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Energy master plan by OMA: North Sea super ring of wind farms

Potential production capacity far overrated

The Office of Metropolitan Architecture (OMA) headquartered in Rotterdam and headed up by the Dutch architect Rem Koolhaas, has developed a master plan for large-scale wind energy production in the North Sea. The operative adjective here is large-scale. The plan projects a potential annual production of 13,400 TWh by 2050.

The principal idea is to develop a huge ring of wind farms on offshore marine sites in the Exclusive Economic Zones of Denmark, Germany, the Netherlands, Norway, and the UK and to connect them by a power cable super ring. Such a ring would enable fewer connections with the coast, avoiding the necessity of connecting every wind farm with the grid separately.

The plan sounds good and looks brilliant. The trouble is that it appallingly neglects some basic technical aspects of wind energy. A quick verification of the annual production figure leads one to suspect that OMA simply "forgot" to take a capacity factor into account...

A call for cross-border initiatives

In many ways this integrated plan for wind energy generation in the North Sea resembles the ambitious scale of DESERTEC, a plan for developing large solar power plants in the Sahara desert and connecting them to Europe via HVDC lines.

According to the Antwerp architect Bob Van Reeth, who supports the OMA plan, 'The EU member states are currently only focussed on their own little projects. There is a need for cross-border initiatives and joint investment projects.' Instead of restricting international cooperation within the EU to defining rules and targets, cross-border investment projects could open up a whole new potential for renewable energy development.

Lacking consistency and clear figures

The idea of cross border cooperation is actually the most valuable aspect of the OMA plan. The plan itself is, unfortunately, fatally flawed. David Mac Kay demands in his book (Sustainable Energy / Without the hot air) an energy debate with clear, traceable, and comparable figures. This is exactly what the OMA plan lacks. Let’s look at a few aspects of the plan in more detail.

1) The annual production

OMA calculates the potential annual electricity production to be 13,400 TWh. This figure is compared with the annual energy production capacity of the Gulf States, namely 11,300 TWh. But is that last figure oil production alone, or oil and natural gas combined? Is it crude oil, or end use products? These essential facts are totally unclear. A more useful figure for comparison would be the total energy demand of the EU, which is approximately 22,000 TWh.

2) Production figure comes out of the air

To calculate the annual production capacity, the project started by calculating the surface where the North Sea is less than 50 metres deep and at least twelve nautical miles away from the coast. From this surface, 15% was subtracted for commercial and military sea routes and other activities. The remaining surface of 193,000 m2 is supposed to be completely filled by wind farms, making use of 5 MW turbines that are spread according to a standard wind turbine distribution pattern. The report does not mention a total installed capacity, or an average capacity factor, but blithely concludes that this huge North Sea wind farm would result in an annual electricity production of 13,400 TWh.

3) No capacity factor taken into account?

Let’s compare the figure of OMA with the figures of David Mac Kay (Sustainable energy / Without the hot air) for the physical off-shore wind potential of the UK. The total surface of shallow waters in the UK Exclusive Economic Zone is 40,000 m2.First of all, Mac Kay subtracts 70% of this surface for sea routes, instead of 15%. But let us make abstraction of this widely differing assumption, and remake the calculations of Mac Kay subtracting only 15% of the surface instead of 70%. According to these assumptions, 40,000 m2 would yield 893 TWh per year, meaning that 193,000 m2 would yield 4308 TWh per year.

This is about one third of the figure of OMA. How strange: one third is exactly the capacity factor! Did the OMA simply forget to take the capacity factor into account in their calculations?

4) Production figure a factor 10 overrated?

If one takes the more realistic assumptions of David Mac Kay into account, the North Sea could produce a maximum of 1400 TWh per year, about one tenth of the prediction of OMA and one fifteenth of the European energy demand. That is still huge, but far from making Europe energy independent, as OMA claims.

5) Shallow water, or deep sea?

Even more disconcerting in the OMA plan is the inconsistency of the capacity calculation with the drawings contained in the report. Instead of one huge wind farm in the shallow parts of the North Sea, those drawings show a ring of numerous wind farms that stretches far into the northern, deeper parts of the sea. Nowhere in the report is this inconsistency explained. Neither is it illustrated how those wind turbines in the deep sea will be constructed – will they be floating turbines?

6) What about maintenance and reliability?

Nowhere does the report mention anything about maintenance of the wind turbines. How much maintenance effort would this North Sea ring require? What will be the annual cost? And how will the current maintenance problems with off-shore wind turbines be overcome?

