliest evidence that we found, uh, of this,
uh, was in the 1920s, um, a Russian theorist, um,
called Constantin Kovski. I think I'm pronouncing that right.
My Russian's not very good proposed deploying gigantic mirrors in space,
um, to, to reflect the, uh,
solo energy back down to earth and adorably.
This was in the context of boiling,
I think it was 10 cups of coffee within two minutes.
Um, but, but he, um, he decided that clouds could be a problem. Um,
so I don't think ever took that idea further. You mentioned sci-fi,
so a little later on in the 1940s, uh, Isaac Asimov, uh,
wrote about weatherproof, uh, microwave beams.
This is in historic reason or reasons. I, I don't remember. Um, and,
and this was beaming microwaves from space, uh,
to power things not only on earth, but uh, uh, in other,
in other space destinations or wherever we would need power on, on the moon or,
or beyond. Um, and so it, it's,
it's sort of rooted in, in, in science fiction. Um, but then since then,
uh, there's been a trend of interests coming and going. Um,
multiple space agencies, big industries have discussed this,
but the barrier has usually been related to unsurprisingly the cost
of the thing, uh, launch costs.
As that landscape is changing and things are generally becoming cheaper to
center space, um, we can put it on the table again. Um,
and we are not the only ones doing this, so it's quite an exciting time.
But is it.
I mean, is like a real feasible thing that might actually happen?
So at the moment, and I, can see your face looking at me,
filled with, uh, skepticism , um, and rightly so,
because this is an enormous, enormous operation.
It'll be a big engineering challenge. Um, at the moment,
uh, what Isa European Space Agency are doing, um, and I'll speak,
I'm not an engineer, but I will use engineering speak for just a hot moment is,
uh, phase zero or pre-phase A studies. And what this means is, uh,
the feasibility study, so we're, um, picking this concept apart,
um, involving, uh, industry industrial partners, um,
to help us ascertain whether or not this is a viable thing. And,
and we've already done a few things, uh, because as I mentioned a bit earlier,
the, the biggest barrier historically was cost.
So first things first money talks,
and we had the advice of two independent studies on cost benefit
analysis,
and they both determined that this could be viable.
Um, but it just depends on a number of factors.
But things getting cheaper means that that could be going, uh,
in a positive direction.
Okay. What's getting cheaper?
Uh, the cost of sending anything to space, um, per kilogram,
um, and things that used to cost, uh,
a hundred billion would now cost 1 billion, uh, for example. And that's,
that's a really like rudimentary kind of statement to make. But, uh,
the cost of, of anything per kilogram, uh, in general is getting cheaper.
SpaceX, for example, um, who have completely, um,
revolutionized the landscape and changed the game with sending things to space
and also making it better, I suppose, in terms of, um,
the reusable launches.
Could you tell me a bit more about how it would work?
How'd you bring the energy from solar panels in space?
If you imagine a solar farm on earth, um, at scale,
and these are actually getting bigger on earth, um, imagine this,
but in orbit, so out in space, um,
and we're targeting something called, uh, geosynchronous orbit. Um,
so that would be quite far away, um,
far enough away from Earth that it would receive. Um,
there's high enough in the atmospheres that it would receive this, uh,
solar radiation, um, or sunlight all of the time. So 24 7,
and that would also be unfiltered.
So unlike on earth where you have the atmosphere
clouds in space, you don't have that. We don't, we don't have space clouds.
We do it with, with cosmic dust, but I'm not gonna get into that. Um, so,
so you have this, uh,
high intensity solar energy that would essentially
interact with the photovoltaic cells.
So you would have these large solar panels, if you like, all joined together.
And when I say large, I'm, I'm not talking about just, um, yeah,
the size of the I s s, which is the largest object that we've put in space.
I mean,
this would be an order of magnitude greater if it was to produce the power that
we needed. So we're talking an enormous, enormous structure.
So just imagine this huge, um, solar farm. It's out there in space,
it's hanging there, and it's receiving energy from the sun.
Then power will be beamed via the microwaves energy
from this structure, um, hanging out there in space, um, to, uh,
a rec 10 or a rectifying antenna array that would be still
fairly big, but not as big at a given location on,
on ground. And then what that would do, that receiving station would then, um,
take that energy and, um,
and process it and transfer it to usable energy to be fed into the grid.
And you're nodding because it, I mean, it is an enormous, an enormous,
uh, it's just an ambitious project, really. And yeah, there are still many,
many questions to do with feasibility,
which is the whole reason we're performing these feasibility studies.
But the technology, uh, or the physics, should I say,
the physics isn't new. Um, and there are several players that have,
um, demonstrated that this can be done. And most recently, um,
in the United States, uh, Caltech, um, did a small, uh, tech demo,
um, obviously yeah, nowhere near, uh, on the scale of what we would like to do.
Um, but they put, uh, they put us a, a smaller structure in space and,
uh, and being the energy back down, uh, to us,
and it's reported to be successful. I'm still waiting to see the,
the full details to come outta that study. Um,
but so this is nothing new. Um, but we're doing it.
And if it can be done and it can be scaled up and it's cost effective
and it's safe, um,
then it could contribute significantly
to the energy mix that we have on earth and try and lessen
our grip on fossil fuels. And so it'll take it on a huge role in,
in decarbonization and achieving net,
the European goal of net zero by 2050. So within the next decade,
we would hope to see the first, um, gigawatts of power,
um, beamed to earth. Oh.
