The Decibel - Turning the tides into renewable energy

Episode Date: January 24, 2024

Companies around the world are trying to harness the power of the tides to create a renewable energy source. Canada’s Bay of Fundy is a promising place to do it because it has the highest tides in the world. But turning the tides into energy has proven to be challenging and costly.Matthew MClearn is an investigative reporter and data journalist with The Globe and Mail’s Energy, Natural Resources and Environment Team. He’s on the show to explain how tidal power works and where we’re at in its development.Questions? Comments? Ideas? Email us at [e-mail]

In the search for renewable energy, we found ways to harness the power of the wind, the sun, rivers. So, what about the ocean? Companies are working on converting the ocean's tides into electricity. And the highest tides in the world are right here in Canada. Matt McClern is an investigative reporter and data journalist for the Globe's Energy and Environment team, and he's on the show to tell us about the promises and the challenges of turning the tides into power. I'm Mainika Raman-Wilms, and this is The Decibel from The Globe and Mail.

Matt, thanks so much for being here today. It's a pleasure to be here. So, Matt, this is a basic question to start, but how exactly does water from the tides turn into energy? Basically, you're trying to capture the horizontal movements of water that are caused by the tides. Imagine, for example, a tide rushing into some sort of tidal bay. When it comes out, if it's going through a narrow channel, it might be moving at a substantial velocity, right? And it's places like that where you might be able to put a turbine or some type of technology there to harness that moving water as it rushes past or when it comes back in as the tide rises again. Okay, yeah. So it's that movement of water kind of coming in or out through this narrowed passage that would generate the power then.

That's right. And in most places, that's not a great source of energy. But there's a few places in the world where it can be. And the Bay of Fundy is one of those places where often the tidal range is, you know, in many places in the world is like a meter or so. And that's not a lot. And that can be hard to harness. But in the Bay of Fundy, it's in many locations there, it's, you know, more than tens of meters,

right? So it's a significant amount of water, right? I mean, if you've ever been to the Bay of Fundy, it's pretty incredible. You know, the tides actually move with astonishing rapidity, right? I was just actually in New Brunswick last summer and, you know, went to see Hopewell Rocks and you can just stand there and watch the tide go out. And, you know, if you're standing at the shore, you wait a few minutes and it's already moved away from you if the tide's going out a substantial distance. And so it's in places like that that you end up getting these currents

that are generated by the tides that are powerful enough that they can be used for this. You know, some people in the field would say it has to be moving at least like one and a half to two meters a second to be powerful enough to warrant trying to harness. Why do we want to do this, Matt? Like, I guess, can you explain why is this appealing? Well, we've always wanted to find new sources of energy. And this is one that is renewable. It's just there. If you're a coastal nation or you're a coastal province, it's always been tantalizing as a source of energy.

And it's predictable. You can predict these things well in advance. You can get tide tables, for example, that will tell you what the tide is going to be in December, right, on a particular day. So, you know, you can know when it's going to be high tide and low tide. Very predictable. More so than, say, wind power. Yeah, we don't really know when the wind's going to blow or when the sun is going to be really strong. But we do know when the tides are going to be up and down. Correct. Is this a new idea?

Well, it is and it isn't. Actually, the history of people trying to use the tides to generate power of some sort probably dates back to the Middle Ages. As early as 900 AD, there have been reports that people used tidal basins. They would basically harness water in them and use them very much like you would use a water mill on a small river, say, to process grain. Just in the same way that we've harnessed wind for a long time, right? The idea of a windmill dates back centuries. But over the centuries, people have recognized it as a potential source of power and have experimented with it to varying degrees of success, usually less than they would

have liked. And we certainly are going to get into some of the challenges. But I think maybe we should just kind of set up how this actually works and what it looks like. Like, how are companies these days trying to harness the power of the tides? So these are all early stage technologies, I think it's fair to say, with the exception of barrages. And so actually there's an awful lot of different types of tidal devices that have been at least sketched out on paper. So many of them have been prototyped. But the barrage is the most simple one. And that is a technology that's decades old. And almost all the ocean technology that's deployed today is in the form of a barrage, which is very much like a hydroelectric dam. Instead of spanning a river,

it spans perhaps a tidal basin. And it will have some turbines and some concrete, you know, it's basically, it can be a large structure. And it's meant to capture water inside that tidal basin and release it in a controlled manner to spin the turbines to generate electricity. Of the about 500 megawatts or so of tidal power technology that's out there today, 98% of it is that technology. In this form. Yeah. And the problem with that technology is A, it's got a lot of the same problems that

traditional hydropower has. It's very expensive to build. But the other problem is there's actually very few places in the world where it makes a lot of sense to do. So it has limited applicability. So in recent decades, people have been looking for new ways to generate electricity from tides. And one of the leading technologies recently has been what are called horizontal axis turbines. Some of them look very much like a wind turbine, right? Only it's mounted on the sea bottom. Some

