Regular readers of this blog have seen the national energy flow diagrams (energy balances) before. I have featured them from many different countries already.

I finally came across a similar Sankey diagram the energy flows of Europe for 2010. It is featured on the European Energy Agency (EEA) website in a report titled ‘Overview of the European energy system (ENER 036) – Assessment published Mar 2013′.

“The figure is a Sankey diagram which shows the composition of the primary energy entering the energy system of the EU-27 in 2010, and where this primary energy was used, either as losses or as consumption by specific sectors of the economy”. It is based on EUROSTAT data for the EU-27 countries.

A legend is available below for the coloured arrows. The diagram is extensively explained and commented on the web page.

In addition to what we have seen in such diagrams, the primary energy (fuels) is further differentiated with two separate input flows whether the energy carrier was imported or is from domestic European production. This is to visualize dependency on imports.

The research institute with the hard-to-pronounce acronymic name INCyTDE (Instituto de Ciencia y Tecnología para el Desarrollo at Universidad Rafael Landívar in Guatemala) has published a Sankey diagram with the energy flows for their country for the year 2011.

In regard to design the diagram has many issues: Apparently it was created using a drawing tool that supports primarily horizontal and vertical arrows and Bezier curves. But the diagram loses a lot with branching and joining of arrows almost non-existent.

Flows are more or less to scale. The unit is not shown in the diagram itself, but explained in the text (kilo barriles equivalentes de petróleo, KBEP = kilo tonnes of oil equivalent, ktoe). Data is from national statistics published by the Energy and Mining Ministry.

The content of the energy balance diagram is quite interesting, especially if you compare it to similar diagrams of other countries or the world average.
Wood is the most important energy in Costa Rica (green arrow ‘Leña’, 37.251 ktoe in 2011). Bagasse from sugar cane (dark green arrow ‘bagazo de caña’, 8.696 ktoe in 2011) is used for almost half of the electricity generation. Petroleum and derivates (dark pink arrow, 24.903 ktoe in 2011) however do play an important role for vehicles (transportation).

Found this via utsapocalypse. The Sankey diagram is originally from the article ‘Preliminary Investigation of the Use of Sankey Diagrams to Enhance Building Performance Simulation-Supported Design’ by William (Liam) O’Brien of Carleton University, Ottawa.

The paper proposes “the outline for a methodology for creating Sankey diagrams to represent energy flows in buildings, with the eventual intent that the methodology be integrated into a software tool.”

The Sankey diagram shows the energy balance of a house for a mid-winter week. Flows are in kWh, total amount 804 kWh. Energy sources/types are from the left (purchased heat, domestic hot water, solar gains), energy consumption and losses to the right (heat loss through windows, ceilings, walls).

Plenty of colors used in the diagram, Sankey arrows glued together from shapes. As the author mentions “the underlying creation process, when performed manually, can be quite complex”.

Following up to my Aug 25, 2011 post on Global Steel and Aluminium Flows, I would like to recommend the follwing book that has just been released: Sustainable Materials – with Both Eyes Open: Future Buildings, Vehicles, Products and Equipment – Made Efficiently and Made with Less New Material by Julian M. Allwood and Jonathan M. Cullen.

I’m hardly a hundred pages into reading, but I already love it. The book is very graphical (to say the least), well illustrated, with many graphs and photos, infographics and even historic images. Plus – and this is why it deserves to be presented here on the blog – it features a great number of Sankey diagrams.

I really enjoy the lego bricks in the steel making flow chart (pp. 121-127). You’re also going to love the ‘WhatsApp’-style chat between Henry Ford and the Wright Brothers (p. 181).

This book “faces up to the impacts of making materials in the 21st century. We’re already making materials well, but demand keeps growing and so we need to start using them well to.” (from the back cover)

Sustainable Materials with Open Eyes by Julian M. Allwood and Jonathan M. Cullen can obtained from Amazon and – I am pretty much sure – from your local book dealer. Here is the book’s website.

This post on the Visual Think Map blog (new addition to my blogroll) guided me to the fantastic 1939 book ‘Graphic Presentation’ by Willard C. Brinton. It is available in full as a PDF on archive.org.

The book with more than 50 chapters features literally hundreds of graphics…

Chapter 8 (pp. 73 to 80) deals with “Flow Charts”, and has the above Sankey diagram on sources of funds and spendings in construction.

The chapter has an emphasis on ‘Cosmographs’ (a brand name of a at that time, apparently by IBM) and how they are made. I will dedicate one of the next blog posts to cosmographs I think. In the meantime, enjoy browsing Brinton’s book.

This article on “Energy Savings in Tissue Production Process: The Case of the Hayat Tissue Mill in Turkey” by A. Isiklar, L. Aydin, D. Mainardi and O. Lopez was published in July 2008 in the TAPPSA Journal (Technical Association of the Pulp and Paper Industry of the Southern Africa). The article describes how energy can be recovered from process air in a tissue plant in Turkey using a cogeneration hood. It features three beautiful Sankey diagrams, one of which is presented here.