Right, okay. The energy from the sun is, you know,
for the lifetime of humanity, always going to be there. If we,
if we could do this, could it power everything?
That's a big question, . Um, I, at this point in time,
I do not think that it would be able to take over from all of
the other, um, sources of energy, um, that we currently use. But indeed for,
for what's known as base load power, so that's uninterrupted power,
so non intermittent, um, sources of power, it could really be a goer. Um,
the problem here with other, um, energy alternatives,
brilliant ones such as wind and hydropower, um,
they're weather dependent and also location dependent. And so space, space,
solar power is, um, is free from those constraints.
Mm-hmm. I mean, I pre I presume it would be,
you wouldn't need batteries as well,
because you know how much power you're getting all the time. It, it.
It would be a constant. Yeah. Um, and so one of these,
to put it into context, one of these, uh, orbiting solar farms, um,
could replace a nuclear power station. Just.
For a further bit of context,
a one gigawatt power plant in space would be comparable to the top five
solar farms on earth.
And a power plant with a capacity of one gigawatt could power around
875,000 households for one year.
But let's get back to that conversation with Nicole in the,
in terms of the location and space, is that gonna be an issue?
'cause there's quite a lot of stuff in space already. There's.
A, there's a lot of stuff in space. indeed. Um, uh, yeah,
we have some very clever folk here at Issa working on exactly where you would
place, um, place such a, a large scale solar farm in space.
And of course, the orbit is very important, um,
because of the day night cycles. So you're going to have to have, um,
the, like I mentioned earlier, a geosynchronous orbit, so it would follow, um,
it would follow a,
a particular location on earth in order to beam that power
continuously. But also the shape of the, the solar farm itself,
um, would need to be created,
such as that you wouldn't get total darkness. You would,
you would always have some illumination, um, on these solar panels.
So I would imagine something like a, like a lattice. Um, I mean,
I'm a biologist,
so I think of everything in a double helix kind of configuration , um,
just like a big, big bit of d n a made of solar panels. That'd be quite cool.
Mm-hmm. How, just quickly while we're there,
how does a biologist end up doing this?
Good question. Um, so I joined the project, um, a couple of months ago.
Reason being is because although we have all of these grand plans,
there are a lot of unknowns and there are a lot of unknowns that we would
really enjoy, uh, learning more about from the scientific community.
So my role is research scientist, uh, on this, on this project.
And I am coordinating, uh,
various research activities that will go into informing, uh, a safety case, uh,
for this. I mean, we already know a lot about radio frequencies, um,
and microwave radiation. I think generally speaking, you can, one,
one could understand that this sort of radiation isn't ionizing, um,
but, or does microwave radiation equal heat?
And so the effects that, um, a beam of, of microwave,
uh, microwaves coming from the, the sun, uh, would have, uh,
would have on humans, on plants, on animals. Um,
we really need to understand this better. And,
and then there's also the case of what would happen, uh, to infrastructure.
If you are, if you're beaming, uh, these microwaves at a site in frequency,
what are the implications for, um, interference, uh, with other,
uh, telecommunications devices, um, other satellites, other spacecraft?
Um, could, could that be a problem? Um,
as well as what the interactions with the atmosphere itself are and the
ionosphere. So there's all of these, um,
specific topics which we're really interested, um, to learn more about. Uh,
and here's a little bit of a plug. There's actually a call out now. Um,
if you go on the ISSA website, uh, ideas,
er t uh, you can apply, uh,
to be a part of this research. If you are, um, an expert in the field of,
uh, of iono spheres or atmospheric, um, atmospheric science,
um, and microwave radiation ,
that would be very useful to.
Us. Yeah. Oh, I'm sure there's people listening who will be, uh,
experts in those fields. So, yeah. So come aboard. Yeah, absolutely. Uh,
we obviously, we'll post links to that on the,
on physics wealth website as well for, for those sorts of, uh,
people who are interested in that. There's fusion energy,
which is always promised 30 years in the future.
And that's why I'm slightly more excited about this.
'cause you've said maybe the first gigawatts in the next decade.
Yeah, it seems a little bit closer. And then, um,
I also wanted to just go back and talk cost for a moment. I mean, a lot,
a lot have been, has, has been invested into, into fusion tech. Um,
and I don't know how much has even been spent
on, um, oil exploration. Um, I mean, in the,
I think in the last couple of years it's been in the hundreds of millions by
certain oil companies. Um, so if you,
if you think about the cost, 'cause people say, well,
this is just going to be too expensive. If you contextualize it like that,
then perhaps not. Um,
and then the build of a nuclear power station,
if you take your local example down the road in Bridgewater,
I think Hinckley point C is reported to cost in the region of
$40 billion, which is what about 30, which we say 33,
um, billion euros. Uh, something like this is going to cost
a similar amount. Um, at the moment we,
we are looking at 15 to 20 billion for the first
operational phase. Um, and of course there's gonna be additional costs with, uh,
with the, with the maintenance.
'cause this thing is going to have to be maintained.
Space is a really harsh environment, so, um,
that's going to have to be taken into consideration. But
it is it expensive? Yes. Um, but it's, I would say,
no more expensive than alternative energy sources.
Uh, presumably it's all gonna be remotely fixed when it goes wrong, right.
