In a presentation on “Low CO2 production in European food and beverage industry” the author Christoph Brunner from AEE – Institute for Sustainable Technologies (AEE INTEC) suggests process flow sheets and Sankey diagrams as tools used for energy efficiency analysis.

This Sankey diagram is used as an example for the creation of mass and energy balances and the visualization of the production process.

The diagram is from Austria and thefore in German. From translating some words I understand this is probably for a food/dairy industry. Flows are in MWh, but without a time span. Two steam generators (one run with natural gas, the other with petroleum) supply heat to different processes. The cooking chambers (“Kochkammern”) require most, followed by “Selch” (?) and heating of a “KSPW Tank”. Some heat is recovered from condensate.

Sankey diagrams can help understanding the energy flows of process systems and detect hotspots for optimization.

Energy flows are visualized on a machine touch screen panel, giving realtime information of energy consumption. This is from the PROFOXY system offered by Kröhnert Infotecs, a German engineering firm.

Basically two pie charts, one for the red part on the left side, and one for the green part on the right, would suffice (… I can’t believe I’m actually advocating pie charts here :-( ), but this Sankey diagram additionally gives a notion of “flow” and allows a grouping of consumers (on the right).

Consulting firm Rytec analyzes energy and heat utilization level of Swiss waste incineration plants and visualizes the processes using Sankey diagrams.

This Sankey diagram from their website is a simplified view and offers no details as to the actual figures. More detail can be found in this project summary (PDF).

Diagram labeled in German, but thanks to my friend Google Translate, I can identify ‘heating’, ‘boiler’, ‘energy conversion’ and ‘flue gas losses’. Orange streams to the top are losses.

This Sankey diagram of energy flows in a “pusher type reheating furnace” illustrates an article on ‘Reheating Furnaces in Steel Plants’ by Satyendra on the ISPAT Guru blog.

Unit of flow is not clear, but the main stream arriving from the top represents the baseline 100% (508 units) of which a portion can be recuperated and fed back into the furnace as preheated air.

A web page of the federal german ministry for Environment, Climate and Energy in Baden-Wurttemberg informs companies about energy efficiency. Sankey diagrams are described as a useful instrument to detect hotspots for improvement and a tool in the framework of energy efficiency analysis.

Spanish company Prosener illustrates its energy efficiency analysis services and support for the introduction of energy management systems with the following Sankey diagram:

This is a simple breakdown of energy consumption in a company. Electricity in green, fuel in grey. Only percentages are shown, no absolute figures.

As a followup to last week’s post on a Sankey diagram from the GEA report. here is another one from the very same report (GEA, 2012: Global Energy Assessment – Toward a Sustainable Future, Cambridge University Press, Cambridge UK and New York, NY, USA and the International Institute for Applied Systems Analysis, Laxenburg, Austria).

This one is an example for losses along the energy supply chain.

The description of the diagram on pp. 116/117 says:

“As an example of energy chain efficiency, Figure 1.13 illustrates the energy flows in the supply chain for illumination services (lighting). In this example, electricity is generated from coal in a thermal power station and transmitted and distributed to the point of end-use, where it is converted to light radiation by means of an incandescent light bulb. Only about 1% of the primary energy is transformed to illumination services provided to the end-user.”

The Sankey diagram shows the primary energy as 100% on the left and branches out the losses at each conversion/transmission step. The actual useful energy (the “energy service” of providing illumination) is only 1%. So in this example one unit of energy service requires 100 units of primary energy, clearly pointing to “abundant opportunities for improving efficiency exist at every link in the energy chain” (p. 116).

I have presented a similar Sankey diagram here before, see this 2007 post ‘What it takes to power a bulb’.

From a collection of case studies on Energy Efficiency found on the website of the Australian Department of Resources, Energy and Tourism (RET) comes the following Sankey diagram.

This is from a synthetic rutile plant of Iluka Resources Ltd. in Western Australia.

Iluka used the output from the energy and mass flows model to generate a Sankey diagram to represent the results in a visually effective and concise manner. The Sankey diagram illustrates where energy is supplied to the process, how it is transformed and where it leaves the process. … The width of the arrows is in proportion to the amount of energy associated with each part of the process. The Sankey diagram is an effective and intuitive way to communicate the energy flows at the plant. The diagram was used extensively during Iluka’s opportunity workshops. The diagram assisted the staff at the workshop to focus their attention on where the largest energy flows exist and identify where the main areas for improvement lie.

Flows are in percent of the energy input. Possible improvement measures are given in the grey boxes.

Full case study here (PDF).