Sally Jackson  0:01  
Welcome to the Hydrofiles, the HR Wallingford podcast. I'm Sally Jackson, and today I'm joined by Iain Gunn and Mike Case, to discuss the role of water in the energy transition to a zero carbon future. Iain is a civil engineer specialising in marine environments; he has more than 20 years experience. And he is also our energy sector lead, looking at where we can help with the energy transition. Mike Case has 10 years experience in renewables, has worked all over the world and hasbeing with HR Wallingford about three years. He's our business sector lead in renewables. And what Mike doesn't know about renewables and nuclear is really not worth knowing. 

So how is the way we're producing energy changing?

Iain Gunn  0:51  
So it's not just the way we're producing energy, it's the way we're consuming energy as well. So we're transitioning from fossil fuels, typically to renewables, which generally produce, or exclusively actually, always produces energy in the form of electricity. And increasingly, we're consuming energy in the form of electricity to avoid consuming it in the form of fossil fuels. For example, in heaing our houses or running our cars,

Mike Case  1:22  
For the UK at least, and for a lot of Northern Europe, we're quite densely populated. And the problem with renewables, onshore wind and solar in particular, they take up a lot of land space. And also the resource for Northern Europe and a lot of countries, wind is the obvious resource, renewable resource and the wind, the quality of the wind, and the sort of power density you get from the wind offshore is much better than it is onshore, because it's much cleaner, there's less turbulence. And so you get a higher capacity factor from from the from the wind turbine. So pushing renewables offshore, makes sense for a lot of countries.

Sally Jackson  2:07  
And onshore as there are other watery options that are available?

Mike Case  2:11  
While there's obviously hydro and hydro is a big is, you know, is the backbone of power in lots of countries, and always has been.  Norway being one of them, which is run, I think over 90% off hydro, and we have some hydro in this country, but we just don't have the geography, we don't have the sorts of high mountains and the kind of the steep valleys, and lots of rivers in the same way they do in some other countries. You know, we don't have the mountain ranges, like the Alps, and the Pyrenees to, you know, to give you the head difference to run hydro. So hydro in the UK is a relatively small resource compared to say, wind or offshore wind.

So it sounds like offshore wind is the obvious choice for this country and for Northern Europe, this building in water more complicated and building on land?

Iain Gunn  3:04  
 Absolutely, yeah. Yeah.

Mike Case  3:08  
So some of the issues you have with building in water, particularly in around Northern Europe, for example, is the water environment, because we have quite high tides, the environments, it's very dynamic, and the seabed is very dynamic. So unlike on land, if you bury a cable a metre deep, you can come back in 20 years time and the likelihood is that cable will still be buried a metre deep. In the sea, because the seabed is so mobile, and then so dynamic and it's moving all the time. And you have all of these features, you have sand waves, you have some kind of sand dunes, ripples, mega ripples, all of this, and  the sand banks as well. And so when you bury cables, or you put a structure on the seabed, you can't guarantee that seabed will be the same in 5, 10 years or even six months time. And it's always moving. So that's quite a big challenge for foundations in particular, and also for cables and how you protect and how you bury cables. It's big; working in the sea is really difficult because of the seabed. And then on top of that you have the additional forces that you wouldn't have for a wind turbine on land because you have the wave forces on the structure itself as well. And then of course all the corrosion from the salt and the the water because it's quite a harsh, harsh environment to put manmade structures  in really.

Sally Jackson  4:36  
It sounds like wind turbines are going to be crucial to a zero carbon future but they're going to be difficult to build over time. Now clearly we've got a lot of wind turbines, wind farms, around the coasts of the UK. So what has been happening to make sure that those wind turbines are safe and are going to be resilient to the future?

Mike Case  4:59  
So we've been working closely with a lot of the developers to look particularly around the seabed, around scar protection. And to make sure that's designed properly and from what we've seen, you know, it's still a relatively young industry. We're talking really 10 years old, maybe 20 years old at a push since the very first pilot project went in. And there's a lot of learning and there's still learning happening. I mean, there's still cable failures, there are still failures in cable protection systems, in underestimation of scour, and how the seabed works so there's lots of learnings still to do. I guess, having the expertise and really understanding what those processes are, having a deep understanding of them, and how they interact with the structures is really important because it's very easy to get it wrong.

Sally Jackson  5:57  
And for any non engineers amongst us, can you tell us what scour is.