, we, we would, um, we would have, uh, yeah. Robotic assembly of these,
of these vast solar arrays. So no crew needed.
Okay, I'm on board. Great.
.
I'll sign you up. I I'll be one of those, um, um, solar energy, uh,
door-to-door sales salespeople.
to planet though, isn't it? Instead.
Instead, instead of having these on your roof, how about you just,
you just look up, actually, um, that's a really interesting, uh,
interesting point as well. Somebody asked me, um, an astronomer said, well,
isn't this going to cause light pollution? Is this just going to be another
thing in the sky that's going to get in the way of my lovely, um, astro,
you know, astronomy and, and, and photography? Um,
and we are going for something that is so far away, uh,
that it should not, uh, cause any light pollution. Mm-hmm.
So we won't see them in any, but like if I got,
if I pointed a telescope in the right direction, would I be able to see the,
the solar.
Probably if you were looking for it. Yeah. Um, maybe at certain angles,
if it was, if it was shining. Um, but, uh, but on the whole note,
we're trying to be Yeah. Uh, discreet. Yeah.
With this one, yeah. But I don't want to ruin the night sky, but.
This, right, there's this one, but may, if this works right, then this,
this is a really good solution. And maybe,
maybe we need 150, a.
Thousand maybe. And, and,
and as the technology for beaming these
vast amounts of power, um, gets better, if we can beam them further and further,
uh, then we could send things further away. Thus, you know,
not having the, uh, the space space junk, I mean, it wouldn't, it would,
it would eventually be space junk, um, that we would have to retrieve and,
and d orbit. Um, but as part of, um,
European Space Agency has a clean space initiative, and that is the,
anything that we're sending up to space, uh,
we need to think about the whole lifecycle, cradle to grave, um,
so that we're not adding to Yeah. The
vast amount of, uh, of space junk that is floating up there.
'cause it is, it is a real problem. Yeah. Especially for human exploration.
If we want to go out there, we don't wanna be dodging.
Solar farms. . No,
you're quite nice to plug your spaceship in though to the,
to the solar farm as you were going. Can you.
Imagine like a little welcome break for your, uh, if you orbiter, that'd.
Be amazing. I mean, so, but solar power is nothing new in space, right?
There's plenty of spacecraft is powered by solar energy.
Sure. And, and, and this isn't, this isn't a new concept at all. I mean, if you,
you could even think of this as a huge telecommunication satellite, um, it's,
it's still sending energy, it's sending information, but it's just, yeah,
it's just a different, different utilization. Okay.
So you talk about the feasibility studies, um, as a,
but how do people get involved in that?
Is that something people get involved in?
Um, so the feasibility, um, is currently underway with industry.
We have selected our industrial partners to, uh,
a couple of industrial partners actually, to, um, to, to,
to do the feasibility and also, um, d design. Uh, so,
so actually putting plans for the architecture, um, to us, for us to review,
um, to see if they make sense. Um, but for,
for getting involved on the research side, um, we have this, uh,
have this announcement of opportunity on our website, um,
which is specifically soliciting for, um, ideas,
uh, to help us better understand, um,
the effects that the microwave radiation could have on, um,
humans, animals, plants, um, atmosphere,
atmosphere and uh, and infrastructure itself.
If people who are maybe not necessarily research scientists,
but want to know more about what's happening at Eissa,
is there anything they can do?
Well, we have something very exciting coming up. Um, uh,
in October we will have our annual open day. Um,
this is taking place weekend of seventh and 8th of October. Uh,
and this is where we open our doors to the general public and they let people
like me out of their cages to come and speak, to speak,
to speak to you about, uh, anything that you want to know about space. Um,
I also want to draw particular attention to the event that we're hosting on the
seventh that is specifically for, um, people, uh,
with disabilities. So this is, um, exclusively, um,
exclusively inclusive . So, so this is, uh, yeah,
just a going to be a quiet day because the open day itself can be a
bit of a challenge. If you need, for example, mobility aids to get around site,
lots of people in a small space might not be an easy thing to, to navigate.
So we have this, uh, special day on the 7th of October, which is, um, uh,
for folk with disabilities to come along and meet us.
And then on the eighth we have the general open day. So same again, um,
just a bit busier.
And that is over in Nord Vike in the Netherlands, um,
not far from, from Amsterdam. Um, and it's free to free to come along. Uh,
you just need to go to our website, um, and the links are all there and,
and you can, you can sign up there for free.
Just as the sun always shines in space on earth,
the tides are a potentially never ending source of power.
Tidal stream energy is a way of harnessing the energy from the daily ebb and
flow of the ocean's tides, which as you'll know,
is primarily driven by the gravitational pull of the moon on the earth.
Here's Danny Coles,
a research fellow at the University of Plymouth working on the Tiger Project.
Tiger is title stream industry Energizer project, a, uh,
almost 50 million Euro project involving universities
and industry and development agencies in the UK and France.
And really,
tiger is designed to try and accelerate thet stream energy sector.
Um, and so it's a huge amount of collaboration going on between academics and
industry partners in order to, you know, get turbines into the water,
um,
get sensors into the water that can allow us to better understand the
tal characteristics and tal flows,
and also to drive cost reduction and better understand cost reduction within the
sector,
which ultimately is gonna get us to a point where tidal stream can deliver,
um, you know, sort of electricity that is,
that is affordable and provides system benefits as well.
I think that my main question really about Talal energy is why don't we have it
already? Yeah.
