The French region Auvergne-Rhône-Alpes in the south-east of the Hexagone borders with Switzerland and Italy. Lyon and Grenoble are located in this region, known for skiing, lush pastures … and great cheese!

Auvergne-Rhône-Alpes Énergie Environnement (AUR-EE) is a regional agency that works to bring together players in the renewable energy field and to promote RE projects.

Given the agricultural character of Auvergne-Rhône-Alpes, biomass use for energy generation has been going strong in recent years. The agency has created energy flow Sankey diagrams for existing biogas installations, as well as a projection for the ones being under development.

Data is for 2017 and for the scenario where all projects currently under development would already completed. The yellow stream (‘déchets ménagers’) is household waste, providing 374 GWh of energy. Manure and other side-products from agriculture (green arrow) contributes another 260 GWh.
The stacked bar on the left hand side of the diagram indicates the potential availability of biomass by 2035, and one can see that only a small fraction of it is currently being taken advantage of.
Biogas is produced in anaerobic digesters (‘méthanisation’) and the region yields some 271 GWh electricity and 200 GWh heat per year from cogeneration plants. Already almost 100 GWh of biogas could be injected to the natural gas network, allowing for storage of the energy.

Note that smaller or even negligible flows are still shown with a minimum width in order to make them visible (these thinner arrows are not to scale with the others).

This Sankey diagram depicting the energy balance of Chile for 2015 can be found on the website Gestiona Energía MiPyMEs (MiPyMEs is the Spanish term for ‘small and medium-sized enterprises’, SMEs).

Flows are in TCal (teracalories), a unit for energy we don’t get to see very often (1 TCal = 4,205 Joules). What surprised me most in this figure was that ‘Biomasa Leña’ (biomass firewood) is the third most used primary energy source. The accompanying pie chart on the same page confirms that crude oil (25%) and coal (20%) are the most important sources, followed by biomass and oil derivates (each 19%). I guess this should read ‘biomass AND firewood’ rather than ‘biomass firewood’.

Some design shortcomings, in particular where the downward sloping stacked Sankey arrow turns to run horizontally to join the node ‘Electricidad’, and at the input side of the primary energy box, where the flows for ‘Petróleo Crudo’, ‘Carbón’ and ‘Biomasa Leña’ overlap and somehow don’t seem to hold their width all the way. My guess is that this is owed to the wish to keep the figure as compact as possible.

This Sankey diagram visualizing the energy balance for the French island Réunion has already been published back in 2010 in an article on reliability of supply in future power systems. (Mathilde Drouineau, Nadia Maïzi, Vincent Mazauric, Edi Assoumou. Long term planning tools and reliability needs: focusing on the Reunion Island. 3rd IAEE Rio 2010 International Conference “The Future of Energy: Global Challenges, Diverse Solutions”, Jun 2010, Rio de Janeiro, Brazil. 14 p., 2010). Access article here.

The flows are in Mtoe for the year 2007. The authors have been using the Markal/TIMES models to obtain data and study alternatives for future energy scenarios for the Réunion Island.

What would daily life in a ‘zero carbon’ Great Britain look like? Since 2007 the Zero Carbon Britain (ZCB) project of the Centre for Alternative Technology (CAT) has worked to “offer the hard data and confidence required for visualising a future where we have risen to the demands of climate science; to remove fear and misunderstandings and open new positive, solution-focused conversations.”

They have presented a Sankey diagram for the energy landscape in the UK, the way it could look like if Britain’s energy production was actually carbon free and 100% renewable energy.


via Open Energy Monitor blog, original image here (under CC BY-NC 2.0 license)

Flows are in TWh/year. The largest energy sources are wind and biomass. Some of the electricity is used to produce synthetic gas, synthetic liquid fuels and hydrogen (used mainly in the transportation sector). In that scenario there is even an electricity surplus that can be exported.

While I can not judge how realistic such a vision of the UK energy landscape is, I can at least say it is very different from the current situation (see here or here), and even from this UK 2050 energy scenario.

The last weeks have been very busy, so I am just quickly firing off a few more Sankey diagrams from the depth of my hard disk before heading into the holiday season.

This one in German, showing the percentage breakdown of energy flows in a company. Haven’t noted the source, sorry.

A rather rare find is this Sankey diagram from Iran, posted on the e!Sankey forum.

Those who don’t read Persian, like me, can just enjoy the visual aspect of this Sankey diagram. The diagram most likely depicts energy flows as I can identify the word energy انرژی

The energy balance of the German city of Stuttgart has been mapped as a Sankey diagram.

This was part of the project ‘SEE Stuttgart’ (City with Energy Efficiency / “Stadt mit Energie-Effizienz”) and has been developed by Fraunhofer IBP research institute.

A vertical layout was chosen. Absolute energy flow quantities are not shown in this version of the diagram, but are available in the underlying study. In 2010 primary energy consumption in Stuttgart was 20.300 GWh.

The diagram is used to promote a better understanding of the consuming sectors in the city, and the types of energy used. The SEE project aims to reduce Stuttgart’s energy consumption by 20% in 10 years and to transition to non-fossil fuels.

Stuttgart has actually won a first prize in a competition for energy efficient cities in 2016. It is thus setting a benchmark for other German cities. The above Sankey diagram is featured in this promotional video (in German) [at 2:36] and also briefly in this video (in German) [at 0:48] by IBP Fraunhofer.

A high resolution version of the Sankey diagram can be found here.

If you don’t use Sankey diagram software and only have Power Point at hand, this is probably what your national energy flow diagram turns out. 😉


Arrow widths are more or less to scale, which is good. But the overall aspect of this Sankey diagram is unorganized, due to diagonal and overlapping arrows. No flow units given.