Mike Case  6:02  
Basically erosion of sands or the seabed around the structure. So, you can get very big holes developing normally behind, on either side of a structure, depending on which direction the flow is going, and it digs a hole basically behind the structure. And it can it can destabilise structures, it can either leave cables kind of free spanning so you end up kind of flapping about in the breeze if you like, or you can have, you know, you can have foundations undermined and they become unstable or they resonate in a different way than they should.

Iain Gunn  6:38  
It's worth noting that the these effects are not unique to renewable structures so that you know, there's plenty of structures have been built in the marine environment, in the past and HR Wallingford has lots of experience dealing with that. What's new with renewable, although the industry is new, some of the technical aspects of what we're dealing with, it's stuff that we're well capable and have good knowledge on. The difference with renewables is the extent of it, or the number of the structures that are going in/

Sally Jackson  7:12  
It;s a really, really interesting point; how many structures are going in it at the moment?

Mike Case  7:18  
At the moment, we've got roughly 10 gigawatts of offshore wind, and there's probably an equal amount of onshore wind, The target for the government to reach net zero is -  I see different figures - the current target is 70 gigawatts installed. But other modelling I've seen says up to 100 gigawatts. And also, what you have to remember is everything that's being installed now, because the lifespan of a wind turbine or a wind farm is between 20 and 25 years. So all the projects are being installed now or have already been installed, will all be decommissioned by 2050. And so it's a bit of a battle to catch up really, so the rate of of construction for offshore wind if you want to reach 70 gigawatts or even 100 gigawatts is enormous. I mean, that's, you know, it's 10, more than tenfold, what we already have. 

Sally Jackson  8:14  
And what does that 100 gigawatts look like in terms of land area, in terms of the amount of turbines going in around our coastlines?

Mike Case  8:22  
Well, it's enormous. And what we're seeing now in the UK,, because the UK are kind of world leaders really in deployment of offshore wind. And what we're seeing is it's becoming quite constrained because once you start overlapping the other uses of the seabed, you know, whether it's for fishing, or whether you have environmental sensitivities in certain areas, you know, for sensitive bird species, or whether it's for military use  or shipping.  And once you start overlapping those different uses, you start really constraining the seabed particularly closer to shore. So there are a number of factors which will probably push offshore wind further offshore.

Sally Jackson  9:10  
And does decommissioning cause other problems or other challenges to be solved? ,

Mike Case  9:17  
I mean, this is something from we can learn, I think, from the from the oil and gas industry. Because it will do; I think there are only a couple of turbines being decommissioned so far. But in the coming years. in the next 10 years, the early rounds of of when wind farms will be decommissioned. And it's how you remove large monopiles which are hammered you know, 10, 20 metres 30 metres or more into the seabed, how you remove them safely, without causing too much disturbance and what you do with the cables how you remove the cables. So there are some challenges coming up with how you decommission wind farms. 

Iain Gunn  9:56  
On decommissioning though, again, a key difference with historic sources of energies with wind farms, while there'll be structures which need to be removed, they don't have the risk, the pollution risk that you have with decommissioning from oil and gas.

Sally Jackson  10:13  
And that brings me really nicely I was just thinking about which was does building these, these new assets in the sea actually cause more environmental problems, and it solves, you know, with with the construction of wind turbines, you know, as you say, bird species. Is there any kind of, is there any trade off, you know, around that?

Mike Case  10:34  
I think the impacts are very low impact on birds there, I think in the early days are lots of concern about bird strike. But what they've found over the years is that birds actually avoid turbines, because it's a sensible thing to do. But there are yet, so the impacts of offshore wind are relatively lower. Remember that whilst they take up a large area, the actual, the real physical footprint of each turbine is relatively small, and even the cables is relatively small, because they're spaced, you know, the large turbines now there'll be over a kilometre between each turbine. And so the relative impacts are still very low. And it's still a very, well for the UK at least, I think it's still probably the the best way the best renewable resource we can access.

Sally Jackson  11:26  
And how about during construction in a noise, underwater noise for fish? And how can you manage that sort of effect?

Mike Case  11:35  
While some of the work we do is on modelling and understanding underwater noise, and how that transmits through the water column. And you can mitigate; there are a number of ways you can mitigate that. Either the type of piling that you - do the way you the way you hammer these foundations into the seabed. You can vibrate them in, for example, or another method is to use bubble curtains, where you create a basically a curtain of bubbles around around the structure. And that absorbs some of the piling energy and reduces the transmission of the noise through through the through the water column.

Sally Jackson  12:11  
And how about other technology apart from wind turbines? Say there is tidal and floating wind is a new capability that's coming through in the UK. Do they have the same sort of challenges?

