Followup to my post a few days ago on energy efficiency in an engine: Someone mentioned the below diagram that can be found on the Nissan Technology website.

Much simpler, actually a straight-forward breakout Sankey diagram. No sequencing of engine elements where power is lost as in the diagram from the Australia Gov report.
Strong emphasis on arrow heads … but worst of all flows are not to scale! 49 out of 100 should be roughly half the height of the ‘Fuel Energy’ node, but it is only 40%. Fail!

Interesting blog post and use case for Sankey diagrams by Dr. Ulrich Sigmund at the ANKHOR Feel Your Data Flow blog. He visualizes compiler file sizes using Sankey diagrams.

I am not an expert at this. But apparently 1 pixel in a Sankey arrow represents 400.00 Bytes being handled by a compiler.

In the above simple pic the main chunk of data is code from the SDK directly.

In the next diagram there are intermediate steps. There are objects from the SDK, but also a fair amount created from project files. They are used to create libraries and finally to compile the product. The bright blue arrow is debug info collected during the build process.

Ulrich concludes: “The Sankey diagrams do not only show why your hard drive is cluttered with intermediate files, they also helped me spot some fragilities in the build process. Sometimes the build order was not 100% correct and some of the intermediate files ended up in the wrong folders (due to the fact that the projects have been moved through five generations of Visual Studio by now).”

Any IT guys following here to comment whether this is helpful?

Was browsing through my bookmarks and saved images and found the below diagram. Blame it on my mood today, but this one calls for bashing.

Published in a 2010 report by Australian Government, Department of Resources, Energy and Tourism. ‘Energy Efficiency Opportunities. Energy–Mass Balance: Transport’ figure 11 on page 26 this so-called Sankey diagram looks like a aerial view of my nephews playing room with his building blocks spread on the floor… While I generally appreciate a Sankey diagram being used in a government report on energy consumption or loss in transport, I think this one is poorly executed.

If you look at the numbers you will even see that they don’t add up correctly at the ‘Motive Power’ node.

The diagram shows how energy from fuel is lost in different stages of a vehicle motor (engine, power train, transmission) with approximately 21% of the energy being used as power at the wheels. This value is just an example, and not for one specific vehicle. But 20% efficiency seems to be more or less the average in a passenger car.

I remembered I had seen another Sankey diagram on the e!Sankey forum with the same topic.

This one is in German but you may be able to understand the main items. The red arrow are losses at the motor. The stacked turquoise-blue arrow to the right (18.5%) is energy-at-wheel. All in all there are many more details, but still the diagram remains rather “compact”.

I am sure there are more Sankey diagrams on energy losses in vehicles out there. Let me know if you find other examples to compare.

Interesting project described in the blog article ‘Understanding your city by understanding its flow: towards Participatory Urban Metabolism Information Systems’ by Sven Eberlein of the Ecocitizen Worldmap Project.

This is a participatory approach where young citizens track the water flows in their city in a crowd-mapping approach. The data is visualized as Sankey diagram (here called MetaFlow diagram). Pilots were carried out in Casablanca and Cairo.

This project is somehow linked to Sebastian Moffat’s activities I have featured in a blog post back in 2008.

This seems to be the result from either the Casablanca or the Cairo field work. Great colorful Sankey flow diagrams. Judging from the photos in the blog post, working with the local community seems to have been fun. The participatory approach is emphasized (Sven calls this a ‘Participatory Urban Metabolism Information System (PUMIS)’).

More Sankey diagrams can be seen in the original blog post.

The below diagram is shown in a short paper ‘A Sankey Diagram for Nickel Production’ by M. Levesque (School of Engineering, Laurentailn University, Sudbury, ON, Canada) and D. Millar (MINARCO, Sudbury, ON, Canada). The paper was presented at the ‘1000 Island Energy Research Forum (TIERF) 2011. It also appears on a poster on the same topic available on the MIRARCO website (large PDF!).

The diagram shows energy production, transformation and consumption in the Nickel production. This not only includes dryers, kilns and furnaces, but also supporting activities such as port handling and transportation.

No absolute values given in the diagram, and even the fuels are not specified (although you can identify what is probably hard coal, lignite, natural gas). Most likely a question of confidentiality. A left-to-right orientation of the diagram is presumed, and no arrow heads are shown. This could lead to an interpretation issue for the green band that leaves the power stations PS1 and PS2 vertically.

The paper concludes “The Sankey diagram highlights the areas in the process where focus is required for subsequent energy management effort.”

The U.S. Department of Energy (DOE), Office of Energy Efficiency & Renewable Energy publishes Sankey diagrams on non process energy on this webiste.

What is non-process energy you might ask. According to DOE, non process energy is “energy used for purposes other than converting raw material into manufactured product. MECS-specified categories of nonprocess energy include facility HVAC, facility lighting, onsite transportation, other facility support (e.g., cooking, water heating), and other nonprocess use.”

You can access the energy flow Sankey diagram for the full U.S. manufacturing sector. Data is from 2010 and flows are in TBtu (Trillion British Thermal Units) per year.

Detailed diagrams on on-site generation, process energy and non-process energy (the three ‘transforming nodes’ in the middle of the full sector) are also presented.

Grey and black arrows show losses. Good work from the Office of Energy Efficiency & Renewable Energy.

I found the below Sankey diagram depicting Romania’s energy flows for 2008 in an article titled ‘A Macro-Micro Perspective on Sustainable Refurbishment of the Housing Sector’ by Ovidiu-Horaţiu Teleche, University of Architecture and Urbanism, Bucharest. Published in Proceedings of 1st International Conference on Architecture & Urban Design, Department of Architecture (2012).

Flows are in ktoe (kilotons of oil-equivalents). Underlying data is from the Romanian National Institute of Statistics and Eurostat 2010. EPP is for ‘Electrical Power Plant’, CHP for ‘Combined Heat & Power Plant’, and DHP for ‘District Heating Plant’.
Note the small flow quantities where arrows are not to scale to be able to view them at all (minimum line width set to 1 or 2 px).

Energy generation is predominantly fossil (coal, petroleum, natural gas). Biomass is the most important energy source in the residential sector. The article doesn’t mention the reason, but my guess is on wood or peat “for preparation of hot water, cooking and direct burning in the stoves for heating” as mentioned in this article on biomass in Romania.

Another quick casual Friday post … again from Austrian company pro-wel, published on their website to market their process engineering services.

Enjoy your weekend!