A new report from the International Energy Agency (IEA) says offshore wind could generate more than 18 times today’s global electricity demand.

Offshore Wind Outlook 2019 highlights the vast untapped wind resources around the world and claims to be the most comprehensive study on the subject to date. It claims offshore wind has the potential to generate more than 420 000 TWh per year worldwide, with approximately 36,000 TWh of this easily accessible in coastal waters no deeper than 60m.
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The report predicts that by 2040, offshore capacity could be 15 times what it is today, having built up a cumulative investment of more than $1 trillion. This will be driven by engineering advances including larger turbines and more efficient floating windfarms.
“Offshore wind currently provides just 0.3 per cent of global power generation, but its potential is vast,” said IEA executive director Dr Fatih Birol. “More and more of that potential is coming within reach, but much work remains to be done by governments and industry for it to become a mainstay of clean energy transitions.”
Europe is currently leading the way, with almost 20GW of installed capacity. That is set to rise to nearly 130 gigawatts by 2040 under existing stated policies. However, the IEA says that if the EU reaches its carbon-neutrality aims, offshore wind capacity would jump to around 180 gigawatts by 2040 and become the region’s largest single source of electricity.
While Europe may be the spiritual home of the technology, China was the leading installer of capacity in 2018. The country’s major population centres near its east and south coasts make offshore wind an attractive prospect and the IEA predicts that by around 2025, China will have overtaken the UK and will be home to the world’s biggest offshore wind fleet. Capacity is set to rise from 4 gigawatts today to 110 gigawatts by 2040.
“In the past decade, two major areas of technological innovation have been game-changers in the energy system by substantially driving down costs: the shale revolution and the rise of solar PV,” said Birol. “And offshore wind has the potential to join their ranks in terms of steep cost reduction.”
As I posted elsewhere today, all that’s missing is the right design of INTEGRAL energy storage.
“Larger turbines” (HAWTs) and “floating windfarms”, made to current design convention, are not fit for purpose and will always be too expensive/inefficient. They’re only built to last 20 years too!
China comes late to offshore wind and onshore turbines (not one NIMBY!) far exceed their grid’s capacity, causing huge levels of curtailment. To make more ‘efficient’ use of a huge windpower resource, they’re building around 45GW of pumped-storage hydro, to add to an existing 27GW.
I can’t see any other nation having the investment to follow that example!!
The fact that something can be done does not mean it is sensible to do it. If one considers the options for carbon free generation, the obvious winner is nuclear. This was demonstrated in a paper in Energy in 2013, where the Energy return on investment (EROI) for power schemes was evaluated: the EROI is the ratio of energy provided over the live of a plant divided by the energy needed to build, operate and decommission it. The EROI for nuclear is about 75, for solar it is about 3.9 and for wind about 16.
A more important assessment of course is the economic one and again nuclear wins hands down as it provides secure, reliable dispatchable power: unreliables need large back-up power or a massive investment in (as yet) unavailable storage.
Jack: More recent papers have concluded it’s not ‘sensible’ to do Hinkley Point C!! Technically and commercially, all thermal (steam turbine) generation is bad news, because of its poor longevity and inefficiency (waste heat). Nuclear is the worst and, financed under the CfD scam, far too expensive. After massive subsidy, EDF still suffers cost overruns, so they’ll make no profit. French taxpayers keep the company afloat. Are these EROI estimates as meaningful as LCOE anyway?
https://www.bbc.co.uk/news/business-49823305
We have to go back 30 years to find the root cause. The Tory privatisation fiasco was compounded by New Labour refusing to build new plant around the turn of the century. Now it’s too late.
Can we rely on any analyses being totally free of massaged data? If we read research that comes to incompatible conclusions, who can resist the charms of confirmation bias?! Windpower advocates routinely quote MW capacity, because the MWh figures just don’t look good!
I am incapable of calculating the amount of reinforced concrete that would be required to build a single BGES accumulator, let alone a 15-mile long barrage, but I can create a viable concept and it’s bound to give a better return on £60bn than three nuclear plants (or HS2) ever could.
What we know for certain is that the concrete used for Hinkley will be an unproductive tomb in 60 years time, whereas an Aberthaw-Minehead Barrage would last three times that and be repairable thereafter. The return would be 25TWh/year of dispatchable power, which is more valuable than the same amount of inflexible nuclear, because it needs no backup or Dinorwig (£1bn in today’s value). The huge benefit for Severn Estuary surge flood prevention hasn’t even been estimated.
