What’s stopping us from converting the open
ocean into a massive solar power plant? To the tune of almost 6 times more energy
than the world uses every year. Several companies are trying to do just that
by floating solar panels out on the open ocean, but that raises so many questions. Won't they get smashed to pieces during storms? Why even bother with the ocean when we have
land? Developing seaworthy panels is a lot more
complicated than just smashing a bottle on the array and setting sail. So, what makes floating photovoltaics on the
ocean worth a shot? And what’s holding it back? I’m Matt Ferrell … welcome to Undecided. This video is brought to you by Brilliant,
but more on that later. When news about companies like HelioRec and
Ocean Sun bubbled up about putting solar panels out on the ocean, it really caught my attention. This wasn’t theoretical, but really happening. Initially, I thought: “How is that going
to work and not get torn apart by storms?” My gut reaction was that the engineering and
maintenance challenges felt insurmountable and the cost would be too high. So my team and I started diving into the world
of floating solar again to see if we could find answers to those questions. If we can keep turbine towers that are taller
than national monuments afloat, why can’t we throw a solar panel array into the deep
end of the earth’s pool? What we found was fascinating … but also
raised as many new questions as it answered. I’ll get to HelioRec and Ocean Sun in a
minute, but there’s a big question we have to answer first: Does floating solar on water
even make sense? To answer that question, we’ll have to start
inland. Floating photovoltaics, or floatovoltaics,
is a relatively new branch of the solar industry. Its global installed capacity only started
to expand beyond 1,000 MW around 2018. But the technology has become more common
over the past few years with about 3.8 GW installed by 2021. That’s a tiny sliver of the thousands of
GW of solar installed worldwide. If you’ve been following the channel for
a while, you might remember last year’s video about floating solar on canals. In case the concept is unfamiliar to you,
though, know that floating PV (FPV) is exactly what it sounds like: solar panels moored within
a body of water. FPV has three major benefits: Floating solar farms aren’t occupying limited
space on land. Solar panels on water stay cooler, and therefore
perform better. Bodies of water shielded by FPV are less prone
to evaporation, which helps preserve freshwater supplies. These perks are the basis for ongoing projects
in places like the United States and India, where miles of canals are being used to determine
if FPV is a boon…or boondoggle. For more details on that, check out that video. It’s that second benefit, about solar performing
better on water, that’s really fascinating. One of the largest solar farms in Europe is
a great example. EDP, a Portugal utility, built floating solar
on the country’s Alqueva reservoir. It’s not exactly a choppy ocean, but still
important to understanding what we can get out of FPV. According to Pedro Oliveira, the company’s
Director of Innovation, its FPV farm has seen increased efficiency thanks to water’s cooling
effect. He cites an efficiency increase of “up to
10%” along with an average annual productivity increase of around 4%. Adding on to that, a separate 2021 ENEL Innovation
Lab FPV study found that floating systems can produce anywhere from 4% to 7% more energy
than ground-based solar. Keep these FPV benefits in mind as we work
through the challenges, and what HelioRec and Ocean Sun are trying to do out at sea. So, if FPV is already an emergent use of canals,
lakes, and artificial reservoirs, we can definitely apply the same tech to the ocean, right? Well, not exactly. Before getting into why, if you’d like to
better understand the principles behind solar power and how photovoltaics work, there’s
a fun and easy way to do so. I'd strongly recommend checking out Brilliant
dot org and the Solar Energy course, which goes into detail on key concepts like photons
and photon absorption, the spectral properties of sunlight, and the band gap. Wrapping your head around these principles
really helps understanding what’s going on with the latest solar panel tech and new
techniques like offshore solar. Recently I’ve been going through courses
like the Thinking in Code course to brush up on my programming basics. I’ve been trying to automate some repetitive
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free for a full 30 days, visit brilliant.org slash Undecided or click on the link in the
description. The first 200 people will get 20% off Brilliant’s
annual premium subscription. Thanks to Brilliant and to all of you for
supporting the channel. What’s different about floating panels on
the ocean? Well, it’s kind of like the distinction
between tap water and seltzer. Unlike the mostly still surfaces of the previous
examples, the ocean would of course be constantly churning and bombarding the panels with salt. Exposure to all that salty water leaves the
panels at risk of corrosion. More movement means more money spent designing
reinforced frames and mooring strong enough to stay afloat. It also means risk of sunlight spreading unevenly
