Tag: energy

Energy Flow in Norway Municipality

ENOVA is a public enterprise owned by the Royal Norwegian Ministry of Petroleum and Energy. It advises the ministry in questions relating to energy efficiency and new renewable energy.

One of their services is the practical development of energy and climate plans (Kommunal energi- og klimaplanlegging) for Norwegian municipalities. On their website they present a sample Sankey diagram to visualize energy flows.

The Sankey diagram shows the energy flows in the Stor-Elvdal municipality in GWh (probably per year, a year is not given). This is very interesting, as the municipality can cover almost all of its energy for industry and private households from renewable energy sources, such as biomass and wind. Energy from fossil sources is consumed through almost entirely transportation. Stor-Elvdal produces 47.5 GWh within the municipality, and imports another 35,8 GWh from wind from outside the municipality.

A small typo can be found in label on the the orange flow (saying 85,8 where it should read 95,8), but this doesn’t spoil the overall quality of this diagram painted with SDraw, I guess.

Download the publication (in Norwegian) as PDF file

Floating 3D Sankey diagram

Another runner-up in my private “Fancy Sankey Diagram” contest definitely is this Sankey diagram shown on a webpage of the Longford Environmental Alliance (LEA) from Ireland.

It visualizes the “Energy Balance for 2005 as a flow diagram showing our inputs from the left hand side and our outputs or usages on the right hand side.” It is a 3-D image, and kind of floats above the ground, although it doesn’t have a fancy shadow effect as this one does.

I have shown similar diagrams for California, Japan, Sri Lanka, Scotland and the U.S. before. In these national energy balances the various energy sources are shown as entries from the left, while consuming sectors (or the “sinks”) are displayed as output arrows. This Irish Sankey diagram distinguishes ‘Agriculture’ as a separate sector.

Well done Éire, home of late Mr. Sankey…

3D Sankey Diagram from WBCSD

The World Business Council on Sustainable Development (WBCSD) in an article on “Making Tomorrow’s Building’s More Energy Efficient” features a great three-dimensional Sankey Diagram, to illustrate that “more than 90% of the energy extracted from the ground is wasted before it becomes useful work”. The article calls for green buildings where energy is produced onsite, and losses are minimized.

The Sankey arrows representing the losses bend down sharply, they remind me of the Iguazu Falls. Neat 3D images of the equipment are placed on the diagram to visualize the process steps where energy is lost. The whole thing hovers over the ground throwing a faint shade. The graphic designer who did this really merits an applause.

If ever I launch a ‘Best Sankey Diagram Award”, this one will have good chances to win it. Any sponsors out there? Any volunteers for the award jury?

Diagramas de Sankey? Si Se Puede!

The Mexican National Commission on Energy Saving (Comisión Nacional para el Ahorro de Energía (CONAE) present several success stories (casos exitosos) on their website.

One success story dates back to 1997, and describes how an energy efficiency study of fired heaters (i.e. boilers) was carried out in a Nafta producing facility in the Veracruz state of Mexico. As a result of the study, several suggestions for optimization were implemented. Fuel consumption could be reduced by 23-24 %, while the efficiency of the ovens could be raised by 13% (calentador BA-2001 B) and 16% respectively (calentador BA-2001 A).

Para los hispanoparlantes: el título oficial del proyecto fue “estudio técnico económico e ingeniería conceptual realizada a los calentadores a fuego directo BA-2001 A/B de la planta hidrodesulfuradora de naftas, del C.P.Q. “La Cangrejera”, ubicado en Coatzacoalcos, Veracruz” (otro candidato para el concurso mundial de titulos largos).

The heat losses are shown as Sankey diagrams. The first describes the optimal situation, with an energy efficiency of 82,4 % “as guaranteed” by the maker of the fired heater.

The two other Sankey diagrams show the energy balance of the heaters A and B before the implementation of the measures. They run with an efficiency of 60,6 % and 62,35 %, a “real world situation of one fired heater” /

The arrows branching off at the top show the heat losses. I like the fancy icons that show how energy is lost through the walls, because of deteriorated or insufficient insulation, and heat energy in the effluent gases. The flows are given in MMBTU/h (millions of BTU per hour).