“The exhaust gases coming from the hood are used for the production of the steam needed to feed the YD and the other auxiliary equipment of the mill (wet strength pulper, hall ventilation). The residual energy in exhaust gases in excess from the boiler are used in order to feed a chiller unit, which in turn runs the air conditioning system of the electrical room”.

This almost symmetric top to bottom oriented diagram shows the energy in MW for a certain production capacity (details not given in the article). It is a section of the other Sankey diagram featured in the article (Fig. 3) showing the whole process including the gas turbines plant, the cogeneration hood and the waste heat boilers (omitting only the absorption chillers). Only the latter shows the reduced heat loss (see light blue arrows labeled “to atmosphere”).

As for me, that’s the kind of curves I love… ;-)

Gabor Doka pointed me to a publication by the Swiss EPA (Federal Office for the Environment, FOEN). The publication titled “Biogene Güterflüsse der Schweiz 2006″ (‘Flows of biogenic goods in Switzerland in 2006′) features many different Sankey diagrams. “Biogenic goods are defined as goods of biological origin, excluding those of fossil origin”. Data is based on Swiss statistical figures and valid for 2006. Available in German only (Download PDF 7,5 MB).

The overall structure of biomass flows is given in a generic layout and as Sankey diagrams with proportional arrow magnitudes for mass flows (unit is in 1000 tons, based on dry matter) as well as for energy content (in GWh, based on lower heat value of dry matter). These overview diagrams are structured in three columns ‘Production’, ‘Conversion’, and ‘Use/Disposal’. Imports are from top, exports to the bottom. This very clear structure for both mass and energy flows makes the complex diagrams easier to comprehend. These overview Sankey diagrams are available for download as a separate PDF file (still 3,2 MB)

The main diagram is then broken down into individual Sankey diagrams for the different sectors involved, such as plant production (PLB), animal farming (THA), and forestry (WAW) in the production column (orange colored processes), or food industry (LMI) and wood/paper industry (HPI) in the conversion sector (green colored process). Finally, in the use/disposal sector (red colored processes) we find goods consumption (WAK) along with energy generation and waste treatments.

This is the sectoral Sankey diagram for the food industry in Switzerland. We can see that a large part of the biomass for food production is imported, and that most production wastes are fed back into animal farming again. The red boxes are different waste treatments receiving input from the food industry.

The above is the goods consumption section. Main biogenic goods inputs are from food industry and wood/paper industry. The meat input is rather small comparatively. A big chunk of the mass output (namely waste wood and waste paper) feeds back into the wood/paper industry. 472.000 tons ended up in waste incineration that year, some 329.000 tons in waste water.

The Sankey diagrams in the study are interesting to browse and reveal a lot more interesting facts. The stuctured approach with the breakdown into smaller diagrams is very useful. The authors Baier and Baum from ZHAW at Wädenswil have done a great job in compiling this.

“The results of this study will serve as useful decision aids for strategic planning and assessments concerning the potential, use and management of biogenic resources (…) makes it possible to detect quantitative changes that occurred during a given period of time and to reach conclusions concerning the efficiency of measures taken.

Actually this way of visualizing statistical data with directional (from-to) information attached to it could serve as a role model for other national mass and energy accounts, I think.

Uh – this has become my largest post ever :o . But I think this was well worth it and the publication merits it. Your comments appreciated.

I was pointed to an article on carbon footprint, that used Sankey diagrams to underline a method of carbon accounting along the supply chain. This article was part of the “first virtual global conference on climate change” CLIMATE 2008 that took place, yes, exclusively on the Internet from November 3 to 7, 2008. (I must admit that this event passed largely unnoticed by me, although reading some of the papers now gives me the impression that it would have merited more attention.)

The paper titled “Carbon Accounting and Carbon Footprint – more than just diced results?” by Prof. Mario Schmidt from Pforzheim University describes the various approaches of corporate carbon accounting, carbon footprint of products, and Life Cycle Assessment LCA. Schmidt introduces a method that allows determining “cumulative emissions … at each point of the supply chain up to the POS”, and calls this the CO2 backpack.




The four Sankey diagrams above from the article illustrate the idea. They show (1) the CO2 equivalent emisisons along the supply chain, (2) the value added in a supply chain, (3) the relative CO2 emissions per value of product, and (4) the total emissions of the products along the supply chain with sectoral gate-to-gate, cradle-to-gate or crade-to-grave approaches.

This article is well worth reading, you should do so while it is still available online. Update: the domain has gone offline
Schmidt is an acclaimed expert in Sankey diagrams and has also published on the history and methodology of Sankey diagrams.