A Swiss software company features a screenshot on their website, depicting a thermal energy model for a building. I’m not mentioning the source, because it is a bit embarassing…

Despite the general good impression of the diagram and the tech labelling of the arrows, the width of these arrows seems completely arbitrary. Well, to be fair … they don’t call it a Sankey diagram.

An updated Sankey diagram for the energy flows in Europe (EU-28 countries) is available on the website of the European Environment Agency (EEA).


Copyright holder: European Environment Agency (EEA).

I have reported previously about the energy picture with data for 2012. The Sankey diagram structure is almost identical, just the values have been updated to reflect 2013 data. Minimal changes only, compare for yourself…

The International Energy Agency (IEA) is a good source for reports on energy, both with a focus on global energy, but also breaking it down to the national level. I have featured their Sankey diagram website that allows to access national energy balances for many countries in this post back in 2013.

Browsing through their reports also sometimes reveals Sankey diagram gems. In their report on ‘Tracking Industrial Energy Efficiency and CO2 Emissions’, however, I found the diagrams on aluminium, steel, pulp/paper and petroleum not particularly sexy.

This is a schematic block diagram. Arrows are labeled with the quantity in Mt/year.

I decided to redo this as a Sankey diagram, maintaining the general structure of the original diagram. The width of the Sankey arrows immediately exhibit where most of the mass (crude oil) is…

I chose three colors: blue for the actual products from petrochemical industry, yellow for recycling streams and losses, purple for the precurors or feedstock (I actually thought I should do away with these, since the ‘hydrogen energy’ flow gave me some headache…). Also decided that the head of the arrow representing 115 Mt/year of post-consumer waste leading towards (!) net additions to stock in the original diagram is erroneous and thus turned the arrow around.

Didn’t spend much time on graphic aspects or fine tuning. I am sure this can be done quite nicely. But even like this I think a Sankey diagram is the better way to get the message across.

What happens to yard waste and biowaste in Germany? This Sankey diagram from a 2014 PowerPoint presentation titled ‘Flächendeckender Ausbau der Biotonne in Deutschland’ by Peter Krause and Rüdiger Oetjen-Dehne (u.e.c. Berlin) shows how these flows were distributed.

In 2012 there were 14.5 mio. tonnes of yard waste andd 6.6 mi. tonnes of bio waste (kitchen/food waste) were disposed of in Germany. Much of it was collected and treated or – such as in the case of yard waste – composted (7.8 mio. tonnes).

In addition to the absolute quantities the labels along the Sankey arrows show the average per inhabitant (kg/E, a).

A large potential is still in bio waste (orange-coloured arrow) being disposed of in regular household waste (“Restabfall”). Calls for separate collection of bio waste for energy recovery are being made.

Following up on my previous post on Iran’s Energy Balance, here is another Sankey diagram from p. 54 the latest edition of ‘Iran and World Energy Facts and Figures, 2012’ by the Ministry of Energy (MOE) of the Islamic Republic of Iran.

Unfortunately the overall national energy balance of Iran is not depicted in the 2012 edition of the report any more.

This Sankey diagram focuses on electric energy only. Flows are in GWh per year (in 2012). Fuel sources for electricity generation are broken down in thr first arrow. Losses branch out at the ‘pow plant’ node as a blue arrow. The generated electricity is further broken down in the vertical arrow into consuming sectors. The overall efficiency of the power plants is at approximately 34%. Note how the small arrow head peeking out to the left is not to scale, and understates the 63.6% transformation losses.

Nuclear energy is less than 1% of the overal electricity production. In 2011, the first year of production 327 GWh were produced from nuclear fuel, upping to 1847 GWh in 2012. See p. 50 of the report.

Stimulated by the media frenzy and the focus Iran gets in recent days (nuclear deal, lifting of sanctions, Iranian oil production and effects on the world market, U.S. navy boats in Iranian waters) I thought it would be wise to look at the country from my narrow Sankey diagram perspective.

Any Sankey diagrams from Iran on the web? Of course!

The Ministry of Energy (MOE) of the Islamic Republic of Iran has been publishing the Energy Balance of the country: here is the Sankey diagram for 2009. This is from p. 67 of the bilingual report ‘Iran and World Energy Facts and Figures, 2009’ available on their web page.

Flows are in Mboe (Millions of barrels of oil equivalent). Out of the total 2587 Mboe primary total energy source, the largest chunk is oil (1585 Mboe), followed by gas (866 Mboe). More than half of the petroleum is exported (blue arrow). Total final consumption is 1144 MBoe. Note that nuclear energy is not shown in this energy balance. Apparently electricity production from nuclear power plants started in 2011 only.

Flows are not always perfectly to scale in the lower range: comparatively thin arrows have been left at a minimum width it seems. At the branch-offs of some wider arrows (oil, petroleum products) the gap has been color-filled, which makes the arrow look wider than it should be. A funny hump of the mauve arrow bridging the refinery node…

I confess I admire the Perso-Arabic script.

I have two more Sankey diagrams from another Iranian report, but these are for another post … soon.

The last Sankey diagram from the maritime sector I presented in this post receievd was shared a couple of times, so here is another one from the same topic area. Sorry, but this one is a little bit blurry even in the original document.

Taken from page 8 of the 2014 report ‘Next Generation Energy Management’ by DNVGL AS (authors George Dimopoulos, Nikolaos Kakalis).

Losses branch out as dark grey arrows. From the 100% energy in fuel only 28.9% are used as propulsive thrust, some other 5.6% as on-board electricity, heat or service steam.

Many more Sankey diagrams in the same report, check out figures 9, 12, 16 and 17.

The Wikipedia article on ‘Earth’s energy balance’ has recently been updated with another figure by user ‘Cmglee’.

It shows energy “in” from solar radiation, reflection, and energy “out” as heat into space.

This is a more abstract, yet at the same time brillant and beautiful representation of the greenhouse effect figure, that appears twice in the same Wikipedia article, and that I have presented in posts some years ago (here and here). These more infographic-ish figures are all derived from the original Kiehl and Trenberth (1997) work, if I am not mistaken.

Cmglee’s visualization reminded me of a bundle of ropes suspended at two points. Ropes of different diameter, of course, as it is common in Sankey diagrams. See more of Cmglee’s artwork here.