ERM’s pioneering Dolphyn project – the first of its kind in the world – aims to produce ‘green’ hydrogen from floating wind turbines situated miles out to sea. Jon Excell reports.
C2I 2020
Category: Energy & Environment / The Engineer Grand Prix
Winner: ERM Dolphyn
Partners: ERM with Offshore Design Engineering (ODE), Tractebel Engie, Principle Power Inc (PPI), NEL, Doosan
Abundant, versatile, energy dense and clean at point of use, hydrogen is viewed as an increasingly important component of our future energy mix and key to the decarbonisation of our heating and transport systems.
The problem is that the bulk of the hydrogen currently used is derived from fossil fuels using processes that the International Energy Authority (IEA) says is responsible for around 830 million tonnes of CO2 emissions per year.
Clearly, if hydrogen is to truly deliver on its environmental potential, cleaner methods of production are going to be critical, and the winner of this year’s energy and environment category ERM Dolphyn (Deepwater Offshore Local Production of HYdrogeN) offers an inspiring and highly innovative example of how that could be achieved.
Led by environmental consultant ERM, the project – which will be a world first- is looking at producing green hydrogen from electrolysers that are directly coupled to floating wind turbines far out at sea.
Project director, ERM partner Kevin Kinsella explained that the team is initially aiming to get a 2MW proof of concept unit up and running in a consented area around 15km off the coast of Aberdeen by 2024.
This will be followed by a full scale 10MW pre-commercial unit, likely connected to the low pressure gas distribution network in Aberdeen by 2026 with the ultimate aim to deploy a 4GW array of floating 10 MW wind turbines in the North Sea by the early 2030s.
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The design is currently at FEED (front end engineering design) stage and consists of a large scale floating wind turbine (10MW) with an integrated water treatment unit and PEM electrolyser for localised hydrogen production. It incorporates its own standby power unit, supplied by hydrogen stored on the facility, and is therefore completely autonomous, requiring no electrical connection to shore.
Hydrogen generated by the initial units will be exported to the shore via a three-inch diameter flexible pipe, but for larger installations the green hydrogen generated by each turbine would be exported at pressure via a single flexible riser. This would connect to a sub-sea manifold, with lines from other individual turbines in the field, and the hydrogen exported back to shore via a single trunkline.
Whilst there are a number of projects around the world exploring the use of offshore wind to generate hydrogen, most of these are focussed on using electricity derived from wind power to drive electrolysers on the shore. One of the key innovations of ERM Dolphyn is that it couples the electrolysis and wind turbine in a marine environment and uses seawater, via onboard desalination, to produce green hydrogen at scale.
Explaining the decision to directly couple the electrolysis to the turbine in this way, Kinsella said that the team initially explored a number of options, such as bringing power back to a centralised platform with electrolysers before piping hydrogen back to shore, or performing electrolysis onshore, but went for direct coupling as it avoids the need for expensive cables, switchgear, and grid connections. “It’s a much cheaper way of doing it over long distances and you don’t get the energy losses that you do with bringing it back electrically,” he said.
Freeing the system from the constraints of grid connectivity also makes it easier to build further out to sea where the wind resource is more plentiful, and it’s possible to build large scale installations without impacting shipping routes or raising environmental concerns.
Whilst the concept is being developed and led by ERM, collaboration has been key to its success so far. Energy firms Tracetebel Engie and Principle Power (PPI) are responsible for the floating sub-structure design the wind turbine, whilst ODE is responsible for the Dolphyn topsides including the desalination and stand-by power unit. Meanwhile, electrolyser specialist NEL and engineering giant Doosan are responsible for the electrolyser design and its integration into the overall system and ensuring that it can withstanding offshore conditions.
“One of the most satisfying aspects of the project to date has been the desire of all parties to make Dolphyn a success,” said Kinsella. “Everyone working on the project is excited and aware of the enormous potential that the technology has to produce green hydrogen at scale from the outstanding offshore wind resource that is available in the North Sea and other UK deepwater locations. This has resulted in a highly motivated team with a strong ‘one-team’ mentality, with openness to discuss and resolve a wide range of technical and operational issues to improve the design and the commercial performance of the technology.”
Kinsella said that a 4GW Dolphyn array could produce enough hydrogen to heat 1.5 million homes, paving the way for a transformation of the UK’s energy landscape. “There’s no reason at all why, by the end of the century, the whole of UK heat couldn’t be provided by green hydrogen from offshore North Sea wind”, he said.
It’s a tantalising vision, and one which is well within the UK’s grasp, thanks to both its geography and the wealth of expertise and infrastructure that can be found in its offshore oil and gas industry. “We’re in the best position in Europe, having the best wind resources by far. We have a leading offshore oil and gas industry and offshore wind industry, supported by the best supply chain in Europe, and all of the technical resources and knowhow to deliver it. With Net Zero by 2050 written into UK law, this is a fantastic opportunity for the oil and gas industry to transition smoothly from fossil fuels to green energy, using the same skills and resources, and at the same time become a net exporter of green energy to Europe.”