That's, that's a question a lot of people ask, and I think if we take the,
the sort of selection of renewables, if you like,
that we have in the UK specifically, um, solar and wind, i,
I sort of see as the low hanging fruit,
they're the cheapest to develop in those initial stages. Um, so, you know,
from sort of 20 years ago or so,
30 years ago that they started getting developed and obviously because onshore
wind and then solar as well is,
is more easily accessible because it's installed on land, um,
that makes it cheaper. And so it's, it's,
that's why I say it's the low hanging fruit,
but what we're seeing now is that now that we've brought on a lot of solar and
wind onto the system, and we'll obviously need to continue doing that,
and rightly so. Um,
that does also provide additional challenges as well. Um,
when it comes to things like, um, balancing supply with demand, for example.
So obviously the sun doesn't always shine and the wind doesn't always blow.
And actually what we're seeing from a research perspective is that by
diversifying the different types of technology that we are using to generate
clean electricity, we can actually enhance supply demand balancing.
So, you know, when the wind doesn't blow or the sun doesn't shine,
then maybe tidal energy or wave energy or whatever else can pick up
that sort of shortfall in order to make sure that we're, you know,
balancing our system.
How does this tidal stream system work then? You know,
compared to using the waves? So.
Tidal stream energy is effectively like putting a, a wind turbine underwater.
And so, you know, when the tide comes in and out every day,
as you see if you visit the beach or something, um,
the flow of water over those blade turbine blades,
it's rotating the blades and that turns a generator to create electricity.
Now that's very different to wave technologies that, uh,
are using the sort of up and down motion, if you like,
of the waves in order to generate electricity.
And that can be done in different waves. Um, so for example,
one approach is to use an oscillating water column, um,
which is essentially a cylinder, um,
that uses the wave motion to pump air through a turbine,
and, and that again, generates electricity.
So they're two very different technologies. Um, and we see that also the,
the way that the,
that the generation is affected by the resource is also different.
So with tidal,
we see these four periods of tidal generation per day as the tide comes in and
out twice a day, especially around the uk. Whereas with wave, what happens,
generally speaking, the waves is created by the wind. Um,
and so what we'd see if we had a wind turbine installed next to a wave device is
that the wind would start generated,
the wind turbine would start generating electricity first,
and then the wave resource sort of lags the, the, the wind resource.
So that that would come later. And again, as I alluded to earlier,
that that sort of provides those system benefits because it helps fill the gaps,
if you like, because of the intermittency of, of renewable power. So.
With the tide or turbines, is that working in the same way that a, uh,
a wind turbine is working on land?
Do they have to be much stronger to be in the sea? Yeah.
So yeah, exactly. So there's some, some,
some similarities and differences if you like. So yeah, if,
if you were to look at a, a tidal stream turbine, generally speaking, they,
they look broadly similar in that they have sort of two or three blades.
They're, um, orientated sort of horizontally. Their,
their axis is horizontal to the, to the flow direction. Um,
but, but, but yeah, the difference,
the main difference at the moment is that tidal turbines can be significantly
smaller than wind turbines. And,
and the reason for that is that the water is significantly more
dense than, than the wind or the air. Um,
and so it's actually possible to, to extract, um, a,
a significant amount of energy from a tidal flow, um, using a,
a sort of, well,
the scale of these things are sort of roughly 20 meter diameter rotors,
whereas wind turbines are getting far in excess of a hundred meters. Um,
so that's one difference. Um,
what we're seeing with tidal also is that you can either connect the tidal
turbine to the seabed sort of in a similar way to you do with a,
a wind turbine,
or what we're also seeing now is floating tidal stream turbines.
So it's essentially a, a,
a sort of almost like a big cylinder that floats on the,
on the free surface of the water. And then the turbine or turbines,
sometimes there's multiple turbines connected to a floating structure are, um,
just underneath. Um,
and that has some benefits when it comes to access to the turbine. Um, if,
for example, there needs to be some maintenance done or you know, that,
that sort of thing, um, that it's far easier to access the,
the components by floating the device.
And it's the tide, the, the, the amount of energy that's generated by the tides,
is that a constant thing or is it d does it ebb and flow? Sorry.
To stop. No, no, no. Yeah, so you're absolutely right. So yeah,
there are different types of sort of tidal behavior that are important to
consider. Um, so the first one is, is the flood and ebb.
So the, the change in direction of the flow, um, that happens on a sort of,
uh, what sort of six hour, um, cycle. Um, and,
and you know, you get a flood tide that comes in, um, and then that's, uh,
the, the tide then changes direction and we call that slack tide,
where there's not really much flow speed, you know, in that period at all.
And then the direction changes, and then we get the air tide that comes out. Um,
and then there's also spring neat cycles. So spring tides are,
um, are when the, the sun and the moon are aligned with the earth.
Um, and because of that, the gravitational force of the sun and the moon,
uh, combining, um, we see, uh, significantly higher, um,
sort of tidal range or, um, in, in those periods,
whereas in, um, ne tides, the sun,
moon and earth are, are not aligned. Um,
and so the gravitational force is no longer sort of combined together.
And for that reason, um, the tidal range becomes, is, is reduced.
Near where I live. And indeed where the physics world offices are in Bristol,
in the southwest of England is the seven estuary,
which has the second largest tidal range in the world.
I wondered if that sort of range makes any difference to this tidal stream.