The Swansea Bay Tidal Lagoon wall (with BGES) would be an excellent demonstration and design model for the next Thames Flood Barrier. (to generate power and protect Westminster!!)
Is it asking too much of a professional publication not to confuse metric tonnes and cubic metres? “The 10-year site construction will use an estimated 1.2 million cubic tonnes of concrete.”!!
https://www.iom3.org/materials-world-magazine/news/2019/aug/06/recordbreaking-concrete-pour-hinkley
Fingers crossed, it’s ‘only’ 1.2 million metric tonnes and not 1.2 million cubic metres, which would be 2.4 times as much!!
Looking in a little more detail:
By 2040 we can have 15 times todays offshore wind capacity if we spend $1 trillion (10 e12?). Today we have 0.3% so by 2040 we can have 4.5%. How many nuclear power plants would £1 trillion buy? How much less material would we use by building nuclear plants instead of offshore wind turbines.
Offshore wind has the potential to generate more than 420 000 TWh per year worldwide. However only 36 000 TWh is easily accessible (is ‘60m deep foundations’ easily accessible?) so around 8%. This lowers the headline figure of 18 times world electricity demand to around 1.5 times.
There is nothing regarding interconnection and distribution. Many countries are completely land locked. Is this a realistic solution for them?
David,
‘What we know for certain is that the concrete used for Hinkley will be an unproductive tomb in 60 years time’ or more likely has received a 20 year extension to the operating licence. First generation NPPs are already achieving 50 years operating life.
‘an Aberthaw-Minehead Barrage would last three times that’ or will have silted up in 20 years. We have no experience to back up a 180 year operating life for a large barrage. NPPs at least have a track record and the lessons learnt in the first systems have been applied to new designs.
https://www.scientificamerican.com/article/nuclear-power-plant-aging-reactor-replacement-/
‘The return would be 25TWh/year of dispatchable power’ Please can you explain this? A tidal barrage is predictable but not dispatchable. 25TWh/year is around 3GW on average. What area of water and head are you using to get this figure remembering that the usable head is no more than half the tidal range?
According to EDF Hinkley Point C will use 3 million tonnes of concrete and 230 000 tonnes of reinforcing steel.
https://www.edf.fr/en/the-edf-group/dedicated-sections/journalists/all-press-releases/edf-energy-sets-out-progress-at-hinkley-point-c-new-nuclear-power-station
How much concrete will an Aberthaw-Minehead Barrage use? The distance between the banks is around 20km. The maximum tidal range is around 15m. Making two assumptions, one: the height of the barrage must be at least twice the tidal range, two: the average width of the barrage will be equal to the tidal range, gives a volume of 20 000 x 30 x 15 = 9 e 6 m3 of concrete which is around 22 million tonnes. Makes Hinkley Point C look quite practical.
Dear Roger, I recall explaining my designs to you some years ago – to refresh, see:-
https://www.theengineer.co.uk/highview-power-energy-storage/
The only pertinent point is, nuclear cannot be refurbished. Smart renewables will have their lives extended over and over again, without ever having to repeat the initial CAPEX. This is a perfectly practical way to escape the curse of planned obsolescence and switch to a circular economy. My designs also slash your total installed capacity by a half, so the energy storage component costs absolutely nothing. Operations costs are reduced too, because there’ll be no Capacity Market.
I thought the Germans were nuts to phase out nuclear (burning coal offends humanity), but it was the high cost of extending the life of NPPs that decided the issue.
The French built La Rance in ’66. “By 1976, the Rance estuary was considered again to be richly diversified; a new biological equilibrium was reached and aquatic life was flourishing again.” Cheap electricity < €0.03/kWh, no silting problem and no reason to ever decommission it. New nuclear will cost what . . . €0.10/kWh?
So, it is 1.2 million cubic metres – shocking, but would one design a barrage in solid concrete? I think not. Seems rather far fetched!
My RE designs are multi-function. e.g. One floating vessel harvests both wind and wave. The tidal barrage saves spending any money on flood prevention upstream. The next London Array will be attached by umbilical water pipe (energy storage) to the next London Flood Barrier, etc. etc.