Mike Case  12:26  
Yeah, certainly the marine energy in general is tidal and tidal energy type, you know, tidal range and tidal stream. And also you've got, you know, hydro kinetic and wave energy devices. The challenges are similar in that it's a very harsh. it's an extreme environment that you're putting these machines in, maybe particularly for tidal stream devices, where they're putting them in really high high flow velocities. And also you have the issue a lot of issues with accessing the machinery for maintenance. So it depends on the on the design. So there are there are a number of challenges there.

Iain Gunn  13:03  
A key difference between that and wind is the amount of locations that are suitable for it. So wind, as Mike says,, we're, really lucky in the UK, we've got huge swathes of seabed that are that are suitable for deployment of wind, power, whereas for tidal energy, there's nowhere near as many suitable locations.

Mike Case  13:28  
Globally, where you have those conditions, it's between islands. So I think for certain island nations, that's probably a very good option. But there's not the breadth of other areas of suitable sites that you have globally in the same way that you do have for offshore wind. So floating has become a really interesting area of development, because you can go further offshore, you can have bigger turbines. And with you know, with less constraints on the seabed, if you like. And then it's also where - I mean wherever we're very blessed in the UK and a lot of Northern Europe is - we have a very shallow continental shelf. And so we're looking at seabed depths of between say 20 and 50 metres. But lots of countries, Japan as an example, or maybe the the West Coast of the US where it shelves very quickly, it's not suitable for fixed bottom offshore wind and, and that's where floating offshore wind is really, really exciting.

Sally Jackson  14:32  
And I think it draws quite a lot of parallels with the oil and gas industry in terms of learning.

Iain Gunn  14:37  
It does I mean, so the oil and gas industry have had floating facilities offshore for many, many years. A big difference again, though, will be the fact that with the oil and gas industry, they typically have one or two positioned over an oil field serving, perhaps different functions. So they're very much bespoke devices. Or bespoke facilities. Whereas for floating offshore, you're going to be deploying many more. The key difference there, that rather than building one or two in some shipyard in, say, Korea that you then ship over to wherever it is, you're more interested in building many, or at least fabricating many, reasonably close to where they're going to be deployed. So that that will have an effect on the UK, certainly, because there'll be jobs potentially helping to fabricate those devices before they're taken out.

Mike Case  15:37  
So there's a whole challenge around understanding the port logistics, and also the transport and the towage to site as well.

Sally Jackson  15:48  
And how about the rest of the world? Where are we seeing exciting developments in marine offshore energy production?

Mike Case  15:57  
All over actually, it's it's incredible. I mean, offshore wind is growing exponentially, and I think floating offshore wind will closely follow suit. And when we've got everywhere, the US is growing a big market, obviously, you've got Northern Europe and the Baltics are now really growing in offshore wind. And then you have the kind of APAC region, where Taiwan is probably the most mature market, where they've developed quite a few offshore wind farms, and they're still developing more. And then Japan, South Korea, Vietnam, even India, Australia. Yeah, there is offshore wind being developed all over the world,

Sally Jackson  16:35  
I suppose we can't talk about the transition to clean energy without mentioning nuclear. So where do we stand on that ? How do we see that as part of the energy transition?

Mike Case  16:45  
Well, I think with with, with all renewables,  they're all intermittent. Whether it's solar, whether it's wind, whether it's hydro, probably to a lesser extent, but certainly wind and offshore wind is intermittent. Whilst the capacity factors now are quite high, over 50%, there are still days or even weeks where you might have an Atlantic high and that can  cover basically the whole of Northern Europe where there's essentially no wind. So if you imagine a situation where we have 100 gigawatts of offshore wind on the grid, and then the next day, there's none and that happens, then how do you replace that offshore wind? What's there to back it up? And at the moment, what we do is we use gas predominantly. So going forward, if we need more as we electrify our power system, if we move up, we will actually transport, particularly heating, which is a big chunk, probably two thirds of domestic energy is on heating. If we electrify that, then obviously  our power demand will, I think some estimates or will at least double by 2050. And then you need something to back that up. So you really need that backbone of power, which is always on, which you can rely on, which is kind of dispatchable power, which is what nuclear is. I think really that at present that's the only alternative I can see for low carbon - for this kind of dispatchable firm, low carbon power - is nuclear.

Iain Gunn  18:20  
And that backbone historically has been provided by coal, hasn't it? So it's, it's great that we've managed to get largely get rid of coal in the UK. But that, in itself, has created a gap. 

Sally Jackson  18:33  
Why is water important to nuclear.  Sort of not an obvious link there.