of these are mounted on floating platforms and there's trade-offs to taking either approach, right? If you think about like one that's actually floating on the surface, it's probably easier to service if there's any mechanical problems, for example, than if it's on the sea bottom. Yeah, you got to get all the way down there to fix something if it breaks, right? That has been a constant problem in this industry is that uh you know especially the bottom mounted turbines when something goes wrong with them it's hugely expensive and can be quite difficult to actually retrieve them to service them or service them in situ and uh by definition you're putting these

things in high energy environments where there's a lot of water moving. So you might only be able to work on it at slack tide when the current has temporarily abated. You might only have an hour or two to work on it for – so some have tried to address that problem by putting them on floating platforms, which makes them easier to service. But it also introduces other problems because now your platform is exposed to the elements and the ocean can be a very harsh environment. Oh, yeah. So you can see like there's trade-offs to each approach and the industry hasn't matured to the point where it's really settled yet on a technology. Interesting.

Okay, so there's a whole bunch of different ways to do this and it sounds like the industry is kind of still figuring out what the best way is. How much energy are we actually talking about here, Matt, though, like when when it compares to I guess, something like wind energy, which we've been talking about, how much energy can we actually pull from the tides? Well, right now, we're pulling very little. So I think I mentioned earlier that we have about 500 megawatts of capacity globally for tidal energy, thereabouts. Just to compare, right now, Ontario is considering whether to refurbish the Pickering Nuclear Power Plant.

Each one of the reactors there is a 500 megawatt reactor. Just one of those four reactors that they're considering refurbishing right now generates as much as all the tidal power in the world. So right now, we're not doing very much of it. And as I said, those are barrages. And there's only two of them that really that account for most of it. There's one in Korea and one in France. These are big tidal energy projects.

One of them has been around since the 1960s. The other is much more recent. But actually, theoretically, we could generate a ton of energy from the oceans. In fact, far more than we consume today. But these are theoretical numbers. And, you know, the obstacle has always been can you do so in an economic fashion? Can you basically do it in an affordable way. One estimate that I've come across is that tidal energy could generate up to 1,200 terawatt hours per year. That could be a substantial source of electricity for

a handful of places where it makes sense, like Nova Scotia or potentially New Brunswick, right, both on the Bay of Fundy. Yeah. And I guess, so it sounds like this area in the Bay of Fundy. historically it's been said that Nova Scotia could generate all of its power from tidal, right? But it's not something that can be realized today. It's just that there is a lot of potential there. They need to decarbonize their electricity sector and they want to. And this is one option that they've been aware of for a while that they've been keeping an eye on and looking to foster to some degree. And I understand that Nova Scotia did actually have a barrage project set up for a while. This is one of the projects that you were talking about off the top, but it's no longer running.

What happened there? So I'm not sure why Nova Scotia Power made the decision to decommission completely. This was a barrage that's in Annapolis Royal, which is again on the Bay of Fundy. And it was built in the 1980s. And it ran until about, I believe it was 2019, that they decommissioned it. Once it had an equipment failure, they just decided that it wasn't worth refurbishing. This was a 20-megawatt plant, so much smaller than the other two barrages in France and Korea. So it's clearly Nova Scotia Power has experience with barrages and they haven't built any more, which I think tells you that this technology has disappointed somewhat. You know, I actually visited that barrage a couple of years ago and there was no activity

there whatsoever because the facility has basically been decommissioned. But when I was there, disassembly, there wasn't any visible signs of it yet, but I believe that it will eventually be removed. We'll be right back. Okay. So, so Matt, we've talked about the promise of tidal power, but there seems to be some really crucial challenges that are standing in the way of this becoming a reality. And one of them is actually physical wreckage. So can you talk about that? Why is this an issue? In layman's terms, every time we try to put one of these things in the ocean, the ocean has a habit of breaking it. There was an Irish developer that was working in Nova Scotia called Open Hydro.

And they had a turbine that they put into Minas Passage. But as soon as they put this turbine down, the Irish parent went bankrupt. And so the thing was never properly commissioned. But anyway, within months, they discovered that the turbine had failed completely. That turbine is still down there. And more recently, Sustainable Marine last year, that's another developer that was – this one was working in – near Briar Island. And this was a floating platform that had six turbines off the stern. And they sort of look like outboard engines, if you remember, with large propellers.

And they were generating electricity using that. But they also folded as a company, or I think it was actually in May. And last November, this thing broke free of its moorings and washed up on shore. So there's been some actual literal wreckage in this industry. And it's kind of a bad advertisement for it because these pictures get widely distributed and published. And they're sort of symbolic about some of the challenges that this industry has faced. Well, so it sounds like the financial side of things is also a really big issue here too. So these things cannot be cheap to make and it sounds like to sustain as well.

