Haven’t posted much in this mini-series recently … not that there would be a lack of Sankey diagrams that have technical defects or simply misrepresent flow quantities with deliberate arrow widths.

In this Sankey diagram from a website by AEPC the blue arrow is grossly exaggerated and not to scale with the other flows.

Flows are in KWh. Energy inputs (solar, fuel for boiler and pumps) on the left. Uses and losses to the right.

Julien Morel of the Swedish Energy Agency (‘Energymyndigheten’) has pointed me to the newly released Swedish Energy Balance for 2014.

The publication (available here) has the English version of the diagram on page 4:


This one is interesting, as it is set up mirrored, to be read from right to left, in contrast to the common way of presenting national energy flows (e.g. here for Australia or here for Iran).

Overall consumption was 368 TWh in 2014. Sweden relies roughly one third on nuclear energy, one third on fossil fuels, and one third on renewables (wind, hydro and biofuels).

The different areas of the energy system are further detailed per consuming sector and per fuel type and shown with individual Sankey diagrams. So if you understand some Swedish, go check out the 17-page presentation.

From my collection of Sankey diagrams here are three very similar samples depicting energy flows in a building. All three are from Germany (did I mention that more than half of the Sankey diagrams seem to be from Germany or Austria?).

These are all very simple Sankey diagrams. This first one is a hand-drawn goodie from the times when reports were still done with a typewriter. It shows use of fuel oil (‘Heizol’) in a school building, and interesting to see, the flows are given in kilograms fuel oil rather than to represent the heating value. The school building consumes 80 tonnes of fuel oil per year.

Note that flows are not to scale (arrow for equivalent of 10580 kg fuel oil annual heat loss through walls is about the same width as the one representing 31770 kg heat loss through windows). So this Sankey diagram doesn’t deserve an A…


The next building energy flow Sankey diagram shows flows in Watts (W). Not sure where I found this one. Flows again are not proportional (spot the 470 W flow and compare it to the others). Main inputs are radiation (‘Strahlung’) and electric energy. A heat pump cycling energy can be seen, so it seems that this one is maybe for a passive house.

This last one done with a Sankey diagram software hence flows are to scale in this one (although I have some doubts regarding the width of the fuel oil input arrow on the left). Flows are in kWh per year. Main fuel type is natural gas (red), some district heating (blue). Electric energy in yellow, consumed by IT, lighting, air compressors, and so on. This energy flow Sankey diagram is probably for a factory building or complex.

I will try to add the sources where I found these three diagrams. Please forgive my negligence this time.

Digging out some gems from folders on my hard disk. I found this one back in 2010 or so, but had not documented the source properly – shame on me. I just know that it is from consulting firm Motiva. Had I really forgotten to features this here on the blog?


This one is the result of an energy analysis in a company. No numbers or units given in this diagram. Fuels by type on the left (‘polttoaineet’), then from left to right bunkers/tanks (‘kattilat’), two turbines (‘turbiinit’) generating electric energy (‘sähkö’) and steam (‘höyry’).

After posting on Australian Metals Flows yesterday I realized I had never presented a Sankey diagram for energy flows in Australia.

Well, here it is. From the Government of Australia, Clean Energy Regulator, Renewable Energy Target program website comes this beauty (CC-BY license Commonwealth of Australia):


One can really say that Australia is mainly exporting its energy. Flows in Petajoule (PJ) for the year 2012/13. Older energy flow diagrams available in the Australian Atlas of Minerals, Resources and Processing Centres here.

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…

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.

I have presented several examples of Sankey diagrams in the field of maritime technology before (see here).

This recent article (Baldi, F., Ahlgren, F., Nguyen, T., Gabrielii, C., Andersson, K. (2015): Energy and exergy analysis of a cruise ship. In: Proceedings of ECOS 2015 – the 28th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems) confirms that “the complexity of the energy system of a [cruise] ship where the energy required by propulsion is no longer the trivial main contributor to the whole energy use thus makes this kind of ship of particular interest for the analysis of how energy is converted from its original form to its final use on board.”

The authors conduct a thorough energy and exergy analysis for a cruise ship in the Baltic Sea. The ship has different operation modes (sea-going, manoeuvring, port stay). The energy analysis “allows identifying propulsion as the main energy user (41% of the total) followed by heat (34%) and electric power (25%) generation”. Nevertheless, “it can be seen that the energy demand for auxiliary power is comparable in size to that for propulsion.”

The data for this Sankey diagrams in the annex of the paper and shows that flows are in TJ for an operation period of 11 months. Blue, yellow and green arrows depict energy use, while the orange arrows reveal heat losses to the environment.

The study continues with an exergy analysis of the ship, since it reveals more on the system inefficiencies. The exergy analysis is shown as a Grassmann diagram in the paper. This is structured similarly to the Sankey diagram above, but has dark orange arrows representing the exergy destruction. This is mainly from the Diesel engines and the oil-fired boilers.

I recommend this paper not only to naval engineers, but to everyone who wishes to get a better understanding of exergy and Grassmann diagrams. Can we consider Grassman diagrams a subset of Sankey diagrams? What do you reckon?