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.

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.

Just a brief casual Friday post: Two schematic Sankey diagrams showing energy supply scenarios for an island.

Scenario 1 relies on solar thermal power and a tidal wave power plant. Mainland connection available (for backup?)

Scenario 2 with wind power and heat pumps.

Who can tell the island’s name by the cloud-like shape depicted at the top right…? 🙂

A group of graduate students form the Center of Industrial Ecology at Yale University in 2005/2006 researched the material flows on the “Big Island of Hawai’i”. Their research report (which can be found on the website of the Kohala Center) shows two Sankey diagrams, one of which is shown here.

Material Flow Accounting (MFA) “is the study of material flows on a national or regional scale. It is therefore sometimes also referred to as regional, national or economy-wide material flow analysis.” (Wikipedia). MFA is a research field in industrial ecology. As the authors of the report write,

Using an island as a unit of analysis is valuable both to the researcher and to those interested in the sustainability of the island itself. The researcher benefits from the island’s clear boundaries (most often defined by a surrounding water body) and a relative advantage in data collection provided by the fact that borders are monitored. Material flows are therefore relatively easier to understand on islands than in larger, more complex non‐island systems.

I have been posting about the use of Sankey diagrams in MFA before, and with few exceptions (Material Flow Sankey Diagram of Japan), have found that examples of Sankey diagrams for national MFA accounts typically are limited to selected bulk materials (e.g. biomass in Switzerland, gold flows in the U.S.).

Flows in the above Sankey diagram for the island of Hawai’i are in gigagrams (kilotonnes) and refer to the year 2005. Inputs are shown on the left side, and the fate of those inputs can be seen as exits to the right. More than 75% of the material flows are imported from off the island, the majority of these flows (57%) are construction materials. Consequently, road and building construction are the largest net addition to stocks with almost 2,000 kilotonnes.

The Sankey diagram has some minor flaws, regarding scale of the flows. Look for example to the division of the landfilled waste arrow (422 kt) into three almost equal portions, which are supposed to represent 79.3 kt, 125.1 kt and 217.7 kt. Also the width of the volcanic rock input flow (429.7 kt) is about four times the width of the machinery input flow (representing 200.2 kt). Still, I think it is a good Sankey diagram, and I wouldn’t mind joining the research group on their next visit to the islands…