The Spanish island of Minorca (Spanish: Menorca) is part of the Balearic islands archipelago in the Mediterranean Sea. Less crowded than Mallorca, and more tranquil than party location Ibiza, this island is popular for family holidays.

The Strategic Directorate of Menorca (Directrius Estratègiques de Menorca, DEM) has recently published this Sankey diagram depicting the energy flows of the island in 2013.


(via DEM Twitter)

Flows are in MWh. Primary energy input was 2.72 mio MWh in 2013, of which 1.56 mio MWh were used, while 1.92 mio MWh were losses. (difference was exported). Labels are in Catalan.

The energy visual is different from others that I have shown on this blog before: The island is almost entirely depending on petroleum as energy source. Maritime and air transport consumes a large part, as does the services sector (hotels). Industry sector is a rather small consumer.

You can find a report in Spanish with a similar Sankey diagram here.

A Sankey diagram of O2 contamination during pressure water scrubbing from a paper on ‘Oxygen Removal during Biogas Upgrading using iron-based Adsorbents’ by Toni Raabe of DBI – Gastechnologisches Institut gGmbH Freiberg in Germany.

Flows of methane, carbon dioxide, nitrogen and oxygen are shown in vol-%. The flow rate (in m³ per hour) is given in a small table at each stage of the process chain (biomethane-process chain via pressure water scrubbing).

From a paper on ‘Exergy analysis and optimization of a biomass gasification, solid oxide fuel cell and micro gas turbine hybrid system’ by C. Bang-Møller, M. Rokni, B. Elmegaard (Section of Thermal Energy Systems, Department of Mechanical Engineering, Technical University of Denmark) published in Energy 36 (2011) 4740-4752

This Sankey diagram of the energy flows (values in kJ/s) is for the SOFC reference case. The wet and dry biomass flows are evaluated using lower heating values, higher heating value (HHV) basis in parentheses.

The Laboratory of Energy Systems Research at Lithuanian Energy Institute (LEI) works on the country’s energy systems and advises policy makers. Here is their diagram of main fuels and energy flows in Lithuania in 2013. Unit is ktoe.

This presentation from 2015 by Alicia Valero of the Spanish Research Centre for Energy Resources and Consumption (CIRCE, Zaragoza) is on critical materials, minerals scarcity, recycling and a “thermodynamic cradle-to-cradle approach”.

It features two Sankey-style diagrams depicting the mineral balance of the European Union (UE).

This first one is a Sankey diagram for the mineral balance without fossil fuels (‘Diagrama de Sankey para el balance mineral de la UE sin combustibles fósiles’).

Data is for the year 2011, Flows are shown in tons. Iron and limestone dominate the picture with 77% of the input. Limestone is produced (extracted) mainly within Europe, while iron is mostly imported.

The second Sankey diagram is a scarcity diagram (‘Diagrama de rareza para el balance mineral de la UE sin combustibles fósiles’) and takes into account thermodynamic exergy to obtain (mine) the minerals. Although it depicts aluminium, gold, ion, nickel and the likes, flows are shown in an en(x)ergy unit (Mtoe).

Iron and limestone which seemed to be the most important mass-wise only constitute some 10% of the input. Aluminium and potash seem to be much more difficult to produce. Rare earth elements (REE) are not included in this diagram.

The author points out that it is important to not only look at materials from a mass perspective. Looking at materials availability taking into account thermodynamic exergy paints a different picture of the real cost and scarcity.

For those interested, please check out the presentation (in Spanish) here.

Browsing my repository of Sankey diagrams I discovered this almost vintage example:


This is from a 1992 ecoprofit poject in Austria. To have 1 kg of dry paint applied to a surface, 2.16 kg material is needed. This includes solvents, overspray, and sludge for example. Interesting take on material efficiency.

Taking it easy with a casual Friday post. This Sankey diagram shows the world wide gold supply and demand in 2013.

This is from a post in the e!Sankey forum and available as sample file in their new release.

Data is from the ‘Thomson Reuters Gold Survey’. 4,736 tons of gold were traded that year with roughly 3,000 tons production from gold mines. Largest demand was from jewelry makers (2,198 tons) followed by people who purchased gold bars (1,337 tons).

The article ‘Aprovechamiento de la energía procedente del frenado regenerativo en ferrocarriles metropolitanos’ by Álvaro López López published in the Spanish journal ‘Anales de Mecánica y Electricidad (May/June 2013)’, pp 12-18 has the following Sankey diagram.

No absolute numbers are given here. Still, we understand that from the motion energy during braking of the train a part (green flow) can be recovered and is being used for secondary systems (‘SSAA’) as well as being fed back into the overhead wire (‘cantenaria’).

Not sure though whether this Sankey diagram is a representation of the energy recovery during braking action only, or of the energy flows on a typical train ride.