Right, first things first. I've got a new background. The thing is,
it was getting a bit cramped in the cabin at the back of my house where I've been doing all
the filming and all the editing for about five years now, so I've decided to keep the cabin
just for editing and I've moved the filming kit inside my house, where it's also a bit warmer!
Some people will like the change, and some of you will probably hate it. But I suspect
the vast majority of you will not be all that bothered either way. And to be honest,
any one of those three reactions is absolutely fine with me. So let's just get straight into
today's topic, which is a look at what is, in my view, one of the most innovative and genuinely
useful pieces of real world sustainable technology I've come across for some time.
Hello and welcome to Just Have a Think. So what's this amazing piece of tech I'm referring to? Well,
to paraphrase a well-known 60s Sci-Fi TV series 'it's desalination Jim but not as we know it!'
Now desalination's obviously been around for a long time - almost six decades in fact,
ever since Alexander Zarchin patented a sea water vacuum freezing device back in 1964.
But desalination technologies have been getting a pretty bad rap in recent years for reasons that
we'll have a look at in a moment. So it was unusually uplifting to discover a completely
new approach to desalination that pretty much does away with all the problems of current technologies
and also manages to recycle hundreds of thousands of single-use plastic bottles that would otherwise
have gone to landfill or been tossed into the sea. I'll explain all that later in the video,
but first of all let's look at why the existing tech is apparently so problematic.
Large-scale desalination is generally achieved in one of two ways. The so-called
thermal method sucks in seawater and then heats it up to produce a pure water vapour,
leaving behind a very concentrated brine that then gets pumped back into the sea.
The more modern, and now much more widely used, method involves something called a
reverse osmosis membrane, which I guess is the one most of us have probably heard of. Essentially,
sea water is forced through one of these membranes at very high pressure so that
all the salt and other contaminants are all filtered out, leaving pure fresh water at the end.
You will still get some brine that needs to be discharged somewhere, but reverse osmosis tends
to produce less brine than the thermal method, plus it's cheaper and more efficient overall,
so reverse osmosis now accounts for about 70 percent of all desalination around the world.
Arguably the biggest criticism of these huge centralized desalination plants though is that
they use enormous amounts of energy to process large volumes of seawater, which in turn results
in high greenhouse gas emissions from the generation of electricity. Those greenhouse
gas emissions warm the climate, which makes water scarcity a bigger and bigger problem,
which means the world needs more and more desalination plants and, well you get the idea!
It's a similar feedback loop to the one causing an exponential rise in air conditioners around
the world, which is something we've talked about in a previous video.
There are some small, medium and even large desalination plants powered by on-grid renewables
like wind and solar, but even if renewable energy was diverted on a mass scale to run
all desalination plans they would still be using a huge amount of energy that arguably could and
should be used elsewhere to displace fossil fuels. So that's problem number one. Problem number two
is the accidental intake of fish, larvae and plankton, and any other kind of small marine
life that's unlucky enough to be swimming next to an intake pipe when the system gets switched on.
Even with grilles on the front of the pipes, millions of tiny marine creatures are still
inadvertently sucked into desalination systems this way each year. The third problem is the brine
itself. If it's released from a single outflow at a large plant or from a cluster of plants in a
small area, which is what happens in the Persian Gulf region for example, then it represents an
extremely sudden and disruptive concentration of very warm, very salty water that does all sorts
of nasty things to the local marine ecosystems. A recent analysis by the United Nations found that
brine discharge from the 16,000 or so desalination plants in operation around the globe today is 50%
higher than previous estimates. In actual numbers that equates to about 142 million
cubic metres of concentrated brine being sent back into localized coastal regions every single
day. That's enough to cover the entire state of Florida in 30 centimetres or 12 inches of liquid.
Last but by no means least is the fact that these enormous desalination plants are extremely
expensive to build and run. Those costs have to be amortized over the lifetime of the project,
and if a large part of that amortization is based on the dollar value of fresh water delivered then
of course, as energy costs rise, then inevitably so does the cost of fresh water to the consumer.
Water scarcity is a growing problem all over the world, even in affluent Western regions
like California and Nevada. In 2020 roughly one percent of the human population relied solely on
desalination for their daily water supply. By 2050 that number is expected to increase to 10 percent.
That'll equate to about a billion people who will have no access to fresh water without some
kind of desalination technology. If the world continues to desalinate water using existing
methods then by mid-century the process will account for about five percent of total global
greenhouse gas emissions which will contribute heavily to the feedback loop I mentioned earlier.
So anyone coming along with a better idea probably needs to be listened to.
And that's where a Canadian start-up called Oneka Technologies comes in. The company was founded in
2015 by a mechanical engineer and entrepreneur called Dragan Tucic, specifically to address
the issues we've just looked at. I caught up with the company's commercial manager Camille
St Pierre via Zoom recently to get a better idea of how their innovation works and why they believe
it could transform an entire sector. Not all desalination takes place in coastal regions
but the vast majority of it does, and that begs the question of whether it might be possible to
harness some of the energy in the ocean itself to provide power for the desalination process.
Now when people like me talk about wave and tidal energy technologies we're almost always talking
about devices that can convert that energy into electricity, either for local use or for
transmission back into an electricity grid system. That's not how Oneka have tackled the problem.
They've developed a system that harnesses the motion of ocean waves in an entirely mechanical
way with no electricity generated or used in any part of their desalination process at all.