There's important distinction to make there between tidal stream technology and
tidal range technology. Um,
so tidal stream turbine sort of, I say using the, the, the stream of,
of, of tidal flow in order to turn a turbine to, to turn a generator,
whereas a tidal range scheme is, is using the,
the height difference, um, of the tide in order to generate. And,
and how that works with the barrage there is that the wall,
the tidal flow comes in through the barrage wall, um,
and then the barrage wall is sort of closed, so no more flow can get through.
Um,
and then as the tide changes and the tidal height reduces outside of
the barrage, um,
the water within the barrage is released and that turns a turbine to generate
power. So they're quite two quite different technologies,
but generally speaking, with a tidal stream turbine, um,
devices that are installed at the moment are roughly about 1.5 megawatts,
uh, in capacity.
So you can compare that to sort of the largest wind offshore wind turbines,
which are now sort of 15 megawatts if you like. So we see technologies,
um, smaller, um, but,
but there's now work being done to increase the scale of these tidal stream
turbines, um, in order to achieve more energy per turbine.
And that helps reduce the cost of energy through economies of scale. Um,
a single turbine typical turbine that's installed in the water at the moment,
um,
would be expected to power approximately 1,500 homes over
a year. So yeah, so it is a,
it is a significant amount of electricity being generated.
So if you, if they were literally hooked up to that,
they wouldn't need anything else for the entire year.
Well, so there's some caveats to this . Yeah. Um,
in that, you know,
obviously the tide is not always generating when you need
electricity, for example. And,
and so a lot of the work we're doing at the university at the moment is, is,
is looking at trying to understand how you could combine energy storage,
for example, with a tidal stream turbine or tidal stream turbines in order to,
um, help match supply with demand, um,
continuously throughout the year. But, but realistically, yes, we'll need a,
a wide range of technologies, wind, solar, tidal wave, and, you know,
geothermal and,
and nuclear and all those things in order to ensure that we can match
supply with demand every single second of every single year, you know? Um, and,
and that's a real challenge moving forward given that renewables are an
intermittent source of, of, of energy.
Tidal stream energy is more consistent than wind energy.
Yeah, exactly. And it's predictable as well.
So we know exactly when a tidal stream turbine will be generating, you know,
even a hundred years from now, we could say at this time,
a hundred years from now,
how much power would we expect the tidal turbine to be generating?
And that's really important when it comes to things like designing the grid
system for the future and how much storage we'll need and all of those sorts of
questions because we already know how much power would be generated at any given
moment in time. Um, and so yes,
it becomes much more compatible with energy storage, um,
and much more compatible with things like demand response as well where you can
shift your demand to when the electricity is being generated by a renewable
source.
We'll return to dunny later in the podcast,
but of course there are concerns about putting any kind of machinery into the
marine environment. Here's Douglas Gillespie.
I work at the Sea mammal research units at the University of St. Andrews,
although the, um, the units dominated biologists and we're studying biology,
my background is actually in physics,
so I specialize in making underwater tracking systems for marine
mammals, mostly using passive acoustics.
So that's picking up the sounds that animals make when they're foraging,
communicating, et cetera, and using those sounds to track,
identify and monitor the behavior of animals underwater.
But recently, some new active sonar tools have become available,
which were becoming increasingly reliant on,
particularly for studying animals which don't vocalize very much in UK waters
such as some species of seals. So there's two seal species in UK waters.
There's um, gray seals and harbor seals and yeah,
they're pretty much all around the UK coasts.
But certainly in the case of harbor seals,
the populations have been declining in recent years.
So they are of conservation concern and um,
it's very important to us to,
as we introduce sort of new technologies into the marine environment,
our kind of role as the sort of national marine mammal lab in many ways is to
try to understand how animals are interacting with these devices.
So some research that colleagues have done on wind farms has actually been shown
a very positive effect in the animals appear to be foraging around the
foundations of the wind farms, but of course with tidal energy devices.
And they look like a kind of short squat,
wind turbine mounted on the sea floor that, that of course got,
have got moving parts underwater.
So just as some birds do get killed by wind turbines,
there's of course a risk that marine mammals and obviously fish species and any
animal moving in that environment could be hinged or killed by the moving parts
of a turbine. Now I,
I won't even put my neck out and say whether we think that's likely or not,
but our job is certainly to study that and find out how animals are moving
around these devices. And.
What are you finding? What can you tell me that you're finding?
I can't tell you where that's a tricky one.
We're moving towards publishing this stuff in the next few months and we've got,
so we've just finished a data collection period where we monitored
a, an operational title turbine off the north coast of Scotland for,
for a 12 month period operating 24 hours a day
with, you know, multi-beam,
active sonar mounted on a platform close to the turbine.
And we have detected a lot of seal tracks going quite close to the turbine.
And we're currently just in the final stages of analyzing how those tracks
move relative to the turbine raters. No, I can't,
I can't tell you any more than that at the moment because we really are just at
the stage as in all research, you know, some,
this is novel devices and a novel environment and yeah, we're,
we're learning how to use these things and we're in the process of sitting
around the computer screen staring at these things thinking what are the metrics
and what are the parameters and how do we turn these kind of pictures of tracks
into kind of good, um,
good sort of repeatable science.
So we're sort of looking at the initial trajectory of the animals relative to
the turbine blades. Are they swimming towards them?
