Poor use of comparison: lack of context before making a judgment


Lately our power company, KCP&L, has been sending out bimonthly letters telling us how we rate in power consumption among 100 neighbors. The 100 neighbors is “approximately 100 occupied, nearby homes that are similar in size to yours (avg. 1,832 sq ft).

What amazes me is over the past 6 months we have varied from a low of 35 (low is good) to a high of 86 — a range of 51 change. During the most recent period we used 47% more electricity than our average neighbor.

So what did we do between June and October to be so efficient in the summer and so bad in October? The paper gives no clue, just the idea that you aren’t being efficient and need to get better.

When I look at the numbers I think the same factor that makes us so efficient in the summer makes us not efficient in the winter. We have the high-efficiency heat pump that does our AC, and we keep the house warm (in the 80s) during the summer. Neighbors probably keep it cooler and have less efficient AC.

That same heat pump runs our heat in the fall until it gets real cold, when the backup natural gas kicks in, and we keep the house around 55-60. So we are using electric, while the neighbors switch from electric to gas.

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I suppose we could increase our electric efficiency by switching to gas instead of the heat pump, but that wouldn’t make much sense. The concept of electric efficiency that the paper suggests is just entirely wrong. Or at least it is entirely wrong about energy efficiency

This piece of paper is just one more example how comparison is a dangerous tool unless you understand what is the same and what is different.


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