Data Logging – real information

I am a strong proponent for measuring things and finding the real information among the data. You may know that it is 14 degrees outside (this mornings temperature here in Enfield, NH), and that it was 36 degrees yesterday and 34 degrees the day before. This is interesting data, but just data, facts without much meaning. Yes, it tells you to put on a warmer coat today.

Similarly if you have a Kill A Watt meter or something that can tell you how much energy a device is using, each measurement is a data point. The real information comes when you can get many data points and start seeing patterns. Data logging refers to the ability to save many points of data.

In the old days data logging was done by hand. All those temperature readings and weather conditions that the weather bureau reports from the late 1800s were written down in books. Today, computers are relatively inexpensive and do a great job of saving what might seem like tons of meaningless data. But when you get a look at the data as a whole you can see patterns and you can glean some real information.

Here is an example that you can do at home. Get your electric bill and see how much electricity you used last month. That is one data point and doesn’t tell you very much until you compare it to what you used the previous month and what you used every month last year. Now you have some real information. Perhaps you can see a pattern in your electrical usage that you didn’t realize was happening. Summer use versus winter use.

If you had even more data points you could figure out what time of the day you used more electricity or what devices in your house used the most electricity. This is good information that is derived from a bunch of data points.

So my resolution for 2010 (related to energy efficiency) is to figure out how to get real information from all the data that I like to collect.

Going back to the Kill A Watt example. If you have one of these devices you can get the number of killawatts currently being used, which is just a data point. You can also leave the device plugged in and get a reading over time of both the hours in use and the total killawatts for those hours. This is a little more information and can be useful.

I read about a DIY (do-it-yourself) project to add data logging to these Kill A Watt meters. Basically each Kill A Watt sends a reading every few minutes to a central computer where all the data is logged. Then you can get graphs of the data and look at the changes over time. Real information.

Here is a link that shows you how to modify a Kill A Watt to be part of a data logging system to provide good information: Tweet A Watt. Fun stuff.