Graphic Design Should Not Be an Afterthought
A couple of months ago, the Energy Circle blog covered a new product called PowerHouse Dynamics eMonitor. It’s a whole house electricity monitor that can measure and report on each individual circuit, giving the homeowner unprecedented levels of information on their home’s energy usage patterns. More data can mean more understanding and more control.
But not always.
The dashboard created by the PowerHouse team was either an afterthought, or willfully flouts the conventions of meaningful graphic design. Because of this, it fails to be as helpful as it could’ve been. Sure, you can pick out nuggets of meaningful information about your home’s energy use, but you have to work at it, and you may miss some things. And if you just spent ~$1,000 for the privilege, that’s a shame.
Start with the “Power Usage Right Now” gauge. Dashboard design best practices say that there are better ways to display this data. Gauges require your eye to compare angles and arcs, and it’s just not our strong suit. We are much better at comparing lengths. Gauges also take up more space than is necessary, and when you want to get a picture of your whole house’s energy use at a glance (which is all the time most of us have to devote to these things), space matters.
But all of this might be forgivable if not for the color choices, scale, redundancy, and “bling”.
- It uses a red-green color scheme (with a green-on-green needle?) which a reasonable percentage of the population cannot see.
- The scale is not uniform, which is sure to confuse people. The left half of the gauge represents 1kW, the right half shows 49kW!
- If the grey box showing 921w is sufficient, why display the gauge at all?
- The 3D reflection is pure chart junk. As Stephen Few often says, “We find glare annoying in real life, why would you want it on your dashboard?
Let’s move to the worst offender in the group. The demon-spawned, 3D, rotated, donut chart!
Where to begin…
As before, arcs and angles are not the best way to display data to a human being, and this chart compounds the error by:
- removing the center (no more angles!),
- rotating in perspective to make nearer slices seem relatively larger,
- adding a 3rd dimension to give meaningless volume to each slice, further compounding the perspective distortion.
Throw on enough pointers to make the whole chart look like a Scutigeromorpha, and you’ve got one of the worst charts I’ve ever seen. Disagree? Then ask yourself why the percentages have to be written next to each label? It’s because the graph is completely uninterpretable! Though not as visual, this information would’ve been much cleaner if you deleted the chart and made a simple table.
| Basement Outlets | 45.6% |
| Basement Lights | 9.1% |
| Dryer | 8.3% |
| etc… |
An even better way to display the same data would be a sorted bar chart, which they apparently did for the cost breakdown:
See how easy it is now to rank each load by its importance? It is immediately obvious, without even having to THINK, that the basement outlets cost 4-5 times more than the next highest circuit. Let’s hope they have this option for the power breakdown as well. The only things I’d change are the gradients and the redundant data labels. The background gradient makes the text less crisp, and the gradient on each bar introduces a weird optical illusion. Take a look:
If you’re looking at “Kitchen Counter Right” or “Tucker’s Room”, it almost appears if there is no bar between them. It’s something like the dreaded “Devil’s Fork!”
Spooky, eh? Perhaps that’s why they’ve included a phantom’s mask on the sidebar. Chart junk abounds!
There are several other graphs that just don’t work, but let’s talk about one that does: the 24 hour comparison.
A real diamond in the rough, the following graph allows the homeowner to ask a question, and answer it, with minimal distraction or mental gymnastics.
The background gradient aside, this analysis is great. Using a grey line with less visual weight to represent the previous day allows the user to compare the time-series profile of a circuit. I can imagine using this to check on how long my heat pump runs each day, or seeing how often the lights are on upstairs on a weekday versus the weekend. The possibilities are endless, and this chart is an excellent way to get a visual understanding of your house’s pulse.
I know I’ve been critical of the visualizations in the PowerHouse Dynamics dashboard, but I hope they’ve been constructive. Each of these issues can and should be corrected, which would make the product a home-run for energy conscious homeowners. The technology is novel, it’s useful, and it’s sorely needed. But without a strong focus on graphic design, it falls well short of its true potential.
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