Tag: efficiency

IPPC Energy Efficiency Report

A 2002 Integrated Pollution Prevention and Control (IPPC) report on energy efficiency by UK’s Environment Agency features the following Sankey diagram on page 10.

It shows energy flows in a paper mill. Unfortuntately no values are given nor a unit. So this is to be considered merely as a schematic diagram, not necessarily based on real energy data.

The guidance document explains (p.9):

“It is useful to supplement energy consumption information with energy balances (e.g. “Sankey” diagrams, other flow diagrams or descriptions) to illustrate how energy is used throughout the process (see Figure 2.1). This is particularly relevant where energy conversion is highly integrated within the activities, in order to illustrate any inter-dependencies between energy use and selection of other operational or environmental control measures.”

Energy Efficient Technologies, Cogeneration

The following Sankey diagrams are from a report published in 2005 by Austrian Environment Protectionn Agency (UBA). The report is on energy efficient technologies and measures to increase efficiency and features practical examples from industry.

Both Sankey diagrams are from the section on cogeneration (chapter 5, p. 105 and p. 106). The first one shows how natural gas is being used to create 118 GWh electricity and 423.5 GWh steam with an efficiency of 90%.

The second diagram is the breakdown of fuels used in another industrial cogeneration plant. It only features percentage values.

Both sets of data could also be displayed in pie charts, but the Sankey diagrams with directed arrows make an allusion to the output from gas, and to the input feed (in the second diagram).

Losses Along the Energy Chain

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’.

Engine Combined Cycle Power Plant Sankey

At the Technical University of Munich a project on Engine Combined Cycle (ECC) Power Plants aims at “improving the electrical efficiency of an engine combined cycle plant by using the exhaust gas heat in a steam cycle”.

The following Sankey diagram is shown to illustrate where heat can be recovered.

No absolute values are given, but the Sankey arrows represent the percentage of the primary energy. Four percent of the energy in the steam process can be recovered to add a total of 47.8% efficiency output of electrical power to grid. Losses branch out to the right side and are primarily via the cooling water and condensate at the steam process. The whole Sankey diagram is presented in a simple single-color design.

Efficient Water Use in Saudi-Arabia

Consumption of water resources in arid and semi-arid areas has become an important issue over the last years. The Wafeer water conservation project is trying to raise awareness and educate people in Saudi-Arabian industry in regard to the efficient use of water. On page 21 of their Water Efficiency Manual, the following Sankey diagram can be found:

The report describes that “Sankey diagrams enable visual representation of both quantitative and qualitative characteristics of water entering and leaving different activities and therefore serve as a good communication aid.”

The above diagram does not show any unit, but presumably is meant to be in cubic metres (per year?). It shows water (blue) and waste water (grey) flows, as well as evaporation losses (red).

More water Sankey diagrams of similar style can be found on pages 19 through 23 in this workshop presentation on ‘The Importance of and Difficulties in Water Accounting’.

Misc Sankey Diagrams Uncommented 02

Here is another one … enjoy!

Same topic as in my previous post, heat flows and losses, this time in a continous furnace. Recovered heat loop is strange: arrows gets wider in the curves, as if painted by hand. Funny serpent arrow for opening (radiation) losses. No values given. All arrows have the same colour. Source: Article ‘Quest for Fire – Combustion Basics’ by by Daniel H. Herring. Published October 2, 2009 on Industrial Heating. The International Journal of Thermal Technology.