across the panels, which lowers energy production. Ensuring that the panels are close enough
to the water to be cooled, but not too close to be overwhelmed by the waves, is yet another
delicate balancing act. Plus, while the sun-blocking element of freshwater
FPV can slow down algae blooms and weed growth, marine fouling is literally a whole different
animal. Just like offshore wind, offshore solar structures
will also act as artificial shelters for aquatic life, adding another dimension to the challenges. Where there’s fish, there’s birds, and
where there’s birds, there’s bird droppings. Not exactly great for solar panels. We also can’t forget that the potential
negative impacts on the local ecosystems are still unclear. Ultimately, as nice as it would be to plop
freshwater FPV into the ocean and call it a day, it’s simply…not that simple. Not to mention the weather. Florida hurricanes, for example, would not
be kind to FPV. In fact, a study published this past June
suggests that the majority of countries are knocked out of the running for practical installation
of offshore solar. According to The Australian National University
researchers, that’s because “most of the world’s maritime areas have experienced
waves larger than 10 m [33 ft] and wind speeds larger than 20 m/s [45 mph] at some time over
the past 40 years.” These conditions are not only linked — in
general, more forceful winds mean more powerful waves — but can also seriously damage FPV
system components like floats and cables. A dangerous example of this happened back
in 2019, when Typhoon Faxai’s 54 m/s (120 mph) winds actually caused a Japanese floating
solar plant to go down in flames. Keep in mind that this was an _inland_ system
installed on top of the Yamakura Dam. As the wind and waves flung panels together,
they overheated in close contact and sparked a fire. The study authors argue that in places where
tropical storms can occur, engineering defenses against incidents like these could be prohibitively
expensive. Where does that leave offshore FPV? Don’t worry: there’s still plenty of places
with calm waters that can theoretically accommodate photovoltaic pontoons. After analyzing 40 years’ worth of weather
data on wind speed and wave height, the Australian research team determined that the best locations
for floating panels lie within the planet’s equatorial zones, like in Southeast Asia and
Northwestern Africa. The researchers emphasize the Indonesian archipelago
and the Gulf of Guinea, which is off the coast of African countries Nigeria and Cameroon,
as prime examples. So, what makes these sites so special? Why are their waters calmer? And what about tropical storms? As we researched this topic, it’s at this
point when I turned to a member of my channel’s science advisory board, meteorologist and
storm chaser Seth Price. He explained that to answer these questions,
all we have to do is look at the shape of a globe. Our big blue marble happens to be wider at
the Equator. Consequently, as Earth rotates, its middle
is actually moving faster than its poles. This is what causes what’s known as the
Coriolis Effect, or the curving movement of water and air as they move over the planet’s
surface. The Coriolis Effect is what makes storms spin. At the Equator, there is _no_ Coriolis force,
so tropical storms virtually never form there — or cross its bounds. Seth also added that because these physics
are based on the Earth’s rotation, they won’t change even as the climate does. That’s particularly important to note in
light of the concerns about how to adapt marine FPV to new weather patterns. It’s already hard enough to design materials
that can survive years of battering by the elements. Having to consider the risk of extreme and
unprecedented weather events doesn’t make things easier. Does the Equator’s protective barrier mean
that offshore FPV is ironclad in those regions? Of course not — otherwise we’d probably
be used to seeing solar panels bobbing on the waves by now. As Seth says, “There will always be a natural scenario
to destroy even the best-engineered project.” Wise words, Seth. Wise words. However, he also pointed out that we’re
already long-accustomed to resilient energy generation on the ocean’s surface…in the
form of oil rigs, and more recently, floating wind turbines. Norwegian petroleum company, Equinor, created
the first offshore wind farm in 2017 using the same spar platforms that are ubiquitous
in the oil and gas industry. Developing technology that can weather storms,
constant wave action, sea spray, and the harsh UV rays emanating from the sun is complex
… but far from impossible. In fact, it’s likely that we can reap the
same benefits of pairing wind and solar that we get on the ground out in the ocean: sharing
grid infrastructure and operational equipment can keep costs down and combat intermittency. Is it worth the trouble, though? The Australian National University research
team certainly seems to think so. In that paper I mentioned earlier, its authors
go as far to say that the eligible equatorial regions they highlighted enable “huge”
energy generation potential for FPV: “The combined offshore floating solar PV
annual generation potential for regions that do not experience waves larger than 4 m [13
