While some of you might think of their favourite lunch time snack, in the UK the term WRAP refers tp the ‘Waste & Resources Action Programme’, an independent not-for-profit company.

WRAP now presented their vision for a circular economy in the United Kingdom by 2020, using Sankey diagrams:

The material flows for the baseline year 2000 are shown in a first diagram here:

In that year, apparently, 212 Mt of material were disposed of as waste (orange arrow), while only 47 Mt were recycled.

The situation in 2010…

… and the vision for 2020 (from this page):

The goal is to use less input materials, to reduce waste output and to recycle 3/4 of the materials.

See diagrams in high resoultion directly on their website.

After writing about VisioGuy’s radial Sankey diagram idea, I went through my bookmarks and collection of Sankey diagrams in search of further candidates for this special class of circular flow graphs.

Here are two goodies… 😉

Below is a black/white Sankey diagram of energy fluxes in a chemical loop combustion cycle from an Imperial College website. It is similar to the radial one Chris designed, however it is not exactly circular. Not all of the entries and exits of the cycle are shown as Sankey arrows. The exit of the arrow labeled W is to the center (would one call this anticentrifugal?). The methane input makes a U-turn before entering the loop.

The other Sankey diagram is from this website of a U.K. based company, and shows greywater recycling. The average consumption of freshwater per person / per day in the UK was 130 litres in 1996.

The water from wash-basins, shower and bathtub could go through a recycling stage and be reused for flushing and watering the garden. The designer gave it a roller coaster style loop, which sure doesn’t add to the information content of the graphic, but immediately draws the reader’s attention to the recycling. I am not sure where the third flow coming from the right goes to. It represents the potential savings of 45 litres/day, but kind of disappears behind the loop.

I’ll post more of these as I come across them.

Chris the VisioGuy recently came up with Radial Sankey Diagrams. Although he didn’t seem to be sure if there is a “need for radially-oriented Sankey diagrams”, the commentators of his post immediately came up with ideas: use for rotating or radiating processes, cigarette rolling, recursive industrial processes, reinvestments, and so on… even stellar nuclear reactions were mentioned.

This is the ‘Everything Radial’ Circular Sankey Diagram

… and this is the ‘Tangential Fly-off’ Circular Sankey Diagram

One concern seems to be that the proportional arrow magnitude doesn’t work that well, since the human eye perceives the arrow area rather than thickness in such a circular Sankey diagram.

Thanks VisisoGuy for this contribution to the big basket of Sankey diagrams

For most Sankey diagrams I find when browsing the web, a ‘left-to-right’ or ‘bottom-to-top’ orientation prevails. ‘Top-to-bottom’ is less common, but there are also examples like this one.

A rather untypical shape for a Sankey diagram has been up on the German page of the e!Sankey webpage.

It shows the energy balance for a pumped storage power plant as a curved shape, with the energy input at the left leg, and the energy that can be recovered (77.3%) at the right one.

Energy is stored “in the form of water, pumped from a lower elevation reservoir to a higher elevation. Low-cost off-peak electric power is used to run the pumps. During periods of high electrical demand, the stored water is released through turbines. Although the losses of the pumping process makes the plant a net consumer of energy overall, the system increases revenue by selling more electricity during periods of peak demand, when electricity prices are highest. Pumped storage is the largest-capacity form of grid energy storage now available.” (Wikipedia)

I searched for the original Sankey diagram in the source given (Quaschning 2007) and found this text with the diagram in chapter 6.1.2. That diagram already featured the curvy shape, and has just been reproduced similarly.

The use of the curve layout seems justified here. The author chose it to point out the difference in altitude. The upper basin is at the apex of the curve. Water pumped up from the lower basin requires energy, which can partly be recovered when the water runs down again.

What goes up…