Published on November 16th, 2020 | by Tina Casey0
Green Hydrogen Scheme Sprouts In Scotland, With Flow Battery
November 16th, 2020 by Tina Casey
Scotland is apparently not satisfied with its position in the offshore wind vanguard. The golfer’s paradise has embarked on a new plan to pair tidal power with vanadium flow batteries to produce green hydrogen. What’s up with that? Tidal power has yet to make an impact on the renewable energy scene and nobody is talking about flow energy storage nowadays — well, almost nobody.
A Place In The Green Hydrogen Sun For Tidal Power
The allure of tidal power runs deep among fans of renewable energy, considering that 70% of the Earth is covered in oceans, aka water that moves back and forth every day all by itself.
That’s where things start to go south. To harness that energy, you could submerge something similar to a wind turbine or a giant screw or even a kite, if you could only figure out how to make it hold up against salt water and other undersea hazards. Then you would have to figure out where to put it, which can be very challenging in coastal areas that are already spoken for by marine traffic, recreation, commercial fishing, and other aquatic industries.
To put some perspective on the situation, the US Atlantic coast is especially ripe for tidal power development, and it only just got its very first tidal power project, the three-turbine RITE array in New York City’s East River, which is not actually a river at all but a tidal waterway.
RITE comes under the banner of a company called Verdant Power. The project has been on the drawing boards as far back as 2002 and the turbines were finally installed in the East River just a few weeks ago, so that’s 18 years, give or take a few.
Scotland Dreams Up Green Hydrogen Scheme
That finally brings us to Scotland, where a firm called Orbital Marine Power may have figured out a way to work around some of the site selection challenges. Instead of anchoring its tidal turbines to the ocean floor, the company is dangling them from a barge-like thing that floats.
Orbital unveiled the design for its so-named Orbital O2 in 2018 with plans to deliver it to Scotland’s European Marine Energy Center at the Orkney island Eday, where it will generate energy to be stored in a flow battery for powering the green hydrogen system.
For those of you new to the green hydrogen topic, hydrogen is a widely used chemical building block and fuel, which is produced mainly from fossil gas and to a lesser extent from industrial waste gases and coal. The emerging green hydrogen field covers several different alternative hydrogen pathways. EMEC is going with the one that “splits” hydrogen from water using an electrolysis system powered by renewable energy.
As for why go through all the trouble of using tidal power to run an electrolyzer when Scotland is already awash in offshore wind turbines that could provide plenty of clean kilowatts for green hydrogen, that’s a good question.
In a press release describing the new project, EMEC noted that industrial processes like electrolysis require a predictable, reliable source of electricity. Energy storage technology can smooth variations in wind turbine output, but that may not be the most optimal solution for industrial-grade energy.
The predictability angle explains EMEC’s focus on tidal energy. The flow battery comes into play because flow technology (more on that in a second) is more durable than the lithium-ion energy storage platforms that are typically paired with wind or solar.
“Tidal generation is predictable yet variable, with two high and two low tides occurring each day,” EMEC explains. “This is an extremely heavy cycling application, requiring up to four cycles per day, compared to solar coupled energy storage projects which typically require just one charge and discharge each day.”
It’s All Part Of The Plan
If all goes according to plan, Scotland’s first-of-its kind green hydrogen experiment will have an impact far beyond its borders.
The the so-named Interreg NWE ITEG project launched in 2018 with the ultimate goal of integrating tidal power and green hydrogen into Europe’s North West region. The idea is to demonstrate feasibility to investors who would otherwise be reluctant to stake the big bucks on unproven technology.
“The cost of pre-commercial demonstration for ocean energy is high and investors are reluctant to invest until the technology has been proven in the sea at scale. ITEG sets out to drive down these costs through the development of an integrated hydrogen production solution,” ITEG observes.
About That Flow Battery…
For those of you new to the flow battery topic, flow means flow, literally. When certain liquids flow adjacent to each other they can generate electricity.