Unfortunately two of the diagrams are not to scale: The arrow to the right in the second diagram should be roughly 2/3 of the width on the left side. It is about 4/5 (or 80 %) of the width, similar to the width in the first Sankey diagram. This is a visual exaggeration of the inefficiency. However, I refrained from featuring this in my informal “Lying with Sankey diagrams” series. 😉

Edit 05/2015: the web pages are not acessible any more. I had to restore the image from a local copy, and removed references to two other diagrams I had references to. -Phineas

Energy Balance for California

California Energy Commission in 2005 published the final report of a project called CALEB (California Energy Balance). The CALEB database is compiled by the Lawrence Berkeley National Laboratory (Berkeley Lab) and contains “data for energy production, transformation, and consumption for the State of California for the period 1990 to present.”

The report shows the California energy balance for the year 2000 as a Sankey diagram. (Source: Murtishaw S, Price L, de la Rue du Can S, Masanet E, Worrell E, and Sathaye J, 2005. Development of Energy Balances for the State of California. Sacramento, CA: California Energy Commission CEC-500-2005-068 (LBNL-54923))

A PDF with this diagram explains how to read it:

Reading from left to right, the figure shows all the inputs of primary (and imported secondary) energy into California’s economy in 2000. These are summed by major fuel types in the middle of the figure: petroleum and associated products, natural gas, and inputs to electricity generation. The right-hand side shows how all of the fuels are allocated to the various end uses.

The executive summary explains that the diagram shows some peculiarities for ‘Arnieland’ compared to other states. It also points out that further research is needed to collect more data and to be able to break down aggregated energy data.

This way of presenting the energy balance seems to develop as a kind of standard for representing energy flows for a state or country. Other examples can be seen here: Japan, Scotland, U.S., or Sweden.

The diagram has two special features which distinguish it from other Sankey diagrams:

Firstly, it shows negative flows as dotted Sankey arrows, indicating “instances where consumption is greater than supply” – something which on a physical level is of course impossible, but is explained with statistical differences and “unexplained transformation gain … in petroleum refineries” (NB: I would prefer to read “data inconsistency” here).

Secondly the breakdown of primary energy and imported secondary energy (input from the left) is fanned out leaving gaps between the arrow lines. The merged arrows are then “condensed” to be to scale again. This creates a 45° gradient at one side of an arrow section (or “slope” for those of you who are into winter sports). In these sections the arrow width can not be proportional to the quantities. A tribute to pay for better legibility of the diagram.

Energy Sankey Diagram for Japan

Some of you might have noticed that I tend to get somewhat excited when I discover Sankey diagrams in other languages.

Here is one I dug out on this webpage of the Tsuji Labs at Osaka University in Japan, and it has the honor to be the first one presented on this blog in Japanese!

The diagram shows the “energy flows” (エネルギーフロー) as relative values for the year 1993 only. On the left side we can see that more than 80% of the energy consumed in Japan were produced from imported fuels (輸入), while only 17.8% came from domestic production (国内生産). The quantities are broken down into the different types of fuels, such as crude oil (原油, 46,1%) , natural gas (天然ガス, 10,5%) or hard coal (石炭, 16,4%). The right side of the diagram shows the consumption sectors, with industry (31%), residential (16,9%) and transport (15,6%).

Losses are at 29% which seems relatively low, if you compare to similar Sankey diagrams from the U.S. But then I am not sure if they accounted for the losses in the same way for this diagram.

There are these two other similar Sankey diagram thumbnails on that site, and my guess is that they represent different energy scenarios, considering renewable energy sources, as an option to reduce dependency from imports. Maybe someone who can read and understand more Japanese than I do wants to comment?

Biomass dominates energy flows in Sri Lanka

Do you know what country uses the top level domain “.lk”? Well, I didn’t know it either, until I came across this fine Sankey diagram of the energy flows of Sri Lanka on the website of the country’s Energy Conservation Fund. This island country (formerly known as Ceylon) has some 20 million inhabitants.

The flows in this Sankey diagram are in ‘kTOE’ (TOE = tons of oil equivalent). It shows that most of Sri Lanka’s energy in 2003 came from domestic biomass, the second largest domestic source is hydro power. Imported sources of energy are crude oil (refined in the -currently- sole Sri Lankan oil refinery), petroleum and a small portion of coal.

On the consumption side the largest energy using sector is domestic/commercial, followed by industry (using biomass generated energy as well) and transportation.

Transmission losses are relatively small compared to the situation in other countries. The energy flow picture of Sri Lanka thus is quite different to those I have previously presented here on this blog, such as for the U.S. or for Scotland.