What is the most efficient renewable energy source in comparison to the number of plants of that type?

Visual Design
#1

Hi VisGuides User!

My name is Martin Griffiths, I’m a third year student at Swansea University and I’m currently studying Data Visualisation. Our task is to find interesting and unique observations within a provided data-set. The following includes an example I made involving renewable power plants and how efficient they can be. Please enjoy the following and would appreciate advice and criticism about the visualisation. If you can, please help by answering the questions at the end of the post.

Thanks!

Average Produced Energy of Renewable Fuel Sources in comparison to the Number of Power Plants from that source
Average Produced Energy of Renewable Fuel Sources in comparison to the Number of Power Plants from that source940×578 86.6 KB

Image Title Average Produced Energy of Renewable Fuel Sources in comparison to the Number of Power Plants from that source
Visual Design Type Stacked Bars
Name of Tool Tableau
Countries All
Year 2013, 2014, 2015, 2016, 2017, Average
Visual Mappings Colour : Fuel Type; Width of Bar : Number of factories; X axis : Years; Y axis : Average produced energy
Data Preparation Filtered out all unrenewable fuel sources.
Data Set Used http://datasets.wri.org/dataset/globalpowerplantdatabase
Observations What’s telling from this image is how efficient some sources are with how many factories they have. What’s most notable is the inefficiency of solar sources. They have a large proportion of plants, yet they can’t produce much energy on average in comparison to other sources. Geothermal and Hydro are clearly quite consistently good in comparison, despite Hydro having more factories. Essentially, we can assume that Geothermal is consistently high as there are less factories, and Solar is extremely inefficient. This doesn’t tell the whole story though as this doesn’t consider the size of the plants themselves nor how expensive they are to build including their payback time. A follow on question might be to understand the physical size of these plants and correlate them with payback time. Does having bigger plants mean there is better payback time, or are there certain sources that are not worth using like we might assume solar energy to be.

Does my visual design make sense?
Is my choice of visualisation optimal for this data? Are there any other types of visual layouts that would be better for this challenge?
How can my visual design be improved?
Is there any oversights or mistakes that needs to be noted either aesthetically or factually?

Thanks again,
Martin Griffiths

#2

Hi Martin,

The chosen visualisation method does clearly show the data being presented, and the colours are distinct enough not to cause confusion.

One area that may be misinterpreted is the width of the bars, i.e. does it make sense that the smaller the bar, the more factories? In my opinion, it might be more apparent if the size increased with the number of factories.

Other than this, the visualisation makes sense given the legends and provides an interesting insight into the dataset being analysed.