The Wasteful Door Unlocker Analysis


This post is partly for the sake of amusement, but may have some useful points. Last night at an event, my collegue Pablo noticed that the locking mechanisms on the door were hot to the touch. Quite Hot. It turns out that the lock had a constant stream of electricity flowing through it in order to keep it engaged. In the event of a fire (or presumably a power outage) the door would lose its charge and unlock. But for the most part it just sits there heating up and wasting electricity. So we sat down and decided to figure out just how wasteful it was (I’ll withold the brand name). Here’s Pablo’s analysis:
The unit uses 8W 24hours day. kWh/year = .008kWh/h x 8760h =70.8kWh
Which, at $0.13/kWh: 70.8kWh x $0.13/kWh = $9.204/year per door

Nine bucks a year is pretty trivial, and surprisingly low given the heat coming off this thing, but it was a useful little exercise in noticing and analysing inefficiencies! Find enough 9 dollar items and you’ll eventually save a fortune.

Nick Aster is a new media architect and the founder of has since grown to become one of the web's leading sources of news and ideas on how business can be used to make the world a better place.

Prior to TriplePundit Nick worked for Mother Jones magazine, successfully re-launching the magazine's online presence. He worked for, managing the technical side of the publication for 3 years and has also been an active consultant for individuals and companies entering the world of micro-publishing. He earned his stripes working for Gawker Media and Moreover Technologies in the early days of blogging.

Nick holds an MBA in sustainable management from the Presidio School of Management and graduated with a BA in History from Washington University in St. Louis.