Interesting comparative Sankey diagram on page 16 of the 2012 environmental declaration of Rosenheim Stadtwerke (Rosenheim City Power?).

The city is building or already running a wood gasification plant. Instead of just using the heat from directly burning wood (with 30% energy loss), they decided to work with a wood gas carburetor and use the wood gas to run a gas motor. This is somewhat similar to CHP where heat and electric power can be produced. Overall loss of energy (“Verluste”) in the system is only 23%.

The green box at the bottom displays the avoided fossil GHG emissions per tonne of wood for both technologies.

Flows are in MWh, but only some selected arrows are labeled. Unfortunately the flows are not always to scale: yellow arrow “Wärme” (heat) in figure at top representing 3,15 MWh, but shown as half the width of the blue arrow 4,5 MWh. I reckon the diagram was build manually from rectangles and triangles.

A web page of the federal german ministry for Environment, Climate and Energy in Baden-Wurttemberg informs companies about energy efficiency. Sankey diagrams are described as a useful instrument to detect hotspots for improvement and a tool in the framework of energy efficiency analysis.

Twenty five years ago Sankey diagram were drawn by hand, like this one… Depicted are energy flows in the city of Dresden. No colors, just black-and-white with hatching. neat architect’s lettering.

Found this on a website of Bauhaus University in Weimar titled “Interactive Sankey Diagrams – a planning and information tool”. Authors are Hanfler, Fröhlich, Riehmann.

Found this Energy Flow Diagram for Bavaria (Germany) on the Bavarian Ministry of Economy website.

Flows are in Terajoule (TJ). Flows from top to bottom with different consuming sectors like private houdholds, traffic and industry. Different shades of green… ;-)

While I generally welcome the fact that these Sankey diagrams are published for nations, regions or states (as is the case here / more examples can be found here on the blog!), I find that care must be taken to respect the basic principles used for these diagrams.

In that respect the above example looks somewhat quirky to me. The reason for this diagram being spoiled is the fat stream (1.195.019 TJ “Umwandlungsverluste insgesamt” – not sure what that means though) merging into the vertical band from the left, and its counterpart (1.701.846 TJ “Umwandlungseinsatz insgesamt”) branching out to the right at more or less the same height. Are these additional inputs and outputs? But then, why do they cross the main direction of the flow? Not clear to me…

Not a good example. I would have expected better from the state where two of my favourite cars are manufactured.

A brochure on efficient use of energy in manufacturing processes in industry was published in 2004 by Bavarian environment agency (LFU). With its catchy title ‘Protect Climate – Reduce Costs’ (German: ‘Klima schützen – Kosten senken’) the brochure targets at small and medium sized companies and aims to raise conciousness about energy efficiency in different areas of a manufacturing company such as pressurized air, air condition, heating/cooling, lighting and others.

On page 6 this Sankey diagram shows an overview of energy flows in the company…

… and on page 7 a detailed view of a process section (extruder, corrugator, spray bath)

The first diagram is in percent of the total energy consumption, directing the interest to the areas that contribute most to energy consumption, losses (and energy costs) in the company. In the second diagram the unit is kW.

Thanks to the blog reader who sent in the brochure and helped out in translating from German.

This simple Sankey diagram is displayed on the Berlin state environmental protection agency (in German only). It shows a breakdown of the input materials and of the outputs of a pharmaceutical synthesis process, with a focus on solvents (“LM”).

Water is the largest chunk of the inputs, as well as on the output side (I understand that the water is polluted with solvents after the synthesis and need special treatment).

Flows are in kg, and mostly to scale. The Sankey arrows for the smaller quantities like the actual product yield (90 kg only) seem to have a minimum width or are emphasized ny a stromger border line in order to remain visible.

I was asked what the largest Sankey diagram I have seen so far was? Not sure about this. The Swiss biomass flows diagram I featured in January 2009 would be a candidate, but I think the following one is much larger, both in the actual diagram size, as well as in respect to the number of nodes and arrows.

It was created by the marketing department of RWE AG, one of Germany’s big four electricity providers. It shows the energy flows in Germany for 1995. The image file I have is 2588 x 1062 pixels, so when you click on the image below, you won’t be seeing the full image, but only a thumbnail… (also because I don’t want to get sued by their legal department!)

The clear structuring of the diagram is what might be called “very German”: energy sources are at the left, with non-renewables at the top and renewables at the bottom. The second section shows energy conversion, the third section the energy use sectors. These are further broken down, before the arrow join again to show useful energy and energy losses (a 50:50 relationship). Losses in the conversion phase are shown as arrows that branch out vertically to the bottom. Exports and bunkering, on the other hands, is shown as vertical flow leaving to the top. Color coding is very clear, and flows are labeled with figures on each arrow. The unit is petajoule (PJ)

Even the black background goes well with the bright colours. Here are two close-ups of two sections from this energy flow diagram. Enjoy the beauty…