{"id":27567,"date":"2011-05-14T00:00:00","date_gmt":"2011-05-14T04:00:00","guid":{"rendered":"http:\/\/ashleydev.com\/2011\/05\/14\/comparing-wind-and-nuclear-in-terms-of-space\/"},"modified":"2020-08-27T11:45:10","modified_gmt":"2020-08-27T15:45:10","slug":"comparing-wind-and-nuclear-in-terms-of-space","status":"publish","type":"post","link":"https:\/\/cna.ca\/fr\/2011\/05\/14\/comparing-wind-and-nuclear-in-terms-of-space\/","title":{"rendered":"Comparing Wind and Nuclear in Terms of Space"},"content":{"rendered":"

One of the reasons I support nuclear power is that it seems to require relatively little space to generate a huge amount of power. Some of Canada\u2019s most powerful reactors can produce up to 881MW (electricity), or 7,717,560,000 kw\/h annually. That\u2019s enough to power about 643,000 households 24\/7 (Average household consumption in Ontario is about 12,000 kw\/h annually<\/a>).<\/p>\n

The Darlington nuclear power station \u2013 which has 4 such reactors \u2013 is about as big as one of the shopping malls in Whitby, ON (including the parking lots). Not bad, considering the plant produces power for up to 2.5 Million households, day in, day out.<\/p>\n

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Based on that alone, I always thought that nuclear power would be a pretty good option for replacing much of the electricity currently produced globally by burning coal and gas.<\/p>\n

But, a recent story published at PhysOrg.com<\/a> suggests that, according to a study written by Derek Abbott (a professor at the University of Adelaide), it would be impossible for nuclear energy to supply the entire global demand for energy because all these nuclear plants would take up far too much space.<\/p>\n

Abbott addresses other factors,\u00a0 too, but for the time being, I\u2019ll just focus on the question on size.<\/p>\n

I haven\u2019t read the actual study, since it is not yet published (but will be soon in the Proceedings of the IEEE<\/a>), so I have to go by what the reporter says about Professor Abbott\u2019s findings.<\/span><\/p>\n

Abbott estimates that<\/p>\n

One nuclear reactor plant requires about 20.5 km2<\/sup> (7.9 mi2<\/sup>) of land to accommodate the nuclear power station itself, its exclusion zone, its enrichment plant, ore processing, and supporting infrastructure.<\/p><\/blockquote>\n

I\u2019m not entirely sure where he got this number from (I suspect the final article will provide the sources), but it seems he does not allow for multiple reactors on a single site.<\/p>\n

The Darlington plant, for example, is a little less than 2 km long (including the parking lot), and roughly 800m or so across. That\u2019s just about 1.6 km2<\/sup>, though my method of measuring that is \u2013 admittedly \u2013 a little crude. However, there are no less than 4 reactors at that site alone. Even after OPG is done adding another two, the site is not going to get much bigger.<\/p>\n

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Be that as it may, I will \u2013 just for the sake of argument \u2013 accept Abbott\u2019s numbers for the time being.<\/p>\n

Professor Abbott then calculates how many nuclear reactors it would take to supply the entire global energy demand of 15 Terawatt by generously assuming that each nuclear reactor can supply 1GW (e). That makes for easy math, and results in no less than 15,000 reactors globally. At 20.5 km2 <\/sup>each, the resulting space requirement is 307,500km2<\/sup> \u2013 just a little less than Poland, or a little bit more than Italy.<\/p>\n

That does, indeed, seem like a lot \u2013 all of Poland or Italy covered end-to-end in nuclear reactors, supporting facilities, fuel manufacturing plants, etc. etc. to supply the entire global energy demand (that is, all the power currently provided by fossil fuels, hydro electricity, nuclear , and other sources combined).<\/p>\n

But how would that compare to other sources of energy under the same assumptions? While Prof. Abbott appears to like solar best, I\u2019m going to do it for wind \u2013 simply because I have spent more time analyzing the spatial requirements for wind (mostly because wind power is the only low-carbon, non-hydro, source of electricity cost-competitive with nuclear<\/a>).<\/p>\n

Calculating the space requirements for wind is tricky business. The actual footprint of a wind turbine is not that much: if one includes the swept area, it\u2019s anywhere from .2 \u2013 2 acres (based on data from Enercon<\/a>, and a little basic geometry. For those who want to dig deeper, the NREL<\/a> has some good information on this).<\/p>\n

Let\u2019s assume we are going to use Enercon\u2019s E101 turbine, which has a nominal capacity of 3,000 kW. Let\u2019s further assume that we can expect an average output is about 25% of rated capacity ( though some studies<\/a> indicate it is much less, and may be as low as 21%). The turbine has a diameter of 101m \u2013 or 331.4 ft \u2013 and therefore sweeps an area of about 1.98 acres. Since turbines need to be spaced several times their diameter apart, let\u2019s assume we space them about 10x their diameter apart on average over a perfectly even plane, with nothing breaking the pattern (as I did with the nuclear plants above).<\/p>\n

How big would a wind farm with such an arrangement have to be to generate 15TW of electricity?<\/p>\n

16,023,693 km2<\/sup> \u2013 a little less than the entire territory of Russia<\/strong>. Or about twice the size of Australia<\/strong>.<\/p>\n

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Or Canada and Greenland with a chunk of the US:<\/p>\n

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Even if we reduce the distance between the wind turbines to just 5x their diameter, we\u2019d still end up with a space requirement of 4,005,923 km2<\/sup> \u2013 22% bigger than India<\/strong>.<\/p>\n

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What about a bigger turbine, like Enercon\u2019s E126, rated at 7,500 kW a piece (spaced 10x diameter)?<\/p>\n

Well, that would require 25,335,374 km2<\/sup> \u2013 more than Russia and Australia combined<\/strong>.<\/p>\n

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If spaced only 5x diameter, it would still require 6,333,843 km2<\/sup> \u2013 almost twice the size of India<\/strong>.<\/p>\n

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[The reason is that the E126 has a diameter of 127m, which results in much greater space requirements even though the output is that much greater than the smaller turbine].<\/p>\n

But this would just be the size of the wind farm itself. It would NOT<\/strong> include:<\/p>\n