Iain Gunn  18:39  
Well, water is the primary source of cooling. So all power stations need to cool themselves as part of the process of generating the power. And in the case of nuclear, that usually comes from water that's taken either out of the sea or out of a river. It's run through the power station through heat exchangers, and then and then put it back in the back in the sea with just heat added to it.

Sally Jackson  19:13  
And so what do we do to help manage that process?

Iain Gunn  19:17  
Well, that particular issue is not unique to nuclear, any form of power station can have water cooling. And so what we do is we can help design, undertake the hydraulic design of the cooling water systems, but also look at the impact of that thermal plume. And so that's in two ways. One is the impact of the plume from an environmental point of view. And the second way is the potential for that plume to recirculate and come back into the intake for the same power station, which obviously you don't want either.

Mike Case  20:00  
A lot of the nuclear sites because of the need for cooling water they're located either close to large rivers or on the coast and then you have the issue of flooding to think about and so and or coastal protection. So a lot of the work we do is around - and because they're very long lived assets as well you know a typical lifespan now of a nuclear plant is about 60 years - so you really have to plan ahead for for storms. You're looking at storms and storm surges and maybe extreme conditions.

Sally Jackson  20:33  
And I suppose because these plants are built in and around water a lot of the access is also via water. 

Mike Case  20:41  
That's right, yeah. W also design the what's often called MOLFs, which is the marine offloading facilities and they are used in the UK for the for most of the UK plants, they have some kind of a marine offloading facility. We help with the design of those and the design and testing of breakwaters you know, as part of protection for those and also the you know, we're blessed to have you know, one of Europe's largest ship navigation simulators so we also do a lot of the navigation simulating and training pilots of how to use new facilities before they're even built. We can be training pilots and how to use them.

Sally Jackson  21:22  
Iain, you've worked in the oil and gas sector for a long time. Do you see a change appetite from the big players? Or was it sort of business as usual from them?

Iain Gunn  21:31  
Well yes. The the oil, it's important to note actually that the oil and gas, the major oil and gas companies, have taken environmental issues very seriously for many years. But the big players really are starting to get into renewables.

Mike Case  21:51  
Yeah, I mean we see that is interesting and it is changing the market dynamics as well . So the big oil the oil and gas majors if you like  - you know your Totals and BPs of this world and Shell - they're actually piling into offshore wind now really in quite a big way. And it will be interesting to see how that changes that the dynamics of the market really which has been led by a few I guess you could you could say you know the likes of Orstead from from Denmark, Equinor from Norway and a few other companies have really been  leading the market and now you've got these big you know, these big oil and gas majors are really entering the offshore wind market in a big way. And also, you see the the oil majors, they're very interested in floating offshore wind. And I think you know, as Ian mentioned, I think because of the skill sets, they kind of they they have a lot more experience in that kind of environment, the deepwater environment and they've got you know, they've they've got those skills and that experience so they're kind of more suited to floating offshore wind in some respects that already have that that knowledge in house.

Iain Gunn  23:04  
And they've got a really good track record of delivering large projects. So you might see a change. I mean up to up to date when projects are typically taken quite a long time to develop for various reasons. The oil and gas majors I suspect will speed that process up. 

Sally Jackson  23:22  
There's a lot of positivity for the future. Perhaps each of you can tell me what you think the most exciting developments in clean energy is; maybe starting with you Mike.

Mike Case  23:32  
I don't know where to start really because I'm, there's lots of exciting things happening in the nuclear sector for example, with small modular reactors and new types of technology. The sodium reactors where you where you have combined nuclear power with storage, and then also potential for hydrogen production for nuclear and then you go into offshore wind in you have the obviously the scaling up of just a massive rolling out of offshore wind - fixed bottom offshore wind, and then obviously really exciting industries in floating offshore wind. And there's also exciting stuff happening in marine energy. So yeah, I don't know where to start really 

Sally Jackson  24:14  
Generally exciting. Iain?

Iain Gunn  24:15  
Well, for me, it's just it's just the energy transition. So you know, we're, we're I wouldn't, say, on the cusp of it, because we're into it, but we're in a position where we know, things are going to change quite rapidly over the next 10 to 20 years. We know, some elements of that. So we know that offshore wind will be a significant component of that. But there's other elements of that that we currently don't really know. And that's quite exciting. So we know that things are going to change in a big way, in all sorts of ways. But for someone that's working in the energy sector, I relish that prospect that there's gonna be lots of new stuff to work on.

Sally Jackson  25:01  
Well that's been an absolutely fascinating discussion. Thanks Mike and Iain for joining me on the Hydrofiles.

Transcribed by https://otter.ai