Are they swimming across them? We're looking at changes in um,
changes in behavior, obviously in response to the turbine.
Is there a sudden change in the angle that they're swimming at?
But then a lot of it's just the kind of boring sorting out the data.
So I just got sent a massive spreadsheet of title data from the turbine company
yesterday.
So obviously our sonars are giving movement of animals relative to the ground.
We can,
we now need to calculate movement to the animals relative to the water to see if
they're actively swimming or drifting and relative to the turbine.
So we're kind of in the process of bringing all these data sets together and you
know, we'll have publications ready I hope,
in over the next six months and I'll be very,
very happy to share them with you when they're there.
But at the moment I genuinely dunno what the results are yet. So .
.
But we, we do see tracks.
Okay. But they, they will tell you the,
the behavior of these mammals, seals, es, et cetera,
based on your measurements. You won't need to, for example,
put cameras in there to actually observe it.
You'll be able to know what they're doing from the data that you're getting.
No,
the easiest analogy is you get something that looks very like a radar image
outta it. So you've got,
they work out to about a 50 meter range like and most people are familiar with a
radar which is looking at 360 degrees all around you.
These are looking at over an angle of about 120 degrees, 120 degrees,
so a good cut of wide wedge of data around the turbine.
And within that they give us the positions of animals to actually a few
centimeters accuracy. So you can see the shape of the animal,
you can see its swim behavior and that all helps identify to species.
And you know, they collect data at a rate of about 10 frames per second.
So you end up with something which looks very much like a video of animal
movements around the turbine. So it's very, very fine scale data.
Cam cameras underwater are notoriously difficult to use just 'cause the water's
so murky that you generally only get a range of a few meters
if you're lucky.
And obviously we've got turbine blades at about 20 meters across.
I think they're 18 meters in diameter though people are talking about putting
larger ones in.
So we're monitoring out to a range of about 55 meters at the moment,
which gives us quite good coverage around the turbine,
whereas cameras just wouldn't be able to do that.
And of course Scotland in winter, you know, you haven't got a hope really.
.
You're gonna remember also we're working in some of the fiercest title currents
in the world. So it's incredibly difficult to work there.
You can't put down all of our marine operations that I'm with remote
vehicles, you know,
robotic vehicles and quite large ships that can work in that environment.
It's a ridiculously hard place to work.
Okay, so there's, there is some research that's been uh, published,
which I just,
the title of this Harbor Porus presence is reduced during tidal turbine
operation. Can you tell me about that?
Yeah, that's right. So, well we've been working with the tidal turbine company,
have got four sort of turbines in or up to four turbines in on the north of
Scotland since about 2016.
And the first thing we did was we installed passive acoustic monitors that's
underwater microphones on the foundation of one of their turbines. And again,
we operated that for a couple of years.
I think the original plan was to go for a year,
but we kept going for another one in the pandemic and so they could,
those underwater microphones went and pick up seals 'cause they very rarely make
any noise underwater. But they're very good at picking up harbor porpoises.
So harbor porpoise is just a small dolphin species of which is probably the most
common marine mammal in European shelf waters. There's thousands,
hundreds of thousands out there.
And we could use this array of these underwater microphones to track
the fine scale movements of animals around the turbine.
We found two main things.
One was that there were fewer animals around when the turbine was operating.
So clearly there is some kind of avoidance response. But we also,
there's a second paper which actually showed that as well as there being just
fewer animals even coming anywhere near our microphones when the turbines
operating that the ones which we did track close to the turbine,
all of them went round it.
And there's quite a strong avoidance response where they just basically go
around the turbine blades, which is, you know,
pretty much what you'd expect an animal to do. In fact,
I think it was in something like 400 or 500 days of monitoring,
we had one animal track that went clearly through the kind of rotor area,
but that happened while the rotors weren't turning.
So there were obviously of no danger at that time. So it's a kind of,
it's a bit of a funny one. This is,
'cause obviously there's a general principle,
we don't want to disturb marine mammals,
but this is a case where we do wanna disturb them a bit 'cause we want to around
. So they've gotta get around the turbine, not through it,
but on the other hand, we don't wanna disturb them too much, you know,
we don't want them to leave the area or if this forms an important migration
route, you don't want them to stop using it.
So trying to understand their behavioral changes that both these scales
is actually quite important. So, you know, you know,
they're not stupid animals but,
and they can definitely sense the presence of the turbine,
so you would hope that they would go around it. But on the other hand,
you know,
these turbines are making a bit of a natural reef out there and there are
certainly the possibility of fish aggregating around the foundations.
So again,
if there's a kind of cheap meal 'cause fish are kind of schooling up behind the
turbine,
then animals might be quite motivated to take a risk to go in there to try to
forage on those fish.
But all of these things we don't know and we're trying to answer. Okay.
And are they noisy these turbines? Do they make a,
a significant noise in the ocean?
Yeah, they're noisy again,
they're not so noisy that they're gonna damage the hearing of a marine mammal,
but they're a big bit of machinery. And again,
anyone can experience this for themselves.
You go and walk under a big wind turbine,
there's a big bit of machinery grinding away and it's, it's not, you know,
necessarily louder than your own car, but it's, you'll sense that it's there.
And there was a paper published by colleagues in the LABA open
and they showed that you should be able to hear these turbines a couple of
kilometers away.
So all Murray mammals have good hearing,
so porpoises and seals would all be able to sense the presence of that turbine.
