Similar to the Sankey diagram shown in a post last week, the below Sankey diagram also shows the energy balance of a house. Found it on an Estonian blog.

Unfortunately just a schematic Sankey diagram without figures or units. Energy “input” and losses. Looks to me like a hand drawn sketch. Valgustus is lighting, Kliimaseadmed is air conditioning, Hoone Küte is heating, and Soe Tarbevesi is warm water (thanks to Google Translate).

I am subscribed to different newsletters and RSS feeds to keep track of the Sankey diagram software market, trying to stay up-to-date on new software available or updated versions.

The latest release of e!Sankey (v3.2, the second one this year after v3.1 in January) seems to be mainly a bugfixing release. However, what’s nice is that they have included a number of new sample diagrams and templates.

This is a Sankey diagram depicting the energy balance of a family home.

The one below has an interesting feature where balance differences (or as they call it: “stocks”) occur at a process, in a top-to-bottom direction.

Most samples feature a description panel, some of them a color legend for flows. There are more in the trial version. Nice

The “personal” energy balance of the Grieger family home for 2010 and a forecast for 2012 were presented in two blog posts here and here on Klaus Grieger’s blog.

All consumptions are traced back to the primary energy demand and include losses (dark rey arrows) in power generation by using efficiency factors.


2012 forecast

The details of these Sankey diagrams are probably most interesting for those who understand German.

A PV system on the roof of the Grieger house permitted to feed back 5930 KWh of electric energy to the grid in 2010. In 2012 some of this energy is used directly (“Eigenverbrauch”), leading to a reduced energy bill for electricity purchased. Note that the Grieger family gets “green power” from hydro, wind and other renewables.

Another change between 2010 and 2012 is an updated mix of energies German Rail use (nuclear, coal and gas fired power plants).

Note that the two diagrams do not have the same scale. The consumption of heat is the same in 2010 and the 2012 forecast, so is primary energy demand from natural gas (grey arrow “Erdgas” at the top). Still, the 2012 Sankey arrows are wider than in the 2010 version. It would be nice to have the two Sankey diagrams side-by-side and be able to compare them by looking at the arrows widths.

Found this via utsapocalypse. The Sankey diagram is originally from the article ‘Preliminary Investigation of the Use of Sankey Diagrams to Enhance Building Performance Simulation-Supported Design’ by William (Liam) O’Brien of Carleton University, Ottawa.

The paper proposes “the outline for a methodology for creating Sankey diagrams to represent energy flows in buildings, with the eventual intent that the methodology be integrated into a software tool.”

The Sankey diagram shows the energy balance of a house for a mid-winter week. Flows are in kWh, total amount 804 kWh. Energy sources/types are from the left (purchased heat, domestic hot water, solar gains), energy consumption and losses to the right (heat loss through windows, ceilings, walls).

Plenty of colors used in the diagram, Sankey arrows glued together from shapes. As the author mentions “the underlying creation process, when performed manually, can be quite complex”.

From the Mostly Uncommented Series, here is another one that has been sitting in my collection.

Black/White Sankey diagram for energy gains and losses in a building. Titles in French. Shadow effects. No values given. Unnecessary crossing of Sankey arrows. Not sure where I downloaded this from, will have to check my bookmarks. In the meantime, pls have a nice week-end…

GWP guy at Green World Pictures blog posted an article on average spendings on energy in an U.S. household.

Data is from an Energy Star flyer, that presents the data in a pie chart. The average yearly 1900 US$ for energy are spent as follows:

Heating and cooling is almost half of the spendings on energy, followed by water heating and lighting.

This article on “Conceptualizing the built environment as a social-ecological system” by Sebastian Moffatt (CONSENSUS Institute) and Niklaus Kohler (University of Karlsruhe) published in Building Research & Information, Volume 36, Issue 3 May 2008 , pages 248-268 has an exciting Sankey diagram in the section ‘Current perspectives, promising methods, missing pieces’ (scroll down about half way).

The authors explain Sankey diagrams as an instrument of Material Flow Analysis (MFA)

“Sankey (directional flow) diagrams are often used to summarize the MFA visually as an entire connected and balanced system. In a Sankey diagram the material flows begin with inputs from nature, then flow into intermediary processes (any infrastructure used for processing, converting, storing, or regulating), and then into the various end use(s). After use, flows may be reconverted by infrastructure systems for reuse or recycling. Ultimately, all flows are directed to a category of output (waste products emitted into air, into water bodies or into landfills; long-term storage; export). The balanced accounting thus tracks every flow from source to sink.”

The original Sankey diagram shown in this article is for an resource efficient house, planned or built in New Delhi (India). It sports the water flows through five groups of processes (sources, converters, demands, re-converters, and sinks). The authors call it a “five-partition metabolic profile”, and suggest that it can be done not only for a single house, but “for the built environment at any scale, from parcel to urban region”.

The unit for the quantities given is not indicated, but I presume the water flows are in litres.

When reproducing the Sankey diagram (see above) I tried to make it a little more clearer by changing the order of the (invisible) nodes, thus avoiding crossing flows.

A software with a Sankey diagram feature that I hadn’t noticed before, and only now have added to the list of Sankey Software tools is CASAnova (new house). From what I understand this freeware tool was the result of a research project at a German university that ran from 2000 to 2002.

The program ‘CASAnova – An Educational Software for Energy and Heating Demand, Solar Heat Gains and Overheating Risk in Buildings’ is designed for an easy-to-use handling in order to get an intuitive understanding of the relations between building geometry, orientation, thermal insulation, glazing, solar heat gains, heat energy demand, heating and primary energy as well as overheating in summer.

CASAnova can be used to enter numerous parameters for a building, such as geometry, window and wall areas and types, insulation, heating system, and climate data etc. The tool will eventually produce a generic Sankey diagram of energy flows as the one above. I have just installed it and played around a little bit only to get an impression. CASAnova is available in German and English. Recommended.