The below diagram is shown in a short paper ‘A Sankey Diagram for Nickel Production’ by M. Levesque (School of Engineering, Laurentailn University, Sudbury, ON, Canada) and D. Millar (MINARCO, Sudbury, ON, Canada). The paper was presented at the ’1000 Island Energy Research Forum (TIERF) 2011. It also appears on a poster on the same topic available on the MIRARCO website (large PDF!).

The diagram shows energy production, transformation and consumption in the Nickel production. This not only includes dryers, kilns and furnaces, but also supporting activities such as port handling and transportation.

No absolute values given in the diagram, and even the fuels are not specified (although you can identify what is probably hard coal, lignite, natural gas). Most likely a question of confidentiality. A left-to-right orientation of the diagram is presumed, and no arrow heads are shown. This could lead to an interpretation issue for the green band that leaves the power stations PS1 and PS2 vertically.

The paper concludes “The Sankey diagram highlights the areas in the process where focus is required for subsequent energy management effort.”

The U.S. Department of Energy (DOE), Office of Energy Efficiency & Renewable Energy publishes Sankey diagrams on non process energy on this webiste.

What is non-process energy you might ask. According to DOE, non process energy is “energy used for purposes other than converting raw material into manufactured product. MECS-specified categories of nonprocess energy include facility HVAC, facility lighting, onsite transportation, other facility support (e.g., cooking, water heating), and other nonprocess use.”

You can access the energy flow Sankey diagram for the full U.S. manufacturing sector. Data is from 2010 and flows are in TBtu (Trillion British Thermal Units) per year.

Detailed diagrams on on-site generation, process energy and non-process energy (the three ‘transforming nodes’ in the middle of the full sector) are also presented.

Grey and black arrows show losses. Good work from the Office of Energy Efficiency & Renewable Energy.

I found the below Sankey diagram depicting Romania’s energy flows for 2008 in an article titled ‘A Macro-Micro Perspective on Sustainable Refurbishment of the Housing Sector’ by Ovidiu-Horaţiu Teleche, University of Architecture and Urbanism, Bucharest. Published in Proceedings of 1st International Conference on Architecture & Urban Design, Department of Architecture (2012).

Flows are in ktoe (kilotons of oil-equivalents). Underlying data is from the Romanian National Institute of Statistics and Eurostat 2010. EPP is for ‘Electrical Power Plant’, CHP for ‘Combined Heat & Power Plant’, and DHP for ‘District Heating Plant’.
Note the small flow quantities where arrows are not to scale to be able to view them at all (minimum line width set to 1 or 2 px).

Energy generation is predominantly fossil (coal, petroleum, natural gas). Biomass is the most important energy source in the residential sector. The article doesn’t mention the reason, but my guess is on wood or peat “for preparation of hot water, cooking and direct burning in the stoves for heating” as mentioned in this article on biomass in Romania.

Another quick casual Friday post … again from Austrian company pro-wel, published on their website to market their process engineering services.

Enjoy your weekend!

Interesting blog post by Steve Wexler of Data Revelations. Long article, long title: “Circles, Labels, Colors, Legends, and Sankey Diagrams – Ask These Three Questions”.

The really interesting part for the Sankey diagram aficionados is Steve’s advice on when to use Sankey diagrams, and when you should avoid using them.

Steve illustrates his point with the below example by ‘Music Major – Data Miner’ Jeffrey A. Shaffer (original post is here)

A combination of a stacked bar chart with a distribution diagram, nicely decorated with a trumpet … “Within this context, this very creative chart works”, Steve writes.

He then goes on and shows another one by Shaffer, also a distribution diagram: the original pie chart data from an energy bill has been redesigned and was presented as a distribution diagram (two stacked bars with bands to link them)

In this case, Steve concludes, the choice of a Sankey diagram is maybe not that wise, since the actual important information (44% of energy cost is for heating) doesn’t really come across quickly and clearly. A bar chart might work better here. Sankey diagrams can create a “cool!” or a “crap!” response, depending on the context. See the original Shaffer post here.

Adding my 2c from a technical perspective I would say that both diagrams have a shortcoming: The bands don’t maintain their width as they cross over the others diagonally. Somewhat acceptable in the trumpet diagram as the right bar on the right side listing the music composers is higher than the one at trumpet bell (sound spreading out). Not acceptable in the second diagram where the two stacked bars have the same height. This is obviously an error in the curve radius calculation (read ‘The Math Behind those Curves’)

Another Sankey diagram of Canada’s energy flows is featured in a blog post titled ‘Dividing the Big Picture: Visualizing Provincial Diversity’. The post appeared May 5, 2014 on the Canadian Energy Systems Analysis Research (CESAR) blog by David B. Layzell, Professor at the University of Calgary. It is a follow up to a previous CESAR blog post that showed “the big picture” for Canada (featured in a recent post here on the blog).

“The Sankey diagram below shows only the domestic portion of Canada’s energy systems. (…) It also shows how much of that demand is met by oil/petroleum (red), natural gas (blue), electricity (yellow), biomass-derived products (green) or other energy resources.”

Flows are in GJ per capita. This relative unit is different to the other national energy flow diagrams I have presented here on the blog. But it is interesting for differentiating energy consumption in the different provinces.

The article explains:

“There are significant inter-provincial differences associated with each end-use category. For example, British Columbia (BC) residents had the lowest residential energy use in the nation, at 63% of the per capita energy use in Alberta (52 GJ/capita), the national leader in this category. The balmy BC climate compared to what Albertans face each winter accounts for most of this difference. However, our model also draws on government data showing that many BC buildings tend to be better insulated than those from much colder Alberta.”

Check out all Sankey diagrams tagged ‘Canada’ here.

Featured on the Canadian Energy Systems Analysis Research (CESAR) blog is the below Sankey diagram on Canada’s Energy Flows in 2010. The article reports about a new model called ‘CanESS’ (Canadian Energy Systems Simulator) developed by Technologies Inc. and the University of Calgary.

Pulling together data from different sources the tool can visualize energy flows as Sankey diagrams.

The big picture of Canadian energy in 2010 is as follows:

“Canadian primary energy production in 2010 was nearly 25,600 PJ, and after including 3,700 PJ of imports, total primary energy availability was 29,500 PJ. As the Sankey diagram shows, 58% was exported, with the remaining 42% or 12,500 PJ being used domestically, 910 PJ for non-energy applications and 11,652 PJ for the provision of energy end use services to Canadians.”

Read the full article by Ralph Torrie on “the big picture” here.

There is an interactive version that allows you to choose the year (1978-2010), to break down the data onto each Canadian province, or change the unit. Try it out!

An energy flow chart for energy use in the residential building sector is shown on the Autodesk Sustainability Workshop page ‘Measuring Building Energy Use’. There is also a similar Sankey diagram for energy sources consumption in the commercial building sector.

Both are taken from a Pacific Northwest National Laboratory (PNNL) report from 2006 prepared for Department of Energy (DOE) titled ‘Energy End-Use Flow Maps for the Buildings Sector by D.B. Belzer (PNNL-16263).

Residential building sector energy flow chart:

Commercial building sector energy flow chart:

Both Sankey diagrams are built up the same way. The top part of each diagram shows electricity generation, the bottom part the energy flows for heating. Significant conversion and transmission losses can be identified by the arrow branching out at the top. Flows from the left represent the energy sources: coal (brown), natural gas (blue), biomass/solar (green). To the right the flows are broken down to the individual consumption, such as heating, cooling, lighting, other electric appliances, etc.

All units are in quadrillion BTUs for the U.S in 2004.