And of course all of the cean species,
all of the dolphin species and the porpoises, they're also echolocating.
So they're using their own kind of sonar beam to sense the environment around
them. And this will be a very, very big target for their sonars. So they'll,
they'll know that that turbine is there, but as I said,
we dunno what motivations they have to use those areas.
And so if there's cheap food or it's an important migration route, then,
you know, they might be strongly motivated to go through there.
But I mean, the noise in the ocean is a problem anyway, right?
With shipping and things. Is this just adding to that?
It's not significant. No.
I would say the Pendleton ferry that goes through that site four times a day is
probably making more noise. But it's,
it is not a significant contribution to noise. No. And again,
it's in this thing where you,
you probably want them to make a bit of noise just to make sure that animals
know they're there.
The last thing you want is a big turbine blade moving completely silently
through the environment. The animals, you know, especially seals,
which they hear, they don't ate,
though I suspect they're very sensitive to vibration. Um, you,
you want 'em to know that this device is there. So again,
a bit of noise is probably a good thing.
So based on the research that that that's happened, may,
maybe not even the research that's published,
should I be hopeful that that tidal turbines are going to be part of our
energy mix in a way that isn't harmful to the marine environment?
Yes, I,
I think of all the things we've done to the marine environment over the years,
over the, over the last couple of centuries,
especially since basically since we invented propellers,
we've been injuring whales and dolphins and for some species in some areas
that is a very significant problem.
So I've done a lot of work on North Atlantic,
right whales in my life and there's a remnant population. Yeah,
they're decimated by whaling and um,
there's a remnant population of a few hundred animals and they seem to favor
living very close to the shipping lanes on the east coast of the United States.
And there's a possibility that, you know,
animals are being killed every year through collisions with ships,
they're being injured by propellers,
as are other sort of endangered populations around the world.
And this is a problem. So
how much tide energy kind of contributes to
those pressures is, is what we're trying to study at the moment.
And it's possible that there's areas where you just shouldn't build tidal
turbines maybe, and there's possible that there are areas there aren't,
but we can't say we're doing the research to try to find out at the moment.
But again, that's not ultimately, you know,
you change from being a scientist who's there to provide information and also to
provide mitigation strategies.
So we're looking at automatic detection strategies using, again,
passive and active sonar,
which could potentially slow or shut down a turbine or plant an alerting sound
which could encourage animals to move away. So we're looking at a,
is there a problem? B, can we mitigate against it?
But then ultimately that is up to our governments and our regulators to
decide what the, um,
decide on the sort of relative costs of these things. You know,
what is the most important,
if it is having a serious impact on a marine mammal population,
what is the most important, the clean energy or the marine mammal population?
And that's a sort a societal question about most human activities. And yes,
I've got my opinion, but that's my private opinion,
which is no more valid than yours or any other person who gets to
turn up at the polling stations on the voting day.
A lot of it comes down to good governance, , you know, again,
you one person's good government will be one that allows the industry one's,
one will be one that protects the marine mammals. So, but quite honestly,
you know,
the threats to marine mammals from climate change are so vast and that's coming
down the tracks really fast.
If you look at the recent warming of our ocean and what that's gonna
do to some of the prey species that marine mammals are dependent on,
they're the big threats to our marine mammal populations and they're the things
that are gonna really seriously change their distribution and the viability of
some populations. So
you do have to be a little bit careful about overprotecting in one area
when actually is stopping humanity dealing with the biggest problem that we've
faced in a long, long time. So, but again,
that's hopefully what governments are there for is to make those decisions.
As the oceans warm on our planet.
And sea levels rise conditions which bring about tropical cyclones,
hurricanes, and typhoons,
which carry higher wind speeds and more rain are likely to be more
prevalent around the globe. I wondered how these storms,
whether increasing or even staying as they are,
are a concern for tidal stream turbines. Here's Danny Coles again.
Yeah, so, so certainly, um, from an engineering perspective, um,
designing the turbines for these sort of extreme cases, you know,
where you have large, very large waves coming through is a real challenge.
And trying to just to even understand, you know,
what is the loading on a tidal turbine in those, in those conditions is,
is is challenging in itself. Um, you know,
so I guess going back to the design of the turbine, um,
I was talking earlier about floating devices versus devices that are put on the
seabed. You know, obviously that's a a, a bigger consideration I guess for,
for the,
for the floating devices in that they're more directly affected by those,
those surface waves. But, but also it,
it is a very serious consideration for the,
for the devices on the seabed as well. Um, so yeah,
there's a lot of work going into that in order to design for these sort of,
you know, 50 year wave sort of things. Um,
so I can't really sort of comment more than that in the, I'm sort of not,
not really on that side of it, but, um, I'm, I'm, I'm, I'm,
I'm certain that that's something that's very much in the,
in the minds of the designers. Yeah. Where.
Where is the best place for these turbines to be because you've got the shipping
lanes where, where is the best location for.
With the seabed devices,
there's actually a clearance between the top of the rotor and the free surface,
you know, top of the water column, um, that, that,
that does allow certain types of vessel to, to pass over. So,
so that's one way of addressing, addressing that sort of problem. Um,
the other point to make is that often the tidal resource is,
is located in sort of channels where, you know,
the flow is basically being funneled through sort of narrow constriction that
accelerates the flow and creates this high energy region. Um,
and in some cases they are the locations that vessels don't tend to
to navigate. Um, and so, you know, in some cases that's the case also.