The report does not address the availability and reliability of the electricity production either. I suppose that it assumes that in the North Sea, the wind will always blow somewhere. Will this claim still hold on the day that a large and stable summer anticyclone happens to settle right above the North Sea?

7) The whole sea a sea reserve?

The plan couples the ring of wind farms with the creation of a massive sea reserve around those farms. In this way, the ring could be a solution for the recovery of the marine fauna in the North Sea. This is a great idea. But how will the fishing industry react? Even if fishermen can find new jobs in the wind industry, will they calmly watch the North Sea fishing industry disappear?

8) A research station in the middle of the sea?

The plan also includes a huge research station for off-shore activities. This station is located in the middle of the ring, at the intersection of the borders of the Dutch, British, Norwegian, Danish and German territories. Why, except for symbolic, political reasons, should such a research station be built as far from the mainland as possible? And why should it be so incredibly huge? The drawing on the map shows an area of no less than 5,000 m2...

A valuable idea to be further developed

In brief, the OMA plan leaves far too many questions open or even unaddressed and its potential energy production is outrageously overrated. However, let’s not throw the baby out with the bath water. Hopefully one day some wind energy experts will get the assignment to discover what if any parts of this plan has merit or potential, and will be assigned to work this plan out in a more realistic and down-to-earth (or should I say down-to-the-sea-floor?) manner.

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Comments

The chart on page 4 of the OMA file does say 13.4TWh "Theoretic" output - which, if the capacity factor was 100%, would be true.

But in the case of off-shore wind in the North Atlantic, one should only expect a capacity factor in the neighborhood of 30%-40%

While it's good that actors outside the energy sector involve themselves in the debate, I was surprised by the figure on page 2 - 65 5 MW turbines can provide Amsterdam's households with their electricity needs. And the statement is factually correct, though misleading.

Europe is actually about 200 million households - i.e. about 600 Amsterdams. To make the exercise for Europe would require 40,000 turbines.

But more seriously, domestic electricity consumption is a misleading metric. We consume electricity at home, but also through public transportation, in the office, through the products we buy, in schools, in retail stores etc. Hence the total electricity use is about 3-4 times higher, or - domestic use is only 25-30% of the full story. Taking this factor into account brings us to 140,000 turbines.

Then we have network losses, as well as losses due to storage of ambient generation. But let's not get into details ...

Bruno: why do you think that MacKay's estimate of needing 70% of the North Sea for shipping lanes is remotely realistic, let alone a better estimate than OMA's 15%? We know that small boats, such as. fishing vessels, can pass happily between turbines, so the exclusion zones are just for the bigger craft.

How do you put turbines in deeper waters? Ask the Norwegians. You float them, out to depths of up to 700m.

Why does the OMA report show only scattered farms? If I understand correctly, that's the scaled down project, designed to be realised by 2020, as explained in the Masterplan Zeekracht website.

Why are their figures high compared to MacKay? Maybe they realise that winds are higher, further from the coast, and MacKay doesn't account for that at all.

Bruno, why did you take the total energy demand of the EU? It's not as if the North Sea is the only game in town for energy, is it? OMA looked at the North Sea, and the 7 countries around it: that seems a pretty sensible start.

Britain's waters alone could produce around 2TW mean power, which works out at over 17,000TWH/y. Once you've got a realistic figure for the area needed for shipping lanes, let us know, and that figure can be scaled accordingly.

What capacity factor did they use? Have you tried emailing them to ask them?

Grandmother,

All I wanted to say is that if you make such a huge claim that you can "make Europe energy independent" as OMA did, you have to show at least a few clear and transparent figures that support this. I'm not saying that the figures of Mc Kay are more precise than those of OMA, but only that he clearly shows where his figures come from and admits that some figures are estimates.

That claim of OMA of making Eupope energy independent is also the reason why I wanted to compare the figure with Europe's energy consumption, that sound completely logic.

Of course I know about floating turbines (I even wrote about it on this blog), but if that's what OMA wants to use, why don't they make any reference to them? And by the way: those floating turbines are only in prototype phase and still far from commercially ready.

Yes of course, winds are higher the further you go from the coast. But the first experiences show that those wind turbines don't have a capacity factor that is much higher. What they win by higher wind yields, they lose again because they need more maintenance time. Hopefully this will change in the future.

To conclude, let me be clear: I hope one day we could make Europe energy independent with wind energy! That would be absolutely great! Only the plan of OMA did very little to confirm this hope... I'm afraid it's not realistic.