The below Sankey diagrams both show wood biomass flows for Finland for the year 2013.

The first one was published in the report VTT Technology 237 ‘Sustainability of forest energy in Northern Europe’ by researchers from VTT Technical Research Centre of Finland and Natural Resources Institute Finland (Luke).


Authors of this figure are Eija Alakangas and Janne Keränen. The diagram is oriented top-to-bottom and shows how the 104.4 Mm³ of round wood that grew in Finnish woods in 2013 were used. Basically there are two (three) main pathways, with a lot of arrows branching out to depict certain uses. 38.3 Mm³ of round wood was used in pulp industry, 26.2 Mm³ in the mechanical wood industry. Another 9.5 Mm³ of wood is used directly for energy generation.

The second Sankey diagram seems to be a remake of the above. It was published in a VTT Research Report on ‘Cascading use of wood in Finland – with comparison to selected EU countries’ by Laura Sokka, Kati Koponen, Janne T. Keränen.


Here the overall orientation is left-left-to right. The color scheme seems similar. There are some minor differences in the energy use part (orange and dark red arrows).

The first diagram has some images and comes across a little more playful than the second one. Although they depict the same data, I perceive them quite differently.
Is it due to the scaling or the vertical vs. horizontal orientation? Let me know your impression in the comments please.

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’).

As part of the Canadian SPRUCE-UP research project one activity is dedicated to Genomic, Ethical, Environmental, Economic, Legal or Social (GE³LS) aspects of this applied genomics project. As part of their work the scientists have developed the Canadian Forest Service – Fiber Cascade Model (CFS-FCM) simulation model.


(see high res image here)

This Sankey diagram shows one specific scenario for a downstream flow of wood fibre from Canadian forests to products. Flows are in metric tonnes (probably for one reference year), with the exception of the ‘Bioenergy’ flow, shown in terajoules (TJ).

The European research project CASCADES’ objective was “to define the cascading use of wood and assess the environmental and socio-economic impacts of cascading, to identify and analyse the barriers preventing cascading”. As a central element of the project a wood flow analysis was conducted.

From page 26 the 2016 final report [Vis M., U. Mantau, B. Allen (Eds.) (2016) Study on the optimised cascading use of wood. No 394/PP/ENT/RCH/14/7689. Final report. Brussels 2016. 337 pages)] comes this Sankey diagram depicting wood flows in the European Union (EU-28).

All flows are in Mm³ swe (solid wood equivalent). No absolute numbers are given to quantify the flows, instead three sample arrows serve a reference to the scale (“Legend of dimensions”).

The wood biomass is either used as material (left branches) or as energy (right branch). On the material side wood industry (yellow path) and paper industry (blue path) take up most of the biomass. Residues of both industries along with a good chunk of the post-consumer paper waste are being recovered and led in a cascading loop, until they eventually shift to the energetic side.

A complex and interesting Sankey diagram with much to discover. The CASCADES report describes all the areas of the wood flow system, identifies hotspots and describes measures for optimization.

A beautifully crafted Sankey diagram on wood in Austria can be found in the 2012 article ‘Die Bedeutung von Holz als erneuerbarer Energieträger’ (translation: ‘The importance of wood as a renewable energy source’) by Kasimir Nemestóthy on the waldwissen.net website. These are the wood streams in Austria in 2010.

All streams in solid cubic metre of wood (“Festmeter”, fm). Smaller streams less than 0.1 mio solid cubic metres are not displayed.

Here is how the diagram is structured: on the left the sources of wood with imports, harvesting from forests and other non-forest wood sources. Imports and harvested wood is directed mainly to sawmills (“Sägeindustrie”) and to paper industry. Non-forest wood as well as losses from wood industry (bark, wood chips) are for energetic use.

The dark green arrow is saw round wood with the bordeaux-colored stream representing bark. The brown arrow is industrial round wood of lesser quality, mainly used in paper industry. The light pink and light green arrows represent wood chips and firewood. Along with remains from the saw mills and paper industry it is destined for energetic use.

One minor design flaw at the top (arrow from imports to saw mills) where the green arrow overlaps the orange and red arrow in the curve), but by the untrained Sankey eye this will probably rarely be noticed.

There is a second Sankey diagram in the article that details the energy use, but I will save that one for a separate post.

From a presentation by Swiss company CTU Clean Technology Universe AG comes this Sankey diagram for energy flows in a wood gas process.

The diagram is set up for wood with 50% humidity and an energy content of 1 MJ. The process steps drying, gasification, methanation, CO2 removal yield gas with an energy content of 0,71 MJ (71%). Much of the offheat is recovered in the process, excess heat is fed to district heating.

Wood in brown, gas in orange, heat in red and electricity in blue.

Another Sankey diagram for wood gas here.

Nicely made infographic from steelconstruction.info wiki. What happens to the building materials on demolition, how much of concrete, timber and steel can be recycled?

The three arrows are curved and start at a 7-o’clock position. Used concrete from building demolition is mostly downcycled. Wood from structural frames is mostly landfilled, or re-used. Steel has a very good recyclability and most of the material can be recovered to make new steel.

The view angle and the images of construction machines make it a very attractive infographic.

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.