The unintended consequence of a massive increase in hydrogen productions is likely to be no ozone layer. At present the world hydrogen production is about 118 tpa. If all methane use were transferred to hydrogen (141 EJ / y) the world’s hydrogen production would be about 1 billion tpa.
The ozone mass in the stratosphere is about 3 m tonnes.
Thus, if the hydrogen leakage exceeded 125 ktonnes / year, the ozone layer would be gone (apart from the slow re-forming rate) in one year.
That is a leakage of one millionth of a percent; several orders of magnitude below practical value.
Nice idea – and maybe a new use of old gas rigs too? What’s the final cost per kWh going to be, compared with old-school North Sea gas?
There’s nothing to be excited about, if this floating wind is restricted to deep water!
It is currently and, in the absence of radical innovation, will always be cheaper to exploit shallow seas, close to shore as the best location for any turbines. Ignoring the UK’s huge resource of wave and tidal energy is a monumental blunder. Wind power, on its own, is untenable.
The first choice for green hydrogen production must be co-location with heavy industrial users, on or near the coast. The running costs would fall dramatically and the savings, on both CapEx and emissions would be significant. We have no shortage of fresh water – desalination makes no sense.
25TWh/year of guaranteed tidal electricity from the Bristol Channel (Aberthaw-Minehead barrage) is a natural marriage with the Port Talbot steelworks. The Swansea Bay Tidal Lagoon would also be an excellent test bed for the combination/integration of wind/wave and tidal with Before-Generator Energy Storage, to develop low-cost green hydrogen production from Welsh Water.
Once banks of these these things are in operation, has any thought been given to the affect on local eco systems of dumping concentrated brine back into the sea? What happens to the O2 produced?
While Boris and BEIS boast about the UK’s “world-leading” (imported) offshore wind. . . .
https://www.theguardian.com/environment/2021/feb/04/denmark-strikes-deal-on-25bn-artificial-wind-energy-island
“In a deal struck on Wednesday, the Social Democrat government agreed with its support parties and the rightwing opposition that the state should hold a 51% stake in the island.” 4 Feb. 2021.
Danish energy minister Dan Jorgensen said: “It’s a huge project. We need to build > five times as much capacity as we have today (Dec. 2019) We need an ambitious plan for development. If we want to realise the enormous potential of offshore wind, we must develop the technologies of the future to convert the green power into fuels for aircraft, ships and industry.”
“Feasibility studies are starting (Nov. 2020) to determine the location of a 3GW energy island in the North Sea. The final decision will take place no later than the spring of 2021, the government said.
“The artificial island will be linked to hundreds of offshore wind turbines and will supply both power to households and green hydrogen for use in shipping, aviation, industry and transport. It will connect to several European countries.” (4 Feb. 2021) “The government says public money will be used to pay for at least half the costs of constructing the island.”
“Denmark, home to wind turbine maker Vestas and offshore wind farm developer Ørsted, was a pioneer, building the world’s first offshore wind farm thirty years ago.” – when the UK government had already forced the CEGB to abandon wind turbine development. You reap what you sow!
Has the real energy balance of this been worked out in detail. Crude calculations suggest a 20% efficiency rating at best. Perhaps the electricity generated would be more useful being wired up to be brought ashore. It is all still intermittent generation.
Confirmation of the utter folly of “utility-scale battery storage”. . .
https://worldbatterynews.com/denmark-gives-green-light-to-construct-%27energy-island%27-hub-in-the-north-sea-p653-120.htm
Or, another hare-brained scheme to store electricity:-
https://www.dnvgl.com/services/large-scale-electricity-storage-7272
“When there is a surplus of wind energy, the excess electricity is used to pump sea water out of the interior ‘subsurface-lake’ into the surrounding sea. When there is a shortage of wind power, sea water is allowed to flow back into the interior ‘lake’ through commercially available generators to produce energy. The IOPAC is unique in that it would be on an artificial island off the Dutch coast and comprised of a ring of dikes surrounding a 50 metre deep reservoir. The island itself would be built from materials dredged to deepen the interior reservoir.”
Although it could potentially gain a little extra energy, if high tide coincides with peak demand. Naturally, efficiency would be further diminished, if low tide coincides with peak demand!
There are two scientific issues related to this technology that ought to be fully evaluated before money is spent on “The Hydrogen Economy. These are:
1. The risk of hydrogen (leakages and unburnt) damaging the ozone layer: this was researched over 20 years ago but seems to have been conveniently forgotten about. Hydrogen travels to the stratosphere very quickly and reacts rapidly with ozone.
2. The risk of ground level ozone production from electrolysis. This is virtually the reverse of the first issue: at low altitudes ozone is very hazardous and is an inevitable by-product of electrolysis.
It takes a long time for a windmill to generate the energy that was used to make the steel to build it. If the efficiency is divided by five to make hydrogen, then a windmill may never pay back the energy used to build it. Does anybody have the numbers for this?
