Florence: Welcome to engineering with Rosie. In today's video, I'm coming back to the topic of
wave energy. One thing that I've noticed in the last few months since I started paying attention
is that wave energy is not at all like wind energy, which started out with a lot of variety
but has really narrowed down to a pretty standard design for the majority of situations. wave energy
converters, on the other hand started out very diverse and continue to be pretty diverse. Why is
there so much variety? Are there any design trends? Today I'm talking with Florence Ungaro who
is a mechanical engineer at EMEC, the European Marine Energy Center, I'm going to get her take on
the issues.
wave energy is very, very site specific,
I don't think we will converge to one one type of technology
not go to big too fast.
Can you tell me what E.M.E.C what EMEC does?
So EMEC, we have the test site, we help people testing on what we do because we are an accredited
laboratory for ISO 17025. we provide power performance assessment, which means we do the
measurement of the electrical power and the power in the resource. So that means we instrument the
sea. So we would measure the wave and count how much power is in there. Or we can also put down a
DCP on the tidal site and measure the tidal currents exactly the location of the device. And
then we can just do the ratio between the electrical power output and the power input from
the sea, beach wave or tidal. performance assessment to developers, which usually help them
demonstrate that the device can produce electricity. How good have they produced
electricity? And that will help them go to investors to ask for the next round of funding to
scale up or to go to commercial projects?
And is that a normal thing to do? Would you say that most investors would require an independent
verification?
it's very hard to compare technologies between each other because they are not really they have
not really tested to exactly the same metrics. Let's say some are tested just after the
generator, some just after the cable. through our accreditation, we are allowed to do an accredited
performance assessment according to the standard. That means that the way we would measure is
following the standard and is exactly the same for everybody. that makes it very comparable, adds a
lot of trust in such reports.
Okay, so that is interesting. I've noticed that there's a lot of debate about the pros and cons of
the various types of wave energy converters, and even a lot of mistrust in the claims that some
wave energy companies are making about their technologies. So obviously, there's a standard for
measuring and reporting the power output of devices when they're tested in wave tanks. But
when you get out in the ocean, things get a lot more complicated. I wanted to know whether we're
able to compare the energy captured by different types of technologies in a standard way that we
can trust.
Okay, so there shouldn't be any [...] But there shouldn't be any, any debate if, if a company says
that they have achieved, you know, this, this output, and they followed the standard, everyone
should know what that means.
yeah, exactly. So for wave as a power output, the way it's normalized and standardized is through
capture length matrix. When we measure the output from the wave device, we also have wave
measurement instruments that exactly measure what is the wave height and period, we would exactly
know from the time series of the electrical power, in which bin of wave height and period they were
so that you would populate this matrix. And then we do a comparison between what power was in the
sea and what power was given out by the device in this sea state. And that's how it represents
performance for a wave device. It's calculated in kilowatts per meter of wave, the power output of
the WEC is basically just power in kilowatts. When you want to do the ratio of that you're left with
a length dimension. So it's a bit like a percentage to be fair. That's way it is at least
everybody is talking this same language.
Rosemary Barnes: Yeah. And I guess it's like any other kind of energy in the end, everyone cares
about what's the what's the cost of, of the energy, the efficiency actually isn't the most
important thing when waves are free.
Florence: And you can see very interesting patterns of some way devices, are let's say very
narrowband, meaning, they are very performant in some sea states, but if the wave period goes very
goes much higher or much lower, or the wave height is too small or too big, then they don't operate
anymore. It may be the site, it's relevant, because those sites have a very consistent wave
climate. Some devices are more broadband, they would work for much more variety of wave heights,
or much wider variety of wave period, they would be quite, maybe less performant than the other
one, but quite performant. So that would mean that from most of the year in, in places where they
have a very varied wave climate, they would still be producing electricity. So it's all wave energy
is very, very site specific.
Okay. So that's really interesting, because that's a big difference to other kinds of I mean,
obviously, it matters how good the wind is where you put a wind turbine,
yeah, you would have like, type 123 classes of wind and wind turbines and water sites.
Rosemary Barnes: Yes, it is. And with solar as well. I mean, some places have more intense
sunlight than others, but it sounds like wave is on a different level for
Yeah, it's like,
Florence: it moves in two ways. So you have devices that would target maybe more monochromatic
seas that is sea that comes from one direction. You have wave technologies that would target wave
like with we call them like, "spread seas" that he seas that is not very monochromatic, but we would
have swell coming from many directions, and they will still be performant. some will align with
this main swell direction, just because their moored on one side, and then will tend to drift
with drifting forces from the wave. Some just stay in place or have some tension legs, so they are
really just working with the heave movement. Everything is really, really interesting.
Rosemary Barnes: One thing I've noticed is there's such a huge variety of wave energy devices, both
in the past but I mean, it doesn't really look like it's narrowing down to me.
No, no.
And maybe this is the reason because there isn't just one kind of wave energy. So how could you end
up one kind of wave energy converter?
No, yeah. No, that's
Florence: a really interesting bit about it is like, I don't think we will converge to one one
type of technology like tidal tend to look a bit like wind turbines. Water based and floating
or seabed mounted. But wave, I think you will. I it breaks through, it will still be diffe
ent technologies co-habit
Rosemary Barnes: I'm interested to hear how the development process works. So I had an idea for a
new kind of wave energy converter, how would I go about commercializing it? Since Florence has
worked with a bunch of different technologies through the development process, I asked her how
this normally works, and what are the common sources of failure in wave energy converters? and
also whether we are seeing the same issues again, and again, as the older wave energy companies
close down and new ones start up? Can they can they learn from earlier failures? Or does progress
start again, new each time?
Florence: A developer must gradually show performance at smaller stages. And not only on the
performance, you need to show your scenarios for installation, maintenance, reliability
survivability of your device in high seas, not go too big too fast. But really, gradual testing and
seeing if this works at small scale, but does scaling up will increase the cost much more or
less or is there a bottleneck technologically that needs to be looked at?
Rosemary Barnes: what kinds of devices do you think are going to be successful moving forward?
Have you got some ideas about what's what's got potential?
Florence: Well, I see is that especially in Europe, and I think in the US as well, we are all
trying to - through standard because of lesson learned from the previous testing - channel or
give lots of guidelines for the industry on how to develop step by step. And make everything reliable
and I think this has been taken on board by investors and laboratories and device developers,
as so I can see that innovation and development is being more and more, less chaotic, to be fair if
you are new to the field or invest in companies or insurance don't really have anything to compare
technology to anything else, because it's usually usually one of its kind.
Rosemary Barnes: Okay, so thanks a lot, Florence for sharing your experiences with us. I found it
really helpful to get a perspective based on a large number of technologies that Florence has
worked with. So I guess that that's what gives her her broad perspective. I thought it was
interesting to hear how the field is maturing how governments and regulatory bodies are stepping in
to help make sure that lessons are getting learned by the industry as a whole. So even if an
individual company fails, then the experiences they got, they don't need to stop when that
particular technology doesn't continue.
Also, the idea that wave energy converters may never converge to a single technology because
there is no single wave type. That was a new idea for me, I had kind of considered that the
diversity was a sign that wave energy is still immature. But I can see now that there could be a
day when there were several different kinds of wave energy converter technologies that were
mature and simply suited to different wave environments.
If you've got any questions or other topics you're interested in about wave energy, then please leave
them for me in the comments. I'll have a couple of other interviews coming out where I can cover
them. So make sure to subscribe and turn on notifications to see when those come out. If you
liked this video, then please support me by liking the video and sharing and I'll see you in the next
one.