You may find this of interest. . . .
https://disqus.com/home/discussion/nipponcom/offshore_wind_power_promises_to_boost_fukushima_recovery/?utm_source=reply&utm_medium=email&utm_content=read_more#comment-1190700455
David, I am aware of your concept but you are not offering any details, calculations, etc. Just how much space and materials do you need for your storage systems?
‘The only pertinent point is, nuclear cannot be refurbished. Smart renewables will have their lives extended over and over again, without ever having to repeat the initial CAPEX’
Nuclear can be refurbished if it is designed to be refurbished. The initial designs were optimised for the production of weapons grade plutonium which requires short burn up times. No consideration was given to decommissioning during the cold war period. We have to deal with this legacy and learn from it. Nuclear offers a high energy density and an optimal use or resources compared to the low energy density renewables.
The Rance Barrage is 750m long with a peak output of 240MW and an average of 60MW. There are environmental and silting problems.
https://tethys.pnnl.gov/annex-iv-sites/la-rance-tidal-barrage
If we go back to the Aberthaw Minehead system that you started with and make some calculations.
Taking an average 12m tidal range what is the daily average power available from 1km2 of water?
1J = 1 Nm
1W = 1Nm/s
1m3 water weighs 1000kg or approx. 10kN.
1km2 water 12m high weighs 1000 x 1000 x 12 x 10kN = 120GN
Average head is 6m so stored energy is 720GJ
The tidal cycle is 11hr = 40 000s.
The average power is 720 exp 9 /40 000 = 18 MJ/s = 18MW
To give an output of 3 GW would require a tidal basin with an area of 165 km2 at 100% efficiency. Pumped storage is reckoned at 70% efficiency overall so I will take 85% efficiency for just the generation part. This gives an area of 195km2 for the tidal basin. As the dam length is around 20km this would require a rectangular basin 10km long or a triangular one 20km long which looks feasible.
If this is corrected with the real capacity factor of 40% from the Rance Barrage it does not look so good.
The next problem is how to deal with the periodicy of generation which will drop to zero at high and low tide. The simplest way would be to have a second basin that is filled and emptied at high and low tide. As it will only have to supply electricity for maybe 2hrs it can be somewhat smaller, maybe only 10-20km2 but it would require a second set of 3GW turbines and a second although smaller dam.
You seem surprised at the concept of making a 20km barrage out of concrete. What would you suggest? It has to retain the water over a 20km length and channel it through the turbines. Part of it could be built up with earth but it would still require a concrete central structure and is also a lot of earth to find and move, all of which becomes part of the energy balance.
You will also note from the Rance project that it has 240MW of turbines and an average output of 96MW so scaling this up to the Aberthaw Minehead Barrage would require Turbines with a peak rating of 7.5GW.
This is the problem with low energy density sources. Similar calculations can be carried out for wind which come out at around 150 km2 per GW and once again higher raw material use than nuclear.
Some somewhat interesting figures coming out of this discussion (and ideas too).
My worries are that the construction industry seems to be married to sudden unexpected (increasing) costs (as at Hinckley) and anticipate more of the same for offshore constructs (though not entirely sure of the designs for the associated windmills – VAWT or HAWT?).
And, also, how much extra capacity needs to be built to cope with periods of calm (for instance days when UK wind-power was running at less than 1% of total capacity) – though perhaps the rather interesting idea of re-configuring the Thames Barrier “The Swansea Bay Tidal Lagoon wall (with BGES) would be an excellent demonstration and design model for the next Thames Flood Barrier. (to generate power and protect Westminster!!)” might have some merit for pumped storage – could we forget the NIMBYs in Westminster ?
Hi Peter,
There are many comments detailing my ideas, which are eminently doable.
30th November 2015:-
https://www.theengineer.co.uk/piezo-sensor-predicts-wind-farm-failure/#comments
That discussion with Roger B was cut short.
25th. October 2019:-
https://www.theengineer.co.uk/power-sharing-building-worlds-longest-subsea-interconnector/
https://www.theengineer.co.uk/highview-power-energy-storage/
17th. September:-
https://www.theengineer.co.uk/poll-uk-low-carbon/
Five years ago I read this profound observation. . .
“The biggest economic impact in the history of the world hinges on the question of whether competitive electricity storage will ever be invented.”
BGES was invented a decade earlier, but disruptive technology is always anathema to any incumbent industry. The Welsh Development Agency, the Welsh and UK governments were all aware of this technology, but did nothing to help.
Please ask me any questions you like. I’m happy to reply.