Yesterday it became known that the European Commission would shelve their circular economy package of waste, recycling and incineration laws for now, in favour of an even more ambitious legislation to be presented by end-2015 (read here or here).

That led me to browse tweets using the hashtag #circulareconomy, and I ended up unearthing two nice Sankey diagrams…

The first one is by WRAP UK, showing the EU-27 material flows estimated in 2020. This is not for a specific type of material, but all material.

Flows are in million tonnes, with the 2020 values in blue, and the current (2010) figures in brackets below for comparison. There are three nodes: ‘Direct Material Input’, ‘Domestic Material Consumption’ and ‘Waste’. Unfortunately the size of the node icons is too large, and the flows are difficult to see. But still, this is a nice idea!

The main message is that in comparison to 2010, Europe could have 350 million tonnes of recycled material in 2020. Check out these Sankey diagrams by WRAP UK that basically convey the same messsage, but are less infographic.

Another Sankey diagram I found when browsing through the tweets was this one below. The title of the diagram is “How circular is th UK?”.

I found it in a blog post ‘Designing Out Waste Consortium’ by Ramon Arratia on Interface’s Cut The Fluff blog on sustainability, but it is originally from this Green Alliance blog post by Julie Hill.

No values shown along the flows in this Sankey diagram, but neatly shaped circular flows. The question raised in the title is answered prominently with the message that 19% of the material in the UK is led in a loop (pink flow).

A research group from INRIA Grenoble engineering school has set up a website for visualization of environmental data. Sankey diagrams are one available visualization option. The below is a sample provided on the website.

The Sankey diagram shows flows along the cereals production chain in France from the 2007/2008 harvesting campaign. Quantities are in 1000 tonnes.

Different grains are shown on the left: wheat (‘blé’), hard wheat (‘blé dur’), maize, barley (‘orge’) and others. Two large end nodes for unprocessed grain exports and use as animal feed (‘consommation animale’). There are further exports as intermediate and processed products. Only a comparatively small fraction is consumed by humans in France as bread, pasta, biscuits.

Could not detect use as energy crops, it is maybe hidden in the ‘industrial use’ flow. Anyway, an interesting application case for Sankey diagrams.

Energy flows in a waste incinerator facility of MVR-HH (‘Mullverwertung Rugenberger Damm’) in Germany are depicted as Sankey diagram on their website.

Flows are for 2013 in MWh per year (MWh/a). The hot red area is the boiler (‘Kessel’), followed by the turbine. Almost half of the energy is used as process steam and for district heating (‘Warmwasser Neugraben’). Losses branch out vertically.

Happy New Year to all followers! Kicking off with a distribution diagram (aka ‘alluvial diagram’) for cobalt (chemical element ‘Co’) by the Geospatial Engineering Research Group at the University of Newcastle, taken from the article ‘Sankey diagram of cobalt life-cycle’ on their blog.

This shows the mining, refining, manufacturing and use stages for cobalt broken down by continent.

Not sure what the orange and green arrows stand for, or what the unit is. Also, there seems to be a mismatch between the input and the output quantitites at some nodes (check, for example, cobalt flows received from mining countries for refining in Europe compared to the deliveries to the manufacturing stage).
This could be due to mismatches in data from the different sources, or caused by changes in cobalt stocks (i.e. Europe mining and importing less but reducing stocks from previous year, thus being able to ship more to manufacturing in the same period). Maybe one of the authors wishes to comment?

The scientific paper ‘A Sankey Framework for Energy and Exergy Flows’ by Kamalakannan Soundararajan, Hiang Kwee Ho, Bin Su (Energy Studies Institute, National University of Singapore) features these two Sankey diagrams.

Energy flow in an open rack vaporiser (ORV):


Exergy flow in an open rack vaporiser (ORV):

The authors explain that “ORVs regasify liquefied natural gas (LNG) from temperatures below -160°C to room temperature through a heat exchange process with sea water at room temperature and pressure. (…) The Sankey representation of energy and exergy flows here presents a large potential for energy savings that could be realised in the regasification process.”

Consulting firm Rytec analyzes energy and heat utilization level of Swiss waste incineration plants and visualizes the processes using Sankey diagrams.

This Sankey diagram from their website is a simplified view and offers no details as to the actual figures. More detail can be found in this project summary (PDF).

Diagram labeled in German, but thanks to my friend Google Translate, I can identify ‘heating’, ‘boiler’, ‘energy conversion’ and ‘flue gas losses’. Orange streams to the top are losses.

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.

The ‘Landscape of Climate Finance’ is a project by the Climate Policy Initiative. CPI “works to improve the most important energy and land use policies around the world, with a particular focus on finance. (This) helps nations grow while addressing increasingly scarce resources and climate risk.”

At http://www.climatefinancelandscape.org/ the have put up graphically appealing and beautifully crafted slideshow with facts on climate finance. How much is spent? Where does the money go to? Who are the receiving countries. Please browse the slideshow here.

Below are two Sankey diagrams from the 2013 report on climate finance.

The first is a rather coarse overview showing the international funding of climate projects by OECD countries and Non-OECD countries. On the right side the recipients breakdown: within their own borders, OECD countries, Non-OECD countries. Details on the countries are available in the report. Flows are in billion US$.

The other Sankey diagram is more complex. Here we can see the sources of climate finance and intermediate agents, the instruments, the recipients and the uses (adaptation and mitigation).

The incoming flows from the left are mostly “not estimated” (NE) and therefore are not to scale with the outgoing arrows. There are many annotations on assumptions and constraints, so please don’t make conclusions directly from the image. In the online version one can hover over the nodes to receive more information.

Congratulations to CPI for this work. They are tackling a complex issue graphically, and make good use of Sankey diagrams for visualization.