It works like this. A floating platform is anchored to the seabed and just like any
other ocean-going vessel it bobs up and down with the motion of the water. As it moves downwards it
draws in seawater via a strainer on the underside which has a very fine mesh across its opening to
vastly reduce the chances of sucking in any tiny marine creatures that may be passing by.
The sea water then goes through filters to remove the worst of any other rough stuff.
As the platform rises with the waves the sea water passes through a mechanical pump followed
by a pressure and flow optimization system. That provides enough pressure to force the
water through a reverse osmosis membrane very similar to the technology I described earlier.
All of this is wave driven don't forget, there's no electricity anywhere in the system.
Now here's where a second key difference comes into play. The system desalinates 25 percent
of the water that passes through the membrane, leaving 75 percent of the water as a relatively
low salinity brine which then gets sent back through the pressure and flow optimization
system before going back into the water below the platform. That means the discharge brine is
only about 30 percent more saline than the sea water that it's being released into, compared
to conventional desalination plant discharge which can have between 100 and 150 percent
higher salinity than the surrounding water. As well as that a typical Oneka installation
will be comprised of multiple relatively small platforms distributed over a very wide area,
as opposed to one huge centralized desalination plant spewing out brine at a single location.
That creates what Oneka describe as 'multiple outfalls' which combine with the natural sea
currents and waves to very quickly diffuse the brine back to nominal levels. In fact Oneka's own
testing has demonstrated that within a distance of only about two to three metres from each
platform no change in salinity can be detected. Those findings are now being formally validated
by university researchers and environmental engineering companies in Chile and California.
The fresh water is then sent to shore under pressure via a single submerged pipeline,
again driven by the mechanical action of the waves with no additional electrical power.
The only electrical components you'll find on one of these platforms are the solar panels that are
there purely to drive the sensors that monitor performance and send data to the cloud where
they're available online in real time. Oneka have developed three distinct categories of platforms
to cater for more or less any size of application. The smallest of the three is the Ice Cube class.
This is a unit that can be disassembled and packed inside a standard size shipping crate,
which makes it extremely easy to send out to remote coastal bases or as an emergency fast
response solution in disaster relief situations. The platform's about 1.5
metres in diameter and produces about one cubic metre of fresh water per day. And for
those of us who work in more basic units, that equates to a thousand litres or 220 gallons.
Having carried out extensive lab testing and computer simulations the Oneka team then produced
a slightly larger prototype for real-world testing. This one was capable of producing 10
cubic metres of fresh water a day and it was taken straight out into the extreme ocean conditions
off the coast of Canada where it endured, and survived, waves of up to seven metres in height.
Next up is the Iceberg Class with about a six metre diameter equivalent, and the capacity
to churn out up to 50 cubic metres of fresh water per day, which is 50,000 litres or 11,000 gallons.
The floating platform is made from recycled polyethylene terephthalate or PET, so it's perhaps
the most environmentally friendly way of chucking discarded soda bottles into the sea that anyone
has ever devised. This size of installation is ideal for small off-grid communities or
perhaps for tourism and remote resorts, or even for smaller industrial applications.
A working example of the Iceberg Class is currently deployed as part of the first phase of a
commercial project in Florida that will eventually have a total generating capacity of 300 cubic
metres of water per day. Full production of the Iceberg Class is scheduled to commence in 2023.
Oneka are now working flat out to develop the largest of the three platforms, which
they call the Glacier class. This one will have a diameter of between 12 and 15 metres and a typical
installation comprising 40 of these platforms will be capable of producing more than 20 million
litres, or almost four and a half million gallons of fresh water a day. An installation that size
would be usable by municipal authorities or in large industrial or agricultural applications.
So what about cost? Well, the numbers can vary quite significantly depending on things like
the size of the plants, the local cost of electricity, the length of the water
supply agreement, cost of capital, the regulatory environment, and even the quality of the water.
Huge centralized desalination plants in the Middle East, typically powered
by cheap electricity from fossil fuels, can produce between 300,000 and 900,000
cubic metres of fresh water per day for around 50 cents to a dollar per cubic metre.
Smaller facilities that are closer in size to Oneka installations typically sell fresh water
for between two and five dollars per cubic metre. But electricity costs represent roughly half the
operating cost of a conventional desalination plant, and that's an overhead that Oneka's system
simply doesn't have. So on a like for like basis Oneka's team reckon their technology
can already produce water at a lower cost, and as they scale up production and start operating
larger arrays they expect to be producing water at only a quarter of the current market price.
So what's your view? Do you think this kind of desalination technology can generally make a
difference, or do you see issues that we perhaps haven't covered in this video? Maybe you're
working in the industry and you have some insights that you can share with us all. If you do then,
as always, leave your thoughts in the comments section below, and I'll be interested to see
what you think. That's it for this week though. If you've enjoyed this video then please do give
us a like and hit that subscribe button if you haven't already done so. And if you want to get
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then why not come and join our amazing channel supporters over at Patreon. And talking of
Patreon, I must just say a massive thank you to some long-term supporters of the channel whose
names are scrolling up the screen here, all of whom reached an anniversary of Patreon membership
during November. This channel would simply not be possible without them, so they all have my
undying gratitude. And if you're Keen to learn more about other sustainable technologies like
the one we've talked about today, then I reckon you'll enjoy this video as well. As always, thanks
very much for watching. Have a great week, and remember to just have a think. See you next week.