Published on August 3rd, 2020 |
by Tina Casey
August 3rd, 2020 by Tina Casey
Offshore wind farms are exciting enough without any accessorizing, but it looks like Shell is determined to gild the renewable energy lily. The company just nailed down rights to build the massive Hollandse Kust (nord, not zuid) wind farm off the coast of The Netherlands in its CrossWind joint venture with Eneco, and 759 megawatts worth of wind turbines will not be the only green goodies sprouting up from the sea.
More Intermittent Energy From Offshore Wind Farms
Shell has been criss-crossing the CleanTechnica radar as it moves into wind power, among other renewable energy ventures. The Hollandse Kust nord wind project builds up the company’s new identity as a clean power fan, while also positioning it as a global leader for innovative solutions to the challenge of integrating massive quantities of intermittent energy into the grid.
The new offshore wind farm will provide more than 1 million Dutch households with clean power, to the tune of 3.3 terawatt-hours per yer and up.
The wind farm will also demonstrate five technology add-ons that are designed to solve the problem of what to do when too much variable energy is introduced into a grid designed for more stable and predictable inputs.
Weather forecasts and other analytical tools have helped grid operators juggle wind and solar. Improvements in those technologies will help make a difference, as will the addition of more energy storage.
However, with more and bigger offshore wind farms looming over the horizon of the sparkling green future, additional solutions are needed.
Gilding The Offshore Wind Power Lily With Floating Solar Panels
One of the five new technologies to be festooned around Hollandse Kust nord will be a set of floating solar panels. The global impact of a successful demonstration could be huge, because solar developers are on the hunt for locations where new solar farms will not run afoul of land use issues, and they are already turning to reservoirs and other bodies of water for a solution.
Here in the US, the Energy Department’s National Renewable Energy Laboratory has estimated that onshore floating solar alone could produce almost 10% of the nation’s electricity supply.
That’s a conservative estimate based on deploying solar panels on less than 30% of the human-made reservoirs and other constructed water bodies in the US. The research team took an initial pool of 24,419 potential sites and narrowed it down to a smaller group where floating solar could provide an economically viable alternative to using farmland.
Now expand that idea out to offshore floating solar, and things really open up. The offshore wind farm movement is finally gathering steam in the US with a focus on the Atlantic coast, where relatively shallow waters beckon and a slew of coastal states have ambitious renewable energy plans.
Things get even more interesting over on the Pacific coast. Much of the coastline is too deep for conventional fixed wind turbine platforms, but new floating wind turbine technology is providing a workaround, and it could provide solar developers with an opportunity to piggyback their solar panels alongside.
Smarter Offshore Wind Farms On The Horizon…With Green Hydrogen!
A second CrossWind project involves those aforementioned analytical improvements. Shell and Eneco will seek to demonstrate how wind turbines can be tuned more precisely to minimize the “wake effect,” in which turbines in a wind farm interfere with each others’ efficiency.
Also in the category of analytical improvements is a third demonstration that aims for a continuous, steady power output regardless of wind conditions. That project will coordinate the wind turbines and solar panels, along with a short term battery energy storage system and a green hydrogen electrolysis system.
And, that’s where things get interesting. For those of you new to the topic, a green hydrogen electrolysis system deploys an electrical current to “split” hydrogen gas from water. The system could run on fossil fuel just as easily, but it only makes sense from a decarbonization perspective when the electricity is sourced from renewables.
Making Green Hydrogen From Wind & Seawater
As applied to Hollandse Kust nord, the electrolysis system could run during periods of low demand, using excess wind power, solar power, or both wind and solar as the opportunities arise.
The language of the CrossWind announcement seems to imply that the systems will be installed offshore at the Hollandse Kust nord site (“…the offshore wind farm will include the following five technology demonstrations…”), but it’s possible that they are using the word “include” in a loose sense. If that’s the case, some or all of the equipment may find its way onshore.
However, if one goal of the project is to reduce the onshore footprint of renewable energy to a bare minimum, then the alternative would be to build electrolysis systems at the turbines or at a central location offshore. The Government of The Netherlands seems to anticipate various sorts of activities that could be co-located with the 69-turbine wind farm, so there’s that.
Another element to consider is the water to be split. Typically, purified water is required for electrolysis, which also means that more energy is required to run the system. That could provide another basis for deploying both wind and solar at the same offshore location. It could also involve the short-term battery storage system, which could also kick in when additional power is needed for water purification and electrolysis.
More Green Hydrogen = More Offshore Wind Farms, Maybe
As for what the partners plan to do with all that green hydrogen, energy storage is the answer. During periods of high demand, the stored hydrogen could generate extra electricity, presumably with fuel cells located offshore or onshore.
The green hydrogen angle also provides an opportunity to continue pumping clean energy out of wind turbines during periods of low demand.
Though not addressed specifically in the announcement, energy transportation could also be in the cards. Excess green hydrogen from the offshore wind farm could be exported by barge or pipeline to onshore users, or to other offshore users.
If that pans out, offshore wind developers would have many more options in terms of site selection. They would not have to depend on the size of the local population or the ability of the regional grid to absorb the entire output of their new wind farms.
A project under way in Denmark illustrates one hydrogen-based approach to the excess capacity issue. The project involves producing green hydrogen with wind power, and shunting it over to hydrogen fuel stations instead of supplying electricity to the grid. The fuel will be used for a new fleet of hydrogen fuel cell buses.
An onshore green hydrogen project illustrates another angle. Recently unveiled by Microsoft, the project involves an Azure data center that operated for two straight days on fuel cells powered with stored green hydrogen. The hydrogen was produced by an in-house electrolyzer system with wind power.
Microsoft is already eyeballing the potential for operating the system as a load balancing service for local grids, much in the way that the CrossWind project seeks to demonstrate reliability and stability.
“For example, the electrolyzer could be turned on during periods of excess wind or solar energy production to store the renewable energy as hydrogen. Then, during periods of high demand, Microsoft could start up the hydrogen fuel cells to generate electricity for the grid,” Microsoft explained in a recent press release.
Microsoft is also considering the potential for its hydrogen-equipped data centers to double as fuel stations for long haul hydrogen fuel cell trucks, so there’s that.
Any thoughts? Is the hydrogen economy a unicorn or are Shell, Eneco, Microsoft, and the Government of The Netherlands really on to something?
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Image: Location of new wind farm in Dutch Sea, courtesy of The Government of The Netherlands.
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