A flow battery stores energy in the form of two specialized liquids kept in separate tanks. When electricity is needed, the two liquids are made to flow next to each other, separated only by a thin membrane (or possibly no membrane at all).
If you’re thinking this arrangement has some advantages over lithium-ion battery arrays, run right out and buy yourself a cigar.
Since the liquids are stored separately, flow batteries can be idled for long periods of time without losing capacity. The liquids can be called into action almost instantly, so there is practically no warm-up waiting time. Flow batteries can also be scaled up by adding more (or bigger) tanks.
The ITEG project is getting its flow batteries from the company Invinity Energy Systems, which specializes in liquids doped with the silvery transition metal vanadium (that’s vanadium, not vibranium).
CleanTechnica took note earlier this year when Invinity took shape out of a merger between the flow battery firms redT energy and Avalon Battery, and it seems it hasn’t let the grass grow under the flow battery feet.
The company will deliver a flow battery system of 1.8 megawatt-hours to the green hydrogen project, featuring a non-flammable, water-based vanadium solution.
So, why vanadium?
“Vanadium is a non-toxic, widely-available metal that is typically used for making steel more ductile, strengthening titanium and even as a dietary supplement,” Invinity explains, while noting the domestic security advantages of reducing the risk of fire and having a broader supply chain.
Also, vanadium can exist in four different stages of oxidation, which comes in handy when you want to recycle the liquids in your flow battery instead of having to start fresh with each charging cycle.
Don’t Mess With Scotland
Circling back around to Scotland, the nation’s offshore wind leadership position has added a curious twist to the nation’s special relationship with one-term US *President Donald J. Trump, who will leave office as constitutionally required on January 20, 2021, having lost both the Electoral College and the popular vote by a wide margin.
The Commander-in-Chief owns golf courses in Scotland through his firm Trump Organization. However, instead of cheerleading for his host nation’s economic development efforts, Trump has become infamous for his hatred of wind power in general and offshore wind in particular (and for coddling white supremacists, but that’s a whole ‘nother kettle of fish).
As with all things Trump, the anti-wind tirades might not pop up out of thin air. They may be rooted in another Scottish marine energy R&D project with global impact, the European Offshore Wind Deployment Center.
When EOWDC announced plans to locate 11 offshore turbines in Aberdeen Bay as part of its research program several years ago, the Trump Organization took them to court, claiming the turbines would spoil the view from — you guessed it — its Aberdeenshire golf course.
Trump ultimately lost the case, the turbines went up, and as of 2018 the Scottish courts decided Trump Organization was on the hook for the legal expenses (if you have any followup on that, drop us a note in the comment thread).
Trump also succeeded in making enemies among local residents for destroying sensitive habitat, among other issues.
Now that the President is losing his grip on both power and on legal immunity, it looks like the Scottish government could take a closer look at Trump’s entire golf operations.
Last week, a group of Scottish MP’s affiliated with the Green Party advocated for an investigation into possible money laundering.
“From the beginning, Trump’s investments in Scotland have seemed unusual,” our friends over at Mother Jones reported last week, describing a situation that does not pass the smell test.
Don’t hold your breath for that investigation. High-level support in the Scottish government reportedly paved the way for Trump’s wheeling and dealing, so it’s not a given that the Green Party MPs and their allies will hold sway.
Regardless, Trump still lost the wind war, bigly. The advent of green hydrogen makes it even more likely that offshore wind turbines will continue to pepper the globe, and the ITEG project could bring a torrent of tidal power into the sustainable H2 fold as well.
To cite just a few recent developments on the wind front, the US launched a new offshore wind R&D collaboration with The Netherlands, renewables-rich Australia is hot on the trail of sustainable H2, and leading global firms like wind-happy Ørsted and BP are not waiting around for data from the ITEG project to make the case for renewable H2 on a commercial scale.
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Photo: “EMEC onshore substation and hydrogen plant, Caldale, Eday (Credit, Orkney Sky Cam, courtesy of EMEC).”
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