Botswana, a country with just over 2 million population, borders South Africa to the North. Would you be able to tell its capital?

Nevertheless, a Sankey diagram with the energy balance of Botswana can be found on the web. Mike Mooiman, a professor at Franklin Pierce University, New Hampshire and a former visiting scholar at University of Botswana featured it on his ‘Energy in Botswana’ blog. These are the energy flows for the African country for 2015 (based on IEA data).


Flows are in terajoule (TJ) and overall energy demand was 120,138 TJ. Biomass (wood) is the predominant fuel in private households (e.g. for cooking). Locally mined coal accounts for 40% of the primary energy and is used for electricity generation with an efficiency factor of below 30%. Imported oil products account for over 40% of the energy consumed (mainly for transportation).

The 2012 energy balance for Botswana is also available on Mike’s blog.

A quick casual-Friday post featuring a distribution diagram of scrap (waste) exported from the United States in 2017. Based on data from the Institute of Scrap Recycling Industries (ISRI). Submitted by a reader of this blog.

Most Sankey diagrams I find on the web are from Germany, Switzerland or Austria. Anybody in the know, if this due to the visualization type being part of the engineering curriculae in these countries?

Here is one I found on ‘The Wood Power Plant’ blog by Austrian firm Syntec. It is originally taken from a student master thesis on ‘Life Cycle Analysis of Electricity and Heat Generation of a Wood Gasification Plant including District Heating Network’ (German title: ‘Lebenszyklusanalyse der Strom- und Wärmeerzeugung einer Holzvergasungsanlage inklusive Nahwärmenetz’, thanks Google Translate – you are my friend!) by Elena Käppler of University of Applied Sciences Vorarlberg.

While being graphically quite appealing there are some issue with this Sankey diagram. Flows don’t seem to add up correctly: for example the main stream 4.838 MWh and the 401 MWh coming in at the top would be larger than 5.171 MWh.
Also, some flows are not true to scale. Check out the red arrow representing 247 MWh (going down to ‘Verteilungsverluste’) and compare it to the red one going back in a loop, which represents 419 MWh (‘Hackguttrocknung’).

The report ‘Nordic Energy Technology Perspectives 2016’ published by IEA looks at energy scenarios for Northern Europe / Scandinavia and pathways to carbon-neutrality. Several Sankey diagrams are included in this extensive study.

These are the energy flows in the nordic countries caused by transport. The first Sankey diagram is for the current situation (data from 2015), the second for a 2050 carbon-neutral scenario (CNS).


© OECD/IEA 2016 Nordic Energy Technology Perspectives 2016, IEA Publishing. Licence: www.iea.org/t&c

In the 2050 scenario we see a massive shift from diesel and gasoline powered transport to biofuels and electricity. This ambitious target could be achieved with “fuel efficiency improvements on existing technologies but also rapid penetration of alternative drivetrain technologies such as hybrids and electric vehicles” (p. 66).

Check out the full report here.

Unpretentious and humble, quietly producing beautifully crafted Sankey diagrams … this is one reason why I admire the Swiss (and also for their Swiss Schoki, cheese and engineering skills).

This is the energy flow chart for the Swiss canton ‘Basel-Stadt’ for 2014 published by the Statistics Agency of the canton (Statistisches Amt des Kantons Basel-Stadt).

Flows are in Gwh. Nine different energy sources on the left, but only three sectors of energy use: transport, residential and non-residential. Observe how the colors of the icons match the corresponding colors of the arrows. Flow quantities below approximately 150 GWh are not true to scale and are drawn with a minimum width to keep them visible. The footnote alerts the reader to this graphical pecularity.

This Sankey diagram does set a standard for other similar energy flow charts, in my opinion.

Download the report from here (in German), the diagram is on page 11.

A vintage black and white Sankey diagram for an efficient wind park is shown in this post on the Hypergeometric blog aka ‘667 per cm’ blog.

Out of the several Sankey diagrams shown, this one was new to me. So I dug a little deeper into the original source.

Published originally in: Koroneos, Christopher & Katopodi, E. (2011). Maximization of wind energy penetration with the use of H2 production — An exergy approach. Renewable and Sustainable Energy Reviews. 15. 648-656. 10.1016/j.rser.2010.06.022.

The authors from Aristotle University of Thessaloniki, Greece argue that Sankey diagrams can also be used to visualize exergy flows, and that they can be used to compare “exergy losses of an efficient and an unefficient wind park”.

The one above has “an excellent exploitation of wind energy for an organised park that operates efficiently and effectively”. They further discuss what factors contribute to losses based on an exergy analysis, and show several exergy Sankey diagrams.

Read full article here.

The below Sankey diagram depicting energy flows in the Netherlands in 2016 is very interesting. Actually it features two dimensions: energy production and consumption (from top to bottom) and energy imports and exports (from left to right). This is quite different from other national energy balances I have presented on this blog before (such as e.g. for Switzerland 2015, Chile 2015, Lithuania 2013, or Sweden 2014)

It can be found in the ‘Compendium voor de Leefomgeving’ (Environmental Data Compendium) a website run by the Dutch Government (Rijksoverheid) and is titled ‘Aanbod en verbruik van energiedragers in Nederland, 2016’ (Supply and consumption of energy carriers in The Netherlands, 2016).

Data for this Sankey diagram is from Centraal Bureau voor de Statistiek (CBS). Flows are in petajoule (PJ). Locally produced energy (‘Winning’) in 2015 was at 2.023 PJ, with a consumption (‘Verbruik’) of 3.155 PJ.
So, the Netherlands still had to import some 1.000 PJ to cover demand. However, it imported 11.275 PJ (‘Invoer’) and exported 9.559 PJ (‘Uitvoer’). In the first pace, the Netherlands seem to be an energy transit country. This is owed to the fact that Rotterdam is the largest oil port in Europe, and is a prime location for handling oil products (‘Aardolieproducten’).

The UK-based non-profit Community Interest Company (CIC) called ‘InfluenceMap’ has produced the below Sankey diagram on obstructive climate lobbying of oil firms and interest groups. These are the spendings in US$ for an unspecified year (possibly 2015).


Source: InfluenceMap, Media Downloads
(via Hypergeometric blog)

Streams are color coded to specify the type of spending (e.g. staff cost, direct lobbying, party donations). Note that the yellow flows (in the range up to 230.000 US$) are not to scale with the others that are on a million US$ range. Some of the elements that represent the sources and the black sum arrow are also overemphasized, showing a height that is larger than the sum of the individual arrow magnitudes. So this is not fully adherent to the principles of a Sankey diagram … but to be fair: they never claimed that it is a Sankey diagram.

This is maybe the first Sankey diagram ever to be featured in the US Senate. Senator [D-RI] Sheldon Whitehouse (yes, that really is his name … you just have to love his “Whitehouse Statement on …” catchphrase) used it in a US Senate testimony in April 2016.

Watch the video how the Whitehouse does quite well explaining the streams of money and to underpin his message with the Sankey diagram. Jump in at 0:25 secs to see Sankey make its Senate appearance…