A reader of the blog, Olov, has produced the following video. He calls this a “Living Sankey Diagram”. The background can be found on the Sweco Blog (in Swedish). Basically he suggests to take energy declarations for buildings (‘Energideklarationen’) one step further and have visual energy monitoring for building using realtime data.

Energy consumption of a house is shown over a period of a year with up to 3 or 4 datasets per day. We can see heat (red) and electricity (orange). Not sure about the temperature indication at the top left, possibly meant to be the difference to a default temperature (Olov, if possible, please explain by commenting below).

Main consumers in the building are hot water generation (‘Tappvarmvatten’), room heating (‘Radiatorer’), ventilation and cooling. Some PV cells (‘Solceller’) at times add to the purchased energy (‘Köpt Energi’). The pink flow shows heat recovery (‘Värmeåtervinning’). The building is classified in energy class B.

Here, a data series has been used to produce the Sankey diagrams and then the frames were converted to a video. This makes for a nice effect and allows watching your energy flows in retrospect. For example, the PV cells feed energy mostly during the months, while in the same period heat demand and recovery is very limited.

This was apparently produced using e!Sankey. To really do an energy monitoring and produce the Sankey diagram every couple of minutes, there is a software development kit (SDK) the allows linking to a data source (energy measurement data) and pushing the “living Sankey diagram” to a website. Another example can be found here.

Deltamarin Ltd, a Finnish maritime engineering and consulting firm has developed a simulation and analysis tool, that allows to study the energy efficiency of ships. The model takes into account not only the vessel speed and fuel consumption, but also the secondary on-board electricity consumers and waste heat recovery. Results are shown in a Sankey diagram like the one below.


The Sankey diagram in this pic doesn’t show any numbers or unit of flow, so we can only conclude from the arrow magnitudes that about 50% of the energy is lost as heat at the engine (some of which is recovered for heating of water).
I am not sure about the propulsion being electric though.

The design of the diagram is rather crude and diagonal lines are visibly pixelated. But nevertheless it seems like a good way to get the energy efficiency model result data across other than in a table.

Watch this video where a Deltamarin engineer explains the simulation model and also the Sankey diagram.

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.