And then in other cases, yeah,
it's gonna have to be a case of sort of working in collaboration with,
um, sort of n navigation, the navigation sector if you like,
in terms of understanding, well, where are these vessels going and,
and how can we work together in order to, to,
to create those necessary shipping lanes, um,
and respect those shipping mains that already exist in terms in, in, in,
in order to, to develop projects side by side. So.
You've just been doing some outreach,
I presume you've done a fair bit over the time. What, what,
what's the public response to this sort of thing?
Yeah, I think, uh, really supportive actually. Um, so yeah, we've been,
we've been doing some outreach at Green Man Festival in Wales. Um,
we have a stand there, uh, demonstrating wave tidal and, and wind energy.
Um, and I think in general there's a, there's a really high level of interest,
especially in wave and tidal in that this,
there's not as much sort of knowledge about about those two technologies,
obviously wind turbines, everyone's sort of aware of. Um, and,
and really an acknowledgement that, you know,
we have this incredible resource around the UK's coastlines, um, and,
and harnessing it seems like such a, such a sensible and,
and and necessary approach in order to achieve our net zero goals. So yeah,
I think, I think in general the feedback was great and I think kids,
kids are really interested in, in these technologies that,
that are really quite innovative. Um, and so I think there's a real,
a real sort of, um, alignment there in terms of h h the feedback we've had,
um, and, and where we're taking the research. So it's really nice to see.
When might I be, uh, turning on my kettle and, and,
and knowing that it's powered partly by the tides. Yeah.
So there's already tidal stream turbines installed, uh, in the water,
especially in Scotland.
So there's the European Marine Energy Center up there that's specifically
designed as a sort of stepping stone for developers to take their tidal
turbines, test them in real life conditions,
real offshore conditions before then moving to a commercial project if
you like. Um, and then there's also the Magen array up in Scotland as well,
that's got four turbines installed, um,
and is generating power and has been doing that for the last sort of, um,
six years or so.
A really important sort of step change that we've seen recently is that
government have now, um, decided to, uh,
provide specific funding subsidy support for title stream energy projects.
So for example, the project I mentioned in at Magen that has,
that has attracted subsidy support,
that will mean that more turbines are gonna be installed in the next sort of
four or five years. Um, so in terms of the installed capacity, uh,
within the UK waters, that's gonna increase significantly, um,
within those sorts of timescales.
And hopefully what we're hoping is that government will continue to provide that
level of subsidy support as it's already done for wind and solar, um,
in order to continue that sort of acceleration and growth.
Energy security is something that people are talking a lot about.
It. Uh, I guess,
I guess a good example of this would be to go back to the start of the energy
crisis back in 2021, um,
where we had a scenario where, um,
there was a significant reduction in the amount of wind power being generated
around Autumn 2021 as a result of just the wind not blowing as hard as,
as we expect for that time of year. Um,
and that was combined with really high electricity prices that were,
were, were from, from imports from Europe as a result of, you know,
the world coming out of covid, uh, things getting back up and running again,
those sorts of things. Um,
and what it really highlighted was the energy security risk that the UK is
facing in other countries as well. Um,
and really I suppose where the research is going,
both from a Tiger perspective and also the University of Plymouth is, is,
is trying to understand well by installing tidal turbines,
how does that improve and enhance our energy security and our energy resilience,
if you like,
against these sort of events that we know are gonna come up in the future. Uh,
we don't know when and we don't know how, and we don't dunno by how much,
but we know they will come up.
And so protecting protecting the energy system in those cases is gonna be really
important.
So I think the research is now providing a really solid evidence base for,
for how it can do that,
by enhancing supply demand and all of those sorts of things. Um,
and, and that can be a real benefit to the UK moving forward.
So I think that's where we wanna take the research further, um,
from a security point of view. Um, and,
and we're seeing that reflected in government now in terms of their move to a
department for energy security and net zero, um,
to really sort of acknowledge that this is something that energy systems of the
future need to be designed for.
Hmm. Because the Tiger project is.
It's actually, it's coming to an end now,
so it's been going for the last four years and it's coming to an end, uh,
it'll finish it at the end of October.
So we are just at the process of now sort of, you know,
finish finalizing all the reports and,
and getting everything submitted in order to, uh, to get that finished off.
Yeah,
it's also worth mentioning actually that the Tiger Project has a website with
all of the outputs from the project and um,
it's a really good sort of knowledge base there.
So very much worth checking out. We'll.
Post links to that and everything else that we've talked about on this episode
of the Physics World Stories podcast,
including that opportunity for you to get involved in that research that the
European Space Agency is doing into the Solaris project on the physics world
website, physics world.com.
You may also be interested to know that IOP Publishing has recently launched a
new open access journal called Environmental Research Energy,
which is a new edition to the IPPs Expanding Environmental Research
Series.
And you may also like to know that i o p publishing have an upcoming conference
called Environmental Research 2023,
a series of free to attend online events from the 16th of October to the
23rd of November that will bring leading environmental experts together
to exchange knowledge and address crucial challenges related to the
environment and sustainability. Of course,
we'll share a link to that on the physics world website.
We'll be back next month when we'll be bringing you that promised episode on the
International Year of Basic Sciences for Sustainable Development.
And thank you very much for listening.
Physics World.