Sunday, June 9, 2013

David MacKay's "Map of the World" - an update

I've updated my "Map of the World" which shows, country by country, how human power-consumption per unit area compares with the power-production per unit area of renewables. I originally published this graph on my blog in August 2009. I've made quite a few improvements to it since then, including the representation of country size by point size, and colour coding of continents in the style of Gapminder.
One interesting thing I figured out while working on this graph is that, while the average power consumption per unit land area of the world is 0.1 W/m2, 78% of the world's population lives in countries where the average power consumption per unit land area of the world is greater than 0.1 W/m2 — much as, in a town with some crowded buses and many empty buses, the average number of passengers per bus may be small, but the vast majority of passengers find themselves on crowded buses.
Please follow this "Map of the World" link to see multiple versions of the graph, and to download high-resolution originals, which everyone is welcome to use.
My "Map of the World" graphs are published this year in two journal papers, which I will blog about shortly.
David J C MacKay (2013a) Could energy-intensive industries be powered by carbon-free electricity? Phil Trans R Soc A 371: 20110560. This paper also contains detailed information about the power per unit area of wind farms in the UK and USA, and of nuclear power facilities
David J C MacKay (2013b) Solar energy in the context of energy use, energy transportation and energy storage. Phil Trans R Soc A 371: 20110431. This paper also contains detailed information about the power per unit area of solar farms


Unknown said...

The second paper sounded interesting ('Solar energy in the context of energy use, energy transportation, and energy storage'), but the link you provided gives an error message. I found it here:‎
with the added advantage of not being behind a paywall...

jte said...

A technical comment -- when I click on the map to enlarge it, I receive the following error message:

Object not found!

The requested URL was not found on this server. The link on the referring page seems to be wrong or outdated. Please inform the author of that page about the error.

If you think this is a server error, please contact the webmaster.

Error 404
Sun Jun 30 18:30:54 2013
Apache/2.0.55 (Ubuntu) mod_python/3.1.4 Python/2.4.3 PHP/5.1.2 mod_ucam_webauth/1.3.0 mod_perl/2.0.2 Perl/v5.8.7

Thomas said...

Dear Mr. MacKay,

I certainly love the way you try to focus the debate on things that matter.

This is exactly the reason why I am kinda frustrated by this chart and the what appears to be the main focus of your talks. You seem to mix relevant with irrelevant data, thus harms the discussion on the future of our energy system.
I just don't get why you are so focused on showcasing that it would be very difficult to meet all of our current primary energy needs with renewable energy sources, instead of showing how our future energy needs could be met by renewables.

I am from Germany and I have read dozens of energy scenarios on future energy needs, conservation & efficiency potentials, ... so on and so forth.

One of the most extreme simulations by the Fraunhofer Institute for Solar Energy Systems looked at a wind & solar centered heat & electricity supply that would supply. Depending on the level of efficiency gains in the building sector 700-900 TWh of gross-electricity were required to meet the entire heat & power demand at every given hour of several simulated years. (The system included short term storage, long term storage as methane, CHPs, heat pumps,...)

Even simplified 1000 TWh of gross electricity are just 0.32 W/m² for Germany.

Considering an average power density per unit area for modern wind farms of 3-5* W/m², I think that repeated claims like "half the country has to be covered in windmills" is a little far fetched & misleading.

We are no longer in the mid-1990s / early 2000s.


*I know you made a hot fuzz about the 2-2.5 W/m² value for wind farms. But while one larger/modern wind turbines does indeed take up as much space as two-three old ones, they get more energy out of that same area.

Quite simply put: They are better & have higher hub heights (=> higher wind speed)

Just consider how building a wind farm of six 3MW Enercon E-101 at a hub height of 130m on an equal area as this one would change the power density. My quick estimate: 4-4.5 W/m²

Unknown said...

I must say that I find the energy-density based approach the most compelling, given the finite limit of energy resources actual distribution. Have you considered the implications of confounding re both positive and negative environmental feed-backs? A recent paper:
Saturation wind power potential and its implications for wind energy
Mark Z. Jacobsona,1 and Cristina L. Archerb (2012) PNAS

considers the down-wake PBL impacts of wind-farms, and the effects on Rn, LE and H.

Do you have any views of this and similiar feed-backs re your globally distributed models?

Dr John Pitman retired KCL.

David MacKay FRS said...

JTE, thank you for alerting me to the typo. I have fixed it now.
To Thomas: taller bigger wind turbines do not have significantly larger power per unit land area - because they have to be spaced further apart to avoid wake effects. See my earlier posts on this topic, my free book, and my recent journal paper (published 2013).
Thanks, David MacKay.

Unknown said...

Dear Pr McKay, I like your idea of looking at the "space constraint". We have done that kind of study for France taking into account the land use... (i.e. much more constraint than yours)

However I think your graph is really missleading because of energy consumption scale (that was noticed by Thomas in an upper comment). For example France is 670000km^2 that makes 6.7*10^11 m^2 and the electricity consumption is around 500TWh/year. this makes 5*10^11Wh/year that is on average 5.7*10^7. Let's say this is 1/4 of the energy consumption in a bad future, that makes 2*10^8 W for 6*10^11 m^2.

This means that the need for france in terms of surface is 2/6* 10^(-3) W/m^2 .... Is this only a simple consequence of the fact that your scale for the country circles is per day while the production mean lines are per hours ?

Also in your famous TED talk you place all this on a UK map, what kind of reasoning did you take for the UK consumption ?


David MacKay FRS said...

Dear Robin,
please check your units carefully. I am confident all my calculations are correct.