I think that Martin Bennett is right about the energy balance. However, until recently it was costs and employment that mattered to the development of economies, the steel will be imported and the electricity used to make concrete etc will be very expensive (from windmills at £ 140 / MWh as these increase). I suspect that, in future generations, the poor will not have any health or social care as the UK squanders its wealth on vanity projects.
Is it really easier to build hydrogen proof underwater pipelines than an hv cable ? Cable is a pretty mature technology, and avoids the energy conversion losses of electrolysis and downstream processing. Instead of diluting the hydogen, and adaptation of gas burner setups, direct use in heat pumps or IOT controlled water heating systems would be more efficient. Hydrogen , at least used in this manner could be seen as a greenwashing laste fling heavily tilted towards the incumbent fossil fuel interests.
@ Steve.
Aside from the very high cost, the problem with HV cable is the nature of the electricity itself. It has to be transmitted in perfect ‘tune’ with supply and demand, whereas hydrogen is stored both ends. Likewise, cheap underwater water pipes could transmit power anytime from floating storage to accumulators onshore, co-located with hydro-turbine generators – with or without the electrolysis to produce green hydrogen. That setup eliminates intermittency by scrapping offshore HAWTs.
You’re right; fossil fuel interests are pushing the government to waste investment in blue hydrogen and CCS, so they can maintain their sales of natural gas.
“One kilowatt-hour (kWh) of electricity in a heat pump may generate 3-5 kWh of heat, while the same kWh of electricity (using electrolysis) gets you only 0.6-0.7 kWh of heat with a hydrogen-fuelled boiler. ”
So no for home heating .
But heat pumps installations need to be designed and installed correctly.
Improving insulation/radiant surface temperatures of buildings will bring more comfort, lower (smaller) equipment and energy bills.
Urban areas are well suited to District Heating DH using MW scale water sourced + air sourced heat pumps on the HV electrical grid. Supplemented by solar thermal (works even in sunny UK), with using waste heat wherever possible ! Large DH heat stores are cheap and can help buffer renewables.
So hydrogen only for niche applications where an electrical alternative is not possible :
https://theconversation.com/hydrogen-where-is-low-carbon-fuel-most-useful-for-decarbonisation-147696
For example but more expensive than using cracked natural gas is Yara’s industrial fertiliser project in Spain using PV + battery >private wire> electrolytic hydrogen
https://www.iberdrola.com/about-us/lines-business/flagship-projects/puertollano-green-hydrogen-plant
PS Dogger bank offshore wind ~ £ 48 / MWh
https://www.lowcarboncontracts.uk/cfds?field_cfd_technology_type=&field_cfd_applicant_name=&field_cfd_unique_id=&page=1
PSS The latest tendering of offshore wind has possibly (would the government do such a thing?) been designed to make wind more expensive so as to justify the horrendously costly nuclear?
Wind and renewable alternatives with infill is less expensive. Follow the money.
PS. Dogger bank offshore wind ~ £ 48 / MWh
https://www.lowcarboncontracts.uk/cfds?field_cfd_technology_type=&field_cfd_applicant_name=&field_cfd_unique_id=&page=1
PSS. The latest tendering of offshore wind has possibly (would the government do such a thing?) been designed to make wind more expensive (ie. option fees) so as to justify the horrendous cost of nuclear?
https://www.offshorewind.biz/2021/02/08/renewableuk-voices-concerns-over-round-4-option-fees/
As a note to John Daglish, the prices for future wind are not contracts, they will be escalated by the rapidly rising carbon trading prices (if the CCC has its way). The present cost of wind power is about £ 140 / MWh while that for gas would be about £ 40 / MWh without carbon taxes that are used to subsidise the wind power. The net effect is that the UK is paying out billions of pounds per year for no benefit apart form a truly trivial (barely measurable in fact) reduction in the world’s CO2 emissions.
An interesting piece on hydrogen from the IET which includes some numbers:
https://eandt.theiet.org/content/articles/2021/02/are-hydrogen-fuelled-vehicles-a-waste-of-our-time-and-energy/
Energy balance from offshore, depending on many factors seems to be about 3-6 months
Perhaps a better option would be electro-synthesis of ammonia (NH3) as a hydrogen carrier, which could be implemented anywhere there is a source of water, air and renewable energy.
It is liquid at modest temperatures and pressures, does not seep through the walls of pressure vessels, embrittle metals, nor interact with the ozone layer (as hydrogen does). A large storage and distribution infrastructure already exists.
We need to move beyond the fossil-intensive Haber-Bosch process regardless; half the protein in our bodies results from manufactured ammonia fertiliser.
Why do some people choose to exaggerate a problem for no apparent reason?
“If it takes more than 50 years for hydrogen to become widely used as a fuel, CFCs will have largely disappeared and ozone depletion will no longer be a problem. By then, hydrogen transport and production might also be less leaky.”
https://www.nature.com/news/2003/030609/full/news030609-14.html