Another way to look at energy flows! Here is a Sankey diagram of US feed-to-food caloric flux. This is from a paper by Shepon titled ‘Energy and protein feed-to-food conversion efficiencies in the US and potential food security gains from dietary changes’ published October 2016 in Environmental Research Letters (Environ. Res. Lett. 11 (2016) 105002 – doi:10.1088/1748-9326/11/10/105002) under Creative Commons CC 3.0

Flows are in Pcal (Peta calories, 1012 kcal). Production figures are based on data from U.S. National Research Council and a “Mean American Diet” (MAD) with an average consumption of 2500 kcal per day is used. We can see energy in three feed classes being transformed into energy in edible animal products. The authors explain:

“On the right, parenthetical percentages are the food-out/feed-in caloric conversion efficiencies of individual livestock categories. (…) Overall, 1187 Pcal of feed are converted into 83 Pcal edible animal products, reflecting a weighted mean conversion efficiency of approximately 7%.”

In light of this, energy conversion efficiencies of 30-40% seem to be fantastic…

Check out the article for another Sankey diagram of protein flux.

Researchers from the Institute for Sustainable Resources (ISR) and the Center for Resource Efficiency & the Environment (CREE) at the University College London (UCL) have set up this Sankey diagram of global material flows in the paper life cycle, from primary inputs to end-of-life waste treatment.

Flows are in megatonnes based on data for 2012. We can see the five phases in the paper life cycle, from wood harvest over pulping, paper making, to use and discard/end-of-life. Almost half of the paper used and discarded worldwide in 2012 was recycled (194 Mt out of 399 mt). However, 154 Mt of used paper still ended up on landfills.

The authors further discuss environmental performance metrics. They point out that looking only at the recycling rate may lead to a wrong impression. They propose to also consider another recycling metrics (recycled input rate, RIR), and a material efficiency metrics.

The paper ‘Global Life Cycle Paper Flows, Recycling Metrics, and Material Efficiency’ by Stijn Van Ewijk, Julia Stegemann, and Paul Ekins has been published in the Journal of Industrial Ecology. A summary can be found here, or access the full article at Wiley Online Library (Open Access under Creative Commons license).

Thanks to the author Stijn van Ewijk for pointing me to this recent publication.

Styria is the second largest state of Austria, in the south eastern part of the country. It is famous for its beautiful mountains, its wines and some decent yodelling 🙂

It is also home to green tech industries, in fact “Styria is home to more than 150 clean technology companies … [whose] revenue totals €2.7 billion. This equals to 8 percent of the Gross Regional Product (GRP), and is one of the highest concentrations of leading clean technology companies in Europe.” (Wikipedia)

The ‘Styrian Promise’ is a project aiming at the implementation of energetically and economically meaningful energy efficiency concepts in Styian production companies. Case studies from food, textiles, metals and other industries are presented on the project wiki.

Above is a Sankey diagram depicting the energy balance at Obersteirische Molkerei Knittelfeld (Upper-Styrian dairy in Knittelfeld). Flows are in MWh per year. The main energy requirement is steam from natural gas: Whey drying and steam for milk pre-heating are the largest consumers of process heat. Read more detail on the dairy production here.

Glass Service s.a., a consulting firm from Czech Republic offers energy audits for companies from the glass industry. This is a Sankey diagram from their website. Flows in kWh for a sample furnace, with energy recovery from flue gas.

Published on the ‘The Efficient Appliances Blog’ is Pakistan’s First Energy Flow Diagram by Nida Rizwan Farid. The Sankey diagram is a piece of work fpr Pakistan’s Integrated Energy Plan and covers energy data for 2012/2013.

A more detailed explanation of the energy situation is given on this page. The author observes that “[o]ut of the 40.2 MTOE of final energy that trickles down the consumers, 72.7% of it is lost by the usage of inefficient appliances, motor vehicles and industrial processes. Only 10.96 MTOE of useful energy is received.”

Good use for a distribution diagram shown in the January 2017 Guardian op-ed ‘Why hasn’t Scotland changed its mind on independence?’. It shows Scottish voter behaviour in the first pre-Brexit vote independence referendum (‘IndyRef1’) and intended vote in the second independence referendum (‘IndyRef2’), based on a poll among some 3,200 Scots in Nov/Dec 2016.

(via Coffee Spoons blog, originally from The Guardian, using YouGov data)

The left columns has two categories (Brexit Leave/Remain and first independence vote ‘Aye’/’Nae’), the second only one category. Both columns have the undecided voters fraction in light grey.

The changeovers from one camp to the other are shown emphasized in strong colors. One can see that the ones who voted “No” in the first referendum and that would now vote “Yes” for Scottish independence are compensated by voters who said “Yes” in the first vote, and who would now probably go for a “No”.

There seem to be less undecided voters (down from 21% to 14%), but the overall outcome would at present be the same: 46% No, 39% Yes (Indyref1: 44% No, 35% Yes). Of course a lot has happened since the poll in Nov/Dec 2016 and there is still a long way to go up to IndyRef2.

This is quite an interesting Sankey diagram from the World Energy Outlook 2014. It visualizes international spending on energy efficiency measures in the transport sector under a hypothetical ‘New Policies Scenario’.

A total of 14.5 trillion US$ would be spent until 2040 to improve energy efficiency in the transport sector. The largest chunk (37%, 5.3 trillion US$) on improving private cars. This amount is further broken down to four geographic regions. The money would be spent mainly on improving the power train, and on development of light-weight components.

The underlying scenarios are described in detail at the beginning of the WEO-2014 study. The authors point out that “[f]or each scenario, we offer a set of internally consistent projections to 2040. None should be considered forecasts.”

“The New Policies Scenario is the central scenario of WEO-2014. It takes into account the policies and implementing measures affecting energy markets that had been adopted as of mid-2014, together with relevant policy proposals, even though specific measures needed to put them into effect have yet to be fully developed. These proposals include targets and programmes to support renewable energy, energy efficiency, and alternative fuels and vehicles, as well as commitments to reduce carbon emissions, reform energy subsidies and expand or phase out nuclear power.”

A new web-based Sankey tool, Sankey Flow Show, is available from German software maker THORTEC Software. It promises “attractive flow diagrams made in minutes”.

And indeed the tool is rich in features and design options: Different node elements, shadow effect for arrows (called ‘connections’), toggle constant/Sankey connections style, and customizable data input are some of the highlights.

Here is one of the Sankey diagrams produced with Sankey Flow Show. See more samples here. You can sign-up for a free trial to check it out yourself.

I have added Sankey Flow Show to the list of Sankey software.