ft] or winds stronger than 15 m/s [33.5 mph] is 220,000 TWh. This is sufficient for all the energy needs
of an affluent global population of 11 billion people.” But that’s not all. The researchers propose that if marine FPV
can survive maximum wave heights of 6 meters (19 feet), the annual energy generation potential
jumps up by _a lot_. To the tune of a collective production of
up to one million TWh per year. To put these figures into perspective, Our
World in Data lists the planet’s annual primary energy consumption (that’s from
all sources) at 167,788 Twh in 2022. So who’s out there actually testing the
waters? There’s more offshore solar farms currently
in operation than you might think. In Indonesia, the country’s Sepuluh Nopember
Institute of Technology and Pattimura University are collaborating with researchers at the
Cranfield University in England to develop offshore floatovoltaics as part of the Solar2Wave
project. According to Luofeng Huang, a mechanical engineering
lecturer at Cranfield’s Centre for Energy Engineering, analysis of the team’s designs
has shown that they can tolerate waves up to 5 meters (16 feet) high. There’s also the Norway-based company Ocean
Sun. Taking inspiration from the Victoria Amazonica
giant water lily and aquaculture, they’ve developed a design with a thin, flexible membrane
that’s stable enough for technicians to walk on. The company has installed multiple FPV projects
along the western coast of its home country, in the Yellow Sea near Shandong, China, and
down the Johor Strait between Malaysia and Singapore. Its first prototype, a 6.6 kWp system commissioned
by Norwegian company Lerøy SeaFood for its fish farm, has been kicking since the summer
of 2018. Ocean Sun also has plans underway to drop
anchors in Greece, Cyprus, and Singapore this year. Interestingly, according to the company’s
website, its products feature a boost of up to ~10% in energy yield relative to other
floating systems as a result of the surrounding water’s cooling effect. To back up that claim, it cites certification
by the Singapore office of the energy consultancy agency DNV and a study conducted by Norway’s
Institute for Energy Technology. It also goes as far to say that the cooling
is consistent enough to prevent the panels from experiencing daily thermal cycling, which
basically means that they’re not constantly bouncing between high and low temperatures. Ocean Sun’s floaters can also withstand
wind speeds as high as 275 km/h (171 mph). That’s impressive. Then there’s the French company HelioRec,
which recently announced the successful installation of a 25kW pilot system in the port city of
Brest. According to the company website, the location
is significant because of its notoriously high wind speeds of over 100 km/h (62 mph)…and
high tides, which can swell up to 7 meters (23 feet). And to date, HelioRec’s 10 kWp system at
the Port of Oostende in Belgium has managed to survive two storms. Perhaps most critically, though, is what we
know about the costs…or rather, what we don’t know. In a 2020 Ocean Sun investor presentation,
the company claims that its systems are between 25% and 30% cheaper than conventional FPV,
and 10% to 15% cheaper than ground-mounted PV. And per its 2023 Second Quarter & Half Year
report, its equipment costs are “closer to that of ground-mounted PV.” What Ocean Sun advertises as a 25% lower capital
expenditure or CAPEX cost partly comes from the fact that its floaters can be easily rolled
up, kind of like a beach umbrella. This allows them to be transported in a single
40 ft. (12 m) shipping container, which the company says reduces the amount of money spent
on logistics. But when it comes to any more explicit information
than that, data like the Levelized Cost of Electricity (LCOE) isn’t clearly stated
on the company website. The most detail we get comes in the form of
the claim that Ocean Sun’s floaters have the “overall lowest material usage of any
floating PV system, enabling the lowest overall LCOE.” We’ll have to take that with a grain of
sea-salt until we can see more independent data. What we do know for sure is that as it stands,
offshore solar is very new. The projects we’ve discussed so far are
not only experimental and small in scale, but relatively “near shore.” Until the technology matures, we won’t be
skimming sunshine off the waves of the open ocean just yet. Overall, it’s less about what’s possible
and more about what’s practical. The same strategies used by the oil and gas
industries to maintain floating drilling operations have already been applied to renewables in
the form of offshore wind. Meteorological research indicates that areas
near the Equator are probably offshore solar’s best bet. Resources exist to meet the concept’s design
challenges, but is it ultimately worth the cost — and the potential ramifications for
aquatic life? We’ll have to “sea” about that. So do you think offshore solar is a good direction? Jump into the comments and let me know. And be sure to check out my follow up podcast
Still TBD where we'll be discussing some of your feedback. Thanks to all of my patrons, who get ad free
versions of every video. Your support really helps to keep me and my
team going and delivering you these videos every week. I’ll see you in the next one.
