The European R&D project RenewIT studied energy concepts for renewable energy supply of data centres. The project partners from Spain, Italy, UK, Germany and The Netherlands looked at 18 different energy models.

In the final project report each of the concepts are described, accompanied by a Sankey diagram.

The above is figure 3.53 from p. 177 of the report showing the “Sankey chart for the distribution of average energy flows per year within different subsystems of concept 7 for scenario 3”.

Many more equally beautifully crafted Sankey diagrams can be found in the report, check chapter 3.5 Simulation Results of the publication Deliverable D4.5 Catalogue of advanced technical concepts for Net Zero Energy Data Centres. Authors: Nirendra Lal Shrestha, Noah Pflugradt, Thorsten Urbaneck (TUC); Angel Carrera (Aiguasol); Eduard Oró, Albert Garcia (IREC); Hans Trapman, Gilbert de Nijis, Joris van Dorp (DEERNS); Mario Macías (BSC) (get it here)

From a July 2013 article titled ‘Energy and exergy analyses of a Zero emission coal system’ by Linbao Yan, Boshu He, Xiaohui Pei, and Chaojun Wang of Beijing Jiaotong University, available at Researchgate. This Sankey diagram is for “the exergy flow of the improved Z[ero] E[mission] C[oal] system at benchmark condition”.

Fig. 4. Sankey diagram of the exergy flow of the improved ZEC system at the benchmark condition.

All flows are in kJ. The individual process steps if the system are only labeled with acronyms. They are explained in the article: GF is gasifier, CL is cleaner, RF is a reformer, and CH is a CO2 heater. The article also features the energy flow Sankey diagram.

Interested in the energy flows of the Euopean countrues (EU-28)? Check out the Sankey diagram tool on the EUROSTAT webpage (the European Statistics Office).

You can choose to view the energy flows for individual countries, or the total for all EU-28. Switching between the data for the years 1990 up to 2014 lets you compare the changes over the last 25 years. The sidebar offers display options for the Sankey diagram.

Nice visualisation and much more fun to work with than statistics data in tables.

A Sankey diagram of a cogeneration equipment from the website of Italian firm Altavia:

Sweden is administratively organized in 21 counties, called “Sveriges län”.

A new report ‘Energistatistik för Sveriges län och kommuner för år 2013’ (Energy Statistics for Swedish Counties and Municipalities on the year 2013), published by Länsstyrelsernas Energi- och Klimatsamordning (LEKS) features energy flow Sankey diagrams for all counties.

Here is an example for Skåne from page 17:

All flows in GWh per year. Percentage breakdown for contribution of fuels (left side) and for consumption (right side).

Actually the energy picture looks quite differently in some counties: For example, Södermanlands län (on page 19) has 33% coal/coke (‘Kol/Koks’). Kronobergs län’s most important energy source with a share of 29% is biomass (‘Biobränsle’).

Twenty-one wonderful Sankey diagrams … a sheer joy for a Sankey fan like me.

Here is a good example of how Sankey diagram and pie chart are used side-by-side. In fact, the Sankey diagram picks up one particular piece of information that is already in the Sankey diagram.

This is from a German research report titled ‘Entwicklung eines EnergieReduzierten Verfahrens für den Erwärmungs- und Umformungsprozess von Parabel-Lenkerfedern durch Verkürzung der Verfahrenskette („EnRed“)’ published in 2010. [Note: no English abstract present, but title translates to sth like ‘Development of an energy-reduced process for heating and forming of…’ and from what I understand it is a hot rolling process]

It compares a conventional process with a new, energy reduced process. Here is the Sankey diagram for the conventional process and the pie chart right below.

The unit is kWh/kg, primary energy per kg of final product. The three colors are picked up again in the pie chart that shows the breakdown of primary energy lost in the provision of heat (brown, 12.3%) and in the ovens (red, 74.3%). Only 13.4% of the primary energy is actually used for heating of the rolled material (yellow).

Now, the pieces of the pie chart correspond to the widths of the brown, red and yellow output arrows as part of the primary energy input at the left. We are, however, typically much more used to percentages being represented in a pie chart.

A nice detail in the Sankey diagram is the split for the three ovens and the losses from the three ovens (red). The flows run in parallel and then are joined again at a bar that reminds me of a bridge, or the nut of a guitar … or the Brandenburg gate turned sideways as my nephew suggested 😉

This Sankey diagram for the water system of Segura river in Spain shows “the interchanged fluxes between the hydrological and the economical system”.

This is an output from the EU-funded ASSET (Accounting System for the SEgura river and Transfers) research project and can be found on the FutureWater website. Authored by Sergio Contreras and Johannes Hunink of Future Water (Contreras, S., J.E. Hunink. 2015. Water accounting at the basin scale: water use and supply (2000-2010) in the Segura River Basin using the SEEA framework. FutureWater Report 138).

Flows are for 2010 and measured in cubic hectometres (hm³, 1 hm³ = 1000000 m3 = 1 GL). The left part with the light blue backdrop is the actual hydric sector, while the right side with the light orange backdrop encompasses the technical/economic sector.

Water is extracted from surface waters (agua de superficie), ground water (acuiferos), and – interesting pespective – from soil water (água edáfica). Water from soil (green arrow, 901 hm³) is directly taken up by plants, so consumption is in the agricultural sector only. Agriculture is the largest consuming sector, followed by industry and energy generation, and water provision to households.

Much of the releases of water from industry and energy generation is returned to the water system (1734 hm³).

Additional tidbits of information below the Sankey diagram almost turn this into an infographic.

A group of people from Idaho’s Office of Performance Evaluations, an independent agency of the state, have contributed a post to the AEA365 blog – A Tip-a-Day by and for Evaluators back in June 2014.

Rakesh Mohan, Lance McCleve, Tony Grange, Bryon Welch, and Margaret Campbell recommend Sankey diagrams as “A Cool Tool for Explaining the Complex Flow of Resources in Large Organizations”

“Communicating the flow of dollars was the trickiest piece of the study. We considered narratives, tables, and traditional flowcharts. Ultimately, we used Sankey diagrams that helped stakeholders visualize funds moving through the department making them the most useful features of our report.”

The Sankey diagram depicted shows Idaho state funds in FY2013. Although the absolute figures or the total sum are not shown in this figure, the diagram is most likely based on real budget data.