So yeah, what are the financial challenges that companies are facing with these projects? Well, these companies have to attract investment and a good number of these developers seem to have been able to get early stages of financing. But as they try to progress, for whatever reason, they're not getting the investment that they need to take it to the next level. And so they eventually run out of money. And sources of investment for these companies have included private investors, but also governments. This is an investment essentially for energy in the future. Yeah. Do we know though, why like so many of these companies are going bankrupt? Like why is it, this seems to be a bit of a trend here? Well, some of these companies point the finger at the government itself. So when you're building a tidal energy platform of any sort, you're working in the ocean and that

brings you into contact with the Department of Fisheries and Oceans, which regulates a lot of offshore activity, especially in areas that are frequented by fish. So one of the challenges that these developers have is that they're expected to demonstrate that they're not harming fish populations in the area, and particularly ones that, you know, if there's a species at risk, for example, um, they have to show that they're not doing that, but that's a hard thing to do. Um, especially in a, in a high current area, for example, you know, our fish striking these turbines, uh, you know, it's a non-trivial thing to actually prove that that's not happening. So there've been various techniques used, but a lot of these

developers, a number of my spoken to have told me, we just can't get permits to go from an experimental deployment to, you know, two or three or four turbines. Right now, there is a task force that's been set up to look at this because the Department of Fisheries and Oceans, their responsibility for regulating hasn't gone away, but they're under pressure to change how they do business, at least to the extent that they can in order to be more helpful to these developers, I guess. So there's a final report that that task force is supposed to release in the coming weeks and months. And we might get some further clarity about how things might change a little bit on the

regulatory front. But for some of these developers, it's too late. Like, sustainable marine is already finished. Okay. So it sounds like, yeah, there definitely are some hurdles in terms of government regulation. But to go back to a point that we just raised briefly, Matt, about the dangers to aquatic life. Like, if you've got turbines on the bottom to aquatic life. Like if you've got turbines

on the bottom of the ocean, yeah, you've got fish, you've got all kinds of animals and different life down there. Are these a potential danger to these creatures? You know, that's a great question. And it has been a difficult thing

to establish. There's some science that needs to happen there. And, you know, most of these developers have programs that they have developed to try to prove to the regulator that they're not doing any harm. Using a variety of technologies, cameras, even AI to interpret a video stream, say, and try to identify fish that are moving into the area to show that these turbines are not impacting these species. But there seems to be uncertainty about what type of evidence the regulator will

accept. I will say that other technologies have encountered similar problems, of course, like we've seen in wind farms, often there's concerns about how they interact with bats, for example. So it's not unique, but I think monitoring is a little easier above ground than it is below the waves. Okay, so Matt, we've talked about a bunch of challenges here. What is actually needed, though, to make tidal power a reality? Further development of the technology. So right now, these experiments that have been done are expensive. So they're generating costly electricity that is not currently very attractive to actual utilities that want to generate electricity. I was speaking to Nova Scotia's energy minister about this and the comparison he made, he said, you know, that the cost of some of the projects that have been working in Nova Scotia to date have been

generating power about like 35, 40 cents a kilowatt hour or something like that. You know, they're able to procure wind energy, for example, at about five cents a kilowatt hour. So and now wind is some of the cheapest power that you can get. You know, it's worth keeping in mind that in the 1990s, wind was a very, very expensive way to generate power. And there were only a handful of jurisdictions that were really prepared to experiment with it and pay for expensive power. And fast forward to today, and a lot of innovation has happened, and we've learned a lot. And now wind energy is among the cheapest options.

It certainly has its own challenges, but it's now being deployed around the world. So tidal developers, that's what they want to happen in their own industry. So I guess the big question, Matt, is, you know, from everyone you've talked to from all the work you've done on this, like, is it worth it to pursue title power? Well, that's really a question for policymakers. I don't know sitting here what decision I would make if that were my responsibility, because probably there's a substantial additional amount of investment that needs to be made in order to help mature this technology. And if you deployed it now at scale, you'd be looking at very expensive power and that would upset rate payers. But the industry does seem to be at a crossroads right now.

Like it seems like a lot of title developers feel that they can't see a way forward at this point without some significant change, without regulatory change, without perhaps more money being made available by governments. But, you know, tidal energy remains tantalizing. And, you know, some of this experimentation may very well lead to robust turbines that can last for, you know, years on end in the ocean generating electricity. It's, you know, the technical challenges are daunting, but not perhaps insurmountable. So there remains potential. Matt, thank you so much for taking the time today. It was a pleasure. Thank you.

That's it for today. I'm Maina Karaman-Wilms. Our producers are Madeline White, Cheryl Sutherland, and Rachel Levy-McLaughlin. David Crosby edits the show. Adrienne Chung is our senior producer, and Angela Pachenza is our executive editor. Thanks so much for listening, and